Product Liability Resource Center
Asbestos - Diseases
Asbestosis | Lung Cancer | Mesothelioma
Mesothelioma
Malignant mesothelioma is an uncommon, but no longer rare, cancer that is difficult to diagnose and responds poorly to therapy. Malignant mesothelioma is the most serious of all asbestos-related diseases.
A layer of specialized cells forms tissue called mesothelium. The mesothelium helps protect the organs by producing a special lubricating fluid that allows organs to move around. For example, this fluid makes it easier for the lungs to move inside the chest during breathing, and reduces friction to ease breathing.
Mesothelium lines the chest cavity (pleura), abdominal cavity (peritoneum), and the cavity around the heart (pericardium), as well as the outer surface of most internal organs. These correspond to pleural mesothelioma (cancer of the lung lining), peritoneal mesothelioma (cancer of the abdomen/stomach)and pericardialmesothelioma.
Tumors of the mesothelium can be benign (noncancerous) or malignant (cancerous). A malignant tumor of the mesothelium is called a malignant mesothelioma. Because most mesothelial tumors are cancerous, malignant mesothelioma is often simply called "mesothelioma."
The incidence of mesothelioma in the United States remains very low, with 14 cases occurring per million people per year. However, mesothelioma cases in menincreased by three timesbetween 1970 and 1984. This increase has been directly associated with environmental and occupational exposure to asbestos, mostly in areas of asbestos product plants and shipbuilding facilities.
Although the disease is much more commonly seen in 60-year-old men, it has been observed in women and young children as well. The cause of the disease is not so well understood in these latter two groups, but there is some evidence of possible asbestos exposure in some of these cases.
Malignant mesothelioma is divided into three main types. About 50% to 70% of mesothelioma occurrences are the epithelioid type. This type has the best prognosis (outlook for survival). The other two types are the sarcomatoid type (7%-20%), and the mixed/biphasic type (20%-35%). Treatment options for all three types are the same.
In almost all cases, mesothelioma is caused by exposure to asbestos. Exposure to asbestos in a work environment accounts for approximately 75 to 80% of all cases in the United States. Although there is a higher frequency of occurrence in men than in women and the risk accelerates with age, mesothelioma can strike anyone at any age.
