Clinical result and follow-up of incidental prostate cancer after radical prostatectomy

Objective To investigate the long-term outcome of radical prostatectomy (RP) in the patients with incidental prostate cancer (IPCa) detected by surgery of benign prostatic hyperplasia (BPH) and to evaluate the risk factors for residual tumour after BPH surgery and biochemical recurrence in patients with IPCa treated with RP. Methods We retrospectively analyzed the clinical and follow-up data of 45 patients with IPCa detected by surgery of BPH and undergoing RP from January 2004 to October 2016 .The age, PSA before and after BPH surgery, prostate volume, T stage and Gleason score after the BPH surgery, T stage at RP(pT0, pT2, pT3), Gleason score at RP and status of biochemical recurrence were recorded. Multivariate logistic regression analysis addressed the association between the factors and the presence of residual cancer after the surgery for BPH. Cox regression was used to analyzed the relationship between the factors and the rate of biochemical recurrence after RP. Results Among 45 IPCa patients, 21 patients were stage T1a and 24 were stage T1b. After RP, 7 (15.6%) patients had no residual tumor (pT0). PSA before BPH surgery(RR=2.58, 95%CI 1.27-5.42, P=0.04), PSA after BPH surgery(RR=4.26, 95%CI 2.57-7.64, P=0.01)and Gleason score after BPH surgery(RR=3.98, 95%CI 1.85-5.77, P=0.02) were significant associated factors with the residual cancer after BPH surgery. With a mean follow-up of 54 months(ranging 5-144 months), the 5- and 10-years. biochemical recurrence-free survival rates were 95.6% and 86.7%, respectively. PSA after surgery for BPH(RR=4.79, 95%CI 2.57-7.64, P=0.02) and Gleason score after RP(RR=2.01, 95%CI 1.74-5.21, P=0.04) were the only independent risk factors for biochemical recurrence. Stage (T1a-T1b) did not predict residual cancer or the rate of biochemical recurrence (P>0.05). Conclusions RP in the patients with IPCa detected by BPH surgery had a good outcome of long-term oncological control. PSA before and after BPH surgery and Gleason score at BPH surgery were the significant associated factors of residual cancer after BPH surgery. PSA after BPH surgery and Gleason score at RP were the only independent risk factors for biochemical recurrence. Key words: Prostatic neoplasms; Incidental cancer; Radical prostatectomy; Biochemical recurrence