A POPULATION-BASED CASE-CONTROL STUDY OF THE RELATIONSHIP BETWEEN CIGARETTE-SMOKING AND NASOPHARYNGEAL CANCER (UNITED-STATES)

This case-control investigation, based on the Selected Cancers Study, assesses the association between cigarette smoking and nasopharyngeal cancer, a relatively rare neoplasm in the United States. Men who were diagnosed pathologically with nasopharyngeal cancer during 1984-88 wer e included as cases in the analysis if they were 15 to 39 years old in 1968, and lived in the areas covered by eight cancer registries in th e US (n = 113). Control men were selected by random-digit telephone di aling (n = 1,910). Using logistic regression analysis with adjustment for potential confounding factors, it was found that relative to nonsm okers, the risks of nasopharyngeal cancer were 2.3 (95 percent confide nce interval [CI] = 1.3-4.0) and 1.4 (CI = 0.8-2.6) for former and cur rent smokers, respectively. Using pack-years as a measure, adjusted od ds ratio (OR) estimates were 1.3, 1.8, 2.5, and 3.9 for smoking for le ss than 15, 15-29, 30-44, and 45 or more pack-years, respectively. Whe n squamous cell carcinoma was used as an outcome, the smoking/nasophar yngeal-cancer association became stronger. The analysis did not show i nteractions between smoking and alcohol consumption, or prior nasal di seases. The results of this study suggest that cigarette smoking may b e related to the occurrence of nasopharyngeal cancer (especially squam ous cell carcinoma) among US men.