Background and objectives: To determine prostate cancer biochemical recurrence rates with respect to surgical margin (SM) status for patients undergoing robotic-assisted laparoscopic radical prostatectomy (RALP).
Methods: IRB-approved radical prostatectomy database was queried. Patients were stratified as low, intermediate, and high risk according to D'Amico's risk classification. Postoperative prostate-specific antigen (PSA) values were obtained every 3 mo for the first year, then biannually and annually thereafter. Biochemical recurrence was defined as ≥0.2ng/mL. Patients receiving adjuvant or salvage treatment were included. Positive surgical margin was defined as presence of cancer cells at inked resection margin in the final specimen. Margin presence (negative/positive), margin multiplicity (single/multiple), and margin length (≤ 3mm focal and >3mm extensive) were noted. Kaplan-Meier curves of biochemical recurrence-free survival (BRFS) as a function of SM were generated. Forward stepwise multivariate Cox regression was performed, with preoperative PSA, Gleason score, pathologic stage, prostate gland weight, and SM as covariates.
Results: At our institution, 1437 patients underwent RALP (2003-2009). Of these, 1159 had sufficient data and were included in our analysis. Mean follow-up was 16 mo. Kaplan-Meier curves demonstrated significant increase in BRFS in low-risk and intermediate-risk groups with negative SM. Overall BRFS at 5 y was 72%. Gleason score, pathologic stage, and SM status were significant prognostic factors in multivariate analysis.
Conclusions: Negative surgical margins resulted in lower biochemical recurrence rates for low-risk and intermediate-risk groups. Multifocal and longer positive margins were associated with higher biochemical recurrence rates compared with unifocal and shorter positive margins. Documenting biochemical recurrence rates for RALP is important, because this treatment for localized prostate cancer is validated.