By Julie Turkewitz
Baltimore Sun
June 07, 2007
The recreation center in Violetville Elementary School was shut down Tuesday after workers discovered asbestos floor tiles in the 3,300 square-foot area near the school's cafeteria.
The center was sealed off after the discovery of the asbestos tiles and it will remain closed until the tiles are replaced and other maintenance work is done, said Kurt Kocher, spokesman for the city's Department of Public Works.
The school remains open and the tiles did not pose a health risk, Kocher said.
Asbestos was widely used as a fireproofing agent in building insulation and other products until it was linked to respiratory diseases. The inhalation of tiny asbestos fibers causes lung cancer, asbestosis and mesothelioma. But asbestos poses a health risk only when its fibers are released into the air.
Kocher said the tiles were old and 'cracked' -- not crushed to the point where fibers could be inhaled by someone. The city made replacement a priority before they could create a problem, he said.
'A lot of old homes and buildings have asbestos in them,' Kocher said. 'It's when they essentially get in a pulverized, almost powder form, that's when they are dangerous. But we don't believe there was any kind of trouble along those lines.'
There are 35 children enrolled in the after-school program at the center, which is also used for activities, said Kia McLeod, director of marketing and media relations at the Department of Recreation and Parks, which operates the center.
Although the recreation center is in the school, the replacement of the floor tiles is the responsibility of the Department of Recreation and Parks, not the school system, said Edie House, a city school spokeswoman.
Principal Catherine Reinholdt sent a letter to parents Tuesday notifying them of the asbestos floor tiles.
It's been a rough week for Violetville students. Last week administrators canceled school because of mite infestation.
Keith Scroggins, the chief operating officer of the city school system, said Violetville Elementary reopened Friday, and he hasn't heard any complaints of mites since. 'There are no more that we are aware of,' he said.
However, the school's letter home -- and the discovery of the asbestos just as the school rid itself of the bugs -- has left some parents with questions.
Bonnie Vogel's four children attend school at Violetville, which has students from kindergarten through eighth grade. Her daughter took dance at the recreation center, Vogel said, but she won't be sending her back.
'I don't really trust her going back in there,' she said. 'I'm a little leery sending her to school now because of all the problems they've been having.'
Saturday, June 9, 2007
Coroner's warning after asbestos death
A CORONER has warned of the dangers of modern chemicals after a pensioner died of asbestos poisoning, 40 years after being in contact with the chemical at a Bradford on Avon company.
Former wages manager Anita Ford, 70, of Barr's Lane, Charmouth, died on January 16 at Dorset County Hospital in Dorchester as a result of malignant mesothelioma.
The inquest was told that Mrs Ford came into contact with asbestos powder - the dangerous form of the chemical, 40 years before when she worked for Avon Rubber plc in Bradford on Avon, which was originally called Spencer Moultons, then Avon Industrial Polymers Ltd.
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West Dorset Coroner Michael Johnston said it was a rare type of cancer that in 85 per cent or more cases is caused by exposure to asbestos.
He said: "Asbestos was regarded as a wonderful material and it is, but it carries these dangers. What worries me is what we're using now which no one's discovered yet.
"I'm a keen gardener and use sprays and I read the other day that spray chemicals can increase the risk of Alzheimer's disease.
"There's all this chemical stuff in supermarkets, is it any wonder kids are getting asthma?"
Mr Johnston said she was taken into hospital on January 13 after becoming dangerously short of breath and died three days later. Consultant pathologist, Mark Deverell, in a written statement, said the cause of death was a massive blood clot in her lung due to the cancer.
Her husband Derek Thomas Quade Ford also worked for Avon Rubber on the factory floor, as did her parents and their son John and the inquest was told Mrs Ford may also have come into contact with asbestos washing their clothes.
Mr Ford said the factory had since been demolished and he was told that 80 tonnes of asbestos was removed from the factory in pulling it down.
Mr Johnston recorded a verdict of death as a result of industrial disease.
Former wages manager Anita Ford, 70, of Barr's Lane, Charmouth, died on January 16 at Dorset County Hospital in Dorchester as a result of malignant mesothelioma.
The inquest was told that Mrs Ford came into contact with asbestos powder - the dangerous form of the chemical, 40 years before when she worked for Avon Rubber plc in Bradford on Avon, which was originally called Spencer Moultons, then Avon Industrial Polymers Ltd.
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West Dorset Coroner Michael Johnston said it was a rare type of cancer that in 85 per cent or more cases is caused by exposure to asbestos.
He said: "Asbestos was regarded as a wonderful material and it is, but it carries these dangers. What worries me is what we're using now which no one's discovered yet.
"I'm a keen gardener and use sprays and I read the other day that spray chemicals can increase the risk of Alzheimer's disease.
"There's all this chemical stuff in supermarkets, is it any wonder kids are getting asthma?"
Mr Johnston said she was taken into hospital on January 13 after becoming dangerously short of breath and died three days later. Consultant pathologist, Mark Deverell, in a written statement, said the cause of death was a massive blood clot in her lung due to the cancer.
Her husband Derek Thomas Quade Ford also worked for Avon Rubber on the factory floor, as did her parents and their son John and the inquest was told Mrs Ford may also have come into contact with asbestos washing their clothes.
Mr Ford said the factory had since been demolished and he was told that 80 tonnes of asbestos was removed from the factory in pulling it down.
Mr Johnston recorded a verdict of death as a result of industrial disease.
Pleural Mesothelioma - The Facts
Pleural Mesothelioma is one of the most intense forms of cancer. It generally attacks the chest’s membrane lining. About three thousand new occurrences each year occur in the US alone. It is now known, as you may also appreciate, that it is caused by coming into contact with Asbestos particles.
Mesothelioma may not necessarily break out immediately. It is not uncommon for it to take 15 years to rear its ugly head, and up to 40 year waits have been recorded. Therefore, most patients diagnosed with this disease are in their sixties or seventies. Because of this long latency period the disease can be in an advanced stage before it is diagnosed correctly. Unfortunately, this leads to the following treatment being less effective.
It is very hard to diagnose pleural mesothelioma because this disease has few distinguishing features at first glance. The alarming indicators are difficulty in swallowing (dysphasia), shortness of breath (dyspnoea), persistent coughing and a tight chest pain. A sore or swollen neck, alongside other indications such as fevers, sweating, hoarseness or over fatigue could (I repeat could) show that the cancer has spread. The movement of blood from the lungs could also show that the disease has spread. In this case those symptoms are mainly caused by a fluid collection in the thoracic area (effusion). It is also possible that the weak pellicle, which is covering the lungs, may fatten and decrease expansion and contraction, therefore making it harder to breathe. Shockingly, in certain circumstances no noticeable signs may show that the cancer has spread until it is out of hand.
