Sex Differences in Time Trends on Incidence Rates of Oropharyngeal and Oral Cavity Cancers in Hong Kong

摘要

Objectives: Worldwide studies have shown an increasing trend of oropharyngeal squamous cell carcinoma (OPSCC) but a decreasing trend of oral cavity cancers over the past 2 decades, particularly in developed countries with successful tobacco control. This trend has been attributed to the increase in the incidence of human papillomavirus (HPV)-associated OPSCC. The aim of this study was to examine sex differences in incidence trends of oropharyngeal and oral cavity cancers in Hong Kong from 1983 to 2014. Methods: Using data from the Hong Kong Cancer Registry from 1983 to 2014, age-standardized incidence rates for potentially HPV-associated sites (oropharyngeal) and non-HPV-associated sites (oral cavity) were calculated, stratified by sex and age groups. Joinpoint regression and an age-period-cohort model were used to assess incidence trends. Results: A total of 1,972 cases of oropharyngeal cancer and 7,389 cases of oral cavity cancer were diagnosed from 1983 to 2014. The male/female ratios were 4.16:1 for oropharyngeal cancers and 1.63:1 for oral cavity cancers. A significant increasing trend was observed in oropharyngeal cancers from 1994 to 2014 (average annual percentage change = 2.66, P .05). In contrast, a significant decreasing trend was observed in oral cavity cancers from 1983 to 1994 (average annual percentage change = -5.36, P .05). The trends were more significant in men and in patients aged 45 to 69 years. A positive birth cohort effect was observed for oropharyngeal cancer in men. Conclusions: The rising trend of oropharyngeal cancer and decreasing trend of oral cavity cancer in Hong Kong from 1983 to 2014 are consistent with worldwide trends. Increase in high-risk sexual behaviors and oral HPV infection may influence the difference in trends.