Aetiological factors of oral cancer in Sri Lanka

Abstract

OBJECTIVE: To determine aetiological factors of oral cancer in three provinces in Sri Lanka DESIGN, SETTING AND METHODS: A matched case-control study on incident cases of oral cancer and age-sex matched neighbourhood controls was conducted in three provinces of Sri Lanka. Risk factors were analysed using matched pair analyses and conditional logistic regression. RESULTS: Among 658 subjects (329 pairs) [males= 82.1%, mean age = 61.6 (30=12.2) years], a higher monthly income, regular betel chewing, age at starting chewing, duration of a chew, retaining the quid in the mouth at night, regular smoking, duration of smoking, amount smoked daily, type of smoke used, regular alcohol consumption and amount of illicit liquor consumed daily were significantly associated with oral cancer on bivariate analysis. Past history of cancer, family history of cancer and family history of cancer of head and neck were also associated with oral cancer. A higher income (OR=0.65; 95% CI 0.44-0.96) and high consumption of raw fruits (OR=0.64; 95% CI 0.46-0.89) were protective. Regular betel chewing (OR=1.94; 95% CI 1.23-3.07), retaining the quid in the mouth at night (OR=20.45; 95% CI 7.23-57.89), consumption of illicit liquor (OR=4,65; 95% CI 2.49-8.71) and the amount smoked per day (OR=1.04 95% CI 1.01-1.07) were significantly associated with oral cancer on multivariate analysis. CONCLUSIONS: Betel chewing is the most important determinant of oral cancer. Retaining the quid in the mouth should be discouraged. The importance of family history demands for preventive programmes for family members of patients.