Prognostic significance of perineural invasion in patients who underwent radical prostatectomy for localized prostate cancer

Purpose: Perineural space invasion (PNI) is an important mechanism for progression of cancer through the prostatic capsule, the prognostic significance of PNI remains controversial. The purpose of the present study was to assess the prognostic significance of PNI between prostate biopsy and radical prostatectomy (RP) samples of patients affected by clinically localized prostate cancer (PCa). Methods: 75 patients undergoing RP who had PNI on prostate needle biopsy were retrospectively reviewed. To evaluate the correlation between PNI and adverse pathological characteristics of PCa we examined these demographic and clinicopathologic variables: patients age, family history, prostate specific antigen (PSA) level at the time of diagnosis, biopsy Gleason score (GS), clinical stage, extraprostatic extension (EPE), positive surgical margins (PSM), biochemical recurrence (BR), positive lymph nodes (PLN) involvement and seminal vesicle invasion (SVI). Results: At RP 24% of patients had organ-confined disease, whereas EPE in neurovascular bundle (NVB) and SVI were present in 76% and 6.7%, respectively. PSM were shown in 32% and PLN in 17.3% of our cases. At a median follow-up of 44 months, 36% had BR, 9.3% developed metastatic disease, and 2.6% died of PCa. GS (>6) on needle biopsy and PSA level (>= 10) were helpful in predicting which patients were likely to have tumor in the NVB (p<0.002). Conclusions: PNI on biopsy is correlated with an increased risk of BR, while is not statistically associated with PSM. Nerve-sparing surgery does not compromise the oncological outcomes for patients with PNI on biopsy.