Clinical stage is the only preoperative variable independently associated with positive surgical margins (PSMs) following robot-assisted laparoscopic radical prostatectomy (RARP) for prostate cancer, according to researchers.
Vipul R. Patel, MD, of the Global Robotics Institute, Florida Hospital Celebration Health in Celebration, Fla., and colleagues prospectively analyzed 876 men who underwent RARP for prostate cancer.
Compared with patients who had clinical stage T1c disease, those who had T2 and T3 disease had a 2.9 and 10.7 times increased likelihood of having PSMs, respectively, the investigators reported in European Urology (2010; published online ahead of print).
Pathologic stage and percentage of tumor in the surgical specimen independently predicted PSMs when the researchers analyzed pre-, intra-, and postoperative variables combined.
Compared with men with pathologic stage PT2 cancer, those with PT3 and PT4 disease had a 3.8 and 27.9 times increased likelihood of PSMs, respectively. Each additional percentage point increase in tumor volume was associated with an 8.7 times increased risk of PSM.
The study also demonstrated that BMI independently predicted apical PSMs, with increasing BMI predicting a higher incidence of an apex location.