Spatial analysis of cholangiocarcinoma in Thailand from 2012 to 2021; a population-based cancer registries study.

BACKGROUND

Cholangiocarcinoma (CCA) is major health issue in Thailand, with high incidences in different parts of country. This study examines the association between spatial variables and CCA in Thailand.

METHODS

Thailand's four population-based cancer registries provided data for this retrospective cohort analysis between January 1, 2012, and December 31, 2021. 6,379 diagnosed CCA cases were found in 554 sub-districts. Moran's I and Local Indicators of Spatial Association (LISA) measured geographic dispersion and estimated sex age-standardized rates (ASRs). Multivariable log-linear regression assessed geography and CCA, calculating adjusted incidence rate ratios (IRRs) and 95% confidence interval (CI).

RESULTS

Of 6,379 CCA cases, 63.9% were male, and the mean age at diagnosis was 66.2 years (standard deviation = 11.07 years). CCA ASRs for both sexes in Thailand was 8.9 per 100,000 person-years. The northeastern region had the greatest ASR at 13.4 per 100 000 person-years. Moran's I and LISA studies grouped regions by spatial variables. The association between spatial variables and CCA demonstrated that the northern region exhibited elevation (adjusted IRRs = 0.82, 95%CI: 0.78 to 0.87) and distance from water sources variable (adjusted IRRs = 0.91, 95%CI: 0.82 to 0.99). The central region elevation variable (adjusted IRRs = 0.85, 95%CI: 0.76 to 0.94). This was the distance from water sources (adjusted IRRs = 0.96, 95%CI: 0.93 to 0.99) and population density variable (adjusted IRRs = 0.94, 95%CI: 0.93 to 0.96) in the northeastern region. Population density (adjusted IRRs = 1.09, 95%CI: 1.02 to 1.15) and average temperature variable (adjusted IRRs = 1.05, 95%CI: 1.02 to 1.09) were significant in the southern region.

CONCLUSION

Spatial variables associated with CCA indicate that ASR differs across Thailand. So environmental and climate factors can inform targeted public health strategies to address CCA in high-risk areas throughout Thailand.