Asbestos exposure has been attributed as a root cause for many types of health complications, with some being more serious than others. Many of these complications affect the respiratory system and can impact breathing and lung function. Because symptoms may be similar (i.e. chronic cough, chest pain, or difficulty breathing), it is important to discuss specific situations with a physician, especially for those who have a known asbestos-exposure history.
Emphysema
Emphysema may be a pre-cursor to smoking-related ailments such as lung cancer, mesothelioma, and asbestosis.
Mesothelioma Lung Cancer
Lung cancer, which is different than mesothelioma because it actually occurs in the lung tissue as opposed to the mesothelium, can also be attributed to asbestos exposure. There are general sub-classifications of lung cancer. These are small cell and non-small cell which are assigned based on how the cancer cells appear within the lung tissue. Each of these types has appeared in those exposed to asbestos.
Asbestosis
Asbestosis is a chronic respiratory condition which, like the name indicates, is directly attributable to asbestos exposure. Asbestosis can cause internal respiratory damage that will seriously limit lung function. Asbestosis has also been known to occur as a precursor to mesothelioma and other malignancies such as lung cancer.
Asbestos Lung Cancer
The difference between lung cancer and asbestos-caused mesothelioma cancer is that mesothelioma develops in the pleura, a thin membrane that forms the lining of the lungs, and not in the lungs themselves.
Asbestos Cancer
Asbestos cancer is the general term for cancers either directly attributable or partly attributable to asbestos exposure. These malignancies tend to be quite aggressive and affect the respiratory system due to inhaled asbestos fibers. The most common asbestos cancers are mesothelioma and asbestos-related lung cancer. These diseases are a summation of those gathered in our research of world medical literature. This information is medical in nature. A timeline of significant dates in the history of the legal and medical ramifications of asbestos diseases can be found within our History of Asbestos Disease section.
Asbestos Disease in Pets and Animals
Animals and pets, like humans, are susceptible to asbestos-related disease as well. Pets that spend a great deal of time with an asbestos-exposed owner or live in an area contaminated by asbestos have developed asbestos-related health complications.
Sunday, April 25, 2010
How do medical professionals diagnose mesothelioma?
If you believe that you may have mesothelioma, a qualified medical professional will use a variety of diagnostic tests and methods to confirm the presence of the disease.
Medical history review and exam.
The first step that your health professional will take in evaluating you for an asbestos related disease is to obtain a full medical history to determine the level and severity of risk factors and presenting symptoms. This interview will look consider among other things, where you were exposed to asbestos, the length of exposure and the amount of asbestos that you were exposed to.
In addition, he/she will perform a medical exam to look for signs and symptoms of various forms of mesothelioma. For example, if pleural mesothelioma is suspected the doctor will look for fluid in the chest, peritoneal mesothelioma often shows fluid in the abdomen and pericardial mesothelioma presents with fluid in the area of the heart.
Diagnostic imaging tests.
Chest x-rays are used to identify abnormalities in the lungs including unusual thickening, mineral deposits and fluid in the chest area. If these conditions are present then it may be evidence that mesothelioma has developed.
Diagnostic image tests like x-rays, CT scans and MRI's are useful in determining more information about the cancer including how far it is progressed. Each method provides another piece of information to your doctor to assist in making an accurate diagnosis. CT scans are capable of providing images of the same location from many different angles. MRI technology uses magnetic fields rather than x-ray to provide additional views.
Testing fluid and tissue samples.
If fluid build-up in the chest, abdomen or heart area is present, your doctor may want to obtain a sample. To accomplish this he/she will use a long needle to obtain fluid from the target area. The fluid will then be sent to the lab for analysis.
If fluid build-up in the chest, abdomen or heart area is present, your doctor may want to obtain a sample. To accomplish this he/she will use a long needle to obtain fluid from the target area. The fluid will then be sent to the lab for analysis.
A bronchoscopy procedure may be recommended for patients who are suspected of having pleural mesothelioma. For this medical test, a soft tube illuminates the trachea and bronchi to determine if any masses are present in the airways. If deemed necessary, the technician my take sample of tissue that appears to be abnormal for further testing.
If lymph node involvement is suspected which is common with lung cancer, patients may also undergo a mediastinoscopy. This procedure is similar to a bronchoscopy in that a soft tube enters the body under the chest bone and illuminates the chest area. In this way, the surgeon can examine lymph nodes for abnormalities, check to see how far disease may have progressed and when necessary help diagnose lung cancer vs. mesothelioma.
Diagnosing mesothelioma is never easy. Fluid build up alone in the chest, belly or heart regions is not enough to confirm a diagnosis. Tissue samples obtained from biopsy procedures are also difficult to discern because mesothelioma cancer cells often resemble other types of cancer. For this reason, specialized laboratory procedures are often employed to identify certain chemicals that are known to exist with mesothelioma and high powered laboratory equipment is used to examine the smallest details of cancer cells to confirm that mesothelioma is present.
Medical history review and exam.
The first step that your health professional will take in evaluating you for an asbestos related disease is to obtain a full medical history to determine the level and severity of risk factors and presenting symptoms. This interview will look consider among other things, where you were exposed to asbestos, the length of exposure and the amount of asbestos that you were exposed to.
In addition, he/she will perform a medical exam to look for signs and symptoms of various forms of mesothelioma. For example, if pleural mesothelioma is suspected the doctor will look for fluid in the chest, peritoneal mesothelioma often shows fluid in the abdomen and pericardial mesothelioma presents with fluid in the area of the heart.
Diagnostic imaging tests.
Chest x-rays are used to identify abnormalities in the lungs including unusual thickening, mineral deposits and fluid in the chest area. If these conditions are present then it may be evidence that mesothelioma has developed.
Diagnostic image tests like x-rays, CT scans and MRI's are useful in determining more information about the cancer including how far it is progressed. Each method provides another piece of information to your doctor to assist in making an accurate diagnosis. CT scans are capable of providing images of the same location from many different angles. MRI technology uses magnetic fields rather than x-ray to provide additional views.
Testing fluid and tissue samples.
If fluid build-up in the chest, abdomen or heart area is present, your doctor may want to obtain a sample. To accomplish this he/she will use a long needle to obtain fluid from the target area. The fluid will then be sent to the lab for analysis.
If fluid build-up in the chest, abdomen or heart area is present, your doctor may want to obtain a sample. To accomplish this he/she will use a long needle to obtain fluid from the target area. The fluid will then be sent to the lab for analysis.
