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Mesothelioma
Malignant mesothelioma (referred to as
mesothelioma from this point forwards) is a
relatively rare form of cancer (2,000 to 3,000
cases diagnosed in the U.S. a year; 0.3% of
all U.S. cancers) that involves the
mesothelium.
The mesothelium is a thin double-layered
protective lining that covers many of the
body’s internal organs such as the lungs,
chest cavity, the pericardium (a sac
surrounding the heart), and the peritoneum
(abdominal cavity lining, near the digestive
tract). Between the two layers of the
mesothelium, the cells produce fluid, which
allows the organs they cover to move easily.
A normal lung (left) compred to one
affected by mesothelioma plaques (right).
When mesothelioma affects the lungs (specifically
the pleura), it is known as pleural mesothelioma.
This is the most common form of mesothelioma,
accounting for about 70% of cases. The pleura is a
smooth, moist double layer of flexible tissue that
lines the lungs and the chest wall. Pleural
mesothelioma usually affects only one side of the
lungs.
When mesothelioma affects the peritoneum (the
lining of the abdominal cavity), it is known as
peritoneal mesothelioma.
FEATURED BOOK: 100 Questions and Answers about Mesothelioma
Mesothelium also lines the male and female reproductive organs. Mesothelioma can
affect these areas but only rarely. Mesothelioma can also affect the tunica vaginalis,
which is a fluid covering of the testicles. This is known as mesothelioma of tunica
vaginalis.
About 20 to 33% of mesothelioma cases are peritoneal. When mesothelioma affects the pericardium (a
sac that surrounds the heart) it is known as pericardial mesothelioma. About 5% of cases are pericardial
mesothelioma, making it a very rare form of the cancer. Physicians hypothesize that asbestos fiber may
impact the heart through the bloodstream.
Mesothelioma usually does not spread to the brain, bone, or adrenal glands. The adrenal glands are a
pair of glands that play an important role in metabolism and help the body respond to physical and
emotional stress by releasing certain hormones. A gland is an organ in the body made of special cells
that form and release materials such as fluid. Metabolism is the chemical actions in cells that release
energy from nutrients or use energy to create other substances. Hormones are natural chemicals
produced by the body and released into the blood that have a specific effect on tissues in the body.
WHAT CAUSES MESOTHELIOMA?
Asbestos and Asbestos-Like Materials
Mesothelioma is almost always causes by exposure to asbestos (a type of mineral) or asbestos-like
fibers, the dust and fibers of which are inhaled or ingested through the nose and/or mouth by people
exposed to the material. An example of an asbestos-like material is erionite which is a fibrous mineral
usually found in volcanic ash that has been changed by weathering and ground water. Increased
exposure to asbestos leads to increased risk of developing mesothelioma. Asbestos or asbestos like
fibers may also be ingested through eating and drinking food products contaminated with asbestos. Food
and water can become contaminated with asbestos after the fibers become airborne when asbestos-
containing products are damaged. Asbestos and asbestos-like materials are known carcinogens (cancer
causing substances).
Before advanced microscopic analytical techniques were developed, mesothelioma was thought to be a
form of lung cancer. The association between asbestos and mesothelioma has been known since the
1940s. However, in 1960, Dr. J.C. Wagner published a very important article in the British Journal of
Medicine entitled “Diffuse pleural mesothelioma and asbestos exposure in the North Western Cape
Province” which established the association between asbestos exposure and mesothelioma. Out of 33
mesothelioma cases, 32 had probable exposure to the crocidolite form of asbestos. In South Africa, an
8,000 square mile area of hills (known as the Asbestos Mountains) contains crocidolite asbestos. Some
of the patients in the study have brief exposure to asbestos while others had more extensive exposure
as mine workers.
In 1962, Dr. J.C. McNulty diagnosed the first Australia patient with mesothelioma. The case was that of
an asbestos mine worker from Wittenoom who was exposed from 1948 to 1950. The town of
Wittenoom, in Western Australia, was built around a crocidolite asbestos mine, which contaminated the
entire town, including schoolyards and playgrounds. Commercial mining of asbestos occurred in
Wittenoom between 1943 and 1966, when the town was shut down. By 1955, no one had died from
asbestos exposure. By 1985, 85 people had died from asbestos-induced mesothelioma. By 1994, 539
deaths in Western Australia were caused by asbestos-induced mesothelioma. Even people who lived in
the neighborhoods of asbestos factories or mines and did not work in them had developed
mesothelioma. In 2007, Wittenoom was stripped of its official status so it could be removed from maps
and road signs. It is now a ghost town and roads have been closed that lead to contaminated areas.
The people exposed to asbestos are usually those who were working with the material in mines or mills,
producers of asbestos products, workers in the heating and construction industries, power plants,
refineries, automobile production facilities, and shipyard workers (see next paragraph). In about 70 to
80% of mesothelioma cases, asbestos exposure at work is reported. Occupations known to be at risk
for asbestos exposure includes electricians, boilermakers, construction workers, pipefitters, plumbers,
carpenters, machinists, mechanics, and shipyard workers (see below). Because occupations where
asbestos exposure occurs are predominantly performed by men, men are more likely than women to
develop mesothelioma. For a detailed list of common industrial products that contain asbestos, see our
asbestos entry. The list is not all-inclusive, however, as there are thousands of products that contain
asbestos.
About 100,000 people have died or will die of asbestos exposure related to ship building (see modern
history section below). This is why mesothelioma occurs seven times greater than the national rate in
Hampton Roads (southeast Virginia) since it is a ship-building center. Other shipyards where there was
known asbestos exposure included the Philadelphia Naval Shipyard, the Brooklyn Navy Yard, the Long
Beach Naval Shipyard, Hunters Point Naval Shipyard, and the Norfolk Navy Shipyard. For every
thousand of the 4.3 million shipyard workers during World War II, about 14 died of mesothelioma. The
type of naval ships where asbestos exposure occurred included submarines, destroyers, battleships,
warships, aircraft carriers, and others. Areas where asbestos exposure was most common included
engine rooms, boiler rooms, sleeping quarters, and other areas of naval vessels. The greatest period of
production in the military shipyard industry was between the 1940s and 1950s and so Navy members
working during this period are at greatest risk of developing mesothelioma.
In addition to naval veterans, veterans from the Army, Air Force, and Marines have also been exposed
to asbestos during their military careers from the 1930s to 1980s. Many buildings (e.g., factories during
WWII) and vehicles in the Armed Forces contained asbestos. The presence of asbestos in the military
is why veterans account for a sizable percentage of mesothelioma patients, with naval veterans being at
the highest risk since they were exposed to asbestos the most.
As the above example indicates, living near naturally occurring asbestos sites will increase the chance
of developing mesothelioma. One of the most famous areas where this occurred was in Libby, Monatana
(see the asbestos entry for more information). Australia and the United Kingdom report a much higher
incidence of mesothelioma cases than many other countries.
Environmental risks for mesothelioma development also occur for asbestos-like materials such as
erionite (see above). For example, in three small villages (Tuzköy, Karain and Sarihidir) of Cappadocia,
Turkey, mesothelioma caused 50% of all deaths. This was due to the presence of erionite in some of the
weathered volcanic rocks from the region. Because the rocks were soft, they were easily quarried,
excavated, and used as building materials. The erionite fibers were then breathed in and mesothelioma
resulted. The villages affected were later extended to include Karacaoren, Boyali, Cokek and Yesiloz.
Research has shown that that erionite mostly caused mesothelioma in families with a genetic
predisposition to develop cancer after being exposed to mineral fibers.
