Mesothelioma


Mesothelioma is an aggressive cancer affecting the membrane lining of the lungs and abdomen.
Malignant mesothelioma is the most serious of all asbestos-related diseases. Exposure to asbestos is the primary cause and risk factor for mesothelioma.
Making a correct mesothelioma diagnosis is particularly difficult for doctors because the disease often presents with symptoms that mimic other common ailments. There is currently no known cure for mesothelioma, but treatments such as surgery and chemotherapy can help to improve the typical mesothelioma prognosis.
Pleural mesothelioma (affecting the lung’s protective lining in the chest cavity) represents about three-quarters of all mesothelioma incidence. Peritoneal mesothelioma, which affects the abdominal cavity, and pericardial mesothelioma, which affects the cardiac cavity, comprise the remainder.
There are three recognized mesothelioma cell types. Between 50% and 70% of all mesotheliomas are of the epithelial variety. While prognosis is generally poor, it is considered less aggressive than sarcomatoid mesothelioma and biphasic mesothelioma, which comprise the remainder of cell-type diagnoses.
The cavities within the body encompassing the chest, abdomen, and heart are surrounded by a membrane of cells known as the mesothelium. Mesothelial cells assist in general organ functions. The mesothelium is particularly important to organs that are commonly in motion, such as expansion or contraction of the lungs, stomach, or heart. Lubrication from the mesothelial cells allows free range of motion within the body. The mesothelium of the chest, abdomen, and cardiac cavity are called the pleura, the peritoneum, and the pericardium, respectively. Each of these groupings of mesothelial cells is extremely critical to the functions of the body structures which they encompass.
Malignancies (cancerous tumors) occurring within the mesothelial membranes are known as malignant mesothelioma, or simply mesothelioma. Benign tumors of the mesothelium are known to occur, but are much more rare than malignant mesothelial tumors.
While tumors of the mesothelium were first recognized in the late 18th century, it was not until the middle of the 20th century that this particular cancer was studied and examined with more detail. It was at this time when suspicions of the cancer’s causal relationship with asbestos exposure became more substantiated. A joint research venture through the Department of Thoracic Surgery at the University of the Witswater and Johannesburg General Hospital in South Africa provided the most compelling evidence of the nexus between asbestos exposure and the development of pleural mesothelioma.
Incidence of mesothelioma is still quite rare, with only 2,500-3,000 diagnoses in the United States each year. There was a spike in reported diagnoses between 1970 and 1984, which has been attributed to the latency period between diagnosis and the height of industrial exposures, which occurred roughly 40-60 years prior to this time. While exposure was common in nearly all industries, it was particularly prevalent in the WWII-era military industrial cycle, including navy shipyards.
Although this cancer is much more common in men over the age of 60, mesothelioma in women and children has been documented as well. Mesothelioma causes for diagnosis in women and children are mainly attributed to secondary exposure to asbestos, as it was not uncommon for men to bring asbestos back into the home on their bodies or clothing.
Mesothelioma is diagnosed through a comprehensive combination of biopsy and imaging scans.
Mesothelioma can be a difficult malignancy to diagnose because the symptoms of the disease closely resemble other respiratory conditions, and because the pathology can be very difficult to distinguish from adenocarcinoma of the lung. For these reasons, misdiagnosis is not uncommon in mesothelioma patients. Symptoms of mesothelioma include chest pain, chronic cough, effusions of the chest and abdomen, and the presence of blood in lung fluid.
Diagnostic surgeries, including a biopsy, will typically be required to determine the type of malignant cells that are present in the body. Typically a body imaging scan, including a magnetic resonance image (MRI), computer topography (CT scan), and/or positron emission tomography (PET), will be required to determine the extent and location of the disease.
While mesothelioma is typically advanced at diagnosis, treatment options are available.
Mesothelioma, while certainly an aggressive disease, is a manageable malignancy. While there is no cure for the cancer, mesothelioma treatment options may potentially include surgery, chemotherapy, and radiation therapy. A combination of Alimta® and cisplatin is currently the only FDA-approved chemotherapy regimen, though several clinical trials are currently in progress utilizing other drugs including gemcitabine and Onconase®, that may lead to new treatment options that provide a benefit for patients.
Radiation therapy is also utilized, but typically in conjunction with other treatment methods like surgery and chemotherapy. Surgical resection of mesothelioma is possible in early-stage-diagnosed patients. Diagnostic and palliative procedures such as thoracentesis and pleurodesis are also commonly performed in patients with malignant mesothelioma in order to minimize cancer-related symptoms. Alternative therapies have also been used effectively by many mesothelioma patients to assist in managing symptoms of the disease and conventional treatments.
Mesothelioma is caused by exposure to asbestos.
Mesothelioma is primarily caused by exposure to asbestos, though cases have been documented in children or other individuals with no asbestos history. Asbestos is a microscopic and naturally-occurring mineral that lodges in the pleural lining of the lungs and the peritoneal lining of the abdominal cavity. In most cases, several years will pass (up to 60) before mesothelioma develops in those who have been exposed to asbestos.
In many cases, those individuals diagnosed with mesothelioma that have been known to be exposed to asbestos may be eligible for financial compensation from asbestos manufacturers for their illness. Those who have been diagnosed with mesothelioma and were exposed to asbestos should fill out the brief form on this page to receive a free information kit detailing new mesothelioma treatments, clinical trials, top doctors and financial resources.

