The Impact of Positive Surgical Margins on Mortality Following Radical Prostatectomy During the Prostate Specific Antigen Era

Purpose: The presence of a positive surgical margin at radical prostatectomy has been linked to an increased risk of postoperative biochemical recurrence. We evaluated the impact of margin status on subsequent clinical progression and mortality. Materials and Methods: We reviewed the records of 11,729 patients who underwent prostatectomy between 1990 and 2006. Survival was estimated for patients with vs without a positive margin and compared using the log rank test. Cox proportional hazards regression models were used to analyze the impact of margin status on survival. Results: Overall 3,651 (31.1%) men were identified with a positive margin. Median postoperative followup was 8.2 years (IQR 4.4, 12.1). The 10-year biochemical recurrence-free rate for patients with and without a positive margin was 56% and 77%, respectively (p <0.001), while 10-year local recurrence-free survival was 89% vs 95% (p <0.001). Margin status also stratified systemic progression-free survival (93% vs 97%, p <0.001), cancer specific survival (96% vs 99%, p <0.001) and overall survival (83% vs 88%, p <0.001). On multivariate analysis the presence of a positive margin was associated with increased risk of biochemical recurrence (HR 1.63, 95% CI 1.47-1.80, p <0.0001), local recurrence (HR 1.78, 95% CI 1.45-2.19, p <0.0001) and receipt of salvage therapy (HR 1.79, 95% CI 1.58-2.02, p <0.0001) but was not a significant predictor of systemic progression (p = 0.95), cancer specific death (p = 0.15) or overall mortality (p = 0.16). Conclusions: The presence of a positive margin increased the risk of biochemical recurrence, local recurrence and the need for salvage treatment but was not independently associated with systemic progression, cancer specific death or overall mortality. These results should be considered when evaluating patients for adjuvant therapy.