Mesothelioma, asbestos, and reported history of cancer in first-degree relatives

BACKGROUND. Although malignant mesothelioma is known to be strongly related to asbestos exposure, its relationship to familial factors is unclear. METHODS. We compared reported histories of cancer in first-degree relatives, obtained from telephone interviews with the next-of-kin of 196 patients who had a pathologic diagnosis of mesothelioma, and with those from 511 deceased controls. RESULTS. Among men exposed to asbestos, we found a statistically significant twofold elevation in the risk of mesothelioma for patients reporting cancer in two or more first-degree relatives. We found no significant elevation in women or among the small number of men without asbestos exposure. The next-of-kin of three patients (but no controls) reported a possible mesothelioma in a first-degree relative; asbestos exposure could not be ruled out in those relatives. Associations of asbestos with pleural mesothelioma were stronger among men with a reported family history of cancer than men without, although no statistical evidence of an interaction was detected. CONCLUSIONS. These results provide suggestive, but limited, evidence that a family history of cancer may be a risk factor for mesothelioma, or may indicate an increased susceptibility to mesothelioma given asbestos exposure. (C) 1996 American Cancer Society.