Men With Organ-confined Prostate Cancer and Positive Surgical Margins Develop Biochemical Failure at a Similar Rate to Men With Extracapsular Extension

Abstract

To define the role of positive surgical margins (PSMs) after radical retropubic prostatectomy as a predictor of biochemical failure (BCF) in prostate cancer with respect to pathologic stage. A retrospective cohort study of 300 patients who had undergone radical retropubic prostatectomy from 1993 to 1995 was performed. The role of margin status and the length of the PSM in the progression to BCF was defined after controlling for the preoperative prostate-specific antigen level, Gleason score, tumor stage, tumor volume, seminal vesical invasion, lymphovascular invasion, and perineural invasion using a multivariate regression model. The median follow-up time was 12 years. The presence of PSMs correlated with a shorter time to BCF in men with Stage pT2 disease (P<.0001) but not in men with Stage pT3 disease (P=.66). Of the patients with Stage pT2 disease and PSMs, the PSM length did not correlate with progression to BCF. PSMs predicted a shorter time to progression to BCF in patients with high- and low-volume pT2 disease (P=.0261 and P=.0003, respectively). Only PSMs predicted a shorter time to BCF on multivariate analysis in patients with Stage pT2 cancer (hazard ratio 2.33, 95% confidence interval 1.495-3.723). In patients with Stage pT3 disease, PSMs were not associated with an increased risk of BCF (hazard ratio 0.747, 95% confidence interval 0.328-1.703). Surgical margin status did not affect the risk of BCF in patients with Stage pT3a disease; however, it did affect patients with Stage pT2 disease, irrespective of PSM length or disease volume. During 12 years of follow-up, the patients with PSMs and Stage pT2 disease had a risk of BCF similar to that of the patients with Stage pT3 disease.