Many buildings in the U.S. constructed before the late 1990s contain asbestos. In countries that have
asbestos bans or restrictions, asbestos was used in building materials for many public and domestic
premises. In England, the blue and brown forms of asbestos were banned in 1985 and the white form
was banned 1999 (see the entry on asbestos for more detailed discussion of the different forms of
asbestos). This is why people doing renovation projects in such homes need to be cautious because
they may unknowingly expose themselves to asbestos dust.
There have been cases of people who have developed mesothelioma (and other asbestos related
illnesses) due to exposure to clothing (e.g., shoes), equipment, skin, and hair of workers that were
contaminated with asbestos dust. This would tend to occur in family members of the exposed worker and
is referred to as paraoccupational exposure or second hand asbestos exposure. Washing the clothes of
a worker exposed to asbestos, for example, is said to be a risk factor for developing mesothelioma. To
reduce the risk of paraoccupational asbestos exposure, asbestos workers are usually required to
shower and put on a new set of clothes before leaving the workplace. Second hand exposure is how
many women developed asbestos-related diseases.
In terms of the long-term risk of general environmental exposure to asbestos, some concerns have been
raised due to the presence of asbestos in some water supplies and food sources. Mesothelioma is more
likely to occur if someone exposed to asbestos also smokes. However, smoking, in and of itself, does
not cause mesothelioma.
Some people may actually have a genetic predisposition to developing mesothelioma when exposed to
asbestos, explaining why some people may develop the disease after brief exposure and others may not
develop the disease after years of exposure.
Other Causes
There have been cases of mesothelioma in people with no known history of exposure to asbestos or
asbestos-like materials. In such cases, suspected causes have included exposure to radiation. Patients
exposed to Thorotrast (thorium dioxide) in the 1920s to 1950s as a contrast agent for x-rays have been
known to develop mesothelioma. In this context, contrast is a substance that radiation cannot pass
through, which helps visualize certain aspects of the body on the x-ray. Mesothelioma has also been
linked to radiation treatment of the chest for treatment of cancers such as breast cancer or lymphoma
(cancer of the lymph system).
Some studies have also suggested (although this is debated) that a virus found in monkeys and humans,
known as SV40 can play a role in development of mesothelioma. Millions of people may have been
exposed to the virus when receiving polio vaccines between 1955 and 1963. This is because the
vaccine was developed from monkey cells. Polio is a type of viral disease that can lead to partial or full
paralysis. Once SV40 was associated with certain cancers, the virus was removed to the vaccine.
CAN SOMEONE ELIMINATE THE RISK OF MESOTHELIOMA WHEN WORKING WITH ASBESTOS?
Wearing personal protecting equipment at work can lower the risk of asbestos exposure. However, the
official position of the EPA and the Occupational Safety and Health Administration is that protections and
permissible exposure limits required by U.S. regulations is not adequate to prevent and protect against
asbestos-related cancers such as mesothelioma.
The British Government’s Health and Safety Executive (HSE) agency’s official position is that if there is
any lower level of asbestos exposure such that it would not cause a risk of mesothelioma it must be very
small. Thus, the HSE assumes that there is no safe level of asbestos exposure. It is widely agreed by
scientists that if such an asbestos threshold does exist that it is so low that it cannot even be quantified.
Thus, for practical purposes, it is widely assumed that there is no safe level of asbestos exposure that
would not put someone at risk for mesothelioma.
WHAT ARE THE SIGNS AND SYMPTOMS OF MESOTHELIOMA?
is a characteristic of many people with peritoneal mesothelioma (affecting the abdominal cavity lining).
Cachexia is the appearance of serious illness, poor nutrition, weakness, massive weight loss, and
wasting away, usually due to severe starvation, an emotional disorder, or a serious long-term and/or
reoccurring disease.
Patients with mesothelioma usually go to the doctor initially due to difficulty breathing and shortness of
breath. This is caused by pleural effusions, as is a cough and chest pain. Pleural effusion is an
accumulation of fluid between the layers of tissue that line the lungs and chest cavity. Other symptoms
of mesothelioma include difficulty breathing, excessive coughing, pain in the abdomen, sleep difficulty,
low back pain, unexplained weight loss, and appetite loss. There can be swelling in the neck and face
caused by pressure from the tumor on the large vein (known as the superior vena cava) that leads from
your upper body to your heart.
Other symptoms of peritoneal mesothelioma can include blockage of the intestine (a tube shaped
structure that is part of the digestive tract), fever, loss of appetite, constipation, fatigue, vomiting,
nausea, night sweats, diarrhea, abnormal clotting of the blood, and anemia. Anemia is a condition in
which there is an abnormally low amount of hemoglobin in the blood. Hemoglobin is substance present in
red blood cells that help carry oxygen to cells in the body. If the cancer has spread to other parts of the
body, signs and symptoms can include neck and facial swelling, pain, and difficulty swallowing. Another
sign is swelling of the abdomen due to ascites. Ascites is a condition in which fluid builds up in the space
between layers that line the belly. Pain or tenderness in the abdomen can also occur as well as lumps of
tissue under the skin in the abdominal region.
Mesothelioma affecting the pleura (lung and chest wall lining) can cause chest pain under the rib cage,
coughing (usually persistent and dry, sometimes violent and painful), spitting or coughing up blood,
shortness of breath (even when resting), reduced chest expansion, wheezing, barely audible of harsh
breath sounds, painful breathing, persistent pain in the rib/chest area, wheezing, night sweats, unusual
lumps of tissue in the chest area, hoarseness, fluid surrounding the lungs (pleural effusion), fatigue,
fever, difficulty swallowing, unexplained weight loss (about 10%), anemia (see last paragraph), or pleural
effusions. Pneumothorax can also develop. A pneumothorax is the presence of air or gas in the pleural
space, causing a lung to collapse.
Mesothelioma affecting the lining of the heart can cause fatigue, night sweats, fever, chest pain,
difficulty breathing, irregular heartbeat, and heart palpitations. Mesothelioma can also spread to other
parts of the body. When this happens, it is known as metastasis. The signs and symptoms of these
other types of mesothelioma are variable and partly depend on the body part affected. For example,
mesothelioma of the tunica vaginalis (which affects tissues surrounding the testicles) can first present
as a mass on the testicle.
Other signs and symptoms of other types of mesothelioma include a low level of glucose (a type of
sugar) in the blood, fluid surrounding the lungs (pleural effusion), severe ascites (see earlier), and
jaundice. Jaundice is a yellow staining of the skin, whites of the eyes, deeper tissues, mucous
membranes, and waste that is discharged from the body. A mucous membrane is one of four major types
of thin sheets of tissue that line or cover various parts of the body, such as the mouth and passages for
breathing.
In severe mesothelioma cases, cancer masses, known as tumors, can develop. When tumors develop
in the abdominal cavity, they normally do not cause signs and symptoms until they are late stage. When
this happens, signs symptoms include ascites (see above), abdominal pain, a palpable mass in the
abdomen, weight loss, and problems with intestine functioning.
Severe mesothelioma cases could also cause blood clots in the veins, which can lead the veins to
become inflamed. When inflammation in the veins occurs due to a blood clot, it is known as
thrombophlebitis. Blood clots in the arteries of the lungs (known as pulmonary emboli) can occur. In the
worst case scenario, DIC can occur. Some doctors refer to DIC as “death is coming” but it actually
mean Disseminated Intravascular Congestion, which is the formation of small blood clots inside the
blood vessels and throughout the body.
