Mesothelioma (or, more precisely, malignant mesothelioma) is a rare form of cancer that develops from transformed cells originating in the mesothelium, the protective lining that covers many of the internal organs of the body. It is usually caused by exposure to asbestos.[1]
The most common anatomical site for the development of mesothelioma is the pleura (the outer lining of the lungs and internal chest wall), but it can also arise in the peritoneum (the lining of the abdominal cavity), and the pericardium (the sac that surrounds the heart),[2] or the tunica vaginalis (a sac that surrounds the testis).
Most people who develop mesothelioma have worked in jobs where they
inhaled asbestos, or were exposed to asbestos dust and fibers in other
ways. It has also been suggested that washing clothes of a family member
who worked with asbestos increases their risk for developing
mesothelioma.[3] Unlike lung cancer, there seems to be no association between mesothelioma and tobacco smoking, but smoking greatly increases the risk of other asbestos-induced cancers.[4]
Some people who were exposed to asbestos have collected damages for
asbestos-related disease, including mesothelioma. Compensation via
asbestos funds or class action lawsuits is an important issue in law
practices regarding mesothelioma (see asbestos and the law).
Signs and symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and constitutional signs such as unexplained weight loss. The diagnosis may be suspected with chest X-ray and CT scan, but must be confirmed pathologically, either with serous effusion cytology or with a biopsy (removing a sample of the suspicious tissue) and microscopic examination. A thoracoscopy
(inserting a tube with a camera into the chest) can be used to acquire
biopsy material, and allows the introduction of substances such as talc to obliterate the pleural space (a procedure called pleurodesis), preventing more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
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Signs and symptoms
Symptoms or signs of mesothelioma may not appear until 20 to 50 years
(or more) after exposure to asbestos. Shortness of breath, cough, and
pain in the chest due to an accumulation of fluid in the pleural space (pleural effusion) are often symptoms of pleural mesothelioma.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever.
If the cancer has spread beyond the mesothelium to other parts of the
body, symptoms may include pain, trouble swallowing, or swelling of the
neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
- Chest wall pain
- Pleural effusion, or fluid surrounding the lung
- Shortness of breath
- Fatigue or anemia
- Wheezing, hoarseness, or cough
- Blood in the sputum (fluid) coughed up (hemoptysis)
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
- Abdominal pain
- Ascites, or an abnormal buildup of fluid in the abdomen
- A mass in the abdomen
- Problems with bowel function
- Weight loss
In severe cases of the disease, the following signs and symptoms may be present:
- Blood clots in the veins, which may cause thrombophlebitis
- Disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
- Jaundice, or yellowing of the eyes and skin
- Low blood sugar level
- Pleural effusion
- Pulmonary emboli, or blood clots in the arteries of the lungs
- Severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal
glands. Pleural tumors are usually found only on one side of the lungs.
Cause
Working with asbestos is the major risk factor for mesothelioma.[5] In the United States, asbestos is the major cause of malignant mesothelioma[6] and has been considered "indisputably"[7]
associated with the development of mesothelioma. Indeed, the
relationship between asbestos and mesothelioma is so strong that many
consider mesothelioma a “signal” or “sentinel” tumor.[8][9][10][11]
A history of asbestos exposure exists in most cases. However,
mesothelioma has been reported in some individuals without any known
exposure to asbestos. In rare cases, mesothelioma has also been
associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite. Some studies suggested that simian virus 40 (SV40) might have acted as a cofactor in the development of mesothelioma,[12] but these studies have not been corroborated by later research.
Asbestos was known in antiquity, but it was not mined and widely used
commercially until the late 19th century. Its use greatly increased
during World War II.
