Friday, February 1, 2008

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Types of Mesothelioma



Mesothelioma is a cancer that primarily affects the cells around the lungs and ribs. The only known cause of this type of cancer is exposure to asbestos. There exist different types of mesothelioma that can be found in the human body. Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. The most common are

pleural mesothelioma peritoneal mesothelioma

Mesothelioma treatment will be based upon which type the subject has.

Pleural mesothelioma is a cancer of the cells that make up the pleura or lining around the outside of the lungs and inside of the ribs. Its only known cause in the U.S. is previous exposure to asbestos fibers, including chrysotile, amosite or crocidolite. This exposure is likely to have happened twenty or more years before the disease becomes evident, since it takes many years for the disease to "incubate." It is the most common type of mesothelioma, accounting for about 75% of all cases. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma.

Peritoneal mesothelioma is a tumor of this membrane. Its only known cause in the U.S. is previous exposure to asbestos, but it can be many years after exposure before the disease appears. Peritoneal mesotheliomas account for about one-fifth of all mesotheliomas. Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever.

While the great majority of mesotheliomas are in either the pleura or the peritoneum, malignant mesotheliomas sometimes occur in other parts of the body, including the testicles (a variety of peritoneal mesothelioma) and the heart (a variety of pleural mesothelioma.) These are also caused by exposure to asbestos fibers. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

Treatment of mesothelioma using conventional cancer therapies has unfortunately not proved successful and patients have a short median survival time of 6 - 12 months after presentation. Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies has also proved disappointing with a 5 year survival rate of less than 10%. Treatment regimens involving immunotherapy have yielded variable results but most of them have been disappointing, which has initiated great interest in the development of alternative forms of therapy, especially those capable of specifically destroying diseased cells without affecting surrounding healthy tissue.

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