Presentation Authors: Ahmed Eldefrawy*, Aaron Bradshaw, San Diego, CA, Robert Uzzo, Philadelphia, PA, Umberto Capitanio, Milan, Italy, Dattatraya Patil, Atlanta, GA, Shreyas Joshi, Philadelphia, PA, Alessandro Larcher, Milan, Italy, Stephen Ryan, Margaret Meagher, Brittney Cotta, Addison Yee, Fang Wan, San Diego, CA, Francesco Montorsi, Milan, Italy, Viraj Master, Atlanta, GA, Ithaar Derweesh, San Diego, CA
Introduction: Impact of positive margins in partial nephrectomy (PN) is controversial. Conflicting data suggest varying conclusions regarding outcomes and survival. We sought to characterize outcomes of PN in Stage 1 Renal Cell Carcinoma (RCC) in a large multi-institutional cohort with respect to margin status and risk of recurrence.
Methods: Retrospective multicenter analysis of patients with clinical T1 RCC who underwent PN. The cohort was divided into cT1a and cT1b subgroups for analysis. Primary outcome was recurrence-free survival (RFS). Secondary outcome was overall survival (OS). Cox regression multivariable analysis (MVA) was used to identify independent predictors of disease recurrence and mortality. Kaplan-Meier analysis (KMA) were conducted to describe RFS and OS and log-rank test compared survival between positive and negative margin groups.
Results: 2737 patients met inclusion criteria for analysis (cT1a 1842, cT1b 774, median follow-up 44.4 months); 113 patients (4.3%) had positive surgical margin. MVA for RFS in all cT1 tumors revealed age (HR 1.02, p=0.015), African American ethnicity (HR 2.58, p=0.001), positive surgical margin (HR 2.76, p=0.004), high tumor grade (HR 1.64, p=0.022), and cT1b staging (HR 1.63, p=0.023) to be independently associated with disease recurrence. MVA for OS in all cT1 tumors revealed age (HR 1.05, p < 0.001), African American ethnicity (HR 1.53, p=0.043), high tumor grade (HR 1.46, p=0.007), and cT1b staging (HR 1.5, p=0.003) to be associated with worsened mortality. KMA demonstrated 5-year RFS of 95.3% for negative margins and 83.4% for positive margins in cT1a (p= 0.074) and 91.5% for negative margins and 68.7% for positive margins in cT1b (p= 0.001). KMA demonstrated 5-year OS of 90.0% for negative margins and 82.9% for positive margins in cT1a (p= 0.068) and 81.4% for negative margins and 60.0% for positive margins in cT1b (p=0.022).
Conclusions: Our findings suggest that patients with clinical T1b RCC and positive margins following PN are at increased risk of disease recurrence and mortality. Post-operative surveillance and management reflective of a higher risk profile may be warranted for these individuals. Further investigation is requisite.
Source of Funding: Stephen Weissman Kidney Cancer Research Fund