A missense substitution A49T in the steroid 5-alpha-reductase gene (SRD5A2) is not associated with prostate cancer in Finland

Prostatic steroid 5-alpha-reductase gene (SRD5A2) encodes a critical enzyme involved in the conversion of testosterone to dihydrotestosterone. A germl ine mis-sense substitution (A49T) leads to a variant SRD5A2 protein, which has a 5-fold higher in vitro V-max than the wild-type protein (Ross et al, 1998; Makridakis et al. 1999). The A49T variant was recently associated wit h 2.5 to 3.28-fold increased risk of prostate cancer (PC) in African-Americ an and Hispanic men (Makridakis et al, 1999). Also, Jaffe et at (2000) repo rted an association between A49T and more aggressive disease among Caucasia n patients. Here, we report that the prevalence of the A49T variant in 449 Finnish PC patients was 6.0%, not significantly different from 6.3% observe d in 223 patients with benign prostatic hyperplasia or 5.8% in 588 populati on-based controls (odds ratio for PC 1.04, 95% C.I. 0.62-1.76, P = 0.89). T here was no association between A49T and the family history of the patients nor with tumour stage or grade. Our results argue against a prominent role of the A49T variant as a genetic risk factor for prostate cancer developme nt and progression in the Finnish population. (C) 2001 Cancer Research Camp aign.