WHAT TYPE OF DOCTOR SHOULD I SEE IF I BELIEVE I MAY HAVE MESOTHELIOMA?
The type of doctor that should be seen for this is usually a pulmonologist, which is a type of lung
specialist. However, if the abdomen is involved, you would see a doctor who specializes in the stomach
and intestines, known as a gastroenterologist. Depending on the results of diagnostic tests, you may be
referred to cancer specialists (oncologists).
HOW IS MESOTHELIOMA DIAGNOSED?
Overview
The diagnosis of mesothelioma is made by combining the patient’s history (paying particular attention to
asbestos exposure) with signs and symptoms, physical examination findings, and diagnostic test
findings. The physical exam will include an examination of the skin for unusual lumps or other unusual
signs, such as abnormal breathing. Lung function tests are also ordered if a disease is suspected in the
lungs. Lung function tests involve several techniques (such as breathing into a tube or walking for six
minutes) to asses the functioning of the lungs.
The diagnosis of mesothelioma is usually delayed because the most common symptoms (difficulty
breathing, shortness of breath, excessive coughing, pain in the chest/abdomen, weight loss, appetite
loss), are similar to less serious conditions such as the flu, a cold, bronchitis, heart disease, and viral
pneumonia. Usually, a patient will present these signs and symptoms to their primary care physician,
who will ultimately refer to patient to other medical specialists, including those with experience in
accurately diagnosing mesothelioma. The earlier the signs and symptoms and assessed, the more likely
that the disease will be caught at an earlier stage, which increases treatment options and can improve
prognosis.
Imaging
Diagnostic testing for mesothelioma usually begins with a chest x-ray, which may detect the thickening
of the pleura that usually occurs after asbestos exposure and can be a sign of mesothelioma. A
computerized axial tomography (CT) scan of the chest or abdomen may also be ordered to look for
abnormalities. CT scanning is a more advanced imaging technique that uses x-rays and computer
technology to produces more clear and detailed pictures than a traditional x-ray. It is more sensitive than
a chest x-ray at detecting asbestos-related lung disease. An MRI (magnetic resonance imaging) test
may also be ordered, which produces more clear pictures than a CT scan. MRI scans produce extremely
detailed pictures of the inside of the body by using very powerful magnets and computer technology. A
positron emission tomography (PET) scan may also be ordered, which involves injecting the patient with
a small radioactive chemical and being placed in a machine that detects and records energy given off by
the substance. The computer translates the energy into 3D pictures which provides information about
how cells in the body are functioning because normal cells react differently to the chemical than healthy
cells. The tests described in this section provide useful information on determining the extent of the
cancer, which is known as staging (see separate section below).
Biopsy
Identifying the presence of asbestos fibers in the lungs involves a biopsy, in which an area of lung tissue
is removed via surgery and studied in a laboratory under the microscope. Biopsy is the most accurate
way to determine if a patient has mesothelioma. There are different biopsy procedures depending on the
area of the body affected.
In a fine needle aspiration, the doctor inserts a small, thin, hollow needle into the affected body area and
removes fluid or a piece of tissue. If fluid is being removed, the needle is inserted under the skin and a
syringe extracts some of the fluid. Cells from the fluid are then stained and analyzed under a
microscope. This analysis of cells is known as cytopathology.
If the analysis of the cells in the fluid do not show the presence of cancer cells, this does not mean that
mesothelioma is not present, but it makes it much less likely, especially if there is evidence for another
diagnosis that can explain the findings. It is very difficult to diagnose mesothelioma solely by analyzing
the cells from bodily fluid, even if the person doing the analysis is an expert.
To make a definitive diagnosis, a biopsy of bodily tissue (not fluid) is usually needed. A biopsy is the
process of removing living tissue or cells from organs or other body parts of patients for examination
under a microscope or in a culture to help make a diagnosis, follow the course of a disease, or estimate
a prognosis. A culture is an artificial way to grow cells or tissues in the laboratory but in the case of
mesothelioma, the tissue is analyzed under a microscope.
The biopsy will be done in different ways depending on where the abnormal tissue is located. If the
tissue that needs to be tested is located in the chest, a thoracoscopy may be performed. In this
procedure, the surgeon makes one or two incisions between the ribs and a lighted tube (known as a
thoracoscope) with a tiny video camera is inserted into the chest to take pictures and special surgical
tools are used to take tissue samples. The use of the video camera sometimes leads the procedure to
sometimes be called a video-assisted thoracoscopic surgery (VATS). A more dramatic procedure to
obtain a tissue sample from the chest is known as a thoracotomy, in which the chest is directly opened
by the surgeon. An alternative to a needle biopsy is a bronchoscopy, in which the lungs are rinsed and
the materials captured are studied under a microscope.
If the cancer is in the abdomen, a laparoscopy may be performed. This involves making one or more
small cuts in the abdomen and inserting a tiny camera in the abdominal cavity that allows the surgeon to
see inside and a special instrument used to take a tissue sample. If this procedure does not allow for
enough tissue to be obtained, a more extensive surgery may be needed. A laparotomy is a more drastic
surgical procedure that involves cutting open the abdomen. During the procedure, the surgeon checks
for signs of disease and can take a tissue sample.
Immunohistochemistry
Another diagnostic tool that physicians use to tell the difference between mesothelioma from other
diseases is called immunohistochemisty. Immunohistochemistry is the process of detecting the
presence of proteins known as antigens in the cells of tissue by visualizing its interaction with
antibodies. Antigens are substances in the body that can produce a defensive reaction by the body.
Antibodies are types of proteins that help stop future infections by the same antigen. There are many
immunohistochemistry tests available and there is no single such test that can tell the difference
between mesothelioma from other diseases that can mimic the condition. Rather, the tests results are
combined with other diagnostic tests noted above to make a decision about the diagnosis.
If the following immunohistochemisty tests are positive (present), this would point towards
mesothelioma. All of these are types of protein: calretinin, cytokeratin 5/6, epithelial membrane antigen
(EMA) in a membrane-like pattern, human mesothelial cell 1 (HBME-1), and Wilms’ tumor (WT1).
If the following immunohistochemisty tests are negative (not present), this would point against
mesothelioma: B72:3, Ber-EP4, CD15, carcinoembryonic antigen (CEA), MOC-3 1, or thyroid
transcription factor-1 (TTF-1). Most of these are also types of proteins.
HOW LONG DOES IT TAKE FOR MESOTHELIOMA TO DEVELOP?
It can take 20 to 50 years (or more) after exposure for mesothelioma to develop (usually 30 years or
more) which is why great efforts have been undertaken to prevent exposure of school children. The time
from exposure to disease presentation is known as the disease latency. Although mesothelioma can
occur after brief exposure (e.g. one to three months) to asbestos, the disease latency is almost never
less than 15 years and tends to be 30 to 40 years. This is why the average age when mesothelioma is
diagnosed is age 62 and usually affects people between age 50 and 70. After the World Trade Center
attacks, which exposed first ground responders, clean up crews, and others to high concentrations of
asbestos, mesothelioma cases developed much more rapidly. A few World Trade Center workers have
already died of the disease.
The dose of asbestos needed to develop mesothelioma appears to be lower than for the development of
lung cancer or asbestosis. Asbestosis is a serious, potentially fatal, long-term, and usually slowly
progressive (worsening) disease characterized by the production of firm scar tissue in the lungs.
Asbestos is most likely to cause mesothelioma compared to other forms of cancer.
HOW IS MESOTHELIOMA TYPED AND STAGED?
