Positive Surgical Margins After Robot-Assisted Partial Nephrectomy Predict Long-Term Oncologic Outcomes For Clinically Localized Renal Masses

Introduction: For patients with clinically localized renal masses, positive surgical margins (PSMs) after robotic partial nephrectomy (RPN) have been associated with a higher risk of disease recurrence, although some studies have challenged this conclusion. Owing to inconsistent reports and a lack of long-term robotic data, the clinical impact of PSM after RPN remains uncertain. We evaluate long-term (>6 years) survival outcomes after RPN in patients with clinically localized disease with respect to surgical margin status.Methods: We conducted a retrospective review of patients who underwent RPN for clinically localized renal masses from June 2007 to December 2012 at Washington University School of Medicine. Disease recurrence and overall survival (OS) were stratified on the presence or absence of PSM. The cohort was analyzed to identify patient- and tumor-specific characteristics associated with PSM.Results: We identified 374 RPNs performed from 2007 to 2012 with a mean follow-up time of 77.7 months (SD 32.2 months). PSM was identified in 12 (3.2%) patients. Patients with PSM were at 14-fold increased risk for recurrence with no difference in OS (p < 0.001, p = 0.130, respectively). Patients with PSM had higher incidence of chronic obstructive pulmonary disease (COPD) (25% vs 6.4%) and greater blood loss (425 mL vs 203 mL).Conclusion: With an extended follow-up period of 77 months after RPN, we found that PSM substantially increased the risk of recurrence without impacting OS. Our finding that PSM may occur more frequently in older patients with COPD must be confirmed in larger studies.