Variation in the Vitamin D Receptor Gene is not Associated with Risk of Colorectal Cancer in the Czech Republic

Abstract

Increased levels of vitamin D may protect against colorectal cancer (CRC) development and recurrence. Accumulating epidemiologic evidence suggests these effects may be partly mediated by genetic variants of the vitamin D receptor (VDR) proposed to be associated with altered risk of CRC. We wished to determine if common VDR polymorphisms affected CRC risk in the Czech Republic, a homogenous European population with a high CRC incidence rate. Frequencies of the common VDR gene polymorphisms rs2238136, rs1544410 (BsmI), rs7975232 (ApaI), and rs731236 (TaqI) were determined using allele-specific PCR in a case control analysis of a series of 754 CRC patients and 627 patients without malignant disease recruited from centers throughout the Czech Republic. Unconditional logistic regression was used to calculate odds ratios and 95% confidence intervals for the association between these variants and risk of CRC. None of the four polymorphisms tested had any significant effect on CRC risk. No significant differences were observed in susceptibility when the population was stratified by anatomical sub-site, sex, BMI, smoking, alcohol, or presence of polyps. We conclude that common variation in the VDR gene had little effect on its own on predisposition to sporadic CRC in the Czech population.