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.