Mesothelioma Risk Factors

What are the risk factors for malignant mesothelioma?
risk factor
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. While smoking does not have a direct causal relationship with mesothelioma, it is a significant compounding factor that increases the likelihood of developing the disease. Other less common secondary factors include exposure to radiation, zeolite, simian virus 40 (SV40), and erionite. Each of these risk factors is discussed in more detail below. Please click on the individual links to learn more about each mesothelioma risk factor.

Exposure to 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.

Smoking and Mesothelioma

Smoking alone is not linked to mesothelioma, but smokers who are exposed to asbestos have a much higher chance of developing asbestos lung cancer (as much as fifty to ninety percent higher) and as much as double the risk of developing mesothelioma.

Less Common Mesothelioma Risk Factors

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.

Erionite Exposure

Erionite is a naturally occurring mineral that possesses properties that are very similar to those of asbestos. There have been several documented cases of mesothelioma in indivuduals living near large erionite deposits.

Carbon Nanotubes

Researchers continue to evaluate nanotube exposure as a possible risk factor for mesothelioma even though scientists have not expressed immediate concern.

Exposure To Asbestos

Exposure to asbestos particles is one of the principal causes of mesothelioma cancer, also known as asbestos cancer. As a naturally occurring mineral with useful commercial applications, asbestos is found in plumbing, insulation and other building materials and products.
Through the liberal commercial use of this material, most people in the United States and other industrial nations have been or will be exposed to loose, airborne particles in their work or home environments, this exposure can create significant health hazards.

Commercial Applications

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. They typically work in aluminum plants, oil refineries, chemical plants, mines, factories, shipyards, construction sites and railroads. Employees at insulation and gas mask manufacturing facilities are also at risk. 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.
There are six different types of asbestos: chrysotile, amosite, crocidolite, tremolite, anthophyllite and actinolite. These six mineral types are divided into two classifications, serpentine and amphibole. Chrysotile is the only mineral in the serpentine class. As known carcinogens both classes of asbestos can cause mesothelioma.
In the United States, chrysotile was the most commonly used asbestos mineral, and is known for its curly fibers that can be easily woven into fabrics. Applications of chrysotile include drywall compound, plaster, vinyl floor tiles, roofing materials, acoustic ceilings, fireproofing, caulk, brake pads and shoes, stage curtains, fire blankets and dental cast linings.
Amosite and crocidolite are the other more common asbestos minerals used, though their application is not as extensive as chrysotile. Products manufactured out of these asbestos minerals include insulation board, ceiling tiles and casing for water services.
In the past ten years, trace amounts of asbestos have been found in talc, a leading ingredient in crayons.

