Malignant pleural mesothelioma is a rare type of cancer in which malignant (cancerous) cells are found in the pleura (the thin layer of tissue lining the chest cavity and covering the lungs) or the peritoneum (the thin layer of tissue lining the abdomen and covering most of the internal organs).
Mesothelioma is a rare cancer, with about 2,000 to 3,000 new cases per year. (In comparison, there are more than 200,000 new cases of lung cancer per year.) Asbestos exposure in the United States peaked in the years from 1940 to 1980. Many disease cases have developed over the past 50 years due to exposure years ago.
Asbestos still exists in older homes and buildings, and fibers can be released if material is loose, crumbling, or disturbed. Asbestos is still used in brake pads, clutches, roofing material, vinyl tile, and some cement pipe. Also, rocks in certain parts of the United States have asbestos that can be released when disturbed or as they weather.
Many people with mesothelioma have either inhaled or swallowed asbestos fibers. While nearly everyone has come into contact with asbestos, those who become sick from it have usually had frequent exposure to high levels over a long period of time. This happens in occupations like shipbuilding, pipefitting, construction, and auto repair (asbestos is used in brakes).
It is also possible to breathe in or swallow asbestos fibers at home if such material comes apart during use, demolition work, construction, or home maintenance, repair, or remodeling. Simply living with someone who has worked with asbestos and brought home fibers on their clothing, shoes, or body can also be a source of exposure.
Asbestos is a natural mineral whose fibers cannot be seen by the naked eye. Fibers come in two forms: serpentine fibers are spiral-shaped, while amphibole fibers look like a needle. It is believed that mesothelioma is caused by amphibole fibers burrowing into tissue, causing long-lasting irritation that leads to the development of cancerous cells. It may take 20 to 30 years after exposure to asbestos before mesothelioma develops.
Besides asbestos, other, less common causes of mesothelioma include exposure to high levels of radiation or an infection from a virus found in monkeys.
People who have mesothelioma may not have symptoms right away. When symptoms do appear, it is often in the disease’s later stages. Symptoms include:
No laboratory test can specifically diagnose mesothelioma, but there are a number of ways to tell if someone has the condition, including the following:
Following treatment, tests that were first used to diagnose or learn the stage of cancer may be repeated. These retests will help determine how well treatments have worked, whether the condition has changed, whether different treatments should be tried, and whether the cancer has come back.
Here are some ways to prevent exposure to asbestos:
There is no known cure for mesothelioma; only about 15% of such patients are able to survive five years or longer.
Surgery appears to improve survival rates, but only in that small number of patients who get treatment at an early stage, and who are otherwise healthy enough to undergo such procedures.
Most patients are not diagnosed at an early stage because symptoms may not appear until later. Also, because of the nature of mesothelioma, it tends to involve most of the lining of the lung when it is found. Chemotherapy is often the main treatment and has been shown to prolong survival and improve quality of life for patients with mesothelioma.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 01/29/2016