A bronchoscopy procedure may be recommended for patients who are suspected of having pleural mesothelioma. For this medical test, a soft tube illuminates the trachea and bronchi to determine if any masses are present in the airways. If deemed necessary, the technician my take sample of tissue that appears to be abnormal for further testing.
If lymph node involvement is suspected which is common with lung cancer, patients may also undergo a mediastinoscopy. This procedure is similar to a bronchoscopy in that a soft tube enters the body under the chest bone and illuminates the chest area. In this way, the surgeon can examine lymph nodes for abnormalities, check to see how far disease may have progressed and when necessary help diagnose lung cancer vs. mesothelioma.
Diagnosing mesothelioma is never easy. Fluid build up alone in the chest, belly or heart regions is not enough to confirm a diagnosis. Tissue samples obtained from biopsy procedures are also difficult to discern because mesothelioma cancer cells often resemble other types of cancer. For this reason, specialized laboratory procedures are often employed to identify certain chemicals that are known to exist with mesothelioma and high powered laboratory equipment is used to examine the smallest details of cancer cells to confirm that mesothelioma is present.
What are the warning signs of mesothelioma?
Mesothelioma is difficult to diagnose because the early signs and symptoms of the disease can be subtle at best. Symptoms are all too frequently ignored or dismissed by people who are inclined to attribute them to common every day ailments. Sometimes patients live with symptoms for up to 6 months before being diagnosed but usually the symptoms are present for two to three months prior to diagnosis.
About 60% of patients diagnosed with pleural mesothelioma experience lower back pain or side chest pain and there are frequent reports of shortness of breath. Lower numbers of people may experience difficulty swallowing, or have a persistent cough, fever, weight loss or fatigue. Symptoms to also consider are muscle weakness, loss of sensory capability, coughing up blood, facial and arm swelling and hoarseness.
Peritoneal mesothelioma originates in the abdomen and as a result, symptoms often include abdominal pain, weight loss, nausea, and vomiting. In the event that there is a hernia present, fluid build up may occur in the abdomen as well.
Anyone previously exposed to asbestos displaying any of these symptoms should seek medical attention right away.
About 60% of patients diagnosed with pleural mesothelioma experience lower back pain or side chest pain and there are frequent reports of shortness of breath. Lower numbers of people may experience difficulty swallowing, or have a persistent cough, fever, weight loss or fatigue. Symptoms to also consider are muscle weakness, loss of sensory capability, coughing up blood, facial and arm swelling and hoarseness.
Peritoneal mesothelioma originates in the abdomen and as a result, symptoms often include abdominal pain, weight loss, nausea, and vomiting. In the event that there is a hernia present, fluid build up may occur in the abdomen as well.
Anyone previously exposed to asbestos displaying any of these symptoms should seek medical attention right away.
What are the main causes of mesothelioma?
Mesothelioma is most predominantly caused by asbestos exposure. Asbestos fibers that are inhaled through the mouth and nose may eventually become embedded in the lining of the lungs, causing damage and resulting in lung cancer or asbestosis (scar tissue formation in the lungs). It has also been found that swallowing asbestos fibers could contribute to a form of mesothelioma originating in the abdomen called peritoneal mesothelioma.
Mesothelioma generally results from occupational exposure but there are instances of environmental exposure to asbestos that can cause the disease. Oftentimes second hand exposure of a family member to an asbestos workers dirty work clothes can result in that family member developing mesothelioma.
Asbestos insulation workers appear to have the highest death rate. One study reports that almost six percent of asbestos workers fall victim to mesothelioma and asbestos insulation workers are over 300 times more likely to die from mesothelioma than the general public.
Find out more about Nanotechnology.
Mesothelioma generally results from occupational exposure but there are instances of environmental exposure to asbestos that can cause the disease. Oftentimes second hand exposure of a family member to an asbestos workers dirty work clothes can result in that family member developing mesothelioma.
Asbestos insulation workers appear to have the highest death rate. One study reports that almost six percent of asbestos workers fall victim to mesothelioma and asbestos insulation workers are over 300 times more likely to die from mesothelioma than the general public.
Find out more about Nanotechnology.
What are the risk factors for malignant mesothelioma?
There are several risk factors that increase the likelihood that a person will develop mesothelioma. The primary risk factor is asbestos exposure. Exposure to this very harmful substance can significantly enhance the chances of contracting the disease. Other secondary factors include exposure to radiation, zeolite, simian virus 40 (SV40) and tobacco. We discuss each of these risk factors in more detail below.
Asbestos
Exposure to asbestos is the leading risk factor associated with mesothelioma. Asbestos is an insulating material comprised of magnesium-silicate mineral fibers. It was favored by builders and contractors for many years for its low heat conductivity and resistance to melting and burning. Since researchers have identified more and more links between mesothelioma and exposure to asbestos, the material is now less widely used. Prior to this discovery, however, millions of Americans have experienced serious exposure to this harmful substance.
Over 700,000 schools and buildings in the United States today contain asbestos insulation as reported by the US Environmental Protection Agency. Asbestos exposure doesn’t stop there, however. Asbestos is often found in ship yards, manufacturing facilities, railway facilities and construction sites. Blue collar workers are at the highest risk for developing mesothelioma due to occupational exposure and include those who work in mines, factories, shipyards, construction sites, railroads and for insulation manufacturers and gas mask manufacturers. The occupations most widely affected are miners, factory workers, railroad workers, ship builders and construction workers - especially those who install asbestos containing insulation. Sometimes family members related to the workers receive second hand exposure to asbestos from the dust and fibers that were brought home on the workers clothes and also become at risk for contracting mesothelioma.
Serpentine fibers and amphiboles are the 2 primary types of asbestos used. Chrysotile is a form of serpentine fiber and the most frequently used. These fibers tend to be curly and flexible. Amphibole fibers, however, are generally straight and thin and usually comprise one of five types: crocidolite, amosite, anthrophylite, tremolite, and actinolyte. The crocidolite type of Amphiboles is thought to be the leading contributor to cancer caused by asbestos. Serpentine fibers are dangerous as well, however, and have also been linked to mesothelioma.
Some research points to the fact that inhaled asbestos fibers cause a physical irritation resulting in cancer rather than the cancer being caused by a reaction that is more chemical in nature. As fibers are inhaled through the mouth and nose they are cleared from the body by adhering to mucus in the nose, throat and airways and then get expelled by coughing or swallowing. The Amphibole fibers (long and thin) do not clear as easily and it is therefore thought that they can embed into the lining of the lungs and chest and result in mesothelioma.
