Incidental Prostate Cancer from Prostate with Benign Biopsies: A Predictive and Survival Analysis from Cohort Study

PURPOSE: This cohort was to evaluate incidental prostate cancer (iPCa) from men with preoperative benign biopsies and demonstrate their outcomes under different managements. PATIENTS AND METHODS: Between 2015 and 2017, we analyzed the risk factors having iPCa from surgical specimens from men provided with benign preoperative biopsies of their prostates. Furthermore, we compared the survival outcomes according to the different managements after iPCa was diagnosed. Receiver operating characteristic (ROC) curve was utilized to find the best thresholds. Univariable and multivariable nested logit regression were performed to estimate the effect size of different independent variables. Odds ratio (OR) was expressed with 95% confidence interval, and the alpha level was 5%. RESULTS: In 295 men we enrolled, there were 57 (19%) men having iPCa from surgical specimens. In univariable logit regression, we found significant variables of age, PSA, prostatic volume, PSA velocity ≥ 0.75 ng/mL/year for 3 years, taking 5α reductase inhibitors, abnormal digital rectal examination, cores of biopsy and surgical methods. In multivariable model, PSA was the strongest variable predicting iPCa (OR 3.81 [2.04–7.07]; Wald: 17.75; p < 0.001). In ROC curve, the best threshold was 9.025 ng/mL (area under curve: 0.95; sensitivity: 0.947; specificity: 0.866). In Kaplan–Meier curve of 27.89-month follow-up, robot-assisted simple prostatectomy (RASP) can provide similar PSA progression-free period as robot-assisted radical prostatectomy (RARP) following transurethral surgeries in organ-confined cancer (Log rank test, p = 0.293), and both of them were better than external-beam radiation therapy (RT) following transurethral surgeries (Log rank test, p < 0.001). CONCLUSION: PSA was the strongest variable to predict iPCa out of prostate with preoperative benign biopsies. RASP was parallel to RARP following transurethral surgeries in organ-confined cancer in the short term.