Incidence rates of oral cancer and oral pre-cancerous 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 pre-cancerous 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 100,000 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.

The effects of chewing areca/betel quid with and without cigarette smoking on oral submucous fibrosis and oral mucosal lesions.

OBJECTIVES: The purpose of this study was to investigate the risk of areca/betel quid chewing with or without cigarette smoking on oral submucous fibrosis (OSF) and other oral mucosal lesions. METHODS: A stratified case-control study was designed. There were in total 102 patients with oral mucosal lesions or OSF (confirmed pathologically) in the case group. OSF (n = 62) and oral mucosal lesions (n = 62) in 102 subjects were separately analyzed for men and women investigating their risks. RESULTS: For OSF, people with both smoking and chewing habits had a statistically significant odds ratio (OR) 8.68 (95% CI = 1.87, 40.23). For the group of people with chewing habit only and without any lifetime cigarette smoking habit, the OR was 4.51 (95% CI = 1.20, 16.94). For other oral mucosal lesions, people with mixed habits and chewing only had also significant risks (OR = 8.37 and 3.95, respectively). For both OSF and other oral lesions, the ORs of mixed habits and chewing only were both higher in women than in men. CONCLUSIONS: The areca/betel quid used in Taiwan does not contain any tobacco product. The only way of areca/betel quid could synergize with any tobacco product is through cigarette smoking. A statistically significant association with oral mucosal lesions and OSF was still found in the group of areca/betel quid chewing only.