Asbestosis (scar tissue in the lungs) or lung cancer can also be caused by the inhalation of asbestos fibers. In fact, people exposed to asbestos are seven times more likely to develop lung cancer over the general public. Workers who sustain high levels of asbestos exposure are more likely to die from asbestosis, lung cancer or mesothelioma than any other disease. It is also believed that the action of coughing up and swallowing asbestos could contribute to a form of mesothelioma originating in the abdomen called peritoneal mesothelioma. Mesothelioma has been found to exist in other organs of the body as well such as the larynx, pancreas and colon, but those instances are extremely limited compared to lung cancer incidents.
The chance of developing mesothelioma is in direct proportion to the duration and amount of asbestos exposure that an individual sustains. Those who are exposed to high levels of asbestos at a young age, for long periods of time have a greater risk of being diagnosed with mesothelioma than those who have short, low level exposure. Another important consideration is that Mesothelioma can take a long time to manifest. Often, twenty to forty years can elapse from the time of exposure to diagnosis. Genetic factors can also play a role which explains why not everyone exposed to asbestos develops and asbestos related disease.
Radiation
Thorium dioxide (Thorotrast), a substance used in x-ray tests in the past has reported links to pleural mesothelioma and peritoneal mesothelioma. The use of Thorotrast has been discontinued for many years due to this discovery.
Zeolite
Some mesothelioma cases in the Anatoli region within Turkey have been linked to Zeolite, a silica based mineral with chemical properties similar to asbestos found in the soil there.
Simian Virus 40 (SV40)
Some scientists have found the simian virus 40 (SV30) in mesothelioma cells from humans and have been able to create mesothelioma in animals with the virus. The relationship between this virus and mesothelioma is still unclear, however, and further research is being conducted to gain clarity on this potential link.
Smoking and Mesothelioma
Smoking alone is not linked to mesothelioma, but smokers who are exposed to asbestos have a much higher chance of developing lung cancer (as much as fifty to ninety percent higher). Research indicates that lung cancer is the leading cause of death among asbestos workers.
Asbestos
Exposure to asbestos is the leading risk factor associated with mesothelioma. Asbestos is an insulating material comprised of magnesium-silicate mineral fibers. It was favored by builders and contractors for many years for its low heat conductivity and resistance to melting and burning. Since researchers have identified more and more links between mesothelioma and exposure to asbestos, the material is now less widely used. Prior to this discovery, however, millions of Americans have experienced serious exposure to this harmful substance.
Over 700,000 schools and buildings in the United States today contain asbestos insulation as reported by the US Environmental Protection Agency. Asbestos exposure doesn’t stop there, however. Asbestos is often found in ship yards, manufacturing facilities, railway facilities and construction sites. Blue collar workers are at the highest risk for developing mesothelioma due to occupational exposure and include those who work in mines, factories, shipyards, construction sites, railroads and for insulation manufacturers and gas mask manufacturers. The occupations most widely affected are miners, factory workers, railroad workers, ship builders and construction workers - especially those who install asbestos containing insulation. Sometimes family members related to the workers receive second hand exposure to asbestos from the dust and fibers that were brought home on the workers clothes and also become at risk for contracting mesothelioma.
Serpentine fibers and amphiboles are the 2 primary types of asbestos used. Chrysotile is a form of serpentine fiber and the most frequently used. These fibers tend to be curly and flexible. Amphibole fibers, however, are generally straight and thin and usually comprise one of five types: crocidolite, amosite, anthrophylite, tremolite, and actinolyte. The crocidolite type of Amphiboles is thought to be the leading contributor to cancer caused by asbestos. Serpentine fibers are dangerous as well, however, and have also been linked to mesothelioma.
Some research points to the fact that inhaled asbestos fibers cause a physical irritation resulting in cancer rather than the cancer being caused by a reaction that is more chemical in nature. As fibers are inhaled through the mouth and nose they are cleared from the body by adhering to mucus in the nose, throat and airways and then get expelled by coughing or swallowing. The Amphibole fibers (long and thin) do not clear as easily and it is therefore thought that they can embed into the lining of the lungs and chest and result in mesothelioma.
Asbestosis (scar tissue in the lungs) or lung cancer can also be caused by the inhalation of asbestos fibers. In fact, people exposed to asbestos are seven times more likely to develop lung cancer over the general public. Workers who sustain high levels of asbestos exposure are more likely to die from asbestosis, lung cancer or mesothelioma than any other disease. It is also believed that the action of coughing up and swallowing asbestos could contribute to a form of mesothelioma originating in the abdomen called peritoneal mesothelioma. Mesothelioma has been found to exist in other organs of the body as well such as the larynx, pancreas and colon, but those instances are extremely limited compared to lung cancer incidents.
The chance of developing mesothelioma is in direct proportion to the duration and amount of asbestos exposure that an individual sustains. Those who are exposed to high levels of asbestos at a young age, for long periods of time have a greater risk of being diagnosed with mesothelioma than those who have short, low level exposure. Another important consideration is that Mesothelioma can take a long time to manifest. Often, twenty to forty years can elapse from the time of exposure to diagnosis. Genetic factors can also play a role which explains why not everyone exposed to asbestos develops and asbestos related disease.
Radiation
Thorium dioxide (Thorotrast), a substance used in x-ray tests in the past has reported links to pleural mesothelioma and peritoneal mesothelioma. The use of Thorotrast has been discontinued for many years due to this discovery.
Zeolite
Some mesothelioma cases in the Anatoli region within Turkey have been linked to Zeolite, a silica based mineral with chemical properties similar to asbestos found in the soil there.
Simian Virus 40 (SV40)
Some scientists have found the simian virus 40 (SV30) in mesothelioma cells from humans and have been able to create mesothelioma in animals with the virus. The relationship between this virus and mesothelioma is still unclear, however, and further research is being conducted to gain clarity on this potential link.
Smoking and Mesothelioma
Smoking alone is not linked to mesothelioma, but smokers who are exposed to asbestos have a much higher chance of developing lung cancer (as much as fifty to ninety percent higher). Research indicates that lung cancer is the leading cause of death among asbestos workers.
What are the different types of mesothelioma?
