Association of vitamin D receptor gene polymorphism with prostate cancer and benign prostatic hyperplasia in a Japanese population

Recent studies have suggested that vitamin D is an important determinant of prostate cancer risk and inherited polymorphisms in the 3'-untranslated re gion (3'UTR) of the vitamin D receptor (VDR) gene are associated with the r isk and progression of prostate cancer. This study was conducted to explore the association of VDR gene polymorphisms with prostate cancer risk in Jap anese men who are considered to be much less influenced by environmental ri sk factors for prostate cancer. We studied 222 prostate cancer patients, 20 9 benign prostatic hyperplasia (BPH) patients, 128 male controls who were o ver 60 years old and without any evidence of prostate cancer or BPH, and 19 8 female controls. A PCR-RFLP method was used to determine three VDR gene p olymorphisms in the 3'UTR characterized by restriction enzymes BsmI, ApaI a nd TaqI, In the BsmI polymorphism, heterozygosity or homozygosity for the a bsence of the BsmI restriction site was associated with one-third the risk of prostate cancer (P < 0.0001; odds ratio, 3.31; 95% confidence interval, 2.05-5.32) and with one-half the risk of BPH (P < 0.005; odds ratio, 2.07; 95% confidence interval, 1.33-3.22) compared with the male controls. The Ta qI and ApaI polymorphisms did not show any significant association with eit her prostate cancer or BPH. The results indicate that the BsmI polymorphism in the VDR gene plays a significant role in protection against prostate ca ncer and BPH. Because of the racial difference in the strength of the linka ge disequilibrium between the three polymorphisms, additional studies are r equired to apply the present results to other racial-ethnic groups.