Influence of pathological factors on oncological outcomes after robot-assisted radical prostatectomy for localized prostate cancer: Results of a prospective study

Abstract

Purpose: To assess the prognostic significance of lymphovascular invasion (LVI), maximum tumor diameter (MTD), high-grade prostatic intraepithelial neoplasia, perineural invasion, and length of positive surgical margins after robot-assisted radical prostatectomy (RARP).

Methods: A single-institution prospective analysis of all patients who underwent RARP for localized prostate cancer was performed between January 2005 and June 2013. The primary end point was biochemical recurrence-free survival (BRFS). BRFS was estimated using the Kaplan-Meier method and compared to that from the log-rank test. Cox׳s proportional hazards regression univariate and multivariate analyses were performed to define the prognostic factors.

Results: Overall, 742 men were included. After a median follow-up of 31.4 months, biochemical recurrence occurred in 80 patients (10.8%). BRFS was 93%, 87%, and 80.7% at 1, 3, and 5 years, respectively. Progression to local recurrence occurred in 49 patients (6.6%). During the follow-up period, 3 patients experienced progression to metastatic disease and were treated with hormonotherapy. No patient died of disease during the study period. In multivariate analyses, Gleason score was the strongest predictor of BRFS (hazard ratio [HR] = 3.4; P<0.001). There were 3 other predictive factors of BRFS were LVI (HR = 7.64; P = 0.005), MTD (HR = 4.04; P =0.009), and margin length ≥ 3 mm (HR = 1.25; P = 0.04).

Conclusion: In the era of serum prostate-specific antigen testing maturity in conjunction with a single approach to extirpation of the prostate gland by RARP, LVI, MTD, and positive surgical margins ≥ 3 mm are prognostic factors associated with BRFS after RARP. Consideration could be given to incorporate them in the pathology report of the radical prostatectomy specimens and they could assist physicians in clinical decision making.

Keywords: Adenocarcinoma; Lymphovascular invasion; Positive surgical margin; Prostate; Tumor volume.