Pleural Mesothelioma – affects the chest and lungs
Malignant pleural mesothelioma often originates within the chest cavity and can, at times, involve the lung. This particular form of mesothelioma can metastasize to numerous organs in the body – even the brain - and tends to do so more frequently than not.
Pleural mesothelioma is not always easily detectable. Frequently, in the early stages of the disease, symptoms may be mild. Patients usually report pain in one area of the chest that never seems to go away, weight loss and fever. Occasionally, other symptoms are more severe and include problems with breathing due to fluid build up in the chest. A CT Scan of the chest area has proven to be the best test for identifying how far along the disease has progressed.
Frequently serum markers are used to diagnose of various forms of cancer. Mesothelioma cannot be diagnosed using this method as no serum markers currently exist. If high levels of hyaluronic acid are present it may be possible to distinguish mesothelioma from other types of cancer or to determine the effectiveness of a treatment protocol.
The survival rate for patients diagnosed with pleural mesothelioma typically is not high. Patients typically do not live beyond seventeen months from the onset of symptoms. Only 8% of those diagnosed with mesothelioma will live three to five years from the onset of symptoms.
Pericardial Mesothelioma – affects the heart
Pericardial mesothelioma is the least common form of mesothelioma. Pericardial mesothelioma, as the name suggests, involves the heart. This rare type of mesothelioma invades the pericardium, the sac that surrounds the heart. As the cancer progresses, the heart is not able to deliver oxygen as efficiently to the body causing further decline in health at an increasingly rapid rate. The symptoms most commonly associated with pericardial mesothelioma mimic those of a heart attack: nausea, pain in the chest and shortness of breath.
Peritoneal Mesothelioma – affects the abdomen
Peritoneal mesothelioma originates in the abdomen and will frequently spread to other organs in area including the liver, spleen or bowel. Severe abdominal pain is the most common complaint that patients present to their doctor. There may also be a discomfort level with fluid build up in the abdomen as well. Other symptoms of peritoneal mesothelioma may include difficult bowel movements, nausea and vomiting, fever and swollen feet.
The survival rate is even worse for those diagnosed with peritoneal mesothelioma will patients typically surviving only ten months from time that they first started experiencing the symptoms noted above.
Malignant Mesothelioma
Malignant mesothelioma is an uncommon form of cancer and of all asbestos related diseases, the most serious. The symptoms associated with the disease make it difficult for doctors to diagnose. Often, by the time that a proper diagnosis is made, the disease has progressed to a point where patients do not respond well to treatment therapy. Malignant mesothelioma is caused almost exclusively by the inhalation of airborne asbestos particles. Another unique factor associated with the disease is that there can be a long latency period between the time an individual is exposed to asbestos and the actual manifestation of the disease in the form of malignant mesothelioma.
Benign Mesothelioma
Benign mesothelioma, or non-malignant mesothelioma, is much easier to treat than the malignant form of the cancer and can be treated successfully in many cases.
Malignant pleural mesothelioma often originates within the chest cavity and can, at times, involve the lung. This particular form of mesothelioma can metastasize to numerous organs in the body – even the brain - and tends to do so more frequently than not.
Pleural mesothelioma is not always easily detectable. Frequently, in the early stages of the disease, symptoms may be mild. Patients usually report pain in one area of the chest that never seems to go away, weight loss and fever. Occasionally, other symptoms are more severe and include problems with breathing due to fluid build up in the chest. A CT Scan of the chest area has proven to be the best test for identifying how far along the disease has progressed.
Frequently serum markers are used to diagnose of various forms of cancer. Mesothelioma cannot be diagnosed using this method as no serum markers currently exist. If high levels of hyaluronic acid are present it may be possible to distinguish mesothelioma from other types of cancer or to determine the effectiveness of a treatment protocol.
The survival rate for patients diagnosed with pleural mesothelioma typically is not high. Patients typically do not live beyond seventeen months from the onset of symptoms. Only 8% of those diagnosed with mesothelioma will live three to five years from the onset of symptoms.
Pericardial Mesothelioma – affects the heart
Pericardial mesothelioma is the least common form of mesothelioma. Pericardial mesothelioma, as the name suggests, involves the heart. This rare type of mesothelioma invades the pericardium, the sac that surrounds the heart. As the cancer progresses, the heart is not able to deliver oxygen as efficiently to the body causing further decline in health at an increasingly rapid rate. The symptoms most commonly associated with pericardial mesothelioma mimic those of a heart attack: nausea, pain in the chest and shortness of breath.
Peritoneal Mesothelioma – affects the abdomen
Peritoneal mesothelioma originates in the abdomen and will frequently spread to other organs in area including the liver, spleen or bowel. Severe abdominal pain is the most common complaint that patients present to their doctor. There may also be a discomfort level with fluid build up in the abdomen as well. Other symptoms of peritoneal mesothelioma may include difficult bowel movements, nausea and vomiting, fever and swollen feet.
The survival rate is even worse for those diagnosed with peritoneal mesothelioma will patients typically surviving only ten months from time that they first started experiencing the symptoms noted above.
Malignant Mesothelioma
Malignant mesothelioma is an uncommon form of cancer and of all asbestos related diseases, the most serious. The symptoms associated with the disease make it difficult for doctors to diagnose. Often, by the time that a proper diagnosis is made, the disease has progressed to a point where patients do not respond well to treatment therapy. Malignant mesothelioma is caused almost exclusively by the inhalation of airborne asbestos particles. Another unique factor associated with the disease is that there can be a long latency period between the time an individual is exposed to asbestos and the actual manifestation of the disease in the form of malignant mesothelioma.
Benign Mesothelioma
Benign mesothelioma, or non-malignant mesothelioma, is much easier to treat than the malignant form of the cancer and can be treated successfully in many cases.
Asbestos Exposure
Asbestos exposure is the single known cause of mesothelioma. Inhaled or ingested asbestos fibers may cause an inflammation of internal tissue and disrupt organ function which leads to the development of the disease. Asbestos products were used extensively throughout the 20th century in a wide variety of applications. Many of these products were responsible for asbestos exposure sustained by both the individuals who manufactured the products as well as those who used them at commercial and industrial jobsites including shipyards, refineries, power plants, steel plants and more. Several asbestos companies continued to produce these products even after they were known to be hazardous and harmful to workers and their families. Those who have become sick because of exposure to these products may now be eligible for financial compensation if they were wrongfully exposed.
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.
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 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.
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.
