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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.
By.Ian Koch |
