Impact of margin status on survival after radical nephrectomy for renal cell carcinoma (RCC).

Abstract

e16084 Background: Data is limited regarding outcomes in patients with RCC with positive surgical margins. We sought to evaluate the impact of margin status after radical nephrectomy (RN) on relapse free survival (RFS) and overall survival (OS). Methods: A retrospective study was conducted evaluating patients with RCC having undergone RN at Methodist University Hospital in Memphis, Tennessee, between January 2009 and December 2013. Patients were identified from the tumor registry at this institution, and IRB approval obtained. Patient and tumor characteristics and survival were analyzed by GraphPad Prism, Microsoft Excel and IBM SPSS. Results: 156 patients that underwent RN for RCC were identified; 12 patients (7.7%) had positive margins and 144 had negative margins. Mediation duration of follow-up was 3.4 years. 5 of 12 patients with positive margins relapsed, versus 20 of 144 with negative margins (41.7% v. 13.9%, p = 0.022) with a RR of 3.10 (95% CI 1.417-6.799). Among those who relapsed, there was a statistically significant difference in time to relapse between patients with positive and negative margins (mean number of days to relapse 275 versus 621, respectively, with p = 0.038). On multivariate analysis of age, gender, ethnicity, laterality, tumor histology, margin status, and tumor size, margin status was not a statistically significant determinant of OS at 1, 3, and 5 years (p = 0.051, 0.124 and 0.185 respectively) or RFS at 1, 3, and 5 years (p = 0.372, 0.271 and 0.242 respectively). Pearson correlation analysis showed significant correlation between tumor size and margin status, R = 0.478, p < 0.001. Conclusions: Positive margins were associated with earlier time to relapse among patients following RN. However, in multivariate analysis, margin status was not a statistically significant determinant of OS or RFS. In the current era of multiple available agents in RCC capable of cytoreduction, the risk factors that are predictive of a positive surgical margin at RN should be considered in the design of neoadjuvant systemic therapy trials, with the goal of improving long-term outcomes.