SAMD5 mRNA was overexpressed in prostate cancer and can predict biochemical recurrence after radical prostatectomy

Purpose To identify a novel biomarker that can predict biochemical recurrence (BCR) after radical prostatectomy. Methods The gene expression profile of SAMD5 in prostate cancer was explored based on the oncomine database and The Cancer Genomic Atlas (TCGA). The follow-up information and clinical pathologic variables were extracted from the following cohort study: TCGA_prostate carcinoma. And then, survival analysis was conducted using the Kaplan–Meier plot and Cox’s proportional hazard regression model. Furthermore, another independent cohort study: Taylor prostate, was also acquired to validate the predictive effect of SAMD5 on BCR. In addition, the expression profile of SAMD5 in other cancer types was investigated using TCGA dataset. Results SAMD5 mRNA was shown to be up-regulated in multiple microarray datasets of prostate cancer with the strict statistic criteria: p < 0.01 and fold change ≥ 2. In TCGA_PCa cohort study, high expression of SAMD5 was a risk factor for patients on post-operative BCR (HR 2.181, 95%CI 1.199–3.966, p = 0.011) and this predictive ability was independent of Gleason score and pathologic T stage (HR 2.018, 95%CI 1.102–3.698, p = 0.023). In another validating cohort study, the statistic trend was similar, and the pooled analysis by combining the two cohort study further confirmed its prognostic effect. Conclusion SAMD5 mRNA was overexpressed in prostate cancer and had powerful prognostic ability on predicting post-operative BCR, independent of Gleason score and pathologic T stage. Its high expression was associated with poor prognosis after RP.