Monday, February 22, 2010
Asbestos Lung Cancer
Asbestos lung cancer is a group of diseases related to asbestos exposure. While the term itself is technically incorrect — only one of the diseases belonging to this group (asbestosis) originates in the lungs (and it is not a form of cancer) — it serves as a way of classifying asbestos-related diseases that affect the lungs.
Asbestos is a naturally occurring mineral that has been mined, processed, and used for more than 6,000 years. The two most common diseases related to asbestos lung cancer are asbestosis and mesothelioma, with pleural mesothelioma being the most common form of mesothelioma. Both mesothelioma and asbestosis are associated with the inhalation of asbestos and subsequent inflammation caused by the lodging of asbestos in the lungs.
Mesothelioma.
Malignant mesothelioma is a rare type of asbestos lung cancer that results from asbestos becoming lodged in the lining of the lung. However, unlike asbestosis, which originates in the lungs, mesothelioma occurs in the serous lining, which is the lining surrounding the outside of the lungs. Another thing that distinguishes mesothelioma from asbestosis is that it leads to the growth of tumors that are malignant (asbestosis leads to the growth of scar tissue, which is benign). This means that the growths in the lungs' serous membranes related to mesothelioma are cancerous, can grow rapidly and can spread to other organs. Asbestosis, on the other hand, does not spread to other organs. When cancer tumors grow and then spread to other organs, this is called metastasis.
Pleural Mesothelioma
Mesothelioma can affect several different organs in the body, not just the lungs. When mesothelioma occurs in the lungs, it is called pleural mesothelioma; when it occurs in the heart lining it is called pericardial mesothelioma; and when it occurs in the abdomen it is called peritoneal mesothelioma. Asbestos exposure is thought to be the primary cause of all three types of mesothelioma.
The timeline between asbestos exposure and the onset of pleural mesothelioma is very long (30 to 40 years). Pleural mesothelioma can be detected by x-rays, but the diagnosis of pleural mesothelioma has to be confirmed with a biopsy. The treatments for pleural mesothelioma are similar to other cancers. They include chemotherapy, radiation therapy and surgical removal of the cancerous tissues. However, it is important to note that different types of cancers respond differently to different types of treatments. As a result, a patient's treatment plan is based on his or her individual case. Unfortunately, the disease is very aggressive, and most treatments do not slow its progression. The life expectancy of those diagnosed with pleural mesothelioma is less than a year.
Asbestosis.
Asbestosis is a disease in which asbestos fibers cause scarring of the lungs; however, it is not a type of lung cancer. This disease occurs because asbestos fibers are tiny, yet durable; when they are inhaled, the lungs' natural filtration system is unable to eliminate them from the air. As a result, asbestos is able to enter the very sterile inner reaches of the lung cavities. When asbestos fibers become lodged in the interstitium — the area surrounding the lungs' air sacs (alveoli) — the lungs become inflamed, which eventually leads to scarring. The timeline between the moment asbestos enters the lungs and the eventual onset of scarring can be as long as 10 years. Eventually, if enough scarring occurs in the lungs, it will be classified as fibrosis. Asbestosis is fibrosis that forms in the interstitium.
Fibrosis is defined as the development of excess fibrous connective tissue in an organ. This connective tissue cripples the areas of the lungs that it invades. Thus, when it spreads across large areas of the lungs over time, the lungs lose their ability to function properly. Similar to pleural mesothelioma, the total timeline between exposure to asbestos and the development of large areas of fibrosis can be as long as 30 or 40 years.
Asbestosis is normally detected with an x-ray showing the large fibrous growths in the lungs. Oftentimes, the initial symptom is difficulty breathing, which may be caused by the fibrous tissue that has formed, or by a pleural effusion (buildup of fluid) caused by the asbestosis. There is no cure for asbestosis, and eventually the fibrous tissue can spread throughout the lungs and make it impossible to breath. A common cause of death related to asbestosis is congestive heart failure, in which the heart becomes overworked in its attempt to push enough blood through the lungs to carry sufficient oxygen to the rest of the body.
Asbestos is a naturally occurring mineral that has been mined, processed, and used for more than 6,000 years. The two most common diseases related to asbestos lung cancer are asbestosis and mesothelioma, with pleural mesothelioma being the most common form of mesothelioma. Both mesothelioma and asbestosis are associated with the inhalation of asbestos and subsequent inflammation caused by the lodging of asbestos in the lungs.
Mesothelioma.
Malignant mesothelioma is a rare type of asbestos lung cancer that results from asbestos becoming lodged in the lining of the lung. However, unlike asbestosis, which originates in the lungs, mesothelioma occurs in the serous lining, which is the lining surrounding the outside of the lungs. Another thing that distinguishes mesothelioma from asbestosis is that it leads to the growth of tumors that are malignant (asbestosis leads to the growth of scar tissue, which is benign). This means that the growths in the lungs' serous membranes related to mesothelioma are cancerous, can grow rapidly and can spread to other organs. Asbestosis, on the other hand, does not spread to other organs. When cancer tumors grow and then spread to other organs, this is called metastasis.
Pleural Mesothelioma
Mesothelioma can affect several different organs in the body, not just the lungs. When mesothelioma occurs in the lungs, it is called pleural mesothelioma; when it occurs in the heart lining it is called pericardial mesothelioma; and when it occurs in the abdomen it is called peritoneal mesothelioma. Asbestos exposure is thought to be the primary cause of all three types of mesothelioma.
The timeline between asbestos exposure and the onset of pleural mesothelioma is very long (30 to 40 years). Pleural mesothelioma can be detected by x-rays, but the diagnosis of pleural mesothelioma has to be confirmed with a biopsy. The treatments for pleural mesothelioma are similar to other cancers. They include chemotherapy, radiation therapy and surgical removal of the cancerous tissues. However, it is important to note that different types of cancers respond differently to different types of treatments. As a result, a patient's treatment plan is based on his or her individual case. Unfortunately, the disease is very aggressive, and most treatments do not slow its progression. The life expectancy of those diagnosed with pleural mesothelioma is less than a year.
Asbestosis.
Asbestosis is a disease in which asbestos fibers cause scarring of the lungs; however, it is not a type of lung cancer. This disease occurs because asbestos fibers are tiny, yet durable; when they are inhaled, the lungs' natural filtration system is unable to eliminate them from the air. As a result, asbestos is able to enter the very sterile inner reaches of the lung cavities. When asbestos fibers become lodged in the interstitium — the area surrounding the lungs' air sacs (alveoli) — the lungs become inflamed, which eventually leads to scarring. The timeline between the moment asbestos enters the lungs and the eventual onset of scarring can be as long as 10 years. Eventually, if enough scarring occurs in the lungs, it will be classified as fibrosis. Asbestosis is fibrosis that forms in the interstitium.
