Nerve-sparing techniques used during radical prostatectomy to preserve erectile function may increase the risk of positive surgical margins (PSM), new findings suggest.
In a prospective cohort of 1,148 men undergoing RP for localized prostate cancer, investigators at the University of Copenhagen, Denmark, led by Martin Andreas Røder, MD, found that nerve-sparing surgery (NSS) increased the risk of PSM by 50% compared with wide resection, according to an online report in the Scandinavian Journal of Urology and Nephrology. The overall PSM rate for the cohort was 31.4%.
Additionally, each doubling of PSA, beginning at 0.5 ng/mL, increased PSM risk by 56%, and each 10% increase in percent positive biopsies (PPBs) increased the risk by 11%. The researchers calculated PPBs from the number of positive cores divided by the total number of cores.
Compared with patients who had T1 tumors, those with T3 tumors had a 2.8 times increased risk of PSM. Contrary to previous studies, biopsy Gleason score did not significantly affect PSM risk.
Possible explanations for the increased risk of PSM associated with NSS include preoperative understaging, poor selection of candidates for this type of surgery, and/or improper surgical skills, the researchers noted.
Of the six surgeons who performed the surgeries, only two performed robotic-assisted laparoscopic prostatectomy (RALP) procedures. NSS was more frequent in RALP compared with open procedures (69.3% vs. 22.8%).
The new findings contrast with those of a recently published study in BJU International (2012;109:533-538), in which Australian investigators concluded that, with appropriate selection of patients, nerve-sparing surgery does not increase the risk of PSM, regardless of whether the cancer was organ-confined or extracapsular extension was present. The study included 945 men who underwent RP by one surgeon.