Positive surgical margins following radical prostatectomy are an important predictor of biochemical, local and systemic progression, and remain a fairly frequent postoperative finding despite improvements in surgical technique and technology. The prognostic power of capsular incision—generally defined as extension of tumor to the surgical margins without documented extraprostatic extension (EPE)—is not so widely accepted. Initially thought to have little effect on the risk of progression, increasing evidence indicates significant prognostic importance for capsular incision in patients undergoing radical prostatectomy for prostate cancer. In a large, retrospective study, Preston et al. evaluated the effects of capsular incision into tumor on outcomes among consecutive men undergoing radical prostatectomy at one of two tertiary academic centers.

Data from a total of 6,855 patients who underwent open, laparoscopic or robot-assisted radical prostatectomy at Ottawa Hospital or at Memorial Sloan–Kettering Cancer Center between 1985 and 2008 were included in the analysis. Patients were assigned to one of four groups according to surgical margin status and EPE: group 1 (capsular incision group), positive surgical margins without EPE (n = 286); group 2, negative surgical margins without EPE (n = 2,447); group 3, negative surgical margins with EPE (n = 3,147); group 4, positive surgical margins with EPE (n = 975). The primary outcome was 5-year recurrence-free survival, with recurrence defined as a rising serum PSA level >0.2 ng/ml. The median duration of follow-up was 37.3 months.

The 5-year recurrence-free survival in group 1 patients was 77% (95% CI 72–83%), which was significantly lower than that in group 2 (94%, 95% CI 93–95%; P <0.0001) and group 3 (86%, 95% CI 84–87%; P = 0.0002). In patients with capsular incision, preoperative Gleason grade was inversely correlated with 5-year recurrence-free survival (logrank P <0.0001).

These results indicate that capsular incision adversely affects recurrence-free survival in patients undergoing radical prostatectomy. Capsular incision seems to be a sign of suboptimal surgical quality, so the findings of this study demonstrate the importance of prostatectomy technique. Owing to the associated risk of disease recurrence, patients with capsular incision might benefit from adjuvant radiation therapy following radical prostatectomy.