To give you some indication of the regularity of the symptoms, 84% of patients have pleural effusions (fluid collection). The major symptoms of the pleural mesothelioma are shortness of breath (88%) and weight loss (28%).
Please visit http://www.asbestosadvice.blogspot.com for more information on Asbestos and Mesothelioma related illness.
Mesothelioma may not necessarily break out immediately. It is not uncommon for it to take 15 years to rear its ugly head, and up to 40 year waits have been recorded. Therefore, most patients diagnosed with this disease are in their sixties or seventies. Because of this long latency period the disease can be in an advanced stage before it is diagnosed correctly. Unfortunately, this leads to the following treatment being less effective.
It is very hard to diagnose pleural mesothelioma because this disease has few distinguishing features at first glance. The alarming indicators are difficulty in swallowing (dysphasia), shortness of breath (dyspnoea), persistent coughing and a tight chest pain. A sore or swollen neck, alongside other indications such as fevers, sweating, hoarseness or over fatigue could (I repeat could) show that the cancer has spread. The movement of blood from the lungs could also show that the disease has spread. In this case those symptoms are mainly caused by a fluid collection in the thoracic area (effusion). It is also possible that the weak pellicle, which is covering the lungs, may fatten and decrease expansion and contraction, therefore making it harder to breathe. Shockingly, in certain circumstances no noticeable signs may show that the cancer has spread until it is out of hand.
To give you some indication of the regularity of the symptoms, 84% of patients have pleural effusions (fluid collection). The major symptoms of the pleural mesothelioma are shortness of breath (88%) and weight loss (28%).
Please visit http://www.asbestosadvice.blogspot.com for more information on Asbestos and Mesothelioma related illness.
A Quick Guide to Mesothelioma
When you talk about the health risks caused by asbestos, mesothelioma is at the top of the list. It is a sad story with a very unhappy ending.
A Quick Guide to Mesothelioma
Beginning in 1926, various studies started revealing that the wide spread use of asbestos for its fire resistant properties might not be such a good thing. The problem? Dust from asbestos materials was easily ingested into the lungs, but was nearly impossible for the body to expel. This resulted in a host of health problems of which Mesothelioma undoubtedly is the worst.
Mesothelioma is a nasty form of cancer. It is almost always caused by exposure to asbestos dust. This primarily occurs when a person has worked directly with or around asbestos materials. For example, a person who works on older buildings with asbestos materials or a person in the ship building industry to mention only a few. The disease can also impact secondary individuals who come in contact with such people, particular said peoples clothes.
On the medical side of things, Mesothelioma is a cancer that attacks the mesothelium. This anatomical term refers to the lining found around most organs of the body including the lungs and chest cavity. The cancer can also attack the sack encompassing the heart as well as other areas of the body. In short, it is a devastating form of cancer.
The truly horrific thing about Mesothelioma is the fact it takes a long time to appear. Gestation periods can be from twenty to fifty years. Even when it begins to show symptoms, it is very difficult to diagnose because it shares many symptoms common to aging and other health issues. These can include chest pain, coughing, shortness of breath, wheezing and blood clotting.
Unfortunately, Mesothelioma is deadly once it fully presents. A variety of treatment methods have been tried, but nothing has worked. The average person presenting with the cancer has a life span of less than a year. Radiation, surgery and pharmaceutical approaches have failed to significantly extend this time.
Mesothelioma is terminal cancer caused by exposure to asbestos dust that takes a long time to manifest, but a short time to kill.
Gerard Simington is with FindAnAttorneyForMe.com - offering asbestos and mesothelioma legal information.
A Quick Guide to Mesothelioma
Beginning in 1926, various studies started revealing that the wide spread use of asbestos for its fire resistant properties might not be such a good thing. The problem? Dust from asbestos materials was easily ingested into the lungs, but was nearly impossible for the body to expel. This resulted in a host of health problems of which Mesothelioma undoubtedly is the worst.
Mesothelioma is a nasty form of cancer. It is almost always caused by exposure to asbestos dust. This primarily occurs when a person has worked directly with or around asbestos materials. For example, a person who works on older buildings with asbestos materials or a person in the ship building industry to mention only a few. The disease can also impact secondary individuals who come in contact with such people, particular said peoples clothes.
On the medical side of things, Mesothelioma is a cancer that attacks the mesothelium. This anatomical term refers to the lining found around most organs of the body including the lungs and chest cavity. The cancer can also attack the sack encompassing the heart as well as other areas of the body. In short, it is a devastating form of cancer.
The truly horrific thing about Mesothelioma is the fact it takes a long time to appear. Gestation periods can be from twenty to fifty years. Even when it begins to show symptoms, it is very difficult to diagnose because it shares many symptoms common to aging and other health issues. These can include chest pain, coughing, shortness of breath, wheezing and blood clotting.
Unfortunately, Mesothelioma is deadly once it fully presents. A variety of treatment methods have been tried, but nothing has worked. The average person presenting with the cancer has a life span of less than a year. Radiation, surgery and pharmaceutical approaches have failed to significantly extend this time.
Mesothelioma is terminal cancer caused by exposure to asbestos dust that takes a long time to manifest, but a short time to kill.
Gerard Simington is with FindAnAttorneyForMe.com - offering asbestos and mesothelioma legal information.
Iron Mine Workers at Higher Risk to Develop Mesothelioma Than Previously Thought
Since 1988, 52 Iron miners have died in Minnesota whose mesothelioma cancers have led the state Health Department to conclude that the rare cancer is killing iron ore miners in significantly greater numbers than previously thought.
The state said last week it will try to determine whether the deaths are caused by asbestos or asbestos-like fibers in iron ore dust. They will also examine whether they think limits should be placed on exposure. According to a 2003 study, commercial asbestos used in taconite-plant furnaces and other mining equipment was the probable cause.
When federal air tests found elevated levels of asbestos last September at the Northshore Mining Co. in Silver Bay, Minn., mine safety officials couldn’t issue fines or order safety improvements.
New, stricter rules on asbestos in mines remain stalled, 20 months after being proposed. And under the current airborne asbestos limit, which is 20 times higher than the limit for other industries, Northshore’s processing plant is not in violation.
Now, regulators find themselves under renewed pressure to deal with dusty conditions in iron mining. This week, the state Health Department reported that 52 male Iron Range miners died of mesothelioma, a rare cancer caused by inhaling asbestos, from 1988 to 2005.
Over 200 miners have filed workers’ compensation claims stating that working in the taconite mines caused their asbestos-related diseases and other lung ailments.
“Hopefully it never blossoms,” Karl Oberstar Jr., 55, said of his asbestosis, which was detected in a screening arranged by his union in the late 1990s. He worked 31 years as a millwright and mechanic for LTV Steel Mining Co. in Hoyt Lakes.
