Familial respiratory tract cancer. Opportunities for research and prevention.

Case studies of two families with lung and other respiratory tract cancers were investigated. Consenting family members underwent comprehensive evaluation, including physical examination, routine laboratory studies, pulmonary function testing, sputum cytology analysis, and lymphocyte karyotyping. In both families, the environmental influence of smoking and, to a lesser extent, occupational exposures were evident risks. Both families had members with multiple primary malignant neoplasms and probably radiogenic cancers, suggestive of inherent predisposition to environmentally induced neoplasia. Furthermore, one family had a newly recognized syndrome of limb and dental anomalies, and, independently, two members were carriers of a balanced translocation between chromosomes 13 and 14. Efforts were made to prevent further respiratory cancer deaths, to search for laboratory markers of risk, and to store blood and tissue specimens for assays in development.