Purpose: Positive surgical margins (PSMs) after radical prostatectomy (RP) are a known factor associated with biochemical recurrence (BCR) and raise the issue of adjuvant treatment by radiotherapy versus salvage treatment at recurrence. To help this choice, our study aimed to analyze BCR-free survival and factors associated with BCR in patients with PSM and undetectable postoperative prostate-specific antigen (PSA).
Methods: Between 2005 and 2008, 630 patients had RP for localized prostate cancer in our center. We included patients with PSM, uninvaded nods, undetectable postoperative PSA and no adjuvant treatment. The 5-year BCR-free survival was calculated using Kaplan-Meier method. Logistic regression models were used to determine the factors associated with BCR in univariate and multivariate analyses (Cox model).
Results: The PSM rate was 32.7 % (n = 206 patients), and 110 patients corresponded to the inclusion criteria. The median follow-up was 72 months. The BCR rate was 30 % with a 5-year BCR-free survival of 83.9 %. The factors significantly associated with BCR were preoperative PSA, predominance and percentage of Gleason 4, tumor volume, PSM length and predominance of Gleason 4 at the margin. In the multivariate analysis, the remaining two significant factors were PSM length [OR 4.35, 95 % CI (1.011-1.421), p = 0.037] and tumor volume [OR 4.29, 95 % CI (1.011-1.483), p = 0.038].
Conclusion: Over a 5-year follow-up, only one-third of patients experienced BCR. It might be reasonable to postpone adjuvant radiotherapy for patients with PSM and undetectable PSA after RP. Tumor volume and PSM length were associated with BCR and should be taken into account in the postoperative treatment management.
Keywords: Adjuvant radiotherapy; Biochemical recurrence; Margin; Prostate cancer; Radical prostatectomy.