Based on tissue analysis, there are three types of mesothelioma. The first is known as epithelioid. The
second is known as sarcomatoid. The differences is based on appearance of the cells, with sarcomatoid
cells being oval or spindle-shaped and epitheliod cells usually being cube-shaped, although some are
shaped like columns and some have a flattened appearance. The third type is known as biphasic (or
mixed) because it has features of both epithelioid and sarcomatoid cells. In other words, both cells are
present in different parts of the tumor.
The epitheliod type often comprises about 50 to 60% of mesothelioma cases and usually has a better
prognosis than the other types. Sarcamotoid is the least common form of mesothelioma, accounting for
about 10 to 15% of cases. The biphasic form is becoming more common (e.g., up to 63% depending on
the study).
Pleural mesothelioma is staged based on the recommendations of the International Mesothelioma
Interest Group (IMIG). Formal stages are not available for other types of mesothelioma because they
are rare and not enough information is known about them. The IMIG system is based on the location of
the primary tumor (the first tumor that began the cancer) and whether it could be operated on, if any
lymph nodes were affected, and if the tumor underwent distant metastasis (spread to distant parts of the
body). This is often referred to as the TNM approach, where T stands for Tumor, N stands for Node
(lymph node), and M stands for distant Metastasis. Lymph nodes are small egg shaped structures in the
body that help fight against infection.
There are five possible mesothelioma stages: Ia, Ib, II, III, IV (staged one-a to four). The higher the
stage, the worse the cancer is. Stage I is localized cancer, meaning that has not spread beyond the
chest. Stage II may have spread beyond the chest lining to the lung or to a diaphragm. The diaphragm is
a muscular-fibrous area that separates the chest and abdomen (belly) that assists with breathing. Stage
III may have spread to other structures within the chest and may involve nearby lymph nodes. Stage IV
is advanced cancer that has spread more extensively within the chest. It may also have spread to other
parts of the body such as the brain.
ARE THERE SCREENING TESTS FOR MESOTHELIOMA?
Research into early screening tests for mesothelioma is currently ongoing but at present, there is no
universally agreed upon mesothelioma screening test for people who have been exposed to asbestos. If
such a screening test were developed, it may lead to an earlier diagnosis and improve the survival
length. There is a type of protein known as osteopontin that can be tested in the serum which may
become a mesothelioma screening tool for people exposed to asbestos. Serum is the clear, thin, and
sticky fluid part of the blood that remains after the blood has changed from a liquid into a solid form.
There is an excess amount of osteopontin present in pleural mesothelioma as well as other cancers and
inflammatory conditions. Another protein, named soluble mesothelium-related protein (SMRP), has been
found to be elevated in 75% of patients with mesothelioma at the time of diagnosis. This may prove
useful as a screening method. Scientists have also begun testing the Mesomark assay as a screening
measure for pleural and peritoneal mesothelioma. The Mesomark assay is a test that was developed in
2007 that measures levels of SMRPs released from mesothelioma cells.
WHAT IS THE PROGNOSIS FOR PEOPLE WITH MESOTHELIOMA?
Unfortunately, most patients with mesothelioma die within a year of diagnosis, although some prognostic
ranges are between 4 to 18 months. Some improvements in prognosis have been seen with newer
chemotherapies and multi-modal therapies (see treatment section). Treatment will depend on the stage
of disease. Treatment at earlier stages (i.e., stages 1 and 2) leads to a better prognosis. However,
cures are extremely rare. The type of tissue underlying the mesothelioma (epithelioid, sarcomatoid, or
biphasic; see diagnosis section) also helps predict prognosis. Epithelioid mesothelioma generally
responds better to treatment and has better survival rates than sarcomatoid mesothelioma. The age and
general health of the patient also affect prognosis. Quitting smoking can improve life expectancy in
mesothelioma patients.
Some patients with favorable prognostic factors receiving trimodal therapy (surgery, chemotherapy, and
radiation) have had significantly extended survival rates (e.g., 3 to 14 years). These favorable
prognostic factors include having the epithelial cell type of the disease (see diagnostic section),
negative resection margins (no cancer cells present on the periphery of the tumor), and no evidence of
cancer spread in lymph nodes outside the pleura.
However, other studies of multimodal mesothelioma treatment have only demonstrated a modest
increase in survival. For example, Borasio and colleagues (2006) showed that patients undergoing
multimodal therapy (including surgery) had a median survival rate of 14.5 months and a two-year survival
rate of 29.6%. Decreasing the size of the tumor through surgery is important to increasing survival.
Despite the generally poor prognosis, there have been exceptions. An example is the famous scientist,
Stephen Jay Gould, who developed peritoneal (abdominal) mesothelioma. He wrote a famous article
after he was diagnosed called “The Median Isn’t the Message” for Discover magazine, which has been
used as a source of inspiration for people diagnosed with serious illnesses. In the article, Gould argued
that statistics about prognosis are abstract concepts based on group data and do not equate to destiny
for the individual. He lived for 20 years after diagnosis and ultimately died of an unrelated form of cancer
(lung cancer that spread to the brain).
Another source of inspiration has been author, Paul Krauss, who was diagnosed with peritoneal
mesothelioma in 1997. He was given less than a year to live but continues to outlive the prognosis. He
wrote a book about surviving mesothelioma called "Surviving Mesothelioma and Other Cancers: A
Patient's Guide." In it, he described his philosophy of healing and deciding to pursue integrative
medicine, which combines conventional medicine with alternative (non-conventional medicine).
However, he has not been treated with radiation, chemotherapy, or surgery because he was told that
these therapies could severely affect his quality of life without significantly prolonging it. His treatments
have included lifestyle changes, a vegetarian diet, intravenous vitamin C, herbal medicine, and
traditional Chinese medicine techniques.
HOW IS MESOTHELIOMA TREATED?
General Overview
The type, location, and stage of mesothelioma largely determines treatment, along with the health of the
patient. If mesothelioma is diagnosed in the earliest stage, the patient may be eligible for surgery or
other established/conventional treatments (e.g., radiation, chemotherapy) to help slow the disease,
although there is no cure. Radiation is a type of energy in the form of waves or streams of particles that
is often used to treat tumors. Chemotherapy for mesothelioma includes cisplatin, carboplatin,
gemcitabine, vinorelbine, raltitrexed, pemetrexed (Alimita), and/or paclitaxel.
Usually, treatment for mesothelioma is palliative rather than curative, which means that the purpose is to
decrease symptoms rather than cure the disease. This is because the disease is usually diagnosed at
an advanced stage, in which it is not possible to remove all of the cancer through an operation.
However, this is possible in some early stage cases.
Chemotherapy is the only treatment option for mesothelioma that has been proven to improve survival
in controlled and randomized trials. It works by shrinking, killing, or slowing the growth of cancer cells.
Chemotherapy is sometimes used before surgery (known as neoadjuvant chemotherapy) to make the
operation easier or after chemotherapy (known as adjuvant chemotherapy) to decrease the chance that
the cancer will return.
In 2003, Vogelzang and colleagues published an important, large, international, randomized study in The
Journal of Clinical Oncology on chemotherapy in mesothelioma. The study was the first to show that
mesothelioma patients (226) treated with chemotherapy (cisplatin and pemetrexed) lived significantly
longer than patients only treated with cisplatin (222). Specifically, the median survival rate improved
from 9.1 months to 12.1 months.
