Objectives: Nasopharyngeal carcinoma (NPC) is rare in most countries but occurs with relatively high frequency among southern Chinese populations throughout the world. A case-control study of NPC was conducted in Taiwan to investigate the importance of active and passive cigarette exposure and alcohol consumption as risk factors for this disease.
Methods: 375 histologically confirmed incident NPC cases (99% response rate) were prospectively identified from two hospitals in Taipei between July 1991 and December 1994 and administered a detailed questionnaire. 327 healthy community controls individually matched to cases on sex, age and residence were selected (88% response rate).
Results: After multivariate adjustment, the odds ratio (OR) and 95% confidence interval (CI) was 1.7 (1.1-2.9 with p = 0.03 for increasing dose-response) for those who smoked for > or = 25 years compared with non-smokers. Passive smoking during childhood or adult life was not associated with an increased risk of disease. Alcohol consumption was not associated with NPC risk. The OR for subjects with > or = 15 grams of ethanol per day compared to non-drinkers was 1.1 (95% CI = 0.7-1.7).
Conclusions: Our results suggest that long term cigarette smoking is associated with NPC but that low level exposure to cigarette smoke via passive exposure and alcohol consumption are not associated with disease risk.