Mesothelioma causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Fatima Shaukat, MD [2]Parminder Dhingra, M.D. [3]

Common causes of mesothelioma include asbestos-fibre exposure, erionite-fibre exposure, Simian virus 40, radiation exposure and genetic predesposition^[1][2]

Mesothelioma is caused by:^[1][2]

• Asbestos-fibre exposure: causes majority of cases
• Erionite-fibre exposure
• Simian virus 40 (SV40)
• Radiation exposure
• Genetic predisposition

• The strongest and most common cause for mesothelioma is occupational exposure to asbestos, which has been widely used in building materials and many industries.^[1]
• Asbestos is naturally occurring group of mineral consisting of very fine,long and thin fibers.
• Being so fine, they can be inhaled easily and may be lodged in the smallest airways of the lung and the mesothelium, eventually leading to pleural mesothelioma.
• Sometimes, instead of inhalation, the fibers are coughed up and swallowed. This way they can settle in the peritoneum to cause peritoneal mesothelioma.
• According to the International Agency for Research on Cancer (IARC) and the US National Toxicology Program, all forms of asbestos are known to cause cancer. Most people with mesothelioma have a history of asbestos exposure.
• Mesothelioma has a long latency period, which means it usually doesn’t develop for 15–40, or more, years after exposure to asbestos.
• There are 2 types of exposure to asbestos:
  • Direct exposure affects people who come into contact with asbestos directly. This may include:^{[1] [3]}
    • Asbestos mines/mills workers
    • Asbestos products/asbestos-based products producers
    • Construction workers, carpenters and painters
    • Shipyard workers
    • Cement manufacturers
    • Insulation workers
    • Electricians and heating tradespeople
    • Plumbers
    • Demolition workers
    • Automotive industry workers, including brake and clutch repair workers
  • Indirect exposure affects people who come in contact with asbestos in other ways. This may include:^[1]
    • Family members who are exposed to asbestos from fibres brought home on a worker’s clothing
    • People who live in or near an asbestos factory or mine

• The risk of developing mesothelioma is related to how much asbestos a person was exposed to and how long the exposure lasted.
• People exposed at an early age, for a long period of time and to greater amounts of asbestos are more likely to develop mesothelioma.
• Occasionally, mesothelioma develops in people who have never been exposed to asbestos.^[4]

• Erionite is another naturally occurring mineral, happens to be a known human carcinogen associated with development of pleural and peritoneal mesothelioma.
• The group of minerals, erionite belongs to is called zeolites.^[1]
• Zeolites are chemically related to asbestos and erionite has asbestos-like fibres.
• Erionite is common in the soil in parts of Turkey and materials made with erionite are used in construction in these regions.
• High rates of mesothelioma in these areas are due to exposure to this mineral.^[1]

• People who have been treated with radiation therapy to the chest or abdomen for lymphoma, breast cancer, lung cancer, or other cancers can cause mesothelioma.^[1]
• Although the risk of mesothelioma is higher in people who have been treated with radiation therapy, mesothelioma is likely to occur in only a very small number of these people.
• There have been reports linking mesothelioma to Thorotrast (thorium dioxide). Thorotrast is a contrast medium once used for imaging tests, but it is no longer used.^[1]

• Infection with SV40 may cause mesothelioma.
• Evidence suggested the contamination of polio vaccines with SV40 from 1955 to 1963, which may have contributed to some cases of mesothelioma.
• It is thought that SV40 may act as a co-factor with asbestos in causing mesothelioma.^[1]

• Based on the fact that malignant mesothelioma clustering was observed in few families, a study was conducted in 2012 on caucasian american population to determine the genetic association.

• It was found that people with a somatic germline mutation in their BAP1 gene is associated with higher risk of developing mesothelioma and uveal melanoma.^[2]

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