A minority of patients in the combined treatment group had more side effects than the cisplatin only
group. These side effects included nausea, vomiting, diarrhea, and stomatitis. Stomatitis is inflammation
of the mucous membrane (type of thin tissue lining) of the mouth. Some patients also received daily
folate (vitamin B9; 350 to 1000 micrograms) and 1000 micrograms of vitamin B12 every nine weeks,
which significantly reduced toxicity and side effects. A microgram is one millionth of a gram.
The study also showed a partial response rate to the combination cisplatin and pemetrexed of 41.3%
compared to 16.7% in the cisplatin only group. In patients receiving vitamin supplementation, the
response rates were 45.5% compared to 19.6%, with the advantage again going to the combination
treatment.
The vitamin supplementation increased the median survival rate from 10 months in the cisplatin group
(163 patients) to 13.3 months in the cisplatin and pemetrexed group (168 patients). The difference
approached statistical significance, in that there was only a .051% chance that the difference was due
to chance.
The findings from this study were all improvements over the generally accepted 6 to 8 month survival
prognosis. The patients in the study had not received chemotherapy previously and were not
candidates for more aggressive surgery. Prior to this study, routine use of chemotherapy had not been
supported by prior research. After this study, the combination of cisplatin and pemetrexed became the
new standard of care for mesothelioma. In fact, in 2004, the Food and Drug Administration approved
premetrexed for the treatment of pleural mesothelioma. There continues to be debate on when to start
chemotherapy and how many cycles to give.
For patients who cannot tolerate pemetrexed, cisplatin can be combined with other chemotherapy
medications such as gemcitabine or vinorelbine although these medications have not been shown to
provide survival benefits. For patients who cannot tolerate cisplatin, carboplatin is sometimes used as a
substitute. The survival rates are similar when comparing cisplatin treatment to carboplatin treatment.
However, non-randomized studies have shown that when carboplatin (as opposed to cisplatin) is used
as the basis for combination therapy with another chemotherapy agent, mesothelioma is less likely to
have lower response rates to treatment and high rates of blood toxicity.
In 2005, van Meerbeeck and colleagues published a study in The Journal of Clinical Oncology showing
that patients treated with cisplatin and raltitrexed had a better anti-cancer response to treatment that
patients treated with cisplatin alone (24% vs 14%). Specifically, 46% of patients receiving the
combined treatment survived for at least a year compared with 40% receiving cisplatin alone. However,
raltitrexed is not yet commercially available in the United States.
Heated Intraoperative Intraperitoneal Chemotherapy
Heated (hyperthermic) intraoperative intraperitoneal chemotherapy (HIIC) is a technique developed by
Dr. Paul Sugarbaker, who is the Director of Surgical Oncology at the Washington Cancer Institute. First,
the surgeon removes as much of the tumor as possible. Second, chemotherapy is directly applied to
affected tissue, which permits the application of high concentrations of the medication. Third, the
chemotherapy is heated (e.g., to 40-48 degrees in the abdomen), which increases the penetration of
the medication into the tissue and damages cancer cells more than normal cells. Fourth, the fluid is
perfused for 60 to 120 minutes and then drained. HIIC is used in patients with pleural and peritoneal
mesothelioma and is known as intraperitoneal and intrapleural chemotherapy, respectively. The
technique prevents chemotherapy form injuring cells in other areas of the body.
Radiation
Treating mesothelioma with radiation (high-energy beams) alone has never been shown to improve
survival from the disease, much less result in a cure. Radiation can be used to shrink tumor size which
can relieve symptoms caused by the tumor blocking a major blood vessel. Another problem is that if
surgery is not used to treat mesothelioma before radiation treatment is begun, the dose necessary to
treat the disease would be very toxic.
Radiation is best used to treat mesothelioma after patients with localized disease (disease that has not
spread) undergo major surgery. The entire side of the chest where the mesothelioma is located is
treated with radiation. Radiation treatment and chemotherapy are often given together. Radiation is
sometimes also applied after biopsy or surgery to prevent mesothelioma spread to the surgical site. An
example is applying radiation to the site where the chest tube was inserted to prevent the tumor from
growing along the track in the chest wall. See the diagnosis section for a discussion of chest tubes.
Surgery and Combination (Multimodal) Treatment
The combination of major surgery followed by chemotherapy and radiation has increased life
expectancy, sometimes up to five years. Surgery as the only treatment is generally not successful.
Combining two or more treatments (known as multimodal therapy) has been helpful in reducing
symptoms and improving life expectancy. Surgery combined with chemotherapy and radiation is known
as trimodal therapy. Some patients with favorable prognostic factors receiving trimodal therapy have
had significantly extended survival rates (e.g., 3 to 14 years). These favorable prognostic factors
include having the epithelial cell type of the disease (see diagnostic section), negative resection
margins (no cancer cells present on the periphery of the tumor), and no evidence of cancer spread in
lymph nodes outside the pleura.
However, other studies of multimodal mesothelioma treatment have only demonstrated a modest
increase in survival. For example, Borasio and colleagues (2006) showed that patients undergoing
multimodal therapy (including surgery) had a median survival rate of 14.5 months and a two-year
survival rate of 29.6%. Decreasing the size of the tumor through surgery is important to increasing
survival.
In 2008, researchers in Italy retrospectively studied 394 (270 men, 124 women) patients with pleural
mesothelioma, 27 of whom underwent surgery followed by chemotherapy. The surgeries included
pleurectomy with decortication or extrapleural pneumectomy (EPP), depending on the extent of disease
present. Pleurectomy with decortication is the most common surgery for mesothelioma and involves
removing the involved pleura and freeing the underlying lung so it can expand and fill the pleural cavity.
An extrapleural pneumectomy is a less common and major surgical procedure that involves removal of
the lining of the chest wall and heart, the affected lung, and the hemi-diaphragm (half of the diaphragm)
on the affected side. Removal of the lung allows doctors to use higher doses of radiation because they
do not need to worry about damaging a lung on the affected side.
Whether EPP or pleurectomy with decortication is chosen depends on the size of the tumor.
Pleurectomy with decortication is performed in patients with early stage disease when the goal is to
remove all of the visible tumor. EPP is performed in otherwise healthy patients with more advanced
tumors that have not spread to lymph nodes or surrounding tissues and organs.
The study above (published in 2008 by Borasio and colleagues) found that 96.7% of the 394 patients
had died. The median survival length was 11.7 months. The median is the number that separates the
higher half of the sample from the lower half of the sample and is thus different from the average (or the
mean). Surgery combined with chemotherapy (cisplatin and paclitaxel) increased the median survival
length to 14.5 months. The authors concluded that the role of surgery in treating mesothelioma was
unclear.
In the United States, researchers at Duke University studied 13 patients who were treated for
mesothelioma with intensity-modulated radiotherapy (IMRT) after EPP for pleural mesothelioma
(published in 2008 by Miles and colleagues). IMRT is an advanced type of high precision radiation that
improves the ability to conform treatment to concave tumor shapes, such as when the tumor is wrapped
around a vulnerable structure in the body. Twelve of the 13 patients were also treated with
chemotherapy (usually with Alimita and cisplatin). Patients were followed-up at a median of 9.5 months
after IMRT. One patient died of treatment related pulmonary (lung toxicity) and three patients (23%) died
of recurrent disease. Three patients were alive with recurrence (23%) and 6 patients (46%) were alive
with no evidence of recurrence. This research led the FDA in 2009 to approve conventional therapies
(e.g., surgery in combination with radiation and/or chemotherapy) for patients with stage I or II
mesothelioma.