Since the early 1940s, millions of American workers have been exposed
to asbestos dust. Initially, the risks associated with asbestos exposure
were not publicly known. However, an increased risk of developing
mesothelioma was later found among shipyard workers, people who work in
asbestos mines and mills, producers of asbestos products, workers in the
heating and construction industries, and other tradespeople. Today, the
official position of the U.S. Occupational Safety and Health Administration
(OSHA) and the U.S. EPA is that protections and "permissible exposure
limits" required by U.S. regulations, while adequate to prevent most
asbestos-related non-malignant disease, they are not adequate to prevent or protect against asbestos-related cancers such as mesothelioma.[13] Likewise, the British Government's Health and Safety Executive
(HSE) states formally that any threshold for mesothelioma must be at a
very low level and it is widely agreed that if any such threshold does
exist at all, then it cannot currently be quantified. For practical
purposes, therefore, HSE assumes that no such "safe" threshold exists.
Others have noted as well that there is no evidence of a threshold level
below which there is no risk of mesothelioma.[14] There appears to be a linear, dose-response relationship, with increasing dose producing increasing disease.[15] Nevertheless, mesothelioma may be related to brief, low level or indirect exposures to asbestos.[7]
The dose necessary for effect appears to be lower for asbestos-induced
mesothelioma than for pulmonary asbestosis or lung cancer.[7] Again, there is no known safe level of exposure to asbestos as it relates to increased risk of mesothelioma.
The duration of exposure to asbestos causing mesothelioma can be
short. For example, cases of mesothelioma have been documented with only
1–3 months of exposure.[16][17] People who work with asbestos wear personal protective equipment to lower their risk of exposure.
Latency, the time from first exposure to manifestation of disease, is
prolonged in the case of mesothelioma. It is virtually never less than
fifteen years and peaks at 30–40 years.[7] In a review of occupationally related mesothelioma cases, the median latency was 32 years.[18] Based upon the data from Peto et al., the risk of mesothelioma appears to increase to the third or fourth power from first exposure.[15]
Environmental exposures
Incidence of mesothelioma had been found to be higher in populations
living near naturally occurring asbestos. For example, in central Cappadocia,
Turkey, mesothelioma was causing 50% of all deaths in three small
villages — Tuzköy, Karain and Sarıhıdır. Initially, this was attributed
to erionite, a zeolite mineral with similar properties to asbestos.
Recently, however, detailed epidemiological investigation showed that
erionite causes mesothelioma mostly in families with a genetic
predisposition.[19][20]
The documented presence of asbestos fibers in water supplies and food
products has fostered concerns about the possible impact of long-term
and, as yet, unknown exposure of the general population to these fibers.
Occupational
Exposure to asbestos fibers has been recognized as an occupational
health hazard since the early 20th century. Numerous epidemiological
studies have associated occupational exposure to asbestos with the
development of pleural plaques, diffuse pleural thickening, asbestosis,
carcinoma of the lung and larynx, gastrointestinal tumors, and diffuse
malignant mesothelioma of the pleura and peritoneum. Asbestos has been
widely used in many industrial products, including cement, brake
linings, gaskets, roof shingles, flooring products, textiles, and
insulation.
Commercial asbestos mining at Wittenoom, Western Australia, occurred
between 1945 and 1966. A cohort study of miners employed at the mine
reported that while no deaths occurred within the first 10 years after crocidolite
exposure, 85 deaths attributable to mesothelioma had occurred by 1985.
By 1994, 539 reported deaths due to mesothelioma had been reported in
Western Australia.
Paraoccupational secondary exposure
Family members and others living with asbestos workers have an
increased risk of developing mesothelioma, and possibly other asbestos
related diseases.[21][22]
This risk may be the result of exposure to asbestos dust brought home
on the clothing and hair of asbestos workers. To reduce the chance of
exposing family members to asbestos fibres, asbestos workers are usually
required to shower and change their clothing before leaving the
workplace.
Asbestos in buildings
Many building materials used in both public and domestic premises
prior to the banning of asbestos may contain asbestos. Those performing
renovation works or DIY
activities may expose themselves to asbestos dust. In the UK use of
Chrysotile asbestos was banned at the end of 1999. Brown and blue asbestos was banned in the UK around 1985. Buildings built or renovated prior to these dates may contain asbestos materials.
