Family cancer history and susceptibility to oral carcinoma in Puerto Rico

Background. Use of alcohol and tobacco are the major risk factors for cance rs of the oral cavity and pharynx in most of the world. A heritable compone nt to oral carcinoma risk also has been suggested, although only limited da ta are available on familial aggregation of this disease. Methods. A population-based case-control study of 342 subjects with carcino mas of the oral cavity and pharynx (oral carcinoma) and 521 controls was co nducted in Puerto Rico. The relation between family history of carcinomas o f the oral cavity, the upper aerodigestive tract (UADT), and other selected sites with risk of oral carcinoma was explored using logistic regression m odeling techniques. Results. Risk of oral carcinoma was elevated for subjects reporting a first -degree relative with carcinoma of the oral cavity (odds ratio [OR], 2.5; 9 5%. confidence interval [CI], 0.8-8.0) or any UADT carcinoma (OR, 2.6; 95% Cl, 1.4-4.8). The increased risk associated with family history of UADT car cinoma tended to be greatest for subjects with known risk factors (i.e., he avy consumption of alcohol and/or tobacco and infrequent intake of raw frui ts and vegetables) and with oral carcinoma diagnoses at ages younger than 6 5 years. Conclusions. These findings are consistent with a heritable component to or al carcinoma, although shared lifestyle risk factors may be partially invol ved. Cancer 2001;92:2102-8. (C) 2001 America Cancer Society.