Fibrosis is defined as the development of excess fibrous connective tissue in an organ. This connective tissue cripples the areas of the lungs that it invades. Thus, when it spreads across large areas of the lungs over time, the lungs lose their ability to function properly. Similar to pleural mesothelioma, the total timeline between exposure to asbestos and the development of large areas of fibrosis can be as long as 30 or 40 years.
Asbestosis is normally detected with an x-ray showing the large fibrous growths in the lungs. Oftentimes, the initial symptom is difficulty breathing, which may be caused by the fibrous tissue that has formed, or by a pleural effusion (buildup of fluid) caused by the asbestosis. There is no cure for asbestosis, and eventually the fibrous tissue can spread throughout the lungs and make it impossible to breath. A common cause of death related to asbestosis is congestive heart failure, in which the heart becomes overworked in its attempt to push enough blood through the lungs to carry sufficient oxygen to the rest of the body.
Types of Mesothelioma
Mesothelioma cancer affects the serous membranes that surround the major organs in the midsection of the body. Different organs can be affected by mesothelioma because the serous membranes surround the lungs, heart, abdomen and others. The most common type of mesothelioma is that which affects the lung lining, and is called pleural mesothelioma. Other types are pericardial mesothelioma, which affects the lining of the heart, and peritoneal mesothelioma, affecting the lining of the abdomen.
Mesothelioma, contrary to what many people think, is not a type of primary lung cancer. That is, mesothelioma does not originate in the lungs, but as described above, it starts in the serous membranes or lining around the lungs (or other organs). However, mesothelioma can spread to the lungs and when this occurs, it is considered to be a secondary lung cancer. Mesothelioma is also commonly referred to as an asbestos lung cancer. Technically, this is also incorrect, since mesothelioma does not originate in the lungs. Asbestosis is a type of asbestos lung disease that is often confused with mesothelioma.
Pleural Mesothelioma.
Pleural mesothelioma represents about 75% of all mesotheliomas. The disease can grow quickly and enlarge the pleural space, causing it to fill with fluid. This fluid leads to the discomfort or pain associated with first detection of the disease. It is thought that pleural mesothelioma is caused by the inhaling of fibrous materials, including asbestos. These fibers become lodged in the pleura and, over time, cause damage that can lead to cancer. Learn more about pleural mesothelioma.
Pericardial Mesothelioma.
The rarest form of mesothelioma is that which affects the linings of the heart cavity, called the pericardium. Less than 10% of all mesothelioma cases are related to the heart. As in the lung, the rapid growth of the cancerous tumors can cause expansion of the tissue and accumulation of fluid. The fluid can interfere with the functioning of the heart and cause chest pain. Mesothelioma cases are known to be caused by exposure to asbestos; but it is completely unknown how the asbestos fibers enter the tissue layers surrounding the heart. Learn more about pericardial mesothelioma.
Peritoneal Mesothelioma.
Mesothelioma of the abdomen is called peritoneal mesothelioma. The serous membrane surrounding the abdomen is known as the peritoneum. This disease accounts for approximately 10% to 20% of mesothelioma cases. In addition, a rare form of peritoneal mesothelioma affects the male testicles. The covering layer of the scrotum is actually an outpouching of the peritoneum. Peritoneal mesothelioma is due to the ingestion of fibrous materials, including asbestos. Learn more about peritoneal mesothelioma.
Mesothelioma, contrary to what many people think, is not a type of primary lung cancer. That is, mesothelioma does not originate in the lungs, but as described above, it starts in the serous membranes or lining around the lungs (or other organs). However, mesothelioma can spread to the lungs and when this occurs, it is considered to be a secondary lung cancer. Mesothelioma is also commonly referred to as an asbestos lung cancer. Technically, this is also incorrect, since mesothelioma does not originate in the lungs. Asbestosis is a type of asbestos lung disease that is often confused with mesothelioma.
Pleural Mesothelioma.
Pleural mesothelioma represents about 75% of all mesotheliomas. The disease can grow quickly and enlarge the pleural space, causing it to fill with fluid. This fluid leads to the discomfort or pain associated with first detection of the disease. It is thought that pleural mesothelioma is caused by the inhaling of fibrous materials, including asbestos. These fibers become lodged in the pleura and, over time, cause damage that can lead to cancer. Learn more about pleural mesothelioma.
Pericardial Mesothelioma.
The rarest form of mesothelioma is that which affects the linings of the heart cavity, called the pericardium. Less than 10% of all mesothelioma cases are related to the heart. As in the lung, the rapid growth of the cancerous tumors can cause expansion of the tissue and accumulation of fluid. The fluid can interfere with the functioning of the heart and cause chest pain. Mesothelioma cases are known to be caused by exposure to asbestos; but it is completely unknown how the asbestos fibers enter the tissue layers surrounding the heart. Learn more about pericardial mesothelioma.
Peritoneal Mesothelioma.
Mesothelioma of the abdomen is called peritoneal mesothelioma. The serous membrane surrounding the abdomen is known as the peritoneum. This disease accounts for approximately 10% to 20% of mesothelioma cases. In addition, a rare form of peritoneal mesothelioma affects the male testicles. The covering layer of the scrotum is actually an outpouching of the peritoneum. Peritoneal mesothelioma is due to the ingestion of fibrous materials, including asbestos. Learn more about peritoneal mesothelioma.
Introduction to Malignant Mesothelioma
Malignant mesothelioma affects the lining or membranes of certain large cavities in the body. These cavities, called the serous cavities, house certain major organs in the body including the heart, lungs, abdomen and others. The membranes that surround these cavities are called the serous membranes. They serve to protect these major organs from the friction and abrasion that occur as the organs move against each other during typical daily functioning, such as breathing and heart beating. The serous membranes derive from specialized cells called mesothelial cells. These cells form to create the mesothelium, which is the major tissue layer of the serous membranes. Cancer that occurs in the mesothelium tissue is called mesothelioma.
Malignant mesothelioma takes on three forms:
•Peritoneal mesothelioma, in the peritoneum or membrane surrounding the abdomen. A rare form of peritoneal mesothelioma can also affect the male testicles, because the lining around the scrotum is an extension of the peritoneum.
