Predictive preoperative factors for positive surgical margins in robotic radical prostatectomy in low-risk prostate cancer.

Abstract

Positive surgical margins after radical prostatectomy for localized prostate cancer is a powerful predictor of PSA recurrence. Clinical stage, Gleason score and preoperative PSA are predictive factors for positive surgical margin after radical prostatectomy. In this study, we aimed to identify preoperative factors affecting surgical margin positivity in low-risk prostate cancer after robotic radical prostatectomy (RARP). Between 2008 and 2011 (<cT2b, PSA <10, Gleason <7), data from 112 patients with low-risk (<cT2b, PSA <10, Gleason <7), prostate cancer who had undergone RARP were examined prospectively. The effects of PSA, body mass index, surgery time after biopsy, percentage of positive cores, tumor length and prostate weight on positive surgical margin were evaluated. For statistical analyses, Mann-Whitney U, Pearson chi-square and logistic regression tests were used. It was observed that mean age and body mass index had no effect on positive surgical margins (p=0.2 and 0.6). According to univariate analysis, it was found that an elapsed time of less than six weeks from biopsy to surgery (p=0.07), tumor percentage of more than 5% in a biopsy specimen (p=0.003), a positive core percentage of more than 20% (p=0.045) and a prostate volume below 50 cc (p=0.037) increased the rate of positive surgical margins. Based on multivariate analysis, PSA levels above 5 ng/mL (OR: 8.006, p=0.012) and an elapsed time of less than 6 weeks between biopsy and surgery (OR: 10.814, p=0.029) increased the risk of positive surgical margins. In low-risk prostate cancer, a waiting time of less than six weeks between biopsy and surgery and PSA levels above 5 ng/mL are predictive of high surgical margin positivity after robotic radical prostatectomy.