Prostate cancer risk and ESR1 TA, ESR2 CA repeat polymorphisms.

BACKGROUND Experimental evidence has suggested that estrogen receptor alpha (coded by the gene ESR1) might increase prostate cancer risk, whereas estrogen receptor beta (coded by the gene ESR2) might reduce prostate cancer risk. METHODS We investigated the relationship with prostate cancer risk of both a TA repeat polymorphism in the ESR1 5' region, ESR1 (TA)(n), and with a CA repeat polymorphism in intron 5 of ESR2, ESR2 (CA)(n), in a case-control study (545 cases and 674 controls) nested in the Physicians' Health Study. RESULTS Prostate cancer risk was highest for carriers of ESR1 (TA)(24) and ESR1 (TA)(25). Replacing one modal ESR1 (TA)(14) allele with one ESR1 (TA)(24) allele yielded an odds ratio of 1.42 (95% confidence interval, 1.00-2.00; P=0.05). Replacing one ESR1 (TA)(14) allele with one ESR1 (TA)(25) allele yielded an odds ratio of 2.10 (95% confidence interval, 1.15-3.84; P=0.02). ESR2 (CA)(n) showed no effects on prostate cancer risk. CONCLUSIONS The ESR1 (TA)(n) polymorphism might play a role in prostate cancer risk.