Betel quid and oral cancer: prospects for prevention.

Betel-quid chewing is an ancient and socially accepted practice. The introduction of tobacco reinforced this practice, and now almost all habitual chewers of betel quids include tobacco. It is well established that chewing of betel quid with tobacco causes oral cancer and is largely responsible for the high incidence of oral cancer in several South Asian countries. The feasibility of primary prevention of oral cancer was studied in a population-based prospective intervention study. A cohort of 12,212 betel-quid chewers and smokers was exposed to a programme of health education for stopping chewing and smoking and subjected to annual examinations for detection of oral precancerous lesions. Evaluations after one, five and eight years showed that primary prevention of oral cancer is feasible and practicable. Early detection of oral cancer is an important control measure. In a secondary prevention study, 53 basic health workers were trained in the detection and referral of lesions suspected of being oral cancer. Over one year, they examined more than 39,000 high-risk individuals, resulting in the detection of 20 cases of oral cancer. The sensitivity and specificity of their diagnoses was assessed through a re-examination of a 5% sample: we concluded that it was possible to incorporate a secondary prevention programme into the existing health care system.