Diagnosis

CT scan of a patient with mesothelioma, coronal section
(the section follows the plane that divides the body in a front and a
back half). The mesothelioma is indicated by yellow arrows, the central pleural effusion (fluid collection) is marked with a yellow star. Red numbers: (1) right lung, (2) spine, (3) left lung, (4) ribs, (5) descending part of the aorta, (6) spleen, (7) left kidney, (8) right kidney, (9) liver.
Micrographs showing mesothelioma in a core biopsy.
Diagnosing mesothelioma is often difficult, because the symptoms are
similar to those of a number of other conditions. Diagnosis begins with a
review of the patient's medical history. A history of exposure to
asbestos may increase clinical suspicion for mesothelioma. A physical
examination is performed, followed by chest X-ray and often lung function tests. The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytopathology if this fluid is aspirated with a syringe. For pleural fluid, this is done by thoracentesis or tube thoracostomy (chest tube); for ascites, with paracentesis or ascitic drain; and for pericardial effusion with pericardiocentesis.
While absence of malignant cells on cytology does not completely
exclude mesothelioma, it makes it much more unlikely, especially if an
alternative diagnosis can be made (e.g. tuberculosis, heart failure).
Using conventional cytology diagnosis of malignant mesothelioma is
difficult, but immunocytochemistry has greatly enhanced the accuracy of
cytology.
Generally, a biopsy
is needed to confirm a diagnosis of malignant mesothelioma. A doctor
removes a sample of tissue for examination under a microscope by a pathologist.
A biopsy may be done in different ways, depending on where the abnormal
area is located. If the cancer is in the chest, the doctor may perform a
thoracoscopy.
In this procedure, the doctor makes a small cut through the chest wall
and puts a thin, lighted tube called a thoracoscope into the chest
between two ribs. Thoracoscopy allows the doctor to look inside the
chest and obtain tissue samples. Alternatively, the chest surgeon might
directly open the chest (thoracotomy). If the cancer is in the abdomen, the doctor may perform a laparoscopy.
To obtain tissue for examination, the doctor makes a small incision in
the abdomen and inserts a special instrument into the abdominal cavity.
If these procedures do not yield enough tissue, more extensive
diagnostic surgery may be necessary.
Immunohistochemical studies play an important role for the
pathologist in differentiating malignant mesothelioma from neoplastic
mimics. There are numerous tests and panels available. No single test is
perfect for distinguishing mesothelioma from carcinoma or even benign
versus malignant.
Positive | Negative |
EMA (epithelial membrane antigen) in a membranous distribution | CEA (carcinoembryonic antigen) |
WT1 (Wilms' tumour 1) | B72.3 |
Calretinin | MOC-3 1 |
Mesothelin-1 | CD15 |
Cytokeratin 5/6 | Ber-EP4 |
HBME-1 (human mesothelial cell 1) | TTF-1 (thyroid transcription factor-1) |
There are three histological types of malignant mesothelioma: (1)
Epithelioid; (2) Sarcomatoid; and (3) Biphasic (Mixed). Epithelioid
comprises about 50-60% of malignant mesothelioma cases and generally
holds a better prognosis than the Sarcomatoid or Biphasic subtypes.[23]
Staging
Staging of mesothelioma is based on the recommendation by the International Mesothelioma Interest Group.[24] TNM classification of the primary tumor, lymph node involvement, and distant metastasis is performed. Mesothelioma is staged Ia–IV (one-A to four) based on the TNM status.[24][25]
Screening
There is no universally agreed protocol for screening people who have
been exposed to asbestos. Screening tests might diagnose mesothelioma
earlier than conventional methods thus improving the survival prospects
for patients. The serum osteopontin
level might be useful in screening asbestos-exposed people for
mesothelioma. The level of soluble mesothelin-related protein is
elevated in the serum of about 75% of patients at diagnosis and it has
been suggested that it may be useful for screening.[26] Doctors have begun testing the Mesomark assay which measures levels of soluble mesothelin-related proteins (SMRPs) released by diseased mesothelioma cells.[27]
Pathophysiology
The mesothelium consists of a single layer of flattened to cuboidal cells forming the epithelial lining of the serous cavities of the body including the peritoneal, pericardial and pleural cavities. Deposition of asbestos fibers in the parenchyma of the lung may result in the penetration of the visceral pleura
from where the fiber can then be carried to the pleural surface, thus
leading to the development of malignant mesothelial plaques. The
processes leading to the development of peritoneal mesothelioma
remain unresolved, although it has been proposed that asbestos fibers
from the lung are transported to the abdomen and associated organs via
the lymphatic system. Additionally, asbestos fibers may be deposited in the gut after ingestion of sputum contaminated with asbestos fibers.