Oberstar, who lives in Gilbert, remembers dumping bags of dusty asbestos into “a big mixing bowl” while making a fire-resistant paste to seal furnaces. “You could just see the particles everywhere,” he said. “The air never seemed clear.”
According to workers at the Eveleth Mines and Inland Steel Mining Co. in Virginia, dirt and dust came with the job.
They complained to the company at one point and were eventually given some respirators but they got clogged right away. After that, the company told them it was just harmless dust.
The brake linings of the trucks were asbestos, the ceiling tiles in his office had it, it was in the insulation of the wires that were stripped and it was in this paste that they smeared onto the pipes when they built the taconite plant.
The best course of action it seems for workers at these plants is to get their lungs scanned for signs of disease early to detect tumors as early as possible when treatment might be more effective.
The state said last week it will try to determine whether the deaths are caused by asbestos or asbestos-like fibers in iron ore dust. They will also examine whether they think limits should be placed on exposure. According to a 2003 study, commercial asbestos used in taconite-plant furnaces and other mining equipment was the probable cause.
When federal air tests found elevated levels of asbestos last September at the Northshore Mining Co. in Silver Bay, Minn., mine safety officials couldn’t issue fines or order safety improvements.
New, stricter rules on asbestos in mines remain stalled, 20 months after being proposed. And under the current airborne asbestos limit, which is 20 times higher than the limit for other industries, Northshore’s processing plant is not in violation.
Now, regulators find themselves under renewed pressure to deal with dusty conditions in iron mining. This week, the state Health Department reported that 52 male Iron Range miners died of mesothelioma, a rare cancer caused by inhaling asbestos, from 1988 to 2005.
Over 200 miners have filed workers’ compensation claims stating that working in the taconite mines caused their asbestos-related diseases and other lung ailments.
“Hopefully it never blossoms,” Karl Oberstar Jr., 55, said of his asbestosis, which was detected in a screening arranged by his union in the late 1990s. He worked 31 years as a millwright and mechanic for LTV Steel Mining Co. in Hoyt Lakes.
Oberstar, who lives in Gilbert, remembers dumping bags of dusty asbestos into “a big mixing bowl” while making a fire-resistant paste to seal furnaces. “You could just see the particles everywhere,” he said. “The air never seemed clear.”
According to workers at the Eveleth Mines and Inland Steel Mining Co. in Virginia, dirt and dust came with the job.
They complained to the company at one point and were eventually given some respirators but they got clogged right away. After that, the company told them it was just harmless dust.
The brake linings of the trucks were asbestos, the ceiling tiles in his office had it, it was in the insulation of the wires that were stripped and it was in this paste that they smeared onto the pipes when they built the taconite plant.
The best course of action it seems for workers at these plants is to get their lungs scanned for signs of disease early to detect tumors as early as possible when treatment might be more effective.
Asbestos Mesothelioma Lawsuit filed by New Jersey Mesothelioma Attorneys Levy Phillips & Konigsberg, LPP, Moves to Trial
The suit is on behalf of a woman who developed Mesothelioma after exposure to asbestos from brake repairs performed by her family members.
New York, NY (PRWEB) June 6, 2007 -- The New Jersey mesothelioma attorneys Levy Phillips & Konigsberg, LLP, with offices also in New York, filed an asbestos mesothelioma lawsuit on behalf of a woman who was exposed to asbestos as a result of her husband and children performing brake work. The woman was diagnosed with mesothelioma in 2002 and died from her illness shortly after mesothelioma treatments were attempted at Virtua West Jersey Hospital. The asbestos mesothelioma lawsuit, case number 03-0007, was filed in Middlesex County in central New Jersey and is set to proceed to trial this summer.
Brake dust, containing asbestos, can be released when a brake disk or drum is removed from a vehicle. The dust is frequently invisible to the naked eye, but if the brakes contain asbestos, then the dust released from the brakes will contain asbestos. The brake work, which will be at issue in this trial, was performed by the woman's husband and children on the family's cars in the garage and driveway of their New Jersey home from the 1960s through the 1980s. During the trial, it will be argued that the brand predominately used for the brake work was asbestos-containing Bendix brakes. The victim was unknowingly exposed to asbestos as a result of her laundering the dusty clothes and the used rags that were used by her husband and children after they performed the brake work. The victim would shake out the dirty clothes and dusty rags and then launder them. She performed the clean-up and laundry without any realization that she was neither in any danger nor that she was being exposed to asbestos-laden dust.
This asbestos mesothelioma lawsuit is coming on the heels of a new set of recommendations from the Environmental Protection Agency regarding automobile repairs and the importance of reducing or eliminating asbestos exposure from such work. The EPA in March 2007 released the guideline brochure entitled, "Current Best Practices for Preventing Asbestos Exposure Among Brake and Clutch Repair Workers" which is similar to guidance that EPA has been distributing since 1986. The EPA states in this publication that by using the recommended practices, home mechanics can minimize potential exposure to asbestos and reduce their potential risk of developing asbestos-related disease. For example, the EPA recommends not using compressed air or dry rags for cleaning. To visit the EPA website to learn more about how to lower the risks of asbestos exposure from asbestos dust while doing brake and auto repairs, please click on the following link: http://www.epa.gov/asbestos/pubs/brakesbrochure.html.
Symptoms of mesothelioma usually don't appear until at least 15 years after the victim's first contact or exposure to asbestos whether it is in workplace, the home environment or elsewhere. Exposure, even for a short duration, can cause mesothelioma. Asbestos fibers are microscopic and exposure can occur without one ever being aware of it. Asbestos mesothelioma lawsuits, may be brought when mesothelioma occurs not only in the people working directly with asbestos products but also in bystanders and family members who were exposed to the asbestos dust, as is the case here. Asbestos is the only known cause of mesothelioma, a cancer that occurs primarily in the lining of the lungs and the abdomen. Mesothelioma treatments can help prolong life, and provide palliative care benefits, but unfortunately there is no mesothelioma cure.
The New Jersey Mesothelioma Attorneys at Levy Phillips & Konigsberg, LLP have filed asbestos mesothelioma lawsuits on behalf of mesothelioma victims in the New York and New Jersey area for more than 25 years. The law firm has worked with some of the top mesothelioma doctors in the world including doctors whose practice focuses on the research of new mesothelioma treatments. Learn more about Levy Phillips & Konigsberg, LLP.
New York, NY (PRWEB) June 6, 2007 -- The New Jersey mesothelioma attorneys Levy Phillips & Konigsberg, LLP, with offices also in New York, filed an asbestos mesothelioma lawsuit on behalf of a woman who was exposed to asbestos as a result of her husband and children performing brake work. The woman was diagnosed with mesothelioma in 2002 and died from her illness shortly after mesothelioma treatments were attempted at Virtua West Jersey Hospital. The asbestos mesothelioma lawsuit, case number 03-0007, was filed in Middlesex County in central New Jersey and is set to proceed to trial this summer.
