Association of breast cancer progression with a vitamin D receptor gene polymorphism

The vitamin D-3 receptor gene (VDR) contains a TaqI RFLP that is associated with increased VDR mRNA stability, increased serum levels of 1 alpha,25-di hydroxyvitamin D-3 (1,25-D-3), and decreased risk for prostate cancer. Dete rmination of the TaqI genotype, in a group of young women with breast cance r (n = 111; age, <37 years) and a control population (n = 130), revealed no overall association to risk for breast cancer. However, patients without T aqI site (TT genotype) showed a significantly increased risk for lymph node metastasis (relative risk, 1.8, 95% confidence interval, 1.3-2.6). Further more, a tendency toward an increased survival was found among estrogen rece ptor-positive, tamoxifen-treated patients who were homozygous for the TaqI site (P = 0.075). We conclude that polymorphism in the VDR gene may influen ce tumor progression and tamoxifen treatment response in early-onset breast carcinomas.