Causes Of Mesothelioma

Causes of Mesothelioma

Mesothelioma is a highly aggressive cancer that is difficult both to diagnose and to treat. Between two and three thousand cases of malignant mesothelioma are diagnosed each year in America, and the incidence of mesothelioma cancers is projected to increase during the next decade.

Causes

An overwhelming body of scientific and medical evidence points to the fact that malignant mesothelioma is caused by asbestos exposure. Currently, there is no other known cause for the disease.
Asbestos is a naturally-occurring fibrous substance that was very widely used in the construction and shipbuilding industries during the first three-quarters of the twentieth century. Asbestos was touted for its durability, fire resistance, and excellent insulating properties, and was used in several thousand different manufactured products, including construction materials, household appliances, and brake linings.

How does Asbestos cause Mesothelioma

Internal organs and body cavities are covered by a thin tissue membrane called mesothelium. This lining covers the lungs (where it is called the pleura), the heart (where it is known as the pericardium), and body cavities such as the abdominal cavity (where it is called the peritoneum). The mesothelium provides both support and protection for organs and body cavities, as well as providing a source of lubrication that helps support organ function and health.
Mesothelioma develops in the linings of organs and body cavities, typically in the pleura, pericardium, or peritoneum. In very rare cases, mesothelioma may develop in the lining of the testicles, known as the tunica vaginalis.
The exact method by which asbestos causes mesothelioma is still being researched, but medical professionals offer four different theories:

• Asbestos causes irritation and inflammation of mesothelial cells, eventually leading to irreversible scarring, cellular damage, and eventually cancer.
• Asbestos fibers enter cells and disrupt the function of cellular structures that are essential for normal cell division, causing cellular changes that lead to cancer.
• Asbestos causes the production of oxygen 'free radicals'. These molecules damage cellular DNA, and cause cells to mutate and become cancerous.
• The presence of asbestos causes cells to produce oncoproteins. These molecules cause mesothelial cells to ignore normal cellular division restraints, leading to cancer.
  

The element that ties each theory together states that asbestos causes cellular damage that causes cells to lose control over their own cycles of normal division and begin dividing uncontrollably. Healthy cells follow cycles of cell division that ensure tissues and organs do not grow beyond normal size - in cancer cells, these restraints are lost.
In cases of mesothelioma, the result is that membranes in the affected location begin to thicken, and fluid builds up in the spaces between membrane layers. As cancer cells continue to divide and pile on top of one another, tumors begin to form. The end result of uncontrolled division of cancer cells is that the function of the body's organs and systems are impaired, due to factors such as internal pressure caused by the growth of tumors, and the reduction of availability of essential nutrients for organs.

Other Causes of Mesothelioma

The answer to this question is a simple "no". Doctors and research scientists have not been able to determine any other causes of mesothelioma other than asbestos exposure. They do know, however, that smoking can aggravate a less serious asbestos-related disease, such as asbestosis, and prompt the formation of tumors and the onset of mesothelioma. Those who have been exposed to asbestos on a regular basis are advised not to smoke.