Mesothelioma is a notorious and lethal form of cancer whose only known cause is asbestos exposure. During most of the twentieth century millions of workers were exposed to asbestos insulation, fireproofing, or one of thousands of industrial and commercial products that contained asbestos. The resilient fibers that make up asbestos are thrown off of asbestos products that are decaying or worn; they can be inadvertently inhaled by someone in the area who is completely unaware of the experience.
Inhaled asbestos fibers have inflicted hundreds of thousands of people with one of several diseases. Asbestosis is a condition caused by scarring of the inner lung tissue resulting in a loss of breathing capacity. Mesothelioma is a form of cancer that develops in the mesothelium, a membrane that exists in several parts of the body. The outer lining of the lungs (the pleura) is mesothelium tissue; it is also the most common place for mesothelioma to develop. For that reason people often mistake mesothelioma for lung cancer, but technically it is not. Pleural mesothelioma is cancer of the lining of the lungs, often spreading to the similar membrane that lines the chest wall. Finally, asbestos can be a cause of lung cancer. It has been linked in particular to small cell lung cancer, a fast moving form of the disease that is just as lethal as mesothelioma.
Mesothelioma and the Lungs
The sections of the mesothelium that involve the lungs are the visceral pleura, that portion of the membrane that wraps around the lungs to protect them. The parietal pleura is the membrane that lines the chest wall. The space between those two membranes under normal circumstances has a thin film of fluid that lubricates the two surfaces so that the lungs don’t encounter a harsh, dry surface when a person inhales.
Pleural mesothelioma is caused by asbestos fibers that work their way through the wall of the lung, from the interior to the outer lining where they are embedded. Eventually they cause the development of abnormal cells which leads to malignant cells and malignant tissue. The disease exhibits many of the same symptoms as lung cancer: a persistent dry cough, chest pain, chest pressure, shortness of breath, and weakness. In many ways it mimics lung cancer during the symptomatic stage.
What is Asbestos Lung Cancer?
Asbestos can cause malignancy on the inner surface of the lungs as well as in the outer lining. Smokers who have been exposed to asbestos are particularly susceptible to asbestos lung cancer; in many of the cases it is small cell lung cancer. However lung cancer exhibits different types of malignant tissue than does mesothelioma. Asbestos lung cancer causes the growth of one or more large tumors, whereas mesothelioma is a diffuse form of cancer made up of many small malignant nodules scattered across an expanse of tissue.
About 15% of all lung cancer cases are small cell lung cancer (SCLC). This form of the disease is as lethal as mesothelioma. It is known for its aggressive, fast moving behavior; most cases of the disease aren’t diagnosed until it reaches an advanced stage. SCLC metastasizes early in development and often doesn’t cause the standard lung cancer symptoms until it is spread throughout the body.
Two forms of Asbestos Cancer
Mesothelioma rises in the outer lining of the lungs, or in a similar membrane in the abdomen or around the heart. It is caused by asbestos fibers that are embedded in that tissue; mesothelioma in the chest cavity is generally a diffuse form of malignancy. Asbestos-caused small cell lung cancer or non-small cell lung cancer cause the larger tumors usually associated with cancer. Asbestos lung cancer is also much more likely to occur in people who not only inhaled asbestos fibers, but have a history of smoking.