Objectives: Genetic factors involved in regulating cell growth, such as the vitamin D receptor (VDR) gene, may contribute to the etiology of colon cancer.
Methods: Using data from a population-based case-control study of colon cancer and from a family-based study of cases with colon cancer and population-based controls, we evaluated the association between four variants of the VDR gene and risk of colon cancer.
Results: The polyA (short), BsmI (BB), and TaqI (tt) variants of the VDR gene were in linkage disequilibrium in this mostly Caucasian population. These variants were associated with reduced risk of colon cancer (OR 0.5, 95% CI 0.3-0.9). The FokI variant was not associated with colon cancer risk. Although estimates of association were imprecise, there were suggestions that associations were slightly stronger for women than men, for people diagnosed at a younger age, and for those with proximal tumors. Consistent associations were observed from sporadic cases of colon cancer from a population-based study as well as from colon cancer cases from a family-based study. There were no interactions observed by family history.
Conclusions: These data suggest that molecular variants of the VDR gene may be related to the development of colon cancer. To further define the impact of the VDR gene on cancer etiology, studies to evaluate the association of these variants with diet and lifestyle factors are needed.