Exposure and Health Risks

The extensive use of asbestos across many different industries exposes not only those individuals working in the manufacturing of raw asbestos or working with asbestos-related products, but also individuals who may have asbestos in their homes, churches or schools. Further, asbestos particles may cling to the clothing or hair of an individual working with asbestos and potentially contaminate others.
Though chrysotile is the most common form of asbestos used in products and is a known carcinogen, amosite and crocidolite asbestos are the most hazardous to health. All types of asbestos can linger in an individual’s lungs for many years after exposure, but amosite and crocidolite are the most persistent, lingering particles.
There is a higher risk for individuals working in asbestos-related environments, though many individuals with minimal exposure can also have damage that can lead to mesothelioma cancer or other diseases.
Although asbestos exposure may have hit its peak from the turn of the twentieth century through the 1970s, many individuals are still being subjected to asbestos particles. Arguably, the most recent and tragic mass exposure resulted from the attacks on 9/11, where tons of asbestos particles were released into the air, harming thousands of rescue workers and individuals living near Ground Zero. Diagnosed with asbestos cancer due to their prolonged, persistent exposure, many brave firefighters, police and rescue workers continue to suffer.
Further, many individuals continue to be exposed to asbestos in older homes. With the boom of Do-It-Yourself projects, many homeowners are tackling renovations without knowing the potential health risks. Attempting renovations in these environments may disturb asbestos causing it to become airborne and inhaled. Without knowledge of where asbestos may be located in these homes, there is a significant risk of accidental exposure, and any homeowner should have professional do a thorough inspection before any projects begin. Removal should always be handled by a professional contractor and should not be attempted by homeowners.
One of the groups hardest hit from asbestos-related diseases are America’s veterans. All branches of the United States military used equipment, gear and products laden with asbestos, unwittingly exposing young men and women between the 1940s and late 1970s. Most veterans repeatedly exposed to asbestos suffer from mesothelioma disease.
For over one hundred years, almost every product that we can come in contact with may have been produced with asbestos components. From decorative household items, to products manufactured to protect firefighters, to dental products, asbestos has been the silent, deadly part of recent American industry.

Asbestos Related Disease

Some research points to the fact that inhaled asbestos fibers cause a physical irritation resulting in mesothelioma 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, chest or stomach causing scarring and inflammation which increases the risk for mesothelioma cancer. Mesothelioma symptoms can be detected as early as ten years after exposure and can incubate as long as forty years.
Asbestosis (scar tissue in the lungs) or mesothelioma 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. This disease 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 the mesothelioma latency period is very long. 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 an asbestos related disease.

Smoking and Mesothelioma

t has long been known that smoking is hazardous to one's health, causing a marked increase in instances of mesothelioma lung cancer among those who smoke regularly. However, smokers who are or have been exposed to asbestos carry a much higher risk of developing an even more serious disease - malignant mesothelioma, a difficult-to-treat cancer that affects the lining of the lungs (pleural mesothelioma), heart (pericardial mesothelioma), or abdomen (peritoneal mesothelioma).
Exposure to asbestos has been identified as the major cause of mesothelioma cancer. The disease occurs when an individual inhales sharp asbestos fibers, which then become lodged in the lungs. Smoking, according to the Centers for Disease Control, weakens the lungs and decreases a body's ability to remove asbestos fibers. Further, cigarette smoke irritates the air passages and causes them to produce more mucus which, in turn, blocks the passage of air and the dispelling of fibers.
According to a variety of studies that have been performed throughout the last two decades, while cigarette smoking alone does not lead to mesothelioma, cigarette smokers who are exposed to asbestos are about 50 to 84 times more likely to develop asbestos lung cancer and, most experts agree, these smokers are at least twice as likely to develop mesothelioma.
Furthermore, mesothelioma risk factors are higher for those who have already developed a less serious asbestos-related disease, namely asbestosis. Also, the more packs a day that an asbestosis sufferer smokes, the higher the chance for developing this aggressive cancer. Simply stated, those who have asbestosis should stop smoking. A cessation of smoking, according to studies by the National Cancer Institute, results in a 50 percent decrease in the risk for a mesothelioma diagnosis within about five years of quitting, a figure that is encouraging for smokers with early asbestos disease.
Smokers who have been exposed to asbestos and have not quit should submit to regular medical check-ups to determine the health of their lungs. Tests to monitor the formation of asbestos cancer, such as mesothelioma, might include a chest x-ray or a lung function test. In addition, a simple blood test known as the Mesomark® assay, used to detect the presence of mesothelioma, may be in order for smokers who suffered asbestos exposure.

