What Is The Difference Between Pleural Mesothelioma And Peritoneal Mesothelioma?

Malignant mesothelioma is a disease in which a cancerous tumor grows on the mesothelium - the sac lining the internal body cavities. The specific type of mesothelioma is named for the tissue where the cancer started. Pleural mesothelioma starts in the chest, in the pleura that surrounds the lungs (outer lining of the lungs and internal chest wall). It makes up about 70% of mesothelioma cases. Peritoneal mesothelioma starts in the lining of the abdominal cavity.

Although sometimes referred to as "asbestos lung cancer", mesothelioma is not the same as lung cancer. Lung cancers occur inside the lung itself; mesothelioma occurs in the lining of the lung. Mesothelioma is rare, striking fewer than 3000 Americans per year.

The incidence rate varies from one country to another, from a low rate of less than 1 per 1,000,000 in Tunisia and Morocco, to the highest rate in Britain, Australia and Belgium: 30 per 1,000,000 per year For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades. It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.

Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States. Between 1973 and 1984, the incidence of pleural mesothelioma among Caucasian males increased 300%. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.