Brake dust, containing asbestos, can be released when a brake disk or drum is removed from a vehicle. The dust is frequently invisible to the naked eye, but if the brakes contain asbestos, then the dust released from the brakes will contain asbestos. The brake work, which will be at issue in this trial, was performed by the woman's husband and children on the family's cars in the garage and driveway of their New Jersey home from the 1960s through the 1980s. During the trial, it will be argued that the brand predominately used for the brake work was asbestos-containing Bendix brakes. The victim was unknowingly exposed to asbestos as a result of her laundering the dusty clothes and the used rags that were used by her husband and children after they performed the brake work. The victim would shake out the dirty clothes and dusty rags and then launder them. She performed the clean-up and laundry without any realization that she was neither in any danger nor that she was being exposed to asbestos-laden dust.
This asbestos mesothelioma lawsuit is coming on the heels of a new set of recommendations from the Environmental Protection Agency regarding automobile repairs and the importance of reducing or eliminating asbestos exposure from such work. The EPA in March 2007 released the guideline brochure entitled, "Current Best Practices for Preventing Asbestos Exposure Among Brake and Clutch Repair Workers" which is similar to guidance that EPA has been distributing since 1986. The EPA states in this publication that by using the recommended practices, home mechanics can minimize potential exposure to asbestos and reduce their potential risk of developing asbestos-related disease. For example, the EPA recommends not using compressed air or dry rags for cleaning. To visit the EPA website to learn more about how to lower the risks of asbestos exposure from asbestos dust while doing brake and auto repairs, please click on the following link: http://www.epa.gov/asbestos/pubs/brakesbrochure.html.
Symptoms of mesothelioma usually don't appear until at least 15 years after the victim's first contact or exposure to asbestos whether it is in workplace, the home environment or elsewhere. Exposure, even for a short duration, can cause mesothelioma. Asbestos fibers are microscopic and exposure can occur without one ever being aware of it. Asbestos mesothelioma lawsuits, may be brought when mesothelioma occurs not only in the people working directly with asbestos products but also in bystanders and family members who were exposed to the asbestos dust, as is the case here. Asbestos is the only known cause of mesothelioma, a cancer that occurs primarily in the lining of the lungs and the abdomen. Mesothelioma treatments can help prolong life, and provide palliative care benefits, but unfortunately there is no mesothelioma cure.
The New Jersey Mesothelioma Attorneys at Levy Phillips & Konigsberg, LLP have filed asbestos mesothelioma lawsuits on behalf of mesothelioma victims in the New York and New Jersey area for more than 25 years. The law firm has worked with some of the top mesothelioma doctors in the world including doctors whose practice focuses on the research of new mesothelioma treatments. Learn more about Levy Phillips & Konigsberg, LLP.
Friday, June 8, 2007
Pemetrexed combined with cisplatin or carboplatin shows promise as a treatment for malignant pleural mesothelioma
The results of a recent medical study confirmed results from earlier studies demonstrating that the chemotherapy drug pemetrexed combined with either cisplatin or carboplatin showed promise as a treatment for previously untreated, inoperable pleural mesothelioma. Malignant pleural mesothelioma is a form of cancer associated with exposure to asbestos.The study, which was reported at the American Society of Clinical Oncology meeting being held in Chicago, was derived from data on 1,704 mesothelioma patients who were among the more than 3,000 patients worldwide who received pemetrexed alone or in combination with a platinum agent such as cisplatin or carboplatin. Pemetrexed is known by the brand name Alimta in the U.S. and other countries.
History
The first lawsuit against asbestos manufacturers was brought in 1929. The parties settled that lawsuit, and as part of the agreement, the attorneys agreed not to pursue further cases. It was not until 1960 that an article published by Wagner et al first officially established mesothelioma as a disease arising from exposure to crocidolite asbestos.[10] The article referred to over 30 case studies of people who had suffered from mesothelioma in South Africa. Some exposures were transient and some were mine workers. In 1962 McNulty reported the first diagnosed case of malignant mesothelioma in an Australian asbestos worker.[11] The worker had worked in the mill at the asbestos mine in Wittenoom from 1948 to 1950.
In the town of Wittenoom, asbestos-containing mine waste was used to cover schoolyards and playgrounds. In 1965 an article in the British Journal of Industrial Medicine established that people who lived in the neighbourhoods of asbestos factories and mines, but did not work in them, had contracted mesothelioma.
Despite proof that the dust associated with asbestos mining and milling causes asbestos related disease, mining began at Wittenoom in 1943 and continued until 1966. In 1974 the first public warnings of the dangers of blue asbestos were published in a cover story called "Is this Killer in Your Home?" in Australia's Bulletin magazine. In 1978 the Western Australian Government decided to phase out the town of Wittenoom, following the publication of a Health Dept. booklet, "The Health Hazard at Wittenoom", containing the results of air sampling and an appraisal of worldwide medical information.
By 1979 the first writs for negligence related to Wittenoom were issued against CSR and its subsidiary ABA, and the Asbestos Diseases Society was formed to represent the Wittenoom victims.
In the town of Wittenoom, asbestos-containing mine waste was used to cover schoolyards and playgrounds. In 1965 an article in the British Journal of Industrial Medicine established that people who lived in the neighbourhoods of asbestos factories and mines, but did not work in them, had contracted mesothelioma.
Despite proof that the dust associated with asbestos mining and milling causes asbestos related disease, mining began at Wittenoom in 1943 and continued until 1966. In 1974 the first public warnings of the dangers of blue asbestos were published in a cover story called "Is this Killer in Your Home?" in Australia's Bulletin magazine. In 1978 the Western Australian Government decided to phase out the town of Wittenoom, following the publication of a Health Dept. booklet, "The Health Hazard at Wittenoom", containing the results of air sampling and an appraisal of worldwide medical information.
By 1979 the first writs for negligence related to Wittenoom were issued against CSR and its subsidiary ABA, and the Asbestos Diseases Society was formed to represent the Wittenoom victims.
Notable people with mesothelioma
Mesothelioma, though rare, has had a number of notable patients. Australian anti-racism activist Bob Bellear died in 2005. British science fiction writer Michael G. Coney, responsible for nearly 100 works also died in 2005. American film and television actor Paul Gleason, perhaps best known for his portrayal of Principal Richard Vernon in the 1985 film The Breakfast Club, died in 2006. Mickie Most, an English record producer, died of mesothelioma in 2003. Paul Rudolph, an American architect known for his cubist building designs, died in 1997.
