Oral cancer in Myanmar: a preliminary survey based on hospital-based cancer registries.

The occurrence of oral cancer is not clearly known in Myanmar, where betel quid chewing habits are widely spread. Since betel quid chewing has been considered to be one of the important causative factors for oral cancer, the circumstantial situation for oral cancer should be investigated in this country. We surveyed oral cancer cases as well as whole body cancers from two cancer registries from Yangon and Mandalay cities, both of which have representative referral hospitals in Myanmar, and we showed that oral cancer stood at the 6th position in males and 10th in females, contributing to 3.5% of whole body cancers. There was a male predominance with a ratio of 2.1:1. Their most frequent site was the tongue, followed by the palate, which was different from that in other countries with betel quid chewing habits. About 90% of male and 44% of female patients had habitual backgrounds of chewing and smoking for more than 15 years. The results revealed for the first time reliable oral cancer frequencies in Myanmar, suggesting that longstanding chewing and smoking habits are etiological backgrounds for oral cancer patients.