Radiation

For many decades, it was assumed that the only cause of mesothelioma was exposure to asbestos. However, while asbestos is indeed responsible for most cases of mesothelioma cancer, it has gradually become apparent that there may be some other risk factors for the disease.
Throughout the world, a number of cases of mesothelioma with no apparent connection to asbestos have been diagnosed. As a matter of fact, a 1980 study (McDonald and McDonald) of patients in the U.S. and Canada determined that somewhere between 25 percent and 33 percent of all cases were not related to asbestos exposure. Doctors found this perplexing at first, but with some in-depth research and several official studies, scientists and medical professionals were able to determine that some of these pleural mesothelioma patients had other factors in common. Exposure to radiation was one of those factors.

Radiation Treatments, X-rays, and Mesothelioma

Several dozen cases of mesothelioma following radiation therapy for Hodgkin’s disease have been discovered. A 2005 study entitled “Clinical Course of Thoracic Cancers in Hodgkin’s Disease Survivors” (P. Das, A.K. Ng, M.A. Stevenson, and P.M. Mauch) definitively determined that Hodgkin’s disease patients who were treated with radiation therapy have a high incidence of mesothelioma disease.
Specifically, the study followed 33 patients who were treated at Harvard-affiliated hospitals for Hodgkin’s and subsequently developed mesothelioma, non-small cell lung cancer, or small cell lung cancer. Of those patients that participated, 88 percent had a history of radiotherapy to the thorax as treatment for their disease. Some patients developed thoracic cancer within just a year of being treated for Hodgkin’s. Others developed it more than two decades later. As is usual with mesothelioma, by the time most of these patients were diagnosed, their disease had reached stage III or IV and the prognosis was grim. The median survival rate was only 9 months.
In some cases, peritoneal mesothelioma has also been linked to radiation therapy for breast cancer or any other cancers that may have included radiation delivered to the chest area.
Other research makes a connection between mesothelioma cancer and thorium dioxide, a radioactive substance that was used along with conventional x-rays to diagnose certain conditions. Thorium dioxide was used abundantly from the 1920s until the 1950s.

Atomic Radiation and Mesothelioma

In 1995, the first case of mesothelioma believed to be associated with the dropping of the atomic bomb in Nagasaki was diagnosed. A report on this case, penned by Masami Mizuki, Keiko Yukishige, Yasuharu Abe, and Tomiyasu Tsuda, and published in the journal Respirology in September 1997, suggested that combined exposure to atomic radiation and asbestos (the patient worked for 2 years as a shipbuilder at a munitions factory) is associated with an increased incidence of mesothelioma.
The doctors who authored the study suggested that “If thickening of the pleura or pleural effusion is found in atomic bomb survivors, malignant mesothelioma should be considered as one of the options in the differential diagnosis, even although the atomic bomb attacks occurred several decades ago.”

Atomic Energy Workers and Mesothelioma

Wherever radiation is present, there seems to be a potential connection to mesothelioma. Throughout the last few decades, several individuals currently or formerly employed at atomic energy plants have been diagnosed with this rare cancer, in these instances thought to be caused by constant exposure to low level radiation. (Ionizing radiation: A risk factor for cancer; JE Goodman et al, 2009) The authors concluded that, considering the low rate of mesothelioma in the general population, the increased risk of the disease among radiation-exposed individuals, including those who work at atomic power plants, is significant and should be duly noted.