•Pericardial mesothelioma, in the perdicardium or lining surrounding the heart.
•Pleural mesothelioma, which is the most common form of malignant mesothelioma and affects the lining of the lung cavity.
All mesotheliomas are now considered to be malignant, or cancerous. They start as a localized tumor and spread rapidly to include most of the surrounding tissues and organs. Originally, fibrous cists and other non-cancerous growths that appeared in the serous membranes were thought to be mesotheliomas and were termed "benign fibrous mesothelioma" and "multicystic mesothelioma." These conditions are now known not to originate in the mesothelial cells, but other cells within the serous membranes. These conditions are typically localized, non-cancerous and do not spread rapidly.
Etiology of Malignant Mesothelioma
Most cases of malignant mesothelioma are associated with a previous exposure to fibrous minerals, of which asbestos is the most important. There is now indisputable evidence of the role of these fibers in the development of this disease. This has been demonstrated in animal experiments and many other experiments. Not everyone who is exposed to asbestos fibers has developed malignant mesothelioma, suggesting that other factors may also be involved.
Although malignant mesothelioma is rare, it is a serious, deadly disease. It is often in the advanced stages when it is detected, so the outlook for the mesothelioma patients is not as good as it is for patients with cancers that are detected earlier. The average survival time after detection is 1 to 2 years. This survival time also depends on the type of mesothelioma.
Malignant mesothelioma takes on three forms:
•Peritoneal mesothelioma, in the peritoneum or membrane surrounding the abdomen. A rare form of peritoneal mesothelioma can also affect the male testicles, because the lining around the scrotum is an extension of the peritoneum.
•Pericardial mesothelioma, in the perdicardium or lining surrounding the heart.
•Pleural mesothelioma, which is the most common form of malignant mesothelioma and affects the lining of the lung cavity.
All mesotheliomas are now considered to be malignant, or cancerous. They start as a localized tumor and spread rapidly to include most of the surrounding tissues and organs. Originally, fibrous cists and other non-cancerous growths that appeared in the serous membranes were thought to be mesotheliomas and were termed "benign fibrous mesothelioma" and "multicystic mesothelioma." These conditions are now known not to originate in the mesothelial cells, but other cells within the serous membranes. These conditions are typically localized, non-cancerous and do not spread rapidly.
Etiology of Malignant Mesothelioma
Most cases of malignant mesothelioma are associated with a previous exposure to fibrous minerals, of which asbestos is the most important. There is now indisputable evidence of the role of these fibers in the development of this disease. This has been demonstrated in animal experiments and many other experiments. Not everyone who is exposed to asbestos fibers has developed malignant mesothelioma, suggesting that other factors may also be involved.
Although malignant mesothelioma is rare, it is a serious, deadly disease. It is often in the advanced stages when it is detected, so the outlook for the mesothelioma patients is not as good as it is for patients with cancers that are detected earlier. The average survival time after detection is 1 to 2 years. This survival time also depends on the type of mesothelioma.
What are the main causes of mesothelioma?
Mesothelioma is most predominantly caused by asbestos exposure. Asbestos fibers that are inhaled through the mouth and nose may eventually become embedded in the lining of the lungs, causing damage and resulting in lung cancer or asbestosis (scar tissue formation in the lungs). It has also been found that swallowing asbestos fibers could contribute to a form of mesothelioma originating in the abdomen called peritoneal mesothelioma.
Mesothelioma generally results from occupational exposure but there are instances of environmental exposure to asbestos that can cause the disease. Oftentimes second hand exposure of a family member to an asbestos workers dirty work clothes can result in that family member developing mesothelioma.
Asbestos insulation workers appear to have the highest death rate. One study reports that almost six percent of asbestos workers fall victim to mesothelioma and asbestos insulation workers are over 300 times more likely to die from mesothelioma than the general public.
Mesothelioma generally results from occupational exposure but there are instances of environmental exposure to asbestos that can cause the disease. Oftentimes second hand exposure of a family member to an asbestos workers dirty work clothes can result in that family member developing mesothelioma.
Asbestos insulation workers appear to have the highest death rate. One study reports that almost six percent of asbestos workers fall victim to mesothelioma and asbestos insulation workers are over 300 times more likely to die from mesothelioma than the general public.
Mesothelioma Information
As with any disease or health condition, mesothelioma researchers have, over time, collected statistical information about mesothelioma. These statistics can help us learn about the proclivities of the disease and its incidence and potentially help future patients as we learn more about mesothelioma.
Incidence of Diagnosis.
New cases of mesothelioma are diagnosed in between 2,500 and 3,000 Americans each year. These numbers, while significant, would indicate that mesothelioma is still a relatively rare disease, though incidence is expected to rise in the next decade according to projections.
Age at Diagnosis
The first diagnosis of mesothelioma typically occurs in men and women between the ages of 50 and 70 years. Mesothelioma patients, certainly, have been diagnosed at ages younger than 50 and older than 70, but diagnoses for those age groups are considered statistical anomalies.
Does Mesothelioma Occur in a Particular Sex or Racial Demographic More than Another?
Mesothelioma is much more common in men than women, due mostly to occupational asbestos exposure being more common among men of industrial labor sites. That is not to say, however, that women cannot be diagnosed with mesothelioma. In fact, recent evidence suggests that mesothelioma incidence in women may rise in the coming years as secondary exposures to asbestos can manifest in the form of a positive mesothelioma diagnosis. Also of note is that mesothelioma is much less common among African Americans than white Americans, the reasons for which researchers are still investigating.
What are Typical Patient Survival Rates Following a Mesothelioma Diagnosis?
As mesothelioma is often diagnosed in its advanced stages, the prognosis is sometimes poor with life expectancy being little more than a year following diagnosis. If diagnosed early enough however, patient prognoses increase dramatically. Patient survival rates are often contingent on the treatments available to the particular patient. Early-stage tumors eligible for surgical resection, for instance, will result in improved prognoses over those diagnosed with later-stage disease. As new therapies and treatments are researched and employed in the future, it is realistic to anticipate an improvement in patient survival rates.
Incidence of Diagnosis.
New cases of mesothelioma are diagnosed in between 2,500 and 3,000 Americans each year. These numbers, while significant, would indicate that mesothelioma is still a relatively rare disease, though incidence is expected to rise in the next decade according to projections.