Steve McQueen was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen sought alternative treatments from clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico, following cancer surgery. He may have been exposed to asbestos while serving with the US Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or because of its use as an insulating material in car racing suits.[8] (It is also reported that he worked in a shipyard during World War II, where he might have been exposed to asbestos.[citation needed]
United States Congressman Bruce Vento died of mesothelioma in 2000. The Bruce Vento Hopebuilder is awarded yearly by his wife at the MARF symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
After a long period of untreated illness and pain, rock and roll musician and songwriter Warren Zevon was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind including the song Keep me in your heart which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
Although life expectancy with this disease is typically limited, there are notable survivors. In July 1982, Stephen Jay Gould was diagnosed with peritoneal mesothelioma. After his diagnosis, Gould wrote the "The Median Isn't the Message"[9] for Discover magazine, in which he argued that statistics such as median survival are just useful abstractions, not destiny. Gould lived for another twenty years eventually succumbing to metastatic adenocarcinoma of the lung, not mesothelioma.
Author Paul Kraus was diagnosed with mesothelioma in June 1997 following an umbilical hernia operation. His prognosis was "a few months." He continues to survive using a variety of integrative and complimentary modalities and has written a book about his experience.
Steve McQueen was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen sought alternative treatments from clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico, following cancer surgery. He may have been exposed to asbestos while serving with the US Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or because of its use as an insulating material in car racing suits.[8] (It is also reported that he worked in a shipyard during World War II, where he might have been exposed to asbestos.[citation needed]
United States Congressman Bruce Vento died of mesothelioma in 2000. The Bruce Vento Hopebuilder is awarded yearly by his wife at the MARF symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
After a long period of untreated illness and pain, rock and roll musician and songwriter Warren Zevon was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind including the song Keep me in your heart which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
Although life expectancy with this disease is typically limited, there are notable survivors. In July 1982, Stephen Jay Gould was diagnosed with peritoneal mesothelioma. After his diagnosis, Gould wrote the "The Median Isn't the Message"[9] for Discover magazine, in which he argued that statistics such as median survival are just useful abstractions, not destiny. Gould lived for another twenty years eventually succumbing to metastatic adenocarcinoma of the lung, not mesothelioma.
Author Paul Kraus was diagnosed with mesothelioma in June 1997 following an umbilical hernia operation. His prognosis was "a few months." He continues to survive using a variety of integrative and complimentary modalities and has written a book about his experience.
Prevention & Expectations
What can be done to prevent the disease? Since the 1970s, the Environmental Protection Agency and the Occupational Safety and Health Administration have regulated the asbestos industry in the U.S. In the past, asbestos was used as a fire retardant and an insulator. Other products are now used in its place. The controversy involving exposure to different forms of asbestos continues.
There are two major types of asbestos: chrysotile and amphibole. It is thought that exposure to the amphibole form is more likely to cause mesothelioma. However, chrysotile has been used more frequently, hence many mesotheliomas are caused by chrysotile.
Removal is taking place in schools and other public buildings throughout the U.S. The hope is that these measures will greatly reduce the occurrence of this cancer.
What are the long-term effects of the disease? A mesothelioma is a highly aggressive tumor that is generally deadly. Current treatment of malignant mesothelioma is designed to make the person with cancer comfortable. Although long-term survival cannot usually be expected, the case of famed paleontologist Stephen Jay Gould is a noted example.
What are the risks to others? Mesothelioma is not contagious and cannot be passed from one person to another. The exposure to the asbestos that caused the cancer occurred many years to several decades before the disease appeared. People who live with asbestos workers have a higher risk of getting this cancer.
There are two major types of asbestos: chrysotile and amphibole. It is thought that exposure to the amphibole form is more likely to cause mesothelioma. However, chrysotile has been used more frequently, hence many mesotheliomas are caused by chrysotile.
Removal is taking place in schools and other public buildings throughout the U.S. The hope is that these measures will greatly reduce the occurrence of this cancer.
What are the long-term effects of the disease? A mesothelioma is a highly aggressive tumor that is generally deadly. Current treatment of malignant mesothelioma is designed to make the person with cancer comfortable. Although long-term survival cannot usually be expected, the case of famed paleontologist Stephen Jay Gould is a noted example.
What are the risks to others? Mesothelioma is not contagious and cannot be passed from one person to another. The exposure to the asbestos that caused the cancer occurred many years to several decades before the disease appeared. People who live with asbestos workers have a higher risk of getting this cancer.
Treatment
Treatment of MM using conventional therapies has not proved successful and patients have a median survival time of 6 - 12 months after presentation. The clinical behaviour of the malignancy is affected by several factors including the continuous mesothelial surface of the pleural cavity which favours local metastasis via exfoliated cells, invasion to underlying tissue and other organs within the pleural cavity, and the extremely long latency period between asbestos exposure and development of the disease.
Surgery
Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies has proved disappointing with a 5 year survival rate of less than 10%. A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed. It is not possible to remove the entire mesothelium without killing the patient.
Radiation
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Radiation Oncology/Lung/Mesothelioma
For patients with localized disease, and who can tolerate a radical surgery, radiation is often given post-operatively as a consolidative treatment. The entire hemi-thorax is treated with radiation therapy, often given simultaneously with chemotherapy. This approach of using surgery followed by radiation with chemotherapy has been pioneered by the thoracic oncology team at Brigham & Women's Hospital in Boston. [7] Delivering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. As part of a curative approach to mesothelioma, radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.
Although mesothelioma is generally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intent has never been shown to improve survival from mesothelioma. The necessary radiation dose to treat mesothelioma that has not been surgically removed would be very toxic.
Chemotherapy
In February 2004, the Food and Drug Administration approved pemetrexed (brand name Alimta) for treatment of malignant pleural mesothelioma. Pemetrexed is given in combination with cisplatin. Folic acid is also used to reduce the side-effects of pemetrexed.
Immunotherapy
Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin (BCG) in an attempt to boost the immune response, was found to be of no benefit to the patient (while it may benefit patients with bladder cancer). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2 (IL-2), but patients undergoing this particular therapy experienced major side effects. Indeed, this trial was suspended in view of the unacceptably high levels of IL-2 toxicity and the severity of side effects such as fever and cachexia. Nonetheless, other trials involving interferon alpha have proved more encouraging with 20% of patients experiencing a greater than 50% reduction in tumor mass combined with minimal side effects.
Heated Intraoperative Intraperitoneal Chemotherapy
A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute.[7] The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and then drained.
This technique permits the administration of high concentrations of selected drugs into the abdominal and pelvic surfaces. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.
Surgery
Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies has proved disappointing with a 5 year survival rate of less than 10%. A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed. It is not possible to remove the entire mesothelium without killing the patient.
