Donsuk Pongnikorn

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: Southeast Asia is undergoing a transition from infectious to chronic diseases, including a dramatic increase in adult cancers. Childhood cancer research in Thailand has focused predominantly on leukemias and lymphomas or only examined children for a short period of time. This comprehensive multisite study examined childhood cancer incidence and survival rates in Thailand across all International Classification of Childhood Cancer (ICCC) groups over a 20-year period. METHODS: Cancer cases diagnosed in children ages 0-19 years (n = 3574) from 1990 to 2011 were extracted from five provincial population-based Thai registries, covering approximately 10% of the population. Descriptive statistics of the quality of the registries were evaluated. Age-standardized incidence rates (ASRs) were calculated using the Segi world standard population, and relative survival was computed using the Kaplan-Meier method. Changes in incidence and survival were analyzed using Joinpoint Regression and reported as annual percent changes (APC). RESULTS: The ASR of all childhood cancers during the study period was 98.5 per million person-years with 91.0 per million person-years in 1990-2000 and 106.2 per million person-years in 2001-2011. Incidence of all childhood cancers increased significantly (APC = 1.2%, P < 0.01). The top three cancer groups were leukemias, brain tumors, and lymphomas. The 5-year survival for all childhood cancers significantly improved from 39.4% in 1990-2000 to 47.2% in 2001-2011 (P < 0.01). CONCLUSIONS: Both childhood cancer incidence and survival rates have increased, suggesting improvement in the health care system as more cases are identified and treated. Analyzing childhood cancer trends in low- and middle-income countries can improve understanding of cancer etiology and pediatric health care disparities.

PURPOSE: Head and neck cancer is the sixth most common cancer in the world, and the largest burden occurs in developing countries. Although the primary risk factors have been well characterized, little is known about temporal trends in head and neck cancer across Thailand. METHODS: Head and neck squamous cell carcinoma (HNSCC) occurrences diagnosed between 1990 and 2014 were selected by International Classification of Diseases (10th revision; ICD10) code from the Songkhla, Lampang, Chiang Mai, and Khon Kaen cancer registries and the US SEER program for oral cavity (ICD10 codes 00, 03-06), tongue (ICD10 codes 01-02), pharynx (ICD10 codes 09-10, 12-14), and larynx (ICD10 code 32). The data were analyzed using R and Joinpoint regression software to determine age-standardized incidence rates and trends of annual percent change (APC). Incidence rates were standardized using the Segi (1960) population. Stratified linear regression models were conducted to assess temporal trends in early-onset HNSCC across 20-year age groups. RESULTS: , 0.77) and in pharyngeal cancer in Khon Kaen and US men (APC, 2.1 and 2.23, respectively). Age-stratified APC analyses to assess young-onset (< 60 years old) trends demonstrated increased incidence in tongue cancer in Thailand and the United States as well as in pharyngeal cancers in Khon Kaen men age 40 to 59 years and US men age 50 to 59 years. CONCLUSION: Although overall trends in HNSCC are decreasing across both Thailand and the United States, there is reason to believe that the etiologic shift to oropharyngeal cancers in the United States may be occurring in Thailand.

Abstract Radon exposure is the second leading cause of lung cancer, after smoking. In upper northern Thailand (UNT), lung cancer incidence was frequently reported by Thailand National Cancer Institute. Besides smoking, radon exposure may also influence the high lung cancer incidence in this region. Indoor radon concentrations were measured in 192 houses in eight provinces of UNT. Indoor radon concentrations ranged from 11 to 405 Bq m −3 and estimated annual effective dose ranged from 0.44 to 12.18 mSv y −1 . There were significant differences in indoor radon concentrations between the houses of lung cancer cases and healthy controls (p = 0.033). We estimated that 26% of lung cancer deaths in males and 28% in females were attributable to indoor radon exposure in this region. Other factors influencing indoor radon levels included house characteristics and ventilation. The open window-to-wall ratio was negatively associated with indoor radon levels (B = −0.69, 95% CI −1.37, −0.02) while the bedroom location in the house and building material showed no association. Indoor radon hence induced the fractal proportion of lung cancer deaths in UNT.