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.

Smoking and smokeless tobacco-associated human buccal cell mutations and their association with oral cancer--a review.

Reported herein are the results of a structured literature review that was undertaken to (a) determine if human buccal (mouth) cell changes are associated with smoking and smokeless ("chewing") tobacco, (b) tabulate different buccal cell alterations that have been reported, (c) delineate buccal cell assays that have been used successfully, (d) determine whether buccal cell changes correlate with oral cancer as defined in clinicopathologic investigations, and (e) assess the feasibility of developing a high-throughput buccal cell assay for screening smokers for the early detection of oral cancer. The results of the studies reported herein have established that diverse buccal cell changes are associated with smoking and smokeless tobacco. This review documents also that buccal cells have been collected in a noninvasive manner, and repetitively for serial studies, from different sites of the mouth (e.g., cheek, gum, and tongue) and from normal tissue, preneoplastic lesions (leukoplakia), and malignant tumors. Tobacco-associated genetic mutations and nongenetic changes have been reported; a partial listing includes (a) micronuclei, (b) bacterial adherence, (c) genetic mutations, (d) DNA polymorphisms, (d) carcinogen-DNA adducts, and (e) chromosomal abnormalities. Clinical studies have correlated buccal cell changes with malignant tumors, and some oral oncologists have reported that the buccal cell changes are practical biomarkers. Summarily, the literature has established that buccal cells are useful not only for characterizing the molecular mechanisms underlying tobacco-associated oral cancers but also as exfoliative cells that express diverse changes that offer promise as candidate biomarkers for the early detection of oral cancer.