Tobacco and alcohol use and oral cancer in Puerto Rico

Objectives: To determine risk for oral cancer in Puerto Rico associated with use of alcohol and tobacco. Methods: In Puerto Rico, alcohol and tobacco use were compared among nonsalivary gland cancers of the mouth and pharynx (n = 342), cancers of major and minor salivary glands (n = 25) and 521 population-based controls. Results: Alcohol (usual use, P-trend < 0.0001 for men and P-trend = 0.02 for women) and tobacco (usual use, Ptrend < 0.0001, for both men and women) were strong independent risk factors for oral cancer in Puerto Rico, with a multiplicative effect from combined exposures. Risks did not vary systematically by use of filter vs. nonfilter cigarettes. Risks with use of other forms of smoked tobacco were about sevenfold among both men and women. Risks decreased only gradually after cessation of tobacco and alcohol use. Tobacco use, but not alcohol, was linked to cancers of the salivary glands. The burden of oral cancer due to alcohol and tobacco use in Puerto Rico (76% for men, 52% for women) agreed closely with earlier estimates for the mainland US population, while about 72% of salivary gland cancer (men and women, combined) was due to tobacco use. Conclusions: Excess risks for oral cancer in Puerto Rico are largely explained by patterns of alcohol and tobacco use. Smoking filter vs. nonfilter cigarettes does not alter risk, while cessation of alcohol and tobacco use appears to reduce risk only gradually.