Chemoprevention of head and neck cancer with aspirin: a case-control study.

OBJECTIVE To evaluate the chemopreventive potential of aspirin against head and neck cancer. DESIGN Hospital-based case-control study. SETTING National Cancer Institute-designated comprehensive cancer center. Patients Individuals who received medical services at the Roswell Park Cancer Institute, Buffalo, NY, between 1982 and 1998 and who completed a comprehensive epidemiologic questionnaire. MAIN OUTCOME MEASURE Aspirin use among 529 patients with head and neck cancer and 529 hospital-based control subjects matched by age, sex, and smoking status. RESULTS Aspirin use was associated with a 25% reduction in the risk of head and neck cancer (adjusted odds ratio, 0.75; 95% confidence interval, 0.58-0.96). Consistent risk reductions were also noted in association with frequent and prolonged aspirin use. Further, a consistently decreasing trend in risk was noted with increasing duration of aspirin use (P(trend) = .005). Risk reduction was observed across all 5 primary tumor sites, with cancers of the oral cavity and oropharynx exhibiting greater risk reduction. When analyzed by smoking and alcohol exposure levels, participants moderately exposed to either showed a statistically significant 33% risk reduction (adjusted odds ratio, 0.67; 95% confidence interval, 0.50-0.91), whereas participants exposed to both heavy smoking and alcohol use did not benefit from the protective effect of aspirin. The reduction in risk was relatively more significant in women. CONCLUSIONS Aspirin use is associated with reduced risk of head and neck cancer. This effect is more pronounced in individuals with low to moderate exposure to cigarette smoke or alcohol consumption.