The population of Songkhla, a province in Southern Thailand, can be divided into a
predominantly Muslim subpopulation (PMSP, approximately 70% Muslim) and a predominantly Buddhist
subpopulation (PBSP, around 14% Muslim). Objectives: This study was conducted to 1) describe the incidence
of various cancers in both PMSP and PBSP, and 2) compare the incidence of various cancers between the two
subpopulations. Materials and Methods: Cancer cases diagnosed between 1990 and 2010 were drawn from the
database of Songkhla Cancer Registry. Population denominators were estimated from the 3 population censuses
surveyed by the National Statistical Office of Thailand in 1990, 2000, and 2010. Results: The age-standardized
incidence 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 the
lung, liver, colon-rectum, and some other cancers were significantly different between the two populations in the
past, but only prostate cancer showed a lower incidence among males in PMSP in recent years. Independent of
sex and year of diagnosis, the incidence of lung, liver, NHL, and colorectal cancers was lower in MPSP compared
to 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), and
0.67 (95% CI: 0.56-0.78) respectively. Conclusions: The differences in incidence of some cancers and religionrelated
culture between the two subpopulations need 2 sets of cancer-control plans and goals to fit the unique
population context in deep Southern Thailand. This plan can be used in the 3 southernmost provinces of Thailand
where the percentage of Muslims is over 85%.