Epidemiology of oral and pharyngeal cancers in Khon Kaen, Thailand: a high incidence in females.

BACKGROUND This study was aimed to describe incidence, trends, and survival of oral and pharyngeal cancers in Khon Kaen, the province situated in the northeast of Thai-land. METHODS Data on oral and pharyngeal cancer cases diagnosed during 1985 - 2001 were retrieved from the population-based cancer registry of Khon Kaen. The final status of the patients was verified by database linkage and follow-up using postcards. RESULTS Of 1,038 cases, 62.6% were female and 37.4% were male, with a mean age of 63 years. The age-standardized incidence rate (ASR) in females (6.2 per 100 000; 95%CI 5.7-6.7) was significantly higher than in males (3.9 per 100 000; 95%CI 3.5-4.4). Annual percent changes in ASR were 1.7 in females (p<0.05), but 1.2 in males. Lip and buccal cancers were the most common sites respectively; however, the incidence of tongue cancer was increasing in the last period. Eighty five percent of all cases were diagnosed in advanced stage (stage III and IV). The overall five-year relative survival was 43.1%. We found stage distribution and survival did not change during the study period. CONCLUSION The considerably high incidence in female suggests a need for research on specific risk factors. Moreover, attempts should be made to detect oral cancers earlier in order to improve the outcomes of cancer control.