Differences in Cancer Incidence among Predominantly Muslim and Buddhist Subpopulations in Songkhla

Background: The population of Songkhla, a province in Southern Thailand, can be divided into apredominantly Muslim subpopulation (PMSP, approximately 70% Muslim) and a predominantly Buddhistsubpopulation (PBSP, around 14% Muslim).
Objectives: This study was conducted to 1) describe the incidenceof various cancers in both PMSP and PBSP, and 2) compare the incidence of various cancers between the twosubpopulations. Materials and
Methods: Cancer cases diagnosed between 1990 and 2010 were drawn from thedatabase of Songkhla Cancer Registry. Population denominators were estimated from the 3 population censusessurveyed by the National Statistical Office of Thailand in 1990, 2000, and 2010.
Results: The age-standardizedincidence rates (ASR) of the 5 commonest male cancers among both subpopulations were calculated. In females,a lower incidence of cancers of the cervix and breast in PMSP compared to PBSP, with odds ratios of 0.54 (95%CI: 0.45-0.64) and 0.51 (95% CI: 0.43-0.60) respectively, was observed. In males, the incidence of cancers of thelung, liver, colon-rectum, and some other cancers were significantly different between the two populations in thepast, but only prostate cancer showed a lower incidence among males in PMSP in recent years. Independent ofsex and year of diagnosis, the incidence of lung, liver, NHL, and colorectal cancers was lower in MPSP comparedto BPSP, with odds ratios of 0.75 (95% CI: 0.65-0.85), 0.74 (95% CI: 0.62-0.88), 0.74 (95% CI: 0.60-0.91), and0.67 (95% CI: 0.56-0.78) respectively.
Conclusions: The differences in incidence of some cancers and religionrelatedculture between the two subpopulations need 2 sets of cancer-control plans and goals to fit the uniquepopulation context in deep Southern Thailand. This plan can be used in the 3 southernmost provinces of Thailandwhere the percentage of Muslims is over 85%.