Causes of Mesothelioma
Between 70% to 80% of all cases of mesothelioma involve patients who have a history of exposure to asbestos at work. Mesothelioma is a cancer caused by inhaling or ingesting asbestos particles, and usually presents as a pleural mesothelioma, or a mass located in the membranes that line the lungs. About 20% of mesothelioma patients have peritoneal mesothelioma, which is located in the lining of the abdomen that encases several abdominal organs.
The mesothelia are membranes that encase the lungs, the heart, or most organs in the abdomen. They consist of two layers, the parietal layer that lines the chest cavity, or the abdominal cavity, and the visceral layer that lines the individual organs. The mesothelia produce a serous fluid between their layers that provide a layer of lubrication on which they glide, allowing the organs within to move freely.
Mesothelioma is a tumor, or mass, that grows in response to many years of irritation and inflammation caused by asbestos fibers that lodge in a mesothilial layer of either the lung or peritoneum. It begins in just one layer of the mesothilia, and usually in the pleura, on one side of the chest. This slow-growing cancer can take up to 50 years to manifest as mesothelioma and produce enough symptoms that the affected person seeks medical help.
Smoking and Mesothelioma
While smoking does not appear to increase the risk of getting mesothelioma, nor does it cause mesothelioma, it significantly increases the risk of getting lung cancer. Lung cancer is a cancer located within the lung tissue, specifically in the lung’s airways. Asbestos has not been shown to cause cancer within the lung tissue. Its sharp, rigid strands move through the soft lung tissue to the pleura, where they become trapped. Asbestos particles that lodge in the lung tissue can cause another serious disease, asbestosis. Asbestosis causes fibrotic changes to the lung that stiffens the lung tissue. The presence of fibrotic lung disease further restricts breathing capacity.
While smoking does not cause mesothelioma, when combined with asbestos exposure it significantly increases the risk of getting lung cancer. The increased risk is not just additive, but synergistic. These terms mean that the risk of getting lung cancer from this combination is more than the sum of the individual risks added together.
Evidence shows that if you have been exposed to asbestos, especially in the work place, you can significantly reduce your risk of getting lung cancer if you quit smoking.
Treatment of mesothelioma varies by stage ranging from surgery, radiation and clinical trial in Stage I, to draining the excess fluid from the chest or abdomen, palliative surgery, radiation therapy, chemotherapy, or a clinical trial of a combination of these treatments.