Clinical Trials for Experimental Treatments
There are clinical trials available for experimental treatments that patients can explore by talking to their
doctor. While experimental treatments can improve prognosis, they are risky because they are
experimental and thus, less is known about their effects compared to well-known established
treatments. Experimental chemotherapies involve targeted drug therapies, which involve attacking
(targeting) specific abnormalities within cancer cells. An example would include targeting a substance
that cancer cells make to attract new blood vessels, which they depend on for oxygen and nutrients.
Without the oxygen and nutrients, the cancer cells would die.
Another example includes gene therapy or photodynamic therapy. Gene therapy is the insertion,
removal, or altering of the genes within a person’s cells and tissues to treat disease. Genes are units of
material contained in a person's cells that contain coded instructions as for how certain bodily
characteristics (such as eye color) will develop. In photodynamic therapy, a patient is given a drug that
is sensitive to light and which contains cancer killing substances that are absorbed by cancer. During
surgery, a light beam is focused at the cancer site, which then activates the drug and kills the cancer
cells.
Immunotherapy
Some patients have reported that taking supplements or designing a nutrition plan to improve the
immune system has been helpful to them. This is known as immunotherapy. Some research suggests
that a strong immune system may be what is common to mesothelioma survivors. However, treatments
using immunotherapy for mesothelioma have led to variable results. One treatment has involved using a
tubercolosis vaccine known as Bacillus Calmette-Guérin (BCG) to treat pleural mesothelioma by
boosting the immune system. The reason why BCG is used for pleural mesothelioma is because pleural
refers to the lungs and tuberculosis is an infectious lung disease. However, this form of treatment has
not been found to be helpful for mesothelioma.
In scientific laboratories, mesothelioma cells have been shown to be vulnerable to destruction by
lymphokine-activated killer (LAK) cells when activated by interleukin-2. LAK cells are types of white
blood cells that have been stimulated to kill cancer cells. This happens when stimulated by interleukin-2.
Interleukin-2 is a type of chemical that transmits information between cells in the immune system.
However, when this treatment was used with patients, they experienced very high levels of toxicity and
serious side effects (e.g, fever, cachexia), leading to discontinuation of the treatment. Cahcexia is an
appearance of serious illness, poor nutrition, weakness, massive weight loss, and wasting away.
Another form of immunotherapy known as interferon alpha has been more promising. Interferon alpha is
a type of interferon. Interferons are proteins released in the body in response to the presence of
harmful substances (such as tumor cells) which then trigger the immune system to fight them. Twenty
percent of mesothelioma patients receiving this treatment in one study showed more than a 50%
decrease in tumor size and few side effects.
Symptomatic Treatment (Surgery)
When ascites develops, the procedure to remove the fluid is called paracentesis. Ascites is a condition
in which fluid builds up in the space between layers that line the belly. A build up of fluid in this area will
cause the belly to look swollen. In paracentesis, a needle is used to drain fluid from a body cavity,
usually in the peritoneal cavity in the abdomen. The drain is known as an ascitic drain. The peritoneal
cavity is the potential space between the two membranes that separate the organs in the wall of the
abdomen from the abdominal cavity. The abdominal cavity holds the bulk of the organs in the human
body.
For fluid that comes from the pleural region (which causes difficulty breathing), the fluid is collected
through thoracentesis or a chest tube. In thoracentesis, a hollow needle is carefully placed into the
thorax (chest), usually after administering local anesthesia. A chest tube (also known as a tube
thoracostomy) is a flexible plastic tube that is placed in the side of the chest into the pleural space (the
thin space between the two pleural layers). During a thoracospy, substances such as talc can be
introduced to destroy the pleural space (the body cavity that surrounds the lungs). This procedure is
known as pleurodesis and it stops more fluid from building up and pressing on the lungs.
When fluid needs to be removed with a needle around the double walled sac that contains the heart
(pericardium), it is known as pericardiocentesis.
A pleurectomy (described in the prior section) is sometimes done to relive signs and symptoms of the
disease, as is a peritonectomy (removal of the tissue lining of the abdominal cavity).
Symptomatic Treatment (Alternative/Holistic Therapy)
Some people use holistic treatment methods for mesothelioma such as acupuncture, massage,
meditation, aromatherapy, yoga, and/or a TENS (transcutaneous electrical nerve stimulation) therapy.
TENS involves electrical stimulation of nerves for treatment purposes. These holistic treatments are
used to decrease side effects associated with established therapies. None of these treatments can
reverse the disease but are used to reduce signs and symptoms of the disease. The main symptom
these treatments are used for is a sense of pressure on the chest which can cause a constant
shortness of breath feeling that can be stressful. Medications and supplemental oxygen can help with
this symptom but so can alternative treatments. Other alternative treatments include breath training,
directing a fan towards the face, and relaxation exercises (tensing and relaxing different muscle
groups).
HOW COMMON IS MESOTHELIOMA?
As noted earlier, mesothelioma is a relatively rare cancer, although the incidence rates have increased
over the past 20 years and is expected to continue to increase in some parts of the world. The
incidence of a disease is the rate at which new cases occur in a population during a specified period.
The incidence rate of mesothelioma varies from country to country. It is as low as 1 cases per one
million people in Morocco and Tunisia. It is as high a 40 cases per million people and Australia.
In the United States, the incidence may have peaked in 2004, at 15 cases per million people. About
27.5 million U.S. workers in high risk industries and occupations were exposed to asbestos between
1940 and 1979. Between 1973 and 1984, the incidence of pleural mesothelioma in Caucasian men
increased 300%. From 1980 to the late 1990s, the yearly death rate from mesothelioma in the U.S.
increased form 2,000 to 3,000.
Mesothelioma occurs much more often in men than women (e.g., 4 times as much), likely because men
tend to work at the types of jobs where asbestos exposure is most common. The risk for mesothelioma
increases with age but it can occur in men and women at any age. In considering mesothelioma
incidence rates, it always needs to be kept in mind that the rates are only estimates and are affected by
misdiagnosis. For example, the incidence rate may be higher because mesothelioma is sometimes
misdiagnosed at adenocarcinoma of the lung. Adenocarcinoma is a type of cancer that involves the
epithelial cells of glands. Epithelial cells are cells that help absorb, move, and distribute some of the
fluids and nutrients in the body. A gland is an organ in the body made of special cells that form and
release materials such as fluid.
HOW DOES MESOTHELIOMA DEVELOP AND SPREAD?
To understand the answer to this question, it is first important to know about the mesothelium, which is
the membrane that lines several body cavities (abdomen, chest, heart). The mesothelium is made up of
a single layer of flat or cube-shaped cells. When asbestos fibers are deposited into the lung tissue they
can penetrate the visceral pleura, which is the part of the pleura that is directly attached to the lungs.
The asbestos fibers can then be carried to the surface of the pleura (potentially a critical step in
mesothelioma development), where they cause the formation of harmful plaques on the mesothelium.
The plaques are areas that are fibrous or hardened areas caused by partial calcium deposits.
Large numbers of macrophages and other cells in the immune system travel to abnormal tissue areas
where asbestos fibers accumulate until cellular changes occur that change the tissue structure into a
tumor(s). Macrophages are types of white blood cells that engulf and digest (eat) harmful substances in
the body.
Exactly how the molecules inside the mesothelial cells turn into cancer cells is unknown. However,
asbestos fibers are known to interact with the cell’s DNA (an abbreviation for deoxyribonucleic acid).
DNA is a chain of many connected genes. Genes contain coded instructions for how proteins should be
constructed and how certain bodily characteristics should develop. The asbestos fibers that have been
attacked by macrophages make contact with the chromosomes. Chromosomes are microscopic
structures in cells that transmit genetic information. Asbestos fibers often become entangled within the
chromosome or stick to the thread-like bodies that make up chromosomes, known as chromatin. When
the asbestos fibers contact these structures, it can cause complex abnormal processes to take place,
leading to cancer development.
