Mesothelioma is an aggressive cancer affecting the membrane lining of the lungs and abdomen.
Malignant mesothelioma is the most serious of all asbestos-related diseases. Exposure to asbestos is the primary cause and risk factor for mesothelioma.Making a correct mesothelioma diagnosis is particularly difficult for doctors because the disease often presents with symptoms that mimic other common ailments. There is currently no known cure for mesothelioma, but treatments such as surgery and chemotherapy can help to improve the typical mesothelioma prognosis and even increase one's life expectancy.
Three major types of mesothelioma exist and they are differentiated by the organs primarily affected. Pleural mesothelioma (affecting the lung’s protective lining in the chest cavity) represents about three-quarters of all mesothelioma incidence. Peritoneal mesothelioma, which affects the abdominal cavity, and pericardial mesothelioma, which affects the cardiac cavity, comprise the remainder.
The cavities within the body encompassing the chest, abdomen, and heart are surrounded by a membrane of cells known as the mesothelium. Mesothelial cells assist in general organ functions. The mesothelium is particularly important to organs that are commonly in motion, such as expansion or contraction of the lungs, stomach, or heart. Lubrication from the mesothelial cells allows free range of motion within the body. The mesothelium of the chest, abdomen, and cardiac cavity are called the pleura, the peritoneum, and the pericardium, respectively. Each of these groupings of mesothelial cells is extremely critical to the functions of the body structures which they encompass.
Malignancies (cancerous tumors) occurring within the mesothelial membranes are known as malignant mesothelioma, or simply mesothelioma. Benign tumors of the mesothelium are known to occur, but are much more rare than malignant mesothelial tumors.
While tumors of the mesothelium were first recognized in the late 18th century, it was not until the middle of the 20th century that this particular cancer was studied and examined with more detail. It was at this time when suspicions of the cancer’s causal relationship with asbestos exposure became more substantiated. A joint research venture through the Department of Thoracic Surgery at the University of the Witswater and Johannesburg General Hospital in South Africa provided the most compelling evidence of the nexus between asbestos exposure and the development of pleural mesothelioma.
Incidence of mesothelioma is still quite rare, with only 2,500-3,000 diagnoses in the United States each year. There was a spike in reported diagnoses between 1970 and 1984, which has been attributed to the latency period between diagnosis and the height of industrial exposures, which occurred roughly 40-60 years prior to this time. While exposure was common across the United States in nearly all industries, it was particularly prevalent in the WWII-era military industrial cycle, including navy shipyards.
Although this cancer is much more common in men over the age of 60, mesothelioma in women and children has been documented as well. Mesothelioma causes for diagnosis in women and children are mainly attributed to secondary exposure to asbestos, as it was not uncommon for men to bring asbestos back into the home on their bodies or clothing.