Age at Diagnosis
The first diagnosis of mesothelioma typically occurs in men and women between the ages of 50 and 70 years. Mesothelioma patients, certainly, have been diagnosed at ages younger than 50 and older than 70, but diagnoses for those age groups are considered statistical anomalies.
Does Mesothelioma Occur in a Particular Sex or Racial Demographic More than Another?
Mesothelioma is much more common in men than women, due mostly to occupational asbestos exposure being more common among men of industrial labor sites. That is not to say, however, that women cannot be diagnosed with mesothelioma. In fact, recent evidence suggests that mesothelioma incidence in women may rise in the coming years as secondary exposures to asbestos can manifest in the form of a positive mesothelioma diagnosis. Also of note is that mesothelioma is much less common among African Americans than white Americans, the reasons for which researchers are still investigating.
What are Typical Patient Survival Rates Following a Mesothelioma Diagnosis?
As mesothelioma is often diagnosed in its advanced stages, the prognosis is sometimes poor with life expectancy being little more than a year following diagnosis. If diagnosed early enough however, patient prognoses increase dramatically. Patient survival rates are often contingent on the treatments available to the particular patient. Early-stage tumors eligible for surgical resection, for instance, will result in improved prognoses over those diagnosed with later-stage disease. As new therapies and treatments are researched and employed in the future, it is realistic to anticipate an improvement in patient survival rates.
What is mesothelioma?
Malignant mesothelioma is the most serious of all asbestos-related diseases. Although uncommon, mesothelioma is no longer considered rare. Mesothelioma is a cancer that is particulary difficult for doctors to diagnose and one that does not respond well to therapy.
The chest cavity, abdominal cavity, and the cavity around the heart are surrounded by a a layer of specialized mesothelial cells. Most other internal organs are also covered by these cells. The tissue formed by these cells is called mesothelium.
A special protective lubricating fluid that allows organs to move around is produced by the mesothelium. This protective fluid helps the lungs to move without resistance inside the chest cavity while breathing. The medical name for the mesothelium of the chest is the pleura and the medical name for the mesothelium of the abdomen is the peritoneum. The mesothelium of the "sac-like" space around the heart is called the pericardium.
A malignant (cancerous) tumor of the mesothelium is called a malignant mesothelioma. As most mesothelial tumors are cancerous, malignant mesothelioma is often simply called mesothelioma. Tumors of the mesothelium can also be benign (noncancerous) but benign mesotheliomas are much more rare.
Mesothelioma was recognized as a tumor of the pleura, peritoneum and pericardium in the late 1700's. However it was not until much later, in 1960, that this particular type of tumor was described in more detail and even more importantly, its association with asbestos exposure was recognized. The first report linking mesothelioma to asbestos exposure was written by J.C.Wagner, and described 32 cases of workers in the "Asbestos Hills" in South Africa. Since than the relationship between mesothelioma and asbestos exposure has been confirmed in studies around the world.
The incidence of mesothelioma in the United States remains very low, with 14 cases occurring per million people per year. Despite these numbers the noticed threefold increase in mesothelioma in males between 1970 and 1984, is directly associated with environmental and occupational exposure to asbestos, mostly in areas of asbestos product plants and shipbuilding facilities.
Although the disease is much more commonly seen in 60-year old men, it has been described in women and early childhood as well. The cause of the disease is not so well understood in these latter two groups, but there is some evidence of possible asbestos exposure for some of these cases as well.
Malignant mesotheliomas are divided into three main types. About 50% to 70% of mesotheliomas are the epithelioid type. This type has the best prognosis (outlook for survival). The other two types are the sarcomatoid type (7%-20%), and the mixed/biphasic type (20%-35%). Treatment options for all three types are the same.
About three-fourths of mesotheliomas start in the chest cavity. They are known as pleural mesothelioma. Another 10% to 20% begin in the abdomen. These are called peritoneal mesothelioma. Pericardial mesothelioma, starts in the cavity around the heart, and is very rare. The covering layer of the testicles is actually an outpouching of peritoneum into the scrotum. Mesotheliomas that affect this covering of the testicles are quite rare.
The chest cavity, abdominal cavity, and the cavity around the heart are surrounded by a a layer of specialized mesothelial cells. Most other internal organs are also covered by these cells. The tissue formed by these cells is called mesothelium.
A special protective lubricating fluid that allows organs to move around is produced by the mesothelium. This protective fluid helps the lungs to move without resistance inside the chest cavity while breathing. The medical name for the mesothelium of the chest is the pleura and the medical name for the mesothelium of the abdomen is the peritoneum. The mesothelium of the "sac-like" space around the heart is called the pericardium.
A malignant (cancerous) tumor of the mesothelium is called a malignant mesothelioma. As most mesothelial tumors are cancerous, malignant mesothelioma is often simply called mesothelioma. Tumors of the mesothelium can also be benign (noncancerous) but benign mesotheliomas are much more rare.
Mesothelioma was recognized as a tumor of the pleura, peritoneum and pericardium in the late 1700's. However it was not until much later, in 1960, that this particular type of tumor was described in more detail and even more importantly, its association with asbestos exposure was recognized. The first report linking mesothelioma to asbestos exposure was written by J.C.Wagner, and described 32 cases of workers in the "Asbestos Hills" in South Africa. Since than the relationship between mesothelioma and asbestos exposure has been confirmed in studies around the world.
The incidence of mesothelioma in the United States remains very low, with 14 cases occurring per million people per year. Despite these numbers the noticed threefold increase in mesothelioma in males between 1970 and 1984, is directly associated with environmental and occupational exposure to asbestos, mostly in areas of asbestos product plants and shipbuilding facilities.
Although the disease is much more commonly seen in 60-year old men, it has been described in women and early childhood as well. The cause of the disease is not so well understood in these latter two groups, but there is some evidence of possible asbestos exposure for some of these cases as well.
Malignant mesotheliomas are divided into three main types. About 50% to 70% of mesotheliomas are the epithelioid type. This type has the best prognosis (outlook for survival). The other two types are the sarcomatoid type (7%-20%), and the mixed/biphasic type (20%-35%). Treatment options for all three types are the same.
About three-fourths of mesotheliomas start in the chest cavity. They are known as pleural mesothelioma. Another 10% to 20% begin in the abdomen. These are called peritoneal mesothelioma. Pericardial mesothelioma, starts in the cavity around the heart, and is very rare. The covering layer of the testicles is actually an outpouching of peritoneum into the scrotum. Mesotheliomas that affect this covering of the testicles are quite rare.
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