Malignant mesothelioma is cancer that starts in the cells that line most organs of the body, especially the chest, belly, and heart. The lining formed by these cells is called mesothelium. The mesothelium forms a protective sac that surrounds internal organs of the body. It consists of two layers: one layer of cells surrounding the organ and another forming a sac around it. These cells secrete a fluid that allows organs to move effortlessly and harmlessly within the space defined by the mesothelium.
Thus, moving organs like the heart and the lungs can function normally only with a functioning mesothelium. Mesothelioma is a disease in which the cells of the mesothelium become abnormal and multiply uncontrollably, invading the surrounding tissues affecting the very organs they are supposed to protect. In most cases of mesothelioma, the lungs are the organs that are affected. The mesothelium of the lungs is known as the pleura. Pleural mesothelioma is the most commonly diagnosed form of the disease.
Risk factors and risk groups
Mesothelioma is associated with asbestos. Around 70-80% of all cases of mesothelioma have a history of exposure to asbestos. Asbestos is a group of minerals that has been widely used in industrial products such as cement, brake linings, flooring’s, textiles and insulation. The first cases of mesothelioma occurred in the 1900s in Britain where workers at asbestos factories began experiencing a high level of lung disease. The disease was then referred to as asbestosis. It was only much later, in 1959, that the link between asbestos and lung cancer was made.
Mesothelioma can also arise as a result of secondary exposure to asbestos. A chance of developing cancer in families and other persons in contact with asbestos workers is great due to exposure to dust from the clothing and hair of the worker. People living in old buildings (prior to banning of asbestos in construction materials) are also at risk. The occupations that are most associated with mesothelioma include: construction industry workers, electricians, plumbers, shipyard workers, textile workers etc.
Incidence of mesothelioma
Most countries now specify the level of asbestos that can be safely present in the working environment of a person. Since the risk of asbestos-related disease increases due to heavy and longer exposure to asbestos, proper working environment led to a reduction in the cases of mesothelioma. Mesothelioma is now a relatively rare disease; only 2000 cases arise every year in the United States.
Living with the disease
Like many other cancers, there is very little one can do where the diagnosis has not been made in the early stages of the disease. Unfortunately, most cases of mesothelioma are diagnosed in its late stages. There is no cure for the disease. In some cases, tumors may be removed by surgery, in the hope that it has not already spread to other parts of the body. Surgery may aim to remove the tumor or the entire lung. Treatments by radiation and chemotherapy are mostly palliative (i.e. aiming to reduce the severity of symptoms rather than treating the disease).