Pleural contamination with asbestos or other mineral fibers has been
shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" (chrysotile or white asbestos fibers).[7]
However, there is now evidence that smaller particles may be more
dangerous than the larger fibers. They remain suspended in the air where
they can be inhaled, and may penetrate more easily and deeper into the
lungs. "We probably will find out a lot more about the health aspects of
asbestos from [the World Trade Center attack], unfortunately," said Dr.
Alan Fein, chief of pulmonary and critical-care medicine at North
Shore-Long Island Jewish Health System. Dr. Fein has treated several
patients for "World Trade Center syndrome" or respiratory ailments from
brief exposures of only a day or two near the collapsed buildings.[28]
Mesothelioma development in rats has been demonstrated following
intra-pleural inoculation of phosphorylated chrysotile fibers. It has
been suggested that in humans, transport of fibers to the pleura is
critical to the pathogenesis of mesothelioma. This is supported by the
observed recruitment of significant numbers of macrophages and other cells of the immune system
to localized lesions of accumulated asbestos fibers in the pleural and
peritoneal cavities of rats. These lesions continued to attract and
accumulate macrophages as the disease progressed, and cellular changes
within the lesion culminated in a morphologically malignant tumor.
Experimental evidence suggests that asbestos acts as a complete
carcinogen with the development of mesothelioma occurring in sequential
stages of initiation and promotion. The molecular mechanisms underlying
the malignant transformation of normal mesothelial cells by asbestos
fibers remain unclear despite the demonstration of its oncogenic
capabilities (see next-but-one paragraph). However, complete in vitro
transformation of normal human mesothelial cells to malignant phenotype
following exposure to asbestos fibers has not yet been achieved. In
general, asbestos fibers are thought to act through direct physical
interactions with the cells of the mesothelium in conjunction with
indirect effects following interaction with inflammatory cells such as
macrophages.
Analysis of the interactions between asbestos fibers and DNA has shown that phagocytosed fibers are able to make contact with chromosomes, often adhering to the chromatin
fibers or becoming entangled within the chromosome. This contact
between the asbestos fiber and the chromosomes or structural proteins of
the spindle apparatus can induce complex abnormalities. The most common
abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.
Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes:
- Neurofibromatosis type 2 at 22q12
- P16INK4A
- P14ARF
Asbestos has also been shown to mediate the entry of foreign DNA into
target cells. Incorporation of this foreign DNA may lead to mutations
and oncogenesis by several possible mechanisms:
- Inactivation of tumor suppressor genes
- Activation of oncogenes
- Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
- Activation of DNA repair enzymes, which may be prone to error
- Activation of telomerase
- Prevention of apoptosis
Asbestos fibers have been shown to alter the function and secretory
properties of macrophages, ultimately creating conditions which favour
the development of mesothelioma. Following asbestos phagocytosis,
macrophages generate increased amounts of hydroxyl radicals, which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic
and membrane-active agents thought to promote asbestos carcinogenicity.
These oxidants can participate in the oncogenic process by directly and
indirectly interacting with DNA, modifying membrane-associated cellular
events, including oncogene activation and perturbation of cellular
antioxidant defences.
Asbestos also may possess immunosuppressive
properties. For example, chrysotile fibres have been shown to depress
the in vitro proliferation of phytohemagglutinin-stimulated peripheral
blood lymphocytes, suppress natural killer cell lysis and significantly
reduce lymphokine-activated killer cell
viability and recovery. Furthermore, genetic alterations in
asbestos-activated macrophages may result in the release of potent
mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor-β
(TGF-β) which in turn, may induce the chronic stimulation and
proliferation of mesothelial cells after injury by asbestos fibres.
