Abstract 1195: Incidence rates of head and neck cancer across Thailand and the USA

Abstract Background: Head and neck cancer is the sixth most common cancer in the world, with the largest burden occurring in developing countries. Although the primary risk factors have been well characterized, little is known about the temporal trends in head and neck cancer across Thailand. Using population based registries from three Thai provinces (Songkhla, Lampang and Khon Kaen), we have characterized the age-standardized incidence rates of head and neck cancer by sex and age and compared them to those observed in the United States. Methods: Cancer cases diagnosed between 1990 and 2014 were selected by ICD-10 code directly from the Songkhla, Lampang and Khon Kaen Cancer Registries as well as the Surveillance, Epidemiology, and End Results Program (SEER) for the following sites: oral cavity (00, 03-06), tongue (01-02), pharynx (09-10, 12-14), and larynx (32). The data were analyzed using R software (3.1.1) and Joinpoint Regression Software (4.4.0) to determine age-standardized incidence rates and trends of annual percent change. Incidence rates were standardized using the Segi (1960). Additional exploratory analyses using stratified linear regression models were conducted to assess temporal trends in head and neck cancer across 10-year age groupings. Results: Overall head and neck cancer rates are decreasing across all registries except Khon Kaen, where there is an observed, albeit not statistically significant, increase among males (APC: 0.53, p=0.3). Subsite analyses demonstrate consistent decreases in both larynx and oral cavity cancers, but suggested increases in pharynx and tongue cancers among both genders in the US (APC: 1.9 and 1.6, p<0.05 respectively) as well as pharynx cancer in Khon Kaen males (APC: 2.1, p<0.05). Furthermore, age-stratified APC analyses showed increased incidence in tongue cancer among Khon Kaen females age 30-39, Khon Kaen males age 30-59, Lampang males age 50-59, Songkhla females age 30-49, US females age 30-49 and 70-85+, as well as US males age 40-79. Pharynx cancers were seen to increase in Khon Kaen males age 40-59 and US males age 50-59. Conclusions: Although overall trends in head and neck cancer do seem to be decreasing across both Thailand and the United States, there is reason to believe that the etiological shift affecting both pharynx and tongue cancers in the US may be similarly presenting in Thailand. While disparities across gender and region do still exist, further investigation into the increased rates of early onset cancer is needed. Citation Format: Ilona Argirion, Katie Rentschler, Patravoot Vatanasapt, Hutcha Sriplung, Laura S. Rozek. Incidence rates of head and neck cancer across Thailand and the USA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1195.