Risk-adjusted analysis of positive surgical margins following laparoscopic and retropubic radical prostatectomy

OBJECTIVES: To prospectively compare in a contemporary and contemporaneous series the positive surgical margin (PSM) rate between laparoscopic (LRP) and retropubic (RRP) radical prostatectomy at the same institution. METHODS: Between 1 January 2003 and 30 June 2005, 1177 consecutive men with clinically localized adenocarcinoma of the prostate underwent radical prostatectomy at the same institution: 485 laparoscopically and 692 through a retropubic approach. Partin table probability of organ-confined (OC) disease was used as an index of disease aggressiveness: The PSM rate between the two approaches was compared, with adjustment for the OC probability. RESULTS: Overall both surgical approaches had a comparable PSM rate of 11.3% after LRP and 11% after RRP. In a logistic regression analysis adjusting for OC probability, there was no statistically significant difference between LRP and RRP (odds ratio [OR]: 1.156; 95% confidence interval [%95 CI], 0.792, 1.686; p=0.5). There was a statistically significant decrease over time in the rate of PSM for LRP (OR: 0.71 per 100 patients treated; %95 CI, 0.57, 0.89; p=0.003), while that of RRP was unchanged (OR: 1.06 per 100 patients treated; %95 CI, 0.94, 1.21; p=0.3; p=0.002 for interaction between change over time and procedure). CONCLUSIONS: In our institution, laparoscopic and retropubic radical prostatectomy provide comparable PSM rates for patients with clinically localized prostate cancer. The PSM rate over the study period remained unchanged in the RRP experience, indicating a mature and well-established operative technique, while that of LRP underwent a significant decrease, demonstrating that the procedure and therefore the results continued to evolve during the study.