Long-term Oncologic Impact of Positive Anterior and Posterior Surgical Margins After Radical Prostatectomy

Objective: The objective of this study was to evaluate the impact of the anterior/posterior status of positive surgical margin (PSM) on long-term outcomes after radical prostatectomy for prostate cancer. Patients and Methods: We included 391 consecutive PSM patients after radical prostatectomy between 1993 and 2007 excluding cases with multiple location PSM or lack of anterior/posterior status data. The oncologic impact of anterior-PSM and posterior-PSM were examined by Kaplan-Meier analysis and the Cox proportional hazards model. Results: There were 115 cases (29.4%) with apex-PSM, 257 cases (65.7%) with peripheral PSM, and 19 cases (4.9%) with bladder neck PSM. Among the 257 peripheral PSM cases, 58 cases (22.6%) were with anterior-PSM, 174 cases (67.7%) were with posterior-PSM, and 25 cases (9.7%) were with both anterior and posterior PSM. Over a median follow-up of 12.6 years, patients with anterior-PSM, especially those with low to intermediate Gleason score (≤7), showed a biochemical recurrence (BCR) prognosis similar to those with apex-PSM. In contrast, patients with posterior-PSM showed significantly higher BCR risk on both univariate and multivariate analyses when compared with those with apex-PSM. No impact on metastasis-free survival or overall survival was observed. Conclusions: In our study, we found that prostate cancer patients with anterior-PSM showed a more favorable BCR prognosis similar to those with apex-PSM when comparing to patients with posterior-PSM. Our study results may help physicians to choose different treatment options for patients diagnosed with different PSM status including considering further adjuvant treatment for patients with posterior-PSM.