Objective To investigate the predictive value of serum microRNA (miRNA) 17-5p in salvage treatment outcomes of patients with lymph node positive prostate cancer (PCa) after radical prostatectomy (RP). Methods The clinical data of 94 patients with lymph node positive PCa who received RP and salvage therapy in the Department of Urology at the hospital between January 2020 and September 2022 were retrospectively collected. The peripheral serum samples within 72 hours before rescue treatment were collected. The expression level of serum miR-17-5p was detected by real-time fluorescence quantitative PCR. Results The level of serum miR-17-5p in the failed salvage treatment group was significantly higher than that in the successful treatment group [0.95 (0.59, 1.22) vs. 1.98 (1.23, 2.97)], and the difference was statistically significant (P<0.001). The area under ROC curve of serum miR-17-5p for predicting salvage treatment outcome was 0.816 (95%CI: 0.717-0.915), corresponding cutoff value was 1.18, sensitivity was 85.2%, and specificity was 75.8%. COX risk regression results showed that serum miR-17-5p≥1.18 was an independent risk factor for salvage treatment failure (P<0.05). According to the cut-off value determined by the ROC curve, during the follow-up period, the median PFS time of patients with low expression of serum miR-17-5p (<1.18) and high expression of serum miR-17-5p (≥1.18) was 25 and 20 months, respectively, and the PFS rate was 73.53% and 13.33%, respectively. The difference was statistically significant (Log Rank x2=15.023, P<0.001). Conclusion The high expression of serum miR-17-5p is associated with the failure of salvage treatment outcome in PCa patients with post-RP lymph node positive, and serum miR-17-5p is expected to be a reliable biomarker for predicting salvage treatment outcome in PCa patients with post-RP lymph node positive. |