Development of colorectal adenoma, the precursors to colorectal cancer, is associated with low circulating 25-hydroxy vitamin D levels. However, less is known about the risk of colorectal neoplasia and variation in genes encoding the enzymes responsible for the synthesis and catabolism of 1α,25-hydroxyvitamin D.
Researchers at the Vanderbilt-Ingram Cancer Center and the University of Arizona Mel and Enid Zuckerman College of Public Health examined associations between CYP27B1 and CYP24A1 polymorphisms, circulating 25(OH)D and 1,25(OH)2D concentrations, and colorectal adenoma recurrence in a pooled sample from 2 clinical trials (n = 1,188). The study is published in the journal Nutrition and Cancer.
Nominal associations were observed between increasing copies of the T allele in CYP24A1 rs927650 and 25(OH)D concentrations (P = 0.02); and colorectal adenoma recurrence, with odds ratios (95% confidence intervals) of 1.30 (0.99–1.70) and 1.38 (1.01–1.89) for heterozygotes and minor allele homozygotes, respectively (P= 0.04). In addition, a statistically significant relationship between CYP24A1 rs35051736, a functional polymorphism, and odds for advanced colorectal adenoma recurrence was observed (P < 0.001).
Overall, CYP24A1 polymorphisms may influence the development of advanced lesions, and modify the effect of vitamin D metabolites on adenoma recurrence. Further study is necessary to characterize the differences between circulating vitamin D metabolite measurements compared to cellular level activity in relation to cancer risk.