2. How long after asbestos exposure does it take for mesothelioma to develop?
1. What is mesothelioma?
A cancer of the mesothelium, the thin membrane that lines the chest and abdominal cavity, and covers the organs within each of these cavities. It is a relatively rare cancer, accounting for only 1% of all cancer diagnoses, and almost all cases of mesothelioma are linked to asbestos exposure. Inhaled asbestos fibers work their way into the chest cavity or the abdominal cavity, and lodge in the mesothelium. The disease progresses slowly; symptoms may not appear for 15 years, sometimes for as long as 40 years after the exposure.
The membrane thickens into a hard, inflexible rind, forming bumps and nodules. The enlarging cancerous tissue produces large amounts of fluid that crowds the pleural or abdominal cavity, and the cancer itself compresses nearby organs. Pleural mesothelioma may invade the heart, the lungs, and the diaphragm. Peritoneal mesothelioma leaks fluid into the abdominal cavity, and the cancer may invade the esophagus, the liver or the stomach and small intestines. It may also encroach on large blood vessels, making surgical removal impossible.
By the time symptoms are troublesome enough for a victim to seek medical attention, the disease may have progressed so far that the life expectancy will be measured in months.
2. How long after exposure does it take for mesothelioma to develop?
Mesothelioma grows slowly, and silently. For 10 years, sometimes for as long as 40 years, the tumor grows within the body, causing no symptoms. Only when it has grown large enough to press on vital organs, and to leak fluid into the chest or abdominal cavity does the victim begin to experience symptoms such as severe chest pain, shortness of breath, and constant fatigue.
3. How is mesothelioma diagnosed?
Diagnosing mesothelioma involves several challenging tasks. The first task is diagnostic inclusion. Mesothelioma's principal symptoms of chest pain shortness of breath and fatigue can be caused by a large number of illnesses. Because mesothelioma is not a common illness it is not usually a primary suspect. This is a problem because by the time mesothelioma causes symptoms it is well advanced and the time remaining in which the disease can be treated is already limited. It is important to alert a diagnosing physician to any previous asbestos exposure so that the physician is sure to include mesothelioma as a possible diagnosis.
If mesothelioma is suspected, a person should be referred to an oncologist (a cancer specialist) who specializes in the diagnosis and treatment of mesothelioma. That doctor may use non-invasive imaging techniques, such as CT scans or PET scans to get a better look at the affected area. The definitive diagnosis requires a surgical biopsy, the removal of a piece of tissue, and microscopic examination by a pulmonary pathologist. See the section Treating mesothelioma for a fuller discussion of diagnostic techniques and terms.
4. Where in the body does mesothelioma develop?
The most common form of mesothelioma is pleural mesothelioma, which starts in the chest cavity, and affects the lungs. About 80% of mesotheliomas are pleural. In pleural mesothelioma usually only one lung is involved. Among victims of pleural mesothelioma there are five times as many men as women, a fact which reflects the historical distribution of men and women in jobs with high exposure to asbestos.
The other 20% are peritoneal mesotheliomas, in which the tumor starts in the abdominal cavity, growing in the mesothelium that covers the abdominal organs. Men and women are equally represented among victims of as peritoneal mesothelioma.