Attribution of oral cancer in the Sudan to Toombak dipping

Background: Toombak dipping-a form of smokeless tobacco-is highly prevalent in the Sudan. Materials and methods: For a case–control study, we selected oral cancer cases ( n = 98) and controls ( n = 98) at the Khartoum Teaching Dental Hospital. They were directly interviewed using a validated and a reliable instrument. For descriptive statistics, χ 2 test was used for determining the odds ratio (OR) measuring the association between exposed and non-exposed. The effects of the confounding factors were tested by multivariate logistic regression analyses. The attributable risk of this agent in oral carcinogenesis was evaluated. Results: Significant risks for Toombak dipping (OR 3.8, 95% CI 1.7–8.6) and cigarette smoking (OR 2.7, 95% CI: 1.2–6.2) were found. The site of Toombak dipping and the tumor location showed positive correlation. The attribute risk for exclusive dippers was found to be 93% and 67% in females and males, respectively, whereas the adjusted attributable risk was 70.1%. The remaining 20–30% risks were attributed to other risk factors. Conclusion: In the Sudan, Toombak dipping is a major risk factor for oral squamous cell carcinoma. We were able to demonstrate a high attributable risk to this agent in oral carcinogenesis.