Mesothelioma caused by asbestos exposure may prove to be a public health crisis as more people are diagnosed with this rare form of cancer.
Mesothelioma, also called malignant mesothelioma, is a rare but deadly form of cancer that typically occurs in the membrane around the lungs, called the pleura. This type of cancer is usually the result of inhaling asbestos fibers over a long period of time. Most people with mesothelioma, were exposed to asbestos at work, such as in a shipyard, an asbestos mine, an automotive plant, or at a construction site.
Mesothelioma: What Is It?
The mesothelium is the generic term used to describe the lining that covers many organs and body cavities. Mesothelial tissue helps to protect organs and minimize trauma during movement. In addition to the pleura, other mesothelia include:
- The peritoneum, which covers the walls of the abdominal cavity
- The pericardium, which encases the heart
- The tunica vaginalis testis, which covers the male internal reproductive organs
- The tunica serosa uteri, which covers the female internal reproductive organs
Mesothelioma can affect any of these mesothelial tissues, though the pleura is by far the most common site.
Mesothelioma: The Asbestos Risk Factor
When asbestos fibers are inhaled into the lungs, they tend to remain there, and with continuous long-term exposure, the fibers begin to collect at the bottom of the lungs, where they become trapped in the pleura. Over time, this can lead to cancer, especially if there are other aggravating factors like a genetic predisposition or a history of smoking.
“Asbestos irritates the lining of the lung and causes inflammation, and then the inflammatory response and the secondary changes in the lungs and pleural space may eventually lead to a malignant degeneration,” explains Timothy Winton, MD, associate professor of surgery and division director of thoracic surgery at the University of Alberta Hospital in Edmonton, Canada.
One of the most striking things about mesothelioma is how long it takes for the disease to develop: Up to five decades may elapse from initial asbestosexposure to the development of cancer. But when mesothelioma finally develops, it often becomes very aggressive and can spread beyond the pleura to other mesothelial tissues. The average survival time for malignant mesothelioma ranges between four and 18 months, and about 10 percent of patient live at least five years after being diagnosed. In rare cases of slow-growing mesothelioma, survival can extend to 20 years.
Mesothelioma: A Public Health Issue
Mesothelioma is a rare disease — only 2,000 to 3,000 new cases are diagnosed each year in the United States. However, in other countries, the incidence of mesothelioma continues to increase.
“Because of the history of the use of asbestos and the known long latency between exposure and development of disease, the incidence of this type of disease around the world is going to continue to go up through the next two to three decades,” Dr. Winton says. “There are a lot of workers around the world who were exposed in an industrial setting and who need to be carefully followed.”
If you think you have been exposed to asbestos, let your doctor know and make sure you get regular checkups. As with most cancers, early diagnosis is important to treating this disease.