Causes Of Pleural Mesothelioma

Mesothelioma had very little medicinal acknowledgment until the 1900s. It was during this century that medical researchers discovered the main cause of the disease: exposure to asbestos. As industries all over the world expanded their use of asbestos, the rates of mesothelioma climbed drastically higher. Studies were published, proving the inhalation or swallowing of microscopic asbestos fibers could start chain reactions leading to different cancers. Though asbestos is overwhelmingly the primary cause of pleural mesothelioma, there are some rare cases where the disease is unrelated to it. This is a breakdown of the leading causes of the disease, from asbestos exposure to rarer ones.

Asbestos

Every kind of asbestos causes pleural mesothelioma, regardless of the length of the fibers. Anyone exposed to it has an increased risk factor for developing mesothelioma. You might have been exposed in an asbestos mine or a processing plant that worked with the material. High-risk occupations like heavy machinery industries or construction work have increased exposure. If you lived in or served on any buildings constructed using asbestos, or if you lived near a contaminated site, you're at risk. Another potential exposure is when asbestos products are disturbed in a home renovation, and proper safety measures have not been taken.

After asbestos is inhaled, it's common for the body to have trouble disposing of the fibers, and even microscopic fibers can build up in a person's abdomen or lungs. They stay there for many years without causing trouble, but over time, they can cause cancer, which begins in the mesothelial cells protecting the heart, abdomen, and lungs.

Minerals Resembling Asbestos

In a great deal of non-asbestos cases, the cause is minerals resembling asbestos. These minerals are structurally comprised in a similar format, leading to the name 'asbestiform minerals.' Two examples of these minerals are winchite and richterite.

Asbestiform minerals aren't the only other minerals associated with pleural mesothelioma. There's an iron formation called taconite, as well as a zeolite mineral, referred to as erionite. When erionite is the cause, the victim usually had a genetic predisposition to developing the disease. In cases where other materials are the cause, the general progression of the disease remains the same. The particles build up in the lungs and other parts of the body over time, because the body has difficulty getting rid of them. This contamination can lead to the mesothelial cells becoming cancerous.

Chemicals

There is some research that points toward chemicals as a leading cause of mesothelioma, but the research remains inconclusive. In particular, thorotrast is a suspected cause. Thorotrast is a suspension compound that contains radioactive particles of thorium dioxide. In the 1930s and 1940s, this material was used in medical radiography as a type of radiocontrast agent.

The main problem with thorium is the body retains it rather than flushing it out, and as the components are radioactive, it harms the body with emitted rays as it decays. Today, it's known to aid in the development of some cancers, including mesothelioma. Thankfully, thorotrast is no longer widely used in the medical field. However, elderly patients who used thorotrast in the past might be at an increased risk of cancer development because of the rays emitted. Mesothelioma is more likely to develop in those with a genetic predisposition.

Radiation

There are rare cases where mesothelioma develops due to irradiation of a person's chest or abdomen, causing cancer to form in the mesothelial cells, which progresses to the same pleural mesothelioma others suffer from. The research into the exact effects of damaging rays on mesothelioma development is minimal and inconclusive.

For the most part, it seems the risk is not that radiation will cause mesothelioma specifically, but that radiation will cause any form of cancer. Because the abdomen and chest were irradiated, lung cancer would be equally likely. It's rare for mesothelioma to form in response to damaging rays alone. When it does, the person often has a genetic predisposition to the disease.

Additional Theories

As mentioned, some people do have a genetic predisposition to developing the disease. People who have a germline mutation found in their BAP1 gene have a higher development risk for both mesothelioma and melanoma. Most of the time, mesothelioma is caused by exposure to some external factor. However, some scientists have reported spontaneous cases in children with a genetic predisposition, seemingly unprompted by any known external forces.

There are also studies indicating simian virus 40, also called SV40, might be a co-factor in mesothelioma development, as it combines with other factors to increase the malignancy. Such a connection has been definitively proven through animal studies. However, the human studies done thus far are inconclusive. More research is necessary to explain when and why SV40 affects mesothelioma.