Radiation
Wikibooks has a book on the topic of
Radiation Oncology/Lung/Mesothelioma
For patients with localized disease, and who can tolerate a radical surgery, radiation is often given post-operatively as a consolidative treatment. The entire hemi-thorax is treated with radiation therapy, often given simultaneously with chemotherapy. This approach of using surgery followed by radiation with chemotherapy has been pioneered by the thoracic oncology team at Brigham & Women's Hospital in Boston. [7] Delivering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. As part of a curative approach to mesothelioma, radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.
Although mesothelioma is generally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intent has never been shown to improve survival from mesothelioma. The necessary radiation dose to treat mesothelioma that has not been surgically removed would be very toxic.
Chemotherapy
In February 2004, the Food and Drug Administration approved pemetrexed (brand name Alimta) for treatment of malignant pleural mesothelioma. Pemetrexed is given in combination with cisplatin. Folic acid is also used to reduce the side-effects of pemetrexed.
Immunotherapy
Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin (BCG) in an attempt to boost the immune response, was found to be of no benefit to the patient (while it may benefit patients with bladder cancer). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2 (IL-2), but patients undergoing this particular therapy experienced major side effects. Indeed, this trial was suspended in view of the unacceptably high levels of IL-2 toxicity and the severity of side effects such as fever and cachexia. Nonetheless, other trials involving interferon alpha have proved more encouraging with 20% of patients experiencing a greater than 50% reduction in tumor mass combined with minimal side effects.
Heated Intraoperative Intraperitoneal Chemotherapy
A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute.[7] The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and then drained.
This technique permits the administration of high concentrations of selected drugs into the abdominal and pelvic surfaces. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.
Epidemiology
Incidence
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence is approximately one per 1,000,000. For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.[5] It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.
Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States [4]. Between 1973 and 1984, there has been a threefold increase in the diagnosis of pleural mesothelioma in Caucasian males. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.
Risk factors
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
The combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the airways (lung cancer, bronchial carcinoma). The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and some cases of mesothelioma have resulted. Smoking modern cigarettes does not appear to increase the risk of mesothelioma.
Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.[6]
Exposure
Asbestos was known in antiquity, but it wasn't mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace, and created guidelines for engineering controls and respirators, protective clothing, exposure monitoring, hygiene facilities and practices, warning signs, labeling, recordkeeping, and medical exams. By contrast, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE does not assume that any such threshold exists. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
Exposure to asbestos fibres has been recognised as an occupational health hazard since the early 1900s. Several epidemiological studies have associated exposure to asbestos with the development of lesions such as asbestos bodies in the sputum, pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumours, and diffuse mesothelioma of the pleura and peritoneum.
The documented presence of asbestos fibres in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibres. Although many authorities consider brief or transient exposure to asbestos fibres as inconsequential and an unlikely risk factor, some epidemiologists claim that there is no risk threshold. Cases of mesothelioma have been found in people whose only exposure was breathing the air through ventilation systems. Other cases had very minimal (3 months or less) direct exposure.
Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.
Family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibres, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence is approximately one per 1,000,000. For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.[5] It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.
Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States [4]. Between 1973 and 1984, there has been a threefold increase in the diagnosis of pleural mesothelioma in Caucasian males. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.
Risk factors
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
The combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the airways (lung cancer, bronchial carcinoma). The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and some cases of mesothelioma have resulted. Smoking modern cigarettes does not appear to increase the risk of mesothelioma.
Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.[6]
Exposure
Asbestos was known in antiquity, but it wasn't mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace, and created guidelines for engineering controls and respirators, protective clothing, exposure monitoring, hygiene facilities and practices, warning signs, labeling, recordkeeping, and medical exams. By contrast, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE does not assume that any such threshold exists. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
Exposure to asbestos fibres has been recognised as an occupational health hazard since the early 1900s. Several epidemiological studies have associated exposure to asbestos with the development of lesions such as asbestos bodies in the sputum, pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumours, and diffuse mesothelioma of the pleura and peritoneum.
The documented presence of asbestos fibres in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibres. Although many authorities consider brief or transient exposure to asbestos fibres as inconsequential and an unlikely risk factor, some epidemiologists claim that there is no risk threshold. Cases of mesothelioma have been found in people whose only exposure was breathing the air through ventilation systems. Other cases had very minimal (3 months or less) direct exposure.
Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.
Family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibres, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
Pathophysiology
The mesothelium consists of a single layer of flattened to cuboidal cells forming the epithelial lining of the serous cavities of the body including the peritoneal, pericardial and pleural cavities. Deposition of asbestos fibres in the parenchyma of the lung may result in the penetration of the visceral pleura from where the fibre can then be carried to the pleural surface, thus leading to the development of malignant mesothelial plaques. The processes leading to the development of peritoneal mesothelioma remain unresolved, although it has been proposed that asbestos fibres from the lung are transported to the abdomen and associated organs via the lymphatic system. Additionally, asbestos fibres may be deposited in the gut after ingestion of sputum contaminated with asbestos fibres.
Pleural contamination with asbestos or other mineral fibres has been shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" (chrysotile or white asbestos fibers). However, there is now evidence that smaller particles may be more dangerous than the larger fibers. They remain suspended in the air where they can be inhaled, and may penetrate more easily and deeper into the lungs. "We probably will find out a lot more about the health aspects of asbestos from [the World Trade Center attack], unfortunately," said Dr. Alan Fein, chief of pulmonary and critical-care medicine at North Shore-Long Island Jewish Health System. Dr. Fein has treated several patients for "World Trade Center syndrome" or respiratory ailments from brief exposures of only a day or two near the collapsed buildings.
Mesothelioma development in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibres. It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of mesothelioma. This is supported by the observed recruitment of significant numbers of macrophages and other cells of the immune system to localised lesions of accumulated asbestos fibres in the pleural and peritoneal cavities of rats. These lesions continued to attract and accumulate macrophages as the disease progressed, and cellular changes within the lesion culminated in a morphologically malignant tumour.
Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion. The molecular mechanisms underlying the malignant transformation of normal mesothelial cells by asbestos fibres remain unclear despite the demonstration of its oncogenic capabilities. However, complete in vitro transformation of normal human mesothelial cells to malignant phenotype following exposure to asbestos fibres has not yet been achieved. In general, asbestos fibres are thought to act through direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.
Analysis of the interactions between asbestos fibres and DNA has shown that phagocytosed fibres are able to make contact with chromosomes, often adhering to the chromatin fibres or becoming entangled within the chromosome. This contact between the asbestos fibre and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.
Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes:
Neurofibromatosis type 2 at 22q12
P16INK4A
P14ARF
Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:
Inactivation of tumor suppressor genes
Activation of oncogenes
Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
Activation of DNA repair enzymes, which may be prone to error
Activation of telomerase
Prevention of apoptosis
Asbestos fibres have been shown to alter the function and secretory properties of macrophages, ultimately creating conditions which favour the development of mesothelioma. Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals, which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences.
Asbestos also may possess immunosuppressive properties. For example, chrysotile fibres have been shown to depress the in vitro proliferation of phytohemagglutinin-stimulated peripheral blood lymphocytes, suppress natural killer cell lysis and significantly reduce lymphokine-activated killer cell viability and recovery. Furthermore, genetic alterations in asbestos-activated macrophages may result in the release of potent mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) which in turn, may induce the chronic stimulation and proliferation of mesothelial cells after injury by asbestos fibres.
Pleural contamination with asbestos or other mineral fibres has been shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" (chrysotile or white asbestos fibers). However, there is now evidence that smaller particles may be more dangerous than the larger fibers. They remain suspended in the air where they can be inhaled, and may penetrate more easily and deeper into the lungs. "We probably will find out a lot more about the health aspects of asbestos from [the World Trade Center attack], unfortunately," said Dr. Alan Fein, chief of pulmonary and critical-care medicine at North Shore-Long Island Jewish Health System. Dr. Fein has treated several patients for "World Trade Center syndrome" or respiratory ailments from brief exposures of only a day or two near the collapsed buildings.
Mesothelioma development in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibres. It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of mesothelioma. This is supported by the observed recruitment of significant numbers of macrophages and other cells of the immune system to localised lesions of accumulated asbestos fibres in the pleural and peritoneal cavities of rats. These lesions continued to attract and accumulate macrophages as the disease progressed, and cellular changes within the lesion culminated in a morphologically malignant tumour.
Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion. The molecular mechanisms underlying the malignant transformation of normal mesothelial cells by asbestos fibres remain unclear despite the demonstration of its oncogenic capabilities. However, complete in vitro transformation of normal human mesothelial cells to malignant phenotype following exposure to asbestos fibres has not yet been achieved. In general, asbestos fibres are thought to act through direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.
Analysis of the interactions between asbestos fibres and DNA has shown that phagocytosed fibres are able to make contact with chromosomes, often adhering to the chromatin fibres or becoming entangled within the chromosome. This contact between the asbestos fibre and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.
Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes:
Neurofibromatosis type 2 at 22q12
P16INK4A
P14ARF
Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:
Inactivation of tumor suppressor genes
Activation of oncogenes
Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
Activation of DNA repair enzymes, which may be prone to error
Activation of telomerase
Prevention of apoptosis
Asbestos fibres have been shown to alter the function and secretory properties of macrophages, ultimately creating conditions which favour the development of mesothelioma. Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals, which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences.
Asbestos also may possess immunosuppressive properties. For example, chrysotile fibres have been shown to depress the in vitro proliferation of phytohemagglutinin-stimulated peripheral blood lymphocytes, suppress natural killer cell lysis and significantly reduce lymphokine-activated killer cell viability and recovery. Furthermore, genetic alterations in asbestos-activated macrophages may result in the release of potent mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) which in turn, may induce the chronic stimulation and proliferation of mesothelial cells after injury by asbestos fibres.
Diagnosis
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history. A history of exposure to asbestos may increase clinical suspicion for mesothelioma. A physical examination is performed, followed by chest X-ray and often lung function tests. The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe. For pleural fluid this is done by a pleural tap or chest drain, in ascites with an paracentesis or asciti drain and in a pericardial effusion with pericardiocentesis. While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (e.g. tuberculosis, heart failure).
If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
Signs and symptoms
Symptoms of mesothelioma may not appear until 20 to 50 years after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space are often symptoms of pleural mesothelioma.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
chest wall pain
pleural effusion, or fluid surrounding the lung
shortness of breath
fatigue or anemia
wheezing, hoarseness, or cough
blood in the sputum (fluid) coughed up
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
abdominal pain
ascites, or an abnormal buildup of fluid in the abdomen
a mass in the abdomen
problems with bowel function
weight loss
In severe cases of the disease, the following signs and symptoms may be present:
blood clots in the veins, which may cause thrombophlebitis
disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
jaundice, or yellowing of the eyes and skin
low blood sugar level
pleural effusion
pulmonary emboli, or blood clots in the arteries of the lungs
severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
chest wall pain
pleural effusion, or fluid surrounding the lung
shortness of breath
fatigue or anemia
wheezing, hoarseness, or cough
blood in the sputum (fluid) coughed up
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
abdominal pain
ascites, or an abnormal buildup of fluid in the abdomen
a mass in the abdomen
problems with bowel function
weight loss
In severe cases of the disease, the following signs and symptoms may be present:
blood clots in the veins, which may cause thrombophlebitis
disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
jaundice, or yellowing of the eyes and skin
low blood sugar level
pleural effusion
pulmonary emboli, or blood clots in the arteries of the lungs
severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
Mesothelioma: Questions and Answers
Mesothelioma is a rare form of cancer in which malignant (cancerous) cells are found in the mesothelium, a protective sac that covers most of the body’s internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles.
What is the mesothelium?
The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.
The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.
What is mesothelioma?
Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum.
How common is mesothelioma?
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. About 2,000 new cases of mesothelioma are diagnosed in the United States each year. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age.
What are the risk factors for mesothelioma?
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
Smoking does not appear to increase the risk of mesothelioma. However, the combination of smoking and asbestos exposure significantly increases a person’s risk of developing cancer of the air passageways in the lung.
Who is at increased risk for developing mesothelioma?
Asbestos has been mined and used commercially since the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
The risk of asbestos-related disease increases with heavier exposure to asbestos and longer exposure time. However, some individuals with only brief exposures have developed mesothelioma. On the other hand, not all workers who are heavily exposed develop asbestos-related diseases.
There is some evidence that family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos-related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibers, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
What are the symptoms of mesothelioma?
Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma. Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a diagnosis.
How is mesothelioma diagnosed?
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient’s medical history, including any history of asbestos exposure. A complete physical examination may be performed, including x-rays of the chest or abdomen and lung function tests. A CT (or CAT) scan or an MRI may also be useful. A CT scan is a series of detailed pictures of areas inside the body created by a computer linked to an x-ray machine. In an MRI, a powerful magnet linked to a computer is used to make detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed.
A biopsy is needed to confirm a diagnosis of mesothelioma. In a biopsy, a surgeon or a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
If the diagnosis is mesothelioma, the doctor will want to learn the stage (or extent) of the disease. Staging involves more tests in a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor plan treatment.
Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.
How is mesothelioma treated?
Treatment for mesothelioma depends on the location of the cancer, the stage of the disease, and the patient’s age and general health. Standard treatment options include surgery, radiation therapy, and chemotherapy. Sometimes, these treatments are combined.