The most common genetic abnormality is causing only one chromosome to be present (instead of the
normal two chromosomes) on chromosome 22. Sometimes, the arms of the chromosomes become
structurally altered. Each chromosome has a short arm (known as p) and a long arm (known as q). For
example, the short arm of chromosome 22 is known as 22p. The arms affected by the cellular changes
in the mesothelioma process are 1p, 3p, 9p and 6q.
Another cellular change that can happen in the mosthelioma development process is that tumor
suppressor genes can be removed. Tumor suppressor genes are genes that protect cells from cancer.
The names of the tumor suppressor genes that are often removed in the mesothelioma process are:
neurofibromatosis type 2 at 22q12, Pi1INK4A, and P14ARF.
Asbestos also allows for foreign DNA to enter normal cells. This can lead to abnormal changes and
cancer development in several ways. First is by inactivated tumor suppressor genes. Second is the
activation of oncogenes, which are genes that have the potential to cause cancer. Third is the
activation of proto-oncogenes which are normal genes that can turn into oncogenes. Fourth is the
activation of DNA repair enzymes that may work incorrectly and thus not fix damaged DNA properly. An
enzyme is a type of protein that helps produce chemical reactions in the body. Fifth is the activation of
telomerase, which is an enzyme that can cause some cells to continuously divide, leading to tumor
development. Sixth is the prevention of normal cell death which results in a similar process to activation
of telomerase. That is, cells continue to divide, leading to tumor development.
In scientific laboratory experiments, a complete change of normal mesothelial cells to cancer cells has
not yet occurred. Thus, the interaction of the affected cells with macrophages and other cells from the
immune system appear to play an important role in the process. One way this happens is that asbestos
fibers change the way in which macrophages secrete (release) substances. When macrophages try to
destroy asbestos fibers, the macrophages make increased amounts of hydroxyl radicals. Radicals (also
known as free radicals) are atoms or groups of atoms that have at least one unpaired electron (normally
atoms have pairs of electrons) which makes them unstable and highly reactive. An electron is a
negatively charged particle that is smaller than an atom. Hydroxyl radicals can disrupt or break
chromosomes and are known to promote cancer in reaction to asbestos. They do this by directly and
indirectly interacting with DNA, changing cellular events that occurs across membranes, and activate
oncogenes (see above), disrupt the protection of cells normally provided by antioxidants (molecules that
prevent cells from producing free radicals).
Based on the above, asbestos and asbestos-like fibers initiate the cancer development process. That
is, they lead to the alteration of normal cells into cancer cells. Once the cell has been changed, it is
susceptible to the effects of promoters, which are compounds that cause the abnormal cells to multiply.
Promoters have no effect on the body unless the cell has first been changed by asbestos.
Asbestos fibers from the lung are taken to the abdomen and associated organs through the lymph
system. The lymphatic system is a system of vessels that drain lymph from all over the body back into
the blood. Lymph is a milky fluid that contains proteins, fats, and white blood cells (which help the body
fight off diseases). Asbestos may also be deposited into the abdominal area and intestines if the fibers
are ingested through saliva. Eventually, the functioning of affected organs becomes disrupted by
mesothelioma. For example, blood flow to the lungs can be impaired and cause the heart to enlarge or
fail.
Long, thin, and needle-like asbestos fibers are more likely to cause cancer than the curly and feathery
fibers that make up the chrysotile form of asbestos. However, research also indicated that smaller
asbestos or asbestos-like particles may be more dangerous than larger fibers because the smaller
fibers remain suspended in the air, where they can be inhaled. This may lead them to penetrate the lung
tissues easier and to a deeper degree. When ingested, the fibers can become lodged in the
peritoneum. Scar tissue forms in the pleura and make the tissue unable to contract, making breathing
painful or impossible. Effusions can also prevent the smooth muscle of the lungs and other organs in the
chest from moving effectively by putting pressure on them. This causes some of the symptoms such as
shortness of breath, chest pain, difficulty swallowing, and other. It can also cause pain by putting
pressure on the nerves and spinal cord.
Asbestos may also have properties that suppress the immune system. Chyrsotile fibers have been
shown in scientific laboratories to decrease the production of lymphocytes (a type of white blood cell)
stimulated by phytohemagglutinin (a lectin found in plants). Lectin is a type of protein. Chyrsotile fibers
have also been shown to decrease the destructive capabilities of natural killer cells. Natural killer cells
are types of lymphocytes that destroy harmful cells. Chyrsotile fibers have also been shown to reduce
the viability and recovery of lymphokine-activated killer (LAK) cells when activated by interleukin-2. LAK
cells are types of white blood cells that have been stimulated to kill cancer cells.
Genetic changes in macrophages that try to destroy asbestos fibers can result in the release of
powerful mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming
growth factor-beta (TGFB). Mitogens are chemical substances that cause cells to divide. When
mitogens are released, it can cause chronic stimulation and spread of mesothelial cells after injury by
asbestos fibers.
The abnormal tissue area created by mesothelioma contains fibrous tissue or spindle cells that may
enclose gland-like spaces lined by cuboidal (cube-shaped) cells. Spindle cells are types of cells with an
abnormal spindle-like appearance that are only found in cancerous tumors. Mesothelioma may form
thick sheets of abnormal cells that cover the internal organs (especially those in the abdomen). Cancer
cells can spread to other tissues and organs within the pleural cavity via exfoliation (when old cells
come off).
CAN MESOTHELIOMA BE PREVENTED?
Yes, mesothelioma can be prevented by reducing asbestos exposure. Some occupations known to be
at risk for asbestos exposure were described earlier in this article. When asbestos exposure levels in
the air exceed legal limits at workplaces where exposure is likely, employers need to further protect
workers by establishing regulated areas, controlling certain work practices, implementing engineering
controls to reduce the levels in the air, providing medical monitoring of workers, and providing protective
equipment. As an example of the latter, workers should use National Institute for Occupational Safety
and Health (NIOSH)-approved respirators that fit properly when required. There are also standards in
place at work sites to limit the risk of bringing asbestos fibers home from the workplace, so that others
do not become ill. Examples would include a requirement to shower before leaving work, change clothes
before leaving work, storing street clothes in a separate area at work, and wash work clothes at home
separate from home clothes. Workers need to follow these protective measures.
People also need to be careful about asbestos in their homes or other buildings they spend time. If
there are structures that contain asbestos, many times it is more dangerous to remove them than to
leave them intact. This is because disturbing the structures causes asbestos fibers to become airborne,
where they can be inhaled. There are experts who can be contacted to determine if asbestos is present
in your home (see the entry on asbestos for who to contact), who can test the air in the home to
determine if asbestos is a risk to your health, and remove it if necessary.
WHAT IS THE HISTORY OF LITIGATION AND MESOTHELIOMA?
The link between asbestos and mesothelioma cases has, and will continue to be, the source of many
lawsuits against companies for people seeking to collect monetary damages. The first lawsuit against
asbestos manufacturers was brought in 1929. Since that time, the U.S. court system has been flooded
with lawsuits against companies for not implementing safety measures after the link between asbestos,
mesothelioma, and other asbestos-related diseases became more widely known. Other countries, such
as Britain, have also seen high numbers of lawsuits for the same reason. More general issues related
to asbestos litigation are covered in detail in the asbestos entry.
