ABSTRACT
<p><b>Objective</b>To explore the expression of I-5α-reductase (SRD5A1)and its prognostic role in prostate cancer .</p><p><b>METHODS</b>Data about SRD5A1 were retrieved from the ONCOMINE database and the role of SRD5A1 in prostate cancer was analyzed.</p><p><b>RESULTS</b>Totally, 992 studies of different types relevant to the expression of SRD5A1 were identified in the ONCOMINE database. The SRD5A1 expression was statistically significant in 239 of the studies, overexpressed in 157 (11 in prostate cancer) and underexpressed in the other 82 (3 in prostate cancer). Eighteen of the studies, with 1 068 samples, addressed the expression of SRD5A1 in prostate cancer and normal tissues, which was significantly higher in the former than in the latter tissue (P<0.05). In 3 of the studies, the SRD5A1 expression was high in primary prostate cancer and increased with its metastasis (P<0.0 5). Two of the studies with prognostic data showed a higher rate of postoperative biochemical recurrence and a higher total mortality rate in the patients with a high than in those with a low expression of SRD5A1 (P<0.05).</p><p><b>CONCLUSIONS</b>SRD5A1 is highly expressed in prostate cancer, especially in metastatic and castration-resistant prostate cancer and its expression is associated with the prognosis of prostate cancer, which may be an important target of medication for prostate cancer.</p>