Family cancer history and susceptibility to oral carcinoma in Puerto Rico.

BACKGROUND: Use of alcohol and tobacco are the major risk factors for cancers of the oral cavity and pharynx in most of the world. A heritable component to oral carcinoma risk also has been suggested, although only limited data are available on familial aggregation of this disease. METHODS: A population-based case-control study of 342 subjects with carcinomas of the oral cavity and pharynx (oral carcinoma) and 521 controls was conducted in Puerto Rico. The relation between family history of carcinomas of the oral cavity, the upper aerodigestive tract (UADT), and other selected sites with risk of oral carcinoma was explored using logistic regression modeling 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; 95% confidence interval [CI], 0.8-8.0) or any UADT carcinoma (OR, 2.6; 95% CI, 1.4-4.8). The increased risk associated with family history of UADT carcinoma tended to be greatest for subjects with known risk factors (i.e., heavy consumption of alcohol and/or tobacco and infrequent intake of raw fruits and vegetables) and with oral carcinoma diagnoses at ages younger than 65 years. CONCLUSIONS: These findings are consistent with a heritable component to oral carcinoma, although shared lifestyle risk factors may be partially involved.

Mouthwash in the etiology of oral cancer in Puerto Rico.

OBJECTIVES: To determine if the risk of cancers of the mouth and pharynx is associated with mouthwash use in Puerto Rico, an area of relatively high risk. METHODS: Interviews were conducted with 342 cases of oral and pharyngeal cancer registered in Puerto Rico and diagnosed between 1992 and 1995 and with 521 population-based controls regarding mouthwash use and other factors. Mouthwash-related risks were estimated using unconditional logistic regression controlling for potential confounders. RESULTS: The adjusted odds ratio associated with using mouthwash with an alcohol content of 25% or greater was 1.0. Risks were not higher with greater frequency, years of use, or lifetime mouthwash exposure. Among tobacco and alcohol abstainers the odds ratio associated with mouthwash use was 2.8 (CI = 0.8-9.9), in contrast to 0.8 (CI = 0.4-1.7) and 0.9 (CI = 0.6-1.3) among those with light and heavy cigarette smoking/alcohol drinking behaviors, respectively. CONCLUSIONS: There was no overall increased risk of oral cancer associated with mouthwash use. An elevated, but not statistically significant, risk was observed among the small number of subjects who neither smoked cigarettes nor drank alcohol, among whom an effect of alcohol-containing mouthwash would be most likely evident. Our findings indicate the need to clarify the mechanisms of oral carcinogenesis, including the possible role of alcohol-containing mouthwash.