Treatment
The prognosis for malignant mesothelioma remains disappointing,
although there have been some modest improvements in prognosis from
newer chemotherapies and multimodality treatments.[29]
Treatment of malignant mesothelioma at earlier stages has a better
prognosis, but cures are exceedingly rare. Clinical behavior of the
malignancy is affected by several factors including the continuous
mesothelial surface of the pleural cavity which favors local metastasis
via exfoliated cells, invasion to underlying tissue and other organs
within the pleural cavity, and the extremely long latency period between
asbestos exposure and development of the disease. The histological
subtype and the patient's age and health status also help predict
prognosis. The epithelioid histology responds better to treatment and
has a survival advantage over sarcomatoid histology.[30]
Surgery
Surgery, by itself, has proved disappointing. In one large series, the median survival with surgery (including extrapleural pneumonectomy) was only 11.7 months.[29]
However, research indicates varied success when used in combination
with radiation and chemotherapy (Duke, 2008). (For more information on
multimodality therapy with surgery, see below). A
pleurectomy/decortication is the most common surgery, in which the
lining of the chest is removed. Less common is an extrapleural
pneumonectomy (EPP), in which the lung, lining of the inside of the
chest, the hemi-diaphragm and the pericardium are removed.
Radiation
For patients with localized disease, and who can tolerate a radical
surgery, radiation is often given post-operatively as a consolidative
treatment. The entire hemi-thorax is treated with radiation therapy,
often given simultaneously with chemotherapy. Delivering radiation and
chemotherapy after a radical surgery has led to extended life expectancy
in selected patient populations with some patients surviving more than 5
years. As part of a curative approach to mesothelioma, radiotherapy is
also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.
Although mesothelioma is generally resistant to curative treatment with radiotherapy
alone, palliative treatment regimens are sometimes used to relieve
symptoms arising from tumor growth, such as obstruction of a major blood
vessel. Radiation therapy when given alone with curative intent has
never been shown to improve survival from mesothelioma. The necessary
radiation dose to treat mesothelioma that has not been surgically
removed would be very toxic.
Chemotherapy
Chemotherapy is the only treatment for mesothelioma that has been
proven to improve survival in randomised and controlled trials. The
landmark study published in 2003 by Vogelzang and colleagues compared cisplatin chemotherapy alone with a combination of cisplatin and pemetrexed
(brand name Alimta) chemotherapy in patients who had not received
chemotherapy for malignant pleural mesothelioma previously and were not
candidates for more aggressive "curative" surgery.[31]
This trial was the first to report a survival advantage from
chemotherapy in malignant pleural mesothelioma, showing a statistically
significant improvement in median
survival from 10 months in the patients treated with cisplatin alone to
13.3 months in the group of patients treated with cisplatin in the
combination with pemetrexed and who also received supplementation with
folate and vitamin B12. Vitamin supplementation was given to
most patients in the trial and pemetrexed related side effects were
significantly less in patients receiving pemetrexed when they also
received daily oral folate 500mcg and intramuscular vitamin B12
1000mcg every 9 weeks compared with patients receiving pemetrexed
without vitamin supplementation. The objective response rate increased
from 20% in the cisplatin group to 46% in the combination pemetrexed
group. Some side effects such as nausea and vomiting, stomatitis,
and diarrhoea were more common in the combination pemetrexed group but
only affected a minority of patients and overall the combination of
pemetrexed and cisplatin was well tolerated when patients received
vitamin supplementation; both quality of life and lung function tests improved in the combination pemetrexed group. In February 2004, the United States Food and Drug Administration
approved pemetrexed for treatment of malignant pleural mesothelioma.
However, there are still unanswered questions about the optimal use of
chemotherapy, including when to start treatment, and the optimal number
of cycles to give.
