Can perineural invasion detected in prostate needle biopsy specimens predict surgical margin positivity in D’Amico low risk patients?

Objectives: In this study, our aim was to estimate the value of perineural invasion (PNI) in prostate needle biopsy (PNB) specimens in the prediction of surgical margin positivity (SMP) and its prognostic significance (upgrade Gleason Score) in patients who had undergone radical retropubic prostatectomy (RRP) with low risk prostate cancer according to D’Amico risk assessment. Materials and Methods: We retrospectively analyzed the data of 65 patients who were diagnosed as clinical stage T1c prostate cancer (PC) and underwent RRP between January 2010 and June 2013. Pathological specimens of PNB and RRP were separately examined for the parameters of PNI, vascular invasion (VI), Gleason Score (GS) and SMP. Results: The patients’ mean age was 63.65 ± 4.93 (range 47- 75) years. PNI in PNB specimens were identified in 12 of 65 patients and 11 of 12 patients showed SMP on RRP specimens. While 53 of 65 patients had not PNI on PNB, only 11 of them demonstrated SMP on RRP specimens. SMP was 30.64-fold more frequently encountered in PNB specimens obtained from PNI-positive patients relative to PNI-negative patients. In our study, PNI detected in PNB specimens was statistically significantly associated with SMP on RRP specimens (P = 0.0001). Conclusion: It is well known that higher PSA values and GS were independent predictors of SMP in clinically localized prostate cancer (CLPC). We think that PNI in PNB specimens may be a useful prognostic factor for predicting SMP in cases with CLPC.