Significance of perineural invasion, lymphovascular invasion, and high-grade prostatic intraepithelial neoplasia in robot-assisted laparoscopic radical prostatectomy

Background: Recently, more detailed histopathological variables such as perineural invasion (PNI), lymphovascular invasion (LVI), and high-grade prostatic intraepithelial neoplasia (HGPIN) have been investigated as prognostic factors for adverse pathologic findings on the radical prostatectomy specimen. We aim to determine whether these pathological factors are associated with adverse pathologic features after robot-assisted laparoscopic radical prostatectomy (RALP). Methods: All 407 patients who underwent RALP with pelvic lymphadenectomy between July 2005 and December 2009 were analyzed, retrospectively. We investigated the association of these three pathological parameters with adverse pathological findings in RALP specimen and biochemical recurrence using Kaplan-Meier analysis with log-rank test and a multivariate Cox proportional hazard model. Results: The PNI and LVI were significantly associated with a higher pathological stage, a higher pathological Gleason score, a higher tumor volume in RALP specimen, a higher frequency of positive surgical margins, and a higher frequency of seminal vesicle invasion. In addition, PNI correlated with preoperative PSA, clinical stage, and Gleason score on needle biopsy. However, the HGPIN was not significantly associated with the clinicopathological characteristics studied. Using log-rank test, presence of PNI (P < 0.001) increases the probability of biochemical recurrence. On multivariate analysis, all three pathological parameters were not significantly correlated with biochemical recurrence. Conclusion: Although presence of PNI and LVI in RALP specimen correlated with multiple adverse clinicopathological factors, it did not predict biochemical recurrence, thus limiting its clinical usefulness. HGPIN was not significantly associated with the clinicopathological characteristics studied.