Cisplatin in combination with raltitrexed
has shown an improvement in survival similar to that reported for
pemetrexed in combination with cisplatin, but raltitrexed is no longer
commercially available for this indication. For patients unable to
tolerate pemetrexed, cisplatin in combination with gemcitabine or
vinorelbine is an alternative, or vinorelbine on its own, although a
survival benefit has not been shown for these drugs. For patients in
whom cisplatin cannot be used, carboplatin can be substituted but
non-randomised data have shown lower response rates and high rates of
haematological toxicity for carboplatin-based combinations, albeit with
similar survival figures to patients receiving cisplatin.[32]
In January 2009, the United States FDA approved using conventional
therapies such as surgery in combination with radiation and or
chemotherapy on stage I or II Mesothelioma after research conducted by a
nationwide study by Duke University concluded an almost 50 point
increase in remission rates.
Immunotherapy
Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin
(BCG) in an attempt to boost the immune response, was found to be of no
benefit to the patient (while it may benefit patients with bladder cancer). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2
(IL-2), but patients undergoing this particular therapy experienced
major side effects. Indeed, this trial was suspended in view of the
unacceptably high levels of IL-2 toxicity and the severity of side
effects such as fever and cachexia. Nonetheless, other trials involving
interferon alpha have proved more encouraging with 20% of patients
experiencing a greater than 50% reduction in tumor mass combined with
minimal side effects.
Heated intraoperative intraperitoneal chemotherapy
A procedure known as heated intraoperative intraperitoneal
chemotherapy was developed by Paul Sugarbaker at the Washington Cancer
Institute.[33]
The surgeon removes as much of the tumor as possible followed by the
direct administration of a chemotherapy agent, heated to between 40 and
48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and
then drained.
This technique permits the administration of high concentrations of
selected drugs into the abdominal and pelvic surfaces. Heating the
chemotherapy treatment increases the penetration of the drugs into
tissues. Also, heating itself damages the malignant cells more than the
normal cells.
This technique is also used in patients with malignant pleural mesothelioma.[34]
Multimodality therapy
All of the standard approaches to treating solid tumors—radiation,
chemotherapy, and surgery—have been investigated in patients with
malignant pleural mesothelioma. Although surgery, by itself, is not very
effective, surgery combined with adjuvant chemotherapy and radiation
(trimodality therapy) has produced significant survival extension (3–14
years) among patients with favorable prognostic factors.[35]
However, other large series of examining multimodality treatment have
only demonstrated modest improvement in survival (median survival 14.5
months and only 29.6% surviving 2 years).[29]
Reducing the bulk of the tumor with cytoreductive surgery is key to
extending survival. Two surgeries have been developed: extrapleural
pneumonectomy and pleurectomy/decortication. The indications for
performing these operations are unique. The choice of operation depends
on the size of the patient's tumor. This is an important consideration
because tumor volume has been identified as a prognostic factor in
mesothelioma.[36]
Pleurectomy/decortication spares the underlying lung and is performed
in patients with early stage disease when the intention is to remove all
gross visible tumor (macroscopic complete resection), not simply
palliation.[37]
Extrapleural pneumonectomy is a more extensive operation that involves
resection of the parietal and visceral pleurae, underlying lung,
ipsilateral diaphragm, and ipsilateral pericardium. This operation is
indicated for a subset of patients with more advanced tumors, who can
tolerate a pneumonectomy.[38]
Epidemiology
Although reported incidence rates have increased in the past 20
years, mesothelioma is still a relatively rare cancer. The incidence
rate varies from one country to another, from a low rate of less than 1
per 1,000,000 in Tunisia and Morocco, to the highest rate in Britain,
Australia and Belgium: 30 per 1,000,000 per year.[39] For comparison, populations with high levels of smoking can have a lung cancer
incidence of over 1,000 per 1,000,000. Incidence of malignant
mesothelioma currently ranges from about 7 to 40 per 1,000,000 in
industrialized Western nations, depending on the amount of asbestos
exposure of the populations during the past several decades.[40]
It has been estimated that incidence may have peaked at 15 per
1,000,000 in the United States in 2004. Incidence is expected to
continue increasing in other parts of the world. Mesothelioma occurs
more often in men than in women and risk increases with age, but this
disease can appear in either men or women at any age. Approximately one
fifth to one third of all mesotheliomas are peritoneal.
Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States.[41]
Between 1973 and 1984, the incidence of pleural mesothelioma among
Caucasian males increased 300%. From 1980 to the late 1990s, the death
rate from mesothelioma in the USA increased from 2,000 per year to
3,000, with men four times more likely to acquire it than women.
The incidence of peritoneal mesothelioma is 0.5–3.0 per million per year in men, and 0.2–2.0 per million per year in women.[42]
Society and culture
Notable cases
Mesothelioma, though rare, has had a number of notable patients:
- Bernie Banton, an Australian workers' rights activist, fought a long battle for compensation from James Hardie after he contracted mesothelioma after working for that company. He claimed James Hardie knew of the dangers of asbestos before he began work with the substance making insulation for power stations. Mesothelioma eventually took his life along with his brothers and hundreds of James Hardie workers. James Hardie made an undisclosed settlement with Banton only when his mesothelioma had reached its final stages and he was expected to have no more than 48 hours to live. Australian Prime Minister Kevin Rudd mentioned Banton's extended struggle in his acceptance speech after winning the 2007 Australian federal election.
- Bob Bellear, Australian anti-racism activist, died in 2005.
- Michael G. Coney, British science fiction writer, responsible for nearly 100 works, also died in 2005.
- Paul Gleason, American film and television actor perhaps best known for his portrayal of Principal Richard Vernon in the 1985 film The Breakfast Club, died in 2006.
- Christie Hennessy, the influential Irish singer-songwriter, died of mesothelioma in 2007, and had stridently refused to accept the prognosis in the weeks before his death.[43] Hennessy's mesothelioma has been attributed to his younger years spent working on building sites in London.[44]
- Richard J. Herrnstein, psychologist and co-author of The Bell Curve, died in 1994.
- Harold Hopkins, Australian actor who appeared in films such as The Club, Don's Party, Gallipoli,and the TV mini series Sara Dane died from mesothelioma on December 11, 2011 in a Sydney hospital.
- Hamilton Jordan, Chief of Staff for U.S. President Jimmy Carter and lifelong cancer activist, died in 2008.
- Lincoln Hall, pioneering Australian mountaineer and a founding director of the Australian Himalayan Foundation. He had previously survived against slim odds stranded near the summit of Mount Everest with altitude sickness in 2006. He passed from mesothelioma in 2012.
- Peter Leonard, Australian journalist and news presenter from Canberra, died September 23, 2008.
- Malcolm McLaren, former manager of New York Dolls and Sex Pistols, died on 8 April 2010.
- John William MacDougall, Scottish Labour MP, died of mesothelioma on August 13, 2008, after fighting the disease for two years.[45]
- Steve McQueen, American actor, was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen subsequently sought alternative treatments at clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico, following cancer surgery. He may have been exposed to asbestos while serving with the U.S. Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or from its use as an insulating material in automobile racing suits (McQueen was an avid racing driver and fan).[46]
- Bob Miner, one of the founders of Software Development Labs, the forerunner of Oracle Corporation, died of mesothelioma in 1994.
- Terrence McCann, Olympic gold medalist and longtime Executive Director of Toastmasters, died of mesothelioma on June 7, 2006, at his home in Dana Point, California.
- Mickie Most, an English record producer, died of mesothelioma in 2003.
- Merlin Olsen, Pro Football Hall of Famer and television actor, died on March 10, 2010, from mesothelioma that had been diagnosed in 2009.
- Paul Rudolph, American architect, died in 1997.
- Billy Vaughn, American bandleader, died in 1991.