Making the Connection

Knowing about the link between radiation and mesothelioma is just one more step to making quicker diagnoses and saving more individuals who have been identified as potential victims of the disease. Anyone who has been exposed to radiation of any sort, whether on a regular basis while at work or through x-rays or via therapy for other types of chest cancers, should always inform their doctor as to their medical and occupational history, even if exposure occurred years before. Hence, when symptoms arise - including chest pain, shortness of breath, and coughing – a possible connection can be determined, the correct diagnosis made, and mesothelioma treatment started as soon as possible.

Zeolite

Mesothelioma and asbestos exposure have long been linked. Since the early days of the Holy Roman Empire, it was noted that slaves who worked in asbestos mines had severe pulmonary problems and died at an early age. However, in the last several decades, it has become apparent that there are other potential causes for the development of this rare form of cancer.
A study conducted by McDonald and McDonald in 1980 indicated that some 25 to 33 percent of all cases of mesothelioma cancer have no connection whatsoever to asbestos exposure. However, studies have been made that zero in on some other specific causes. One of those is exposure to zeolite.

What is Zeolite?

Known in scientific terms as hydrated alkali aluminum silicate, zeolites are a group of minerals that contain mostly hydrated aluminum and silicon compounds. Their common names are Clinoptilolite, Erionite, Phillipsite, andMordenite. They are found in volcanic rock and ashes and sometimes used as additives in animal feeds. Because of their porous structure, zeolites may be used as absorbents, desiccants, detergents, and as water and air purifiers.
Zeolites have enjoyed some use in the health field as well including as dietary supplements for hangovers and an adjuvant therapy for various types of cancer. (These are not FDA-approved treatments.) However, there is a lack of data supporting zeolite’s efficacy and there is no conclusion as to whether zeolites are safe, as the mineral’s systemic effects on the body are not totally clear at this point without more research.

The Link to Mesothelioma

What is clear, however, is that exposure to zeolite dust is associated with an increased risk for developing malignant mesothelioma. Simply put, zeolites are carcinogenic when inhaled. As a matter of fact, the International Agency for Research on Cancer lists zeolite as a Group 1 Carcinogen, a categorization used when there is sufficient evidence of mesothelioma carcinogenity in humans.
Erionite, a form of zeolite fibers, has been definitively linked to a mesothelioma epidemic in the villages of the Anatolian Plateau in Turkey. In these villages, the local volcanic tuff was filled with toxic zeolite fibers. A report on the epidemic was published in the March 15, 2006 issue of The Journal of the National Cancer Institute.
Doctors in Turkey embarked on a 23-year study that followed 891 men and women who lived in three different Turkish villages in the Cappadocia region. In two of the villages, the residents were exposed to erionite. The third was used as a control. During the study, which stretched from 1979 until 2003, 372 individuals died. Of all those who passed away, 119 were stricken with mesothelioma cancer and died as a result of the disease or complications of the disease. In the two villages where residents were exposed to the toxic mineral, the pleural mesothelioma death rate was 44.5 percent. There were only 2 deaths from mesothelioma in the control village and both of those individuals were born outside of that control village.
Those who analyzed the data, including Harvard professor Philippe Grandjean, M.D., Ph.D., determined the incidence of mesothelioma in the two erionite-laden villages to be 200 and 700 per 100,000 people annually. In the control village, there were only 10 cases per 100,000 individuals. Hence, the conclusion was that long-term erionite exposure was responsible for the very high incidence of asbestos cancer in certain Cappadocian villages on the Anatolian Plateau.
After the study was complete, the authors suggested that local officials concentrate on ways to prevent environmental exposure to these dangerous zeolite fibers in the hopes of lowering residents’ risk for developing mesothelioma disease.
In the United States, natural deposits of erionite have been located in a handful of western states, particularly Arizona, Nevada, Utah, Oregon, North Dakota, South Dakota, and Montana. A report on ereonite/zeolite in the U.S. (Rom, W. N., K. R. Casey, W. T. Parry, C. H. Mjaatvedt and F. Moatamed. 1983. Health implications of natural fibrous zeolites for the Intermountain West. Environ Res 30(1): 1-8) notes that residents of what is considered the “intermountain West” may be exposed to fibrous zeolite in ambient air and, hence, susceptible to the development of mesothelioma. North Dakota is currently conducting a study relating to erionite exposure among residents of that vast mountainous state.