Leeds, England was the site of what is known as the Armley asbestos disaster. Armley refers to a
suburb of Leeds. In a part of the city known as Armley Lodge, an area containing about 1000 houses
was contaminated with asbestos dust due to the activities of a local asbestos factory which was part of
the Turner and Newell Group (T&N) (also known as JW Roberts). The exposure occurred between the
end of the 19th century and 1959 when the factory closed. At least 300 former employees died of
asbestos-related diseases and there were a number of deaths in the neighborhood area. Several
lawsuits were brought against T&N from people who had contracted mesothelioma. One well known
case was June Turner who contracted the disease in 1993. She won a landmark judgment from the
company just before she died in 1997.
WHAT IS THE DIFFERENCE BETWEEN MALIGNANT MESOTHELIOMA AND BENIGN
MESOTHELIOMA?
Benign mesothelioma is a noncancerous type of tumor that can occur in the chest. However, benign
mesotheelioma occurs in different cells than malignant mesothelioma. In a minority of cases, benign
mesothelioma can be very aggressive which is why the term “benign” is misleading. This is why the term
is now referred to as solitary fibrous tumor. This condition usually does not cause signs and symptoms.
Most cases are accidentally discovered when being tested for other conditions. The causes of benign
mesothelioma are not clear but the cause is not asbestos exposure. The treatment usually involves
surgery.
WHAT FAMOUS PEOPLE HAVE HAD MESOTHELIOMA?
There are many famous people who have developed mesothelioma over the years. A list is provided
below, organized by last name.
BANTON, BERNIE (October 13, 1946 - November 27, 2007): Australian workers rights activist who
developed pleural mesothelioma. He fought a long battle for compensation against James Hardie
Industries, Ltd., which is an industrial building materials company he worked at that specialized in fiber
cement. He claimed that the company knew of the dangers of asbestos before he began working with
the substance to make insulation for power stations. An undisclosed settlement was reached when he
had less than 48 hours to live.
BELLEAR, BOB (1944 - 15 March 2005): Austrailia anti-racism activist. He died or peritoneal
mesothelioma, which he contracted as a naval engineer when exposed to asbestos fibers.
CONEY, MICHAEL (September 28, 1932 - November 4, 2005): British science fiction author. He died of
pleural mesothelioma.
GLEASON, PAUL (May 4, 1939 - May 27, 2006): American film actor. He died of pleural mesothelioma,
which he is believed to have contracted based on asbestos exposure when working on building sites
with his father when he was a teenager.
HENNESSEY, CHRISTIE (19 November 1945 - 11 December 2007): Irish singer-songwriter. Diagnosed
with pleural mesothelioma attributed to working on building sites in London. He refused to accept his
prognosis weeks before his death.
HERNSTEIN, RICHARD (May 20, 1930 - September 13, 1994): Famous psychologist who wrote the
book, The Bell Curve. He died of peritoneal mesothelioma shortly after the book was released.
JORDAN, HAMILTON (September 21, 1944 - May 20, 2008): Chief of Staff for President Jimmy Carter.
He was also a lifelong cancer activist. He died of peritoneal mesothelioma but had several other forms
of cancer throughout his life.
LEONARD, PETER (21 February 1942 - 23 September 2008): Australian journalist and news presenter
who was diagnosed with mesothelioma in January 2008.
MACDOUGAL, JOHN WILLIAM (8 December 1947 - 13 August 2008): Scottish politician who was
diagnosed with mesthelioma in 2007 attributed to work in shipyards. He underwent an operation for
mesothelioma.
McCANN, TERRENCE (March 23, 1934 - June 7, 2006): American wrestler and executive director of
Toastmaster. Diagnosed with mesothelioma. He sued numerous companies for product liability,
including Forest Wheeler, because it manufactured a boiler at an Oklahoma oil refinery where he had
been in 1957 for a couple of weeks. Even though the boiler did not come with any insulation, his
attorneys argued that the company knew or should have known that use of the boiler would involve
asbestos insulation and that the company should have wanted people using the boiler.
McCLAREN, MALCOLM (January 22, 1946 - April 8, 2010): Former manager of the rock bands the
Sex Pistols and New York Dolls. He was diagnosed with peritoneal mesothelioma in October 2009. He
tried to treat the disease with natural remedies (e.g., special foods, vitamins) as an outpatient in
Switzerland. He deteriorated rapidly and was sent to a Swiss hospital, where he passed away.
McQUENN, STEPHEN (March 24, 1930 - November 7, 1980): American movie actor. He was
diagnosed with peritoneal mesothelioma in December 1979 and was not offered chemotherapy or
surgery because the disease was too advanced. He sought alterative treatments in clinics in Mexico.
The treatment he received was highly non-conventional and included frequent shampoos, injection of
live cells from cows and sheep, massage, an ineffective and potentially toxic chemical known as
laetrile, supposed use of a “natural” Mexican anti-cancer drug, and coffee enemas (inserting coffee
into the anus to cleans the large intestine).
He ultimately died of a heart attack one following surgery in Mexico to remove a neck tumor. He may
have been exposed to asbestos as a young Marine since asbestos was used to insulate pipe shipping
and he removed a lot of asbestos from these pipes at the time. He also may have been exposed to
asbestos when wearing automobile racing suits when driving racecars since it was used an insulating
material for protective racing suits and helmets. Another possibility is that he was exposed to
asbestos used in soundstage insulation.
MINER, BOB (December 23, 1941 - November 11, 1994): Co-founder or the Oracle Corporation.
Diagnosed with pleural mesothelioma.
MOST, MICKIE (June 20, 1938 - May 30 2003): English record producer. He died from peritoneal
mesothelioma. He died from peritoneal mesothelioma.
OLSEN, MERLIN (September 15, 1940 - March 11, 2010): Professional football player, commentator,
and actor who was diagnosed with peritoneal mesothelioma in 2009. He was treated with three
courses of chemotherapy. In December 2009, he sued NBC Studios, NBC Universal, and 20th Century
Fox for allegedly exposing him to asbestos, which he claimed caused his condition. He also sued
Lennox Industries and Sherwin Williams after also alleging that he was exposed to asbestos at a job
around age 11 and while working at a job involving drywall as a young adult.
RUDOLPH, PAUL (October 23, 1918 - August 8, 1997): American architect. Died of mesothelioma.
VAUGHN, BILLY (April 12, 1919 - September 26, 1991): Famous American singer. He died of
perintoneal mesothelioma.
VENTO, BRUCE (October 7, 1940-October 10, 2000): U.S. Congressman. He died of pleural
mesothelioma. His wife presents the Bruce Vento Hopebuilder award to the persons or organizations
who have done the most to support mesothelioma research and advocacy. The award is presented
every year at the Mesothelioma Applied Research Foundation.
ZEVON, WARREN (January 24, 1947 - September 7, 2003): American rock singer and song writer. He
was diagnosed with peritoneal meothelioma in the fall of 2002. His condition was inoperable. He
refused treatments that might incapacitate him and focused on recording his final album, The Wind
WHAT ELSE IS MESOTHELIOMA KNOWN AS?
Mesothelioma is also known as asbestos cancer.
WHAT IS THE ORIGIN OF THE TERM, “MESOTHELIOMA”?
The term “mesothelioma” was first used in the medical literature in 1931. Mesothelioma comes from
the Greek word “mesos” meaning “middle,” the Greek word “thele” meaning “nipple,” and the Greek
word “oma” meaning “nipple.” Put the words together and you get “middle nipple tumor,” which is a
reference to the cancer occurring in the chest area.