Surgery is a common treatment for mesothelioma. The doctor may remove part of the lining of the chest or abdomen and some of the tissue around it. For cancer of the pleura (pleural mesothelioma), a lung may be removed in an operation called a pneumonectomy. Sometimes part of the diaphragm, the muscle below the lungs that helps with breathing, is also removed.
Radiation therapy, also called radiotherapy, involves the use of high-energy rays to kill cancer cells and shrink tumors. Radiation therapy affects the cancer cells only in the treated area. The radiation may come from a machine (external radiation) or from putting materials that produce radiation through thin plastic tubes into the area where the cancer cells are found (internal radiation therapy).
Chemotherapy is the use of anticancer drugs to kill cancer cells throughout the body. Most drugs used to treat mesothelioma are given by injection into a vein (intravenous, or IV). Doctors are also studying the effectiveness of putting chemotherapy directly into the chest or abdomen (intracavitary chemotherapy).
To relieve symptoms and control pain, the doctor may use a needle or a thin tube to drain fluid that has built up in the chest or abdomen. The procedure for removing fluid from the chest is called thoracentesis. Removal of fluid from the abdomen is called paracentesis. Drugs may be given through a tube in the chest to prevent more fluid from accumulating. Radiation therapy and surgery may also be helpful in relieving symptoms.
Are new treatments for mesothelioma being studied?
Yes. Because mesothelioma is very hard to control, the National Cancer Institute (NCI) is sponsoring clinical trials (research studies with people) that are designed to find new treatments and better ways to use current treatments. Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is safe for patients and effective against the disease. Participation in clinical trials is an important treatment option for many patients with mesothelioma.
People interested in taking part in a clinical trial should talk with their doctor. Information about clinical trials is available from the Cancer Information Service (CIS) (see below) at 1–800–4–CANCER. Information specialists at the CIS use PDQ®, NCI’s cancer information database, to identify and provide detailed information about specific ongoing clinical trials. Patients also have the option of searching for clinical trials on their own. The clinical trials page on the NCI’s Cancer.gov Web site, located at http://www.cancer.gov/clinical_trials on the Internet, provides general information about clinical trials and links to PDQ.
People considering clinical trials may be interested in the NCI booklet Taking Part in Clinical Trials: What Cancer Patients Need To Know. This booklet describes how research studies are carried out and explains their possible benefits and risks. The booklet is available by calling the CIS, or from the NCI Publications Locator Web site at http://www.cancer.gov/publications on the Internet.
What is the mesothelium?
The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.
The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.
What is mesothelioma?
Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum.
How common is mesothelioma?
Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. About 2,000 new cases of mesothelioma are diagnosed in the United States each year. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age.
What are the risk factors for mesothelioma?
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
Smoking does not appear to increase the risk of mesothelioma. However, the combination of smoking and asbestos exposure significantly increases a person’s risk of developing cancer of the air passageways in the lung.
Who is at increased risk for developing mesothelioma?
Asbestos has been mined and used commercially since the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
The risk of asbestos-related disease increases with heavier exposure to asbestos and longer exposure time. However, some individuals with only brief exposures have developed mesothelioma. On the other hand, not all workers who are heavily exposed develop asbestos-related diseases.
There is some evidence that family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos-related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibers, asbestos workers are usually required to shower and change their clothing before leaving the workplace.
What are the symptoms of mesothelioma?
Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma. Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a diagnosis.
How is mesothelioma diagnosed?
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient’s medical history, including any history of asbestos exposure. A complete physical examination may be performed, including x-rays of the chest or abdomen and lung function tests. A CT (or CAT) scan or an MRI may also be useful. A CT scan is a series of detailed pictures of areas inside the body created by a computer linked to an x-ray machine. In an MRI, a powerful magnet linked to a computer is used to make detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed.
A biopsy is needed to confirm a diagnosis of mesothelioma. In a biopsy, a surgeon or a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
If the diagnosis is mesothelioma, the doctor will want to learn the stage (or extent) of the disease. Staging involves more tests in a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor plan treatment.
Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.
How is mesothelioma treated?
Treatment for mesothelioma depends on the location of the cancer, the stage of the disease, and the patient’s age and general health. Standard treatment options include surgery, radiation therapy, and chemotherapy. Sometimes, these treatments are combined.
Surgery is a common treatment for mesothelioma. The doctor may remove part of the lining of the chest or abdomen and some of the tissue around it. For cancer of the pleura (pleural mesothelioma), a lung may be removed in an operation called a pneumonectomy. Sometimes part of the diaphragm, the muscle below the lungs that helps with breathing, is also removed.
Radiation therapy, also called radiotherapy, involves the use of high-energy rays to kill cancer cells and shrink tumors. Radiation therapy affects the cancer cells only in the treated area. The radiation may come from a machine (external radiation) or from putting materials that produce radiation through thin plastic tubes into the area where the cancer cells are found (internal radiation therapy).
Chemotherapy is the use of anticancer drugs to kill cancer cells throughout the body. Most drugs used to treat mesothelioma are given by injection into a vein (intravenous, or IV). Doctors are also studying the effectiveness of putting chemotherapy directly into the chest or abdomen (intracavitary chemotherapy).
To relieve symptoms and control pain, the doctor may use a needle or a thin tube to drain fluid that has built up in the chest or abdomen. The procedure for removing fluid from the chest is called thoracentesis. Removal of fluid from the abdomen is called paracentesis. Drugs may be given through a tube in the chest to prevent more fluid from accumulating. Radiation therapy and surgery may also be helpful in relieving symptoms.
Are new treatments for mesothelioma being studied?
Yes. Because mesothelioma is very hard to control, the National Cancer Institute (NCI) is sponsoring clinical trials (research studies with people) that are designed to find new treatments and better ways to use current treatments. Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is safe for patients and effective against the disease. Participation in clinical trials is an important treatment option for many patients with mesothelioma.
People interested in taking part in a clinical trial should talk with their doctor. Information about clinical trials is available from the Cancer Information Service (CIS) (see below) at 1–800–4–CANCER. Information specialists at the CIS use PDQ®, NCI’s cancer information database, to identify and provide detailed information about specific ongoing clinical trials. Patients also have the option of searching for clinical trials on their own. The clinical trials page on the NCI’s Cancer.gov Web site, located at http://www.cancer.gov/clinical_trials on the Internet, provides general information about clinical trials and links to PDQ.
People considering clinical trials may be interested in the NCI booklet Taking Part in Clinical Trials: What Cancer Patients Need To Know. This booklet describes how research studies are carried out and explains their possible benefits and risks. The booklet is available by calling the CIS, or from the NCI Publications Locator Web site at http://www.cancer.gov/publications on the Internet.
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