Tobacco (kretek) smoking, betel quid chewing and risk of oral cancer in a selected Jakarta population.

PURPOSE This study aimed to determine the association between tobacco consumption (kretek) and betel quid chewing with oral cancer risk. MATERIALS AND METHODS A total of 81 cases of oral cancers were matched with 162 controls in this hospital-based study. Information on sociodemographic characteristics and details of risk habits (duration, frequency and type of tobacco consumption and betel quid chewing) were collected. Association between smoking and betel quid chewing with oral cancer were analysed using conditional logistic regression. RESULTS Slightly more than half of the cases (55.6%) were smokers where 88.9% of them smoked kretek. After adjusting for confounders, smokers have two fold increased risk, while the risk for kretek consumers and those smoking for more than 10 years was increased to almost three-fold. Prevalence of betel quid chewing among cases and controls was low (7.4% and 1.9% respectively). Chewing of at least one quid per day, and quid combination of betel leaf, areca nut, lime and tobacco conferred a 5-6 fold increased risk. CONCLUSIONS Smoking is positively associated with oral cancer risk. A similar direct association was also seen among betel quid chewers.