Incidence rates of oral cancer and oral pre-cancercous lesions in a 6-year follow-up study of a Taiwanese aboriginal community

Background: In a previous article, we reported the prevalence rates of oral mucosal lesions in an aboriginal community from an epidemiological survey of oral precancerous lesions. Methods: Since 1997, the authors have started regular follow-up of the study population originally investigated. Thus, it has been possible to obtain incidence rates for the various oral pre-cancerous lesions and conditions. Results: There were 194 persons without any oral lesion in the 1997 screening. During the clinical follow-up investigation and during the analysis of biopsies from pre-cancerous lesions, we discovered six new lesions (including cancer and pre-cancerous lesions) from five participants. All of the five persons were areca/betel quid chewers, and only one mixed areca/betel quid chewing with cigarette smoking habit. The age-standardized incidence rates for quid lesion, oral submucous fibrosis (OSF) and squamous cell carcinoma (SCC) were 267.0, 374.1 and 146.2 per 100000 person-years, respectively, for areca/betel quid chewers. Conclusions: As compared with the rates from India and the general Taiwanese population, the study community encountered a serious problem of oral lesions.