(P05-065-20) Dietary Vitamin D, Vitamin D Metabolism-Related Gene Polymorphisms and Colorectal Cancer Risk in a Chinese Case-Control Study
Objectives: Vitamin D has anticarcinogenic properties. Vitamin D metabolism-related gene polymorphisms can influence vitamin D levels and its impact on carcinogenesis. This study aimed to explore the independent and combined effects of dietary vitamin D and vitamin D metabolism-related gene polymorphisms on colorectal cancer risk in a Chinese population.
Methods: Incident cases with histologically confirmed colorectal cancer, and sex and age-matched controls were recruited in this ongoing case-control study. Of them, 488 cases and 496 controls were both successfully interviewed and collected blood samples. Vitamin D intake was assessed by a validated food frequency questionnaire. Genotyping was performed for CYP2R1 rs10741657, CYP2R1 rs12794714, CYP24A1 rs6013897, CYP24A1 rs6068816, CYP27B1 rs4646536 and GC rs7041 by using an improved multiplex ligation detection reaction (iMLDR) technique. Unconditional multivariable logistic regression was used to calculate odds ratio (OR) and 95% confidence interval (CI) after adjusting for various confounders.
Results: Higher intake of dietary vitamin D was associated with 47% reduction in colorectal cancer with OR of 0.53 (95% CI: 0.34, 0.82) for the highest quartile (vs. lowest quartile) intake. Compared with persons with CYP24A1 rs6068816 CC genotype, lower risk of colorectal cancer was observed among carriers of TT genotype (OR=0.57, 95%CI 0.36, 0.89). No significant association was found between CYP2R1 rs10741657, CYP2R1 rs12794714, CYP24A1 rs6013897, CYP27B1 rs4646536, GC rs7041 and colorectal cancer risk. No significant interaction was observed between dietary vitamin D intake and six examined single nucleotide polymorphisms on the risk of colorectal cancer.
Conclusions: Our study supports a protective effect of high intake of dietary vitamin D on colorectal cancer. CYP24A1 rs6068816 TT genotype was significantly associated with a decreased risk of colorectal cancer. No interaction was observed between dietary vitamin D intake and six examined single nucleotide polymorphisms in a Chinese population.
Funding Sources: Guangdong Natural Science Foundation (No: 2019A1515011931)
Prof. Department of Epidemiology, School of Public Health, Sun Yat-sen University Guangzhou, Guangdong, China (People's Republic)