MP70-15 INCREASING COMPLEXITY OF TUMOR THROMBI IN RENAL CELL CARCINOMA OVER 40 YEARS OF EXPERIENCE

Abstract

INTRODUCTION AND OBJECTIVES: Our objective was to report determinants of oncologic outcome and temporal changes in presentation of patients treated with surgical intervention for renal cell carcinoma (RCC) with venous tumor thrombus (VTT). METHODS: We identified 845 patients with RCC and VTT treated with nephrectomy and tumor thrombectomy from 1970-2009. Perioperative complications and mortality were assessed in early (1970-89), mid (1990-99), and late (2000-09) time periods. Following pathological re-review, clinicopathologic features and outcomes were compared. Cancer-specific survival (CSS) was estimated using the Kaplan-Meier method and Cox proportional multivariate modeling was used to determine factors prognostic of cancer specific mortality (CSM). Median follow-up was 7.9 years. RESULTS: There were 510 (60%), 91 (11%), 139 (16%), 57 (7%), and 48 (6%) patients with levels 0, I, II, III, and IV VTT, respectively. The proportion of level III-IV VTT increased between 1970-89 (5.5%), 1990-99 (14.6%), and 2000-09, (18.9%, p<0.001). In total, 717 patients died, of whom 550 died from RCC. Although 30-day Clavien IIIIV complications (overall n1⁄447, 5.6%) have increased over time (early: 4.6% to late: 8.7%, p 1⁄4 0.03), 30-day perioperative mortality (overall n 1⁄4 25, 3%) decreased from 4.6% (early) to 1.9% (late, p 1⁄4 0.04). Median CSS for patients with levels 0-IV VTT occurred at 4.9, 2.2, 2.4, 2.0, and 1.7 years (p<0.001). Patients with levels I-IV VTT had increased CSM compared to level 0 VTT (HR 1.59, p<0.001); however, no incremental risk in CSS was noted within levels I-IV (p1⁄40.81). Median CSS by pNM status occurred at 7.4, 1.9, 1.2, and 0.8 years in pNx/0M0, pN1M0, pNx/ 0M1, and pN1M1 disease (p<0.001). Independent predictors of CSM (table) include increasing tumor thrombus level (Level II e IV, HR 1.4 e 1.55, p < 0.05), surgery in 2000-09 (HR 0.5, p < 0.001), fat invasion (HR 1.5, p < 0.001), pN1 (HR 1.7, p < 0.001) or M1 disease (HR 2.7, p < 0.001), coagulative tumor necrosis (HR 1.7, p < 0.001), and sarcomatoid differentiation (HR 1.7, p 1⁄4 0.003). CONCLUSIONS: CSS is inferior in patients with IVC VTT compared to renal vein VTT alone and in those with simultaneous nodal and metastatic disease at presentation. Despite increasing rates of level III-IV VTT in recent years, perioperative mortality and cancer-specific mortality has declined. Multivariate Cox proportional hazards model evaluating predictors of cancer-specific mortality among patients with tumor thrombus treated with radical nephrectomy and tumor thrombectomy (n 1⁄4 845, treated 1970 2009).