The most identifiable cause of mesothelioma is exposure to asbestos, primarily through occupational contact. The majority of epidemiologic surveys have revealed a prior exposure to asbestos in approximately 70 to 80 percent of all cases of mesothelioma. Increased mesothelioma risk has been documented among workers in asbestos mines, insulation manufacture and installation, construction, shipbuilding, railroad machinery and automobile brake fabrication, with approximately five percent of asbestos workers developing mesothelioma. The fact that these occupations are dominated by men may account for the 4:1 male to female ratio of mesothelioma incidence. Secondary exposures may also contribute to disease pathogenesis or sensitize individuals to the adverse health effects of asbestos. For instance, family members exposed to dust brought home on the clothing of asbestos workers, and people living or working in buildings with asbestos insulation that is deteriorating or disturbed, have developed the disease. Mesothelioma in non-exposed individuals has been attributed to chest irradiation for treatment of Hodgkin’s disease, and to exposure to SV-40 virus via contaminated polio vaccines administered in the mid 20th century, although evidence for the former is more convincing than for the latter.
Mesothelioma is thought to have a genetic susceptibility component due to the low number of cases among asbestos workers with high levels of exposure, and due to the pattern of disease observed in populations of people who are all exposed to high levels of asbestos, such as those living in Capadocia, Turkey. What is needed is a comprehensive epidemiologic investigation of this disease integrating all elements of genetics, exposure, and tumor biology.
Co-authored by Hannah Eisen