In Thailand, five cancer types—breast, cervical, colorectal, liver and lung cancer—contribute to over half of the cancer burden. The magnitude of these cancers must be quantified over time to assess previous health policies and highlight future trajectories for targeted prevention efforts. We provide a comprehensive assessment of these five cancers nationally and subnationally, with trend analysis, projections, and number of cases expected for the year 2025 using cancer registry data. We found that breast (average annual percent change (AAPC): 3.1%) and colorectal cancer (female AAPC: 3.3%, male AAPC: 4.1%) are increasing while cervical cancer (AAPC: −4.4%) is decreasing nationwide. However, liver and lung cancers exhibit disproportionately higher burdens in the northeast and north regions, respectively. Lung cancer increased significantly in northeastern and southern women, despite low smoking rates. Liver cancers are expected to increase in the northern males and females. Liver cancer increased in the south, despite the absence of the liver fluke, a known factor, in this region. Our findings are presented in the context of health policy, population dynamics and serve to provide evidence for future prevention strategies. Our subnational estimates provide a basis for understanding variations in region-specific risk factor profiles that contribute to incidence trends over time.

Background:Among developing countries, Thailand shows no increase in the incidence of human papillomavirus–driven oropharyngeal cancer. The causal role of human papillomavirus infection in this pathology has not been researched thoroughly.Methods:A hospital-based, case–control study was performed which included 104 patients with newly diagnosed oral and oropharyngeal squamous cell carcinomas and 104 individuals without cancer. The Cervista high-risk human papillomavirus and 16/18 assays were used to detect human papillomavirus. Odds ratios were used to assess the association between high-risk genotypes of human papillomavirus and the cancers.Results:High-risk human papillomavirus was detected in 4 of 52 (7.7%) oral cancer cases, 6 of 52 (11.5%) oropharyngeal cancer cases, and 1 of 104 (0.96%) control subjects. Of 104 cancer patients in the study, 83 were smokers. High-risk human papillomavirus was significantly associated with oropharyngeal cancer (odds ratio = 13.44, 95% confidence interval = 1.6–114.8) but was nonsignificantly associated with oral cancer (odds ratio = 8.58, 95% confidence interval = 0.9–78.9). However, after adjustment for smoking, high-risk human papillomavirus was determined to be nonsignificantly associated with oropharyngeal cancer (adjusted odds ratio = 5.83, 95% confidence interval = 0.8–43.5).Conclusion:Although low human papillomavirus prevalence was observed, the rate of high-risk human papillomavirus infection in the cancer group was still higher than that in the control group. Smoking may have an influence on the etiology of human papillomavirus–related cancers. However, the study is underpowered to clarify the role of human papillomavirus as the independent risk factor for oral and oropharyngeal cancers in the Thai population.