Simian Virus

Malignant mesothelioma has long been linked to asbestos exposure. Throughout the last century, thousands of cases of the disease were found in individuals who worked regularly with the toxic mineral in a variety of different jobs. However, a report released about 30 years ago by McDonald and McDonald determined that some 25 to 33 percent of all diagnosed cases of mesothelioma cancer did not have a definitive connection to asbestos exposure; the diagnosed individual was never in contact with asbestos or any sort of asbestos-containing materials.
Over the years, researchers have found a few other potential causes for the development of mesothelioma. One of those may be exposure to the Simian Virus 40 (SV40).

What is SV40?

SV40 is a virus that was first discovered in 1960. It was discovered in the kidney cells of rhesus monkeys. It was found to cause kidney disease and certain cancers in the monkey population. The virus also attacks a particular tumor suppressant gene and interrupts cell death.
Simian Virus 40 came to the attention of the U.S. public when it was determined that these same rhesus monkey kidney cells were being used in the manufacture of polio vaccine that was being given to humans. This particular strain of vaccine was in use from 1958 until 1963 and given to nearly 100 million Americans. A sizeable portion of the vaccines that were administered during that time period was contaminated with Simian Virus 40. Though no exact number has been given as to how many doses may have been contaminated, an estimate stands at somewhere between 10 and 30 million.

SV40 and Mesothelioma

Since the time it was discovered that the Simian Virus 40 could be found in millions of doses of polio vaccine, researchers have been looking for a connection between the virus and cancer development in humans. A few of these studies have found that SV40 is present in many individuals who are diagnosed with mesothelioma disease.
A study led by Dr. Michele Carbone, one of the leading mesothelioma specialists in the U.S., determined that more than half (about 54%) of all malignant mesothelioma cases had SV40 infection within the diseased mesothelial cells. (Carbone, M. "Simian virus 40 and human tumors: It is time to study mechanisms.") However, they did not locate any SV40 contamination among individuals with other types of lung cancer. This reinforced their findings as to a link between SV40 and asbestos cancer, but there was no concluding evidence that linked SV40 alone to mesothelioma. Doctors hypothesized that exposure to asbestos or immunosuppression may have also been involved in these cases.
A similar study conducted in 2008 at the Cancer Research Center of Hawaii and Department of Pathology, University of Hawaii, concluded that while 60 percent of hamsters injected intracardially with Simian Virus 40 died of mesothelioma, the role and significance of SV40 in malignant mesothelioma in humans remains cloudy. (Rivera et al, “The Relationship between Simian Virus 40 and Mesothelioma.”) In summary, the authors reported: “Available evidence appears sufficient to link simian virus 40 either alone or in conjunction with asbestos in causing malignant mesotheliomas; however, it is still insufficient to speculate about the contribution of simian virus 40 to the overall incidence of pleural mesothelioma.”

SV40 and Asbestos

Additional studies which note that the combination of the presence of SV40 and asbestos exposure greatly increases the chance of developing mesothelioma are prevalent as well. In a 2005 report by a number of Italian doctors and scientists (Cristaudo et al, “SV40 Enhances the Risk of Malignant Mesothelioma among People Exposed to Asbestos: A Molecular Epidemiologic Case-Control Study”), the authors hypothesize that SV40 contributes to the development of the cancer only as a co-factor and not as a direct cause.
More importantly, this study determined that “detection of SV40 among a cohort of individuals exposed to asbestos could represent a useful marker to identify those at higher risk for MM. This subgroup of high-risk individuals could be closely monitored for early detection and possibly curative surgical excision.” As doctors continue to search for ways to better diagnose mesothelioma at an earlier stage, identifying high-risk individuals such as these is tantamount to saving more lives
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