Does seminal vesicle-sparing robotic radical prostatectomy influence postoperative prostate-specific antigen measured with an ultrasensitive immunoassay?

PURPOSE Sparing of the seminal vesicles during robotic radical prostatectomy (SVRP) is an attempt to reduce potential damage to the hypogastric pelvic nerves. However, the seminal vesicles are known to express prostate-specific antigen (PSA) and it is unknown whether SVRP influences oncological outcome measured with ultrasensitive PSA immunoassays. In a retrospective study we analysed whether SVRP affects oncological outcome in terms of ultrasensitive PSA nadir and biochemical recurrence as compared with standard robotic assisted laparoscopic radical prostatectomy (sRALP). METHODS Overall, 102 patients underwent robotic prostatectomy. Patients were non-randomly allocated to the following surgical techniques: a SVRP group of 39 patients who underwent robotic radical prostatectomy sparing the tips of the seminal vesicles; a standard group of 63 patients who were treated with sRALP. Inclusion criteria were histologically proven negative margins (R0) and negative lymph node status (pN0). PSA was measured with an ultrasensitive assay. The Mann-Whitney U-test was used to compare the differences in PSA nadir and follow-up PSA. Biochemical recurrence was diagnosed if PSA rose to ≥0.2 mg/ml. RESULTS Median (range) follow-up was 31.4 (16.4­43.8) months. Preoperative PSA was 5.8 (0.13­15.29) ng/ml in the SVRP group and 7.1 (0.8­46) ng/ml in the sRALP group. Two cases of biochemical recurrence occurred in the sRALP group during follow-up. One of these two patients presented with locally advanced prostate carcinoma diagnosed from the definitive pathological specimen (pT3b). No patient of the SVRP group had seminal vesicle invasion or biochemical recurrence. No significant between-group difference in terms of PSA nadir and follow-up PSA was recorded. However, the percentage of patients who did not reach PSA nadir values of <0.01 ng/ml was higher in the SVRP group (10 vs 5% in the sRALP group). CONCLUSIONS Compared with sRALP, SVRP had no clinical impact on oncological outcome in terms of PSA nadir or biochemical recurrence measured with an ultrasensitive PSA immunoassay. A slightly higher PSA nadir after SVRP seems to be expected, which needs to be mentioned during follow-up of these patients.