Prostate biopsy perineural invasion is not independently associated with positive surgical margins following radical retropubic prostatectomy

Abstract

Purpose: Perineural invasion (PNI) in prostate cancer has been associated with poor prognosis. We sought to determine whether biopsy and radical prostatectomy (RP) PNI are associated with adverse outcomes. A secondary objective was to determine whether prostate biopsy PNI should alter surgical technique.

Methods: Patients were categorized by PNI on biopsy and RP specimens. Associations between PNI, clinicopathologic characteristics, and biochemical recurrence (BCR) rates were assessed.

Results: A total of 2,500 patients undergoing open RP by a single-surgeon from 1999 to 2011 were analyzed. In unadjusted univariate analyses, biopsy PNI was significantly associated with Gleason score, clinical stage, positive surgical margins, extraprostatic extension (EPE), seminal vesicle invasion (SVI), positive lymph nodes, and BCR (p < 0.001). On multivariate analysis, EPE (p < 0.001), and SVI (p = 0.022) remained associated with biopsy PNI. Biopsy PNI was not associated with positive margins at RP (OR 1.3, 95 % CI 0.92-1.9). The presence of PNI in the final RP specimen conferred a greater than 4 times increased odds of positive margin (OR 4.6, 95 % CI 2.30-9.22; p < 0.0001). Men with PNI on biopsy were 1.5 times more likely to experience BCR (OR 1.5, 1.06-2.01). PNI on biopsy or RP specimens was not associated with overall survival.

Conclusions: In men undergoing open RP for clinically localized prostate adenocarcinoma, biopsy PNI is associated with an increased risk of BCR. PNI on prostate biopsy was not associated with positive surgical margins after adjusting for related co-variables. The presence of PNI on prostate biopsy should not preclude utilization of a nerve-sparing approach.