Impact of positive surgical margin location and perineural invasion on biochemical recurrence in patients undergoing radical prostatectomy

OBJECTIVE: To estimate the prognostic value of positive surgical margins (PSM) location and perineural invasion (PNI) for biochemical recurrence (BCR) in patients undergoing radical prostatectomy (RP). METHODS: All men with prostate cancer (PCa) who received RP in the second hospital of Tianjin Medical University from 2014 to 2018 were retrospectively identified. All patients met the following criteria: no neoadjuvant or adjuvant treatment, absence of lymph node invasion, or distant metastasis confirmed by surgery or imaging. Comparisons were made between cases with only apex positive (AM), isolated nonapical positive (OM), multiple positive (MM), and negative surgical margins (NSM). Patients were also subdivided according to the Gleason score and pathological tumor stage for analysis. RESULTS: A total of 416 patients available for analysis, of which 132 (31.7%) were PSM, 43 were AM, 37 were OM, and 52 were MM at a median follow-up of 27 months. The PNI was in 30.5% of patients. BCR occurred in 22.6% of patients during follow-up. Both AM and MM were noticed to be independent predictors of BCR with a hazard ratio of 4.192 (95% CI 2.185–8.042; p < 0.001) and 2.758 (95% CI 1.559–4.880; p < 0.001), respectively, when compared to NSM. Though the correlation was significant in univariate analysis, PNI was not an independent risk factor for BCR (p = 0.369). Subgroup analyses suggested that MM was not particularly predictive for BCR in the Gleason score < 8. The hole Cox regression model for the C-index was 0.843 CONCLUSIONS: PSM location was a significant independent predictor of BCR in PCa, especially in patients with AM or MM, while PNI is a non-independent risk factor. Compared with other locations, AM has a higher BCR risk.