Pharmacogenomics Laboratory, Centre Hospitalier Universitaire de Québec (CHUQ) Research Centre and Faculty of Pharmacy, Laval University, Québec, Canada.
The relationship between inherited germ-line variations in the 5α-reductase pathways of androgen biosynthesis and the risk of biochemical recurrence (BCR) after radical prostatectomy (RP) remains an unexplored area.
To determine the link between germ-line variations in the steroid-5α-reductase, α-polypeptide 1 (SRD5A1) and steroid-5α-reductase, α-polypeptide 2 (SRD5A2) genes and BCR.
We studied retrospectively two independent cohorts composed of 526 white (25% BCR) and 320 Asian men (36% BCR) with pathologically organ-confined prostate cancer who had a median follow-up of 88.8 and 30.8 mo after surgery, respectively.
Patients were genotyped for 19 haplotype-tagging single nucleotide polymorphisms (htSNPs) in SRD5A1 and SRD5A2 genes, and their prognostic significance on prostate-specific antigen recurrence was assessed using Kaplan-Meier analysis and the Cox regression model.
After adjusting for all clinicopathologic risk factors, four SNPs (rs2208532, rs12470143, rs523349, and rs4952197) were associated with BCR in both whites and Asians. The strongest effect was conferred by the SRD5A2 V89L nonsynonymous SNP (rs523349C) with a hazard ratio (HR) of 2.87 (95% confidence interval [CI], 2.07-4.00; p=4 × 10(-10); 48% BCR). In addition, in whites, the combination of two SNPs, rs518673T in SRD5A1 and rs12470143A in SRD5A2, was associated with a reduced BCR rate for carriers of three or four alleles (HR: 0.37; 95% CI, 0.19-0.71; p=0.003;16% BCR) compared with noncarriers (38% BCR), whereas the SRD5A2 rs12470143A was significant in Asians (HR: 0.46; 95% CI, 0.28-0.73; p=0.001). Limitations of our study include few events of androgen-deprivation resistance or cancer-specific death.
Our study is the first to show positive associations of several SRD5A1 and SRD5A2 variations as independent predictors of BCR after RP.
Audet-Walsh E, Bellemare J, Nadeau G, Lacombe L, Fradet Y, Fradet V, Huang SP, Bao BY, Douville P, Girard H, Guillemette C, Lévesque E. Are you the author?
Reference: Eur Urol. 2011 Jun 27. Epub ahead of print.