- Bruce Vento, U.S. Congressman, died of mesothelioma in 2000. The Bruce Vento Hopebuilder award is given yearly by his wife at the MARF Symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
- Warren Zevon, rock and roll musician and songwriter. After a long period of untreated illness and pain, Zevon was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments that he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind, including the song "Keep Me in Your Heart," which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
- Admiral Elmo Zumwalt, former head of the U.S. Navy [47]
Notable people who have lived for some time with mesothelioma
Although life expectancy with this disease is typically limited, there are notable survivors. In July 1982, Stephen Jay Gould was diagnosed with peritoneal mesothelioma. After his diagnosis, Gould wrote "The Median Isn't the Message"[48] for Discover
magazine, in which he argued that statistics such as median survival
are just useful abstractions, not destiny. Gould lived for another 20
years, eventually succumbing to metastatic adenocarcinoma of the lung,
not mesothelioma.
Heather Von St James,
whose case of the disease was considered an anomaly when diagnosed at
age 31, serves as a survivor advocate for the Mesothelioma Applied
Research Foundation and International Mesothelioma Program. In 2006, Von
St. James underwent a radical thoracic procedure known as extrapleural
pneumonectomy. Today she serves as a legislative advocate for cancer
research funding and blogs about her experiences with the disease.
Author Paul Kraus was diagnosed with peritoneal mesothelioma
in July 1997. He was given a prognosis of less than a year to live and
used a variety of complementary modalities. He continues to outlive his
prognosis and wrote a book about his experience "Surviving Mesothelioma
and Other Cancers: A Patient's Guide"[49] in which he presented his philosophy about healing and the decision making that led him to use integrative medicine.
Legal issues
Main article: Asbestos and the law
The first lawsuits against asbestos manufacturers were in 1929. Since
then, many lawsuits have been filed against asbestos manufacturers and
employers, for neglecting to implement safety measures after the links
between asbestos, asbestosis, and mesothelioma became known (some
reports seem to place this as early as 1898). The liability resulting from the sheer number of lawsuits and people affected has reached billions of dollars.[50]
The amounts and method of allocating compensation have been the source
of many court cases, reaching up to the United States Supreme Court, and
government attempts at resolution of existing and future cases.
However, to date, the US Congress has not stepped in and there are no
federal laws governing asbestos compensation.[51]
- History
The first lawsuit against asbestos manufacturers was brought in 1929.
The parties settled that lawsuit, and as part of the agreement, the
attorneys agreed not to pursue further cases. In 1960, an article
published by Wagner et al. was seminal in establishing mesothelioma as a
disease arising from exposure to asbestos.[52]
The article referred to over 30 case studies of people who had suffered
from mesothelioma in South Africa. Some exposures were transient and
some were mine workers. Prior to the use of advanced microscopy
techniques, malignant mesothelioma was often diagnosed as a variant form
of lung cancer.[53] In 1962 McNulty reported the first diagnosed case of malignant mesothelioma in an Australian asbestos worker.[54] The worker had worked in the mill at the asbestos mine in Wittenoom from 1948 to 1950.
In the town of Wittenoom,
asbestos-containing mine waste was used to cover schoolyards and
playgrounds. In 1965 an article in the British Journal of Industrial
Medicine established that people who lived in the neighbourhoods of
asbestos factories and mines, but did not work in them, had contracted
mesothelioma.
Despite proof that the dust associated with asbestos mining and
milling causes asbestos-related disease, mining began at Wittenoom in
1943 and continued until 1966. In 1974 the first public warnings of the
dangers of blue asbestos were published in a cover story called "Is this
Killer in Your Home?" in Australia's Bulletin magazine. In 1978 the Western Australian
Government decided to phase out the town of Wittenoom, following the
publication of a Health Dept. booklet, "The Health Hazard at Wittenoom",
containing the results of air sampling and an appraisal of worldwide
medical information.
By 1979 the first writs for negligence related to Wittenoom were
issued against CSR and its subsidiary ABA, and the Asbestos Diseases
Society was formed to represent the Wittenoom victims.
In Leeds, England the Armley asbestos disaster involved several court cases against Turner & Newall
where local residents who contracted mesothelioma claimed compensation
because of the asbestos pollution from the company's factory. One
notable case was that of June Hancock, who contracted the disease in
1993 and died in 1997.[55]
Source : http://en.wikipedia.org/wiki/Mesothelioma
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