Sex Differences in the Heterogeneous Dynamic Incidence of Oral Cancer: A Comparison between Taiwan and Thailand

BACKGROUND: This study aims at investigating differences in oral cancer (OC) incidence trends between two populations in Taiwan and Thailand. METHODS: We used the population-based cancer registry data from Taiwan (1979-2016) and Khon Kaen (KK), Thailand (1985-2016). We performed joinpoint analyses to detect the trend change points for the OC incidence and to quantify the time trends in both sexes and regions. Age-period-cohort curves were plotted to explain the incidence trends. RESULTS: In Taiwan, the estimated annual increases in OC were approximately 6.0% in males, although the increase slowed after 2009, and 2.6% in females. In KK, the OC incidence steadily decreased by -2.5% per year in females, but there was no obvious change in males. A strong period effect observed in those aged 45-69 years in Taiwanese males resulted in a peak incidence in the middle age group. Decreased period and cohort effects were observed in females in KK. CONCLUSIONS: Taiwanese males are the predominant sex affected by OC in Taiwan, and the trend has decelerated since 2009. Age, period, and cohort effects were different between males and females in the two regions.