Survival outcomes after cytoreductive nephrectomy with tumor thrombectomy: results from the Intercontinental Collaboration on Renal Cell Carcinoma

BACKGROUND: Outcomes of cytoreductive nephrectomy with tumor thrombectomy are poorly characterized in the literature. The objective of this study was to report survival in patients with metastatic renal cell carcinoma with tumor thrombus who underwent cytoreductive nephrectomy with tumor thrombectomy. METHODS: This was a retrospective, multi-institutional study. To be included, patients required an imaging confirmed diagnosis of metastatic renal cell carcinoma with a tumor thrombus on either computerized tomography and/or magnetic resonance imaging and underwent cytoreductive nephrectomy with tumor thrombectomy. Tumor thrombus was graded using the Mayo Clinic classification system. Overall survival, cancer-specific survival, and progression-free survival were evaluated. Cox proportional hazards regression and competing risks regression was used to assess the significance of demographic variables, treatment characteristics, and location of metastases on survival time-to-event measures within five years of surgery. RESULTS: Overall, 131 patients were included. Median number of metastatic sites at the time of cytoreductive nephrectomy was one. Fifty-six (44%) patients had a level I thrombus, 31 (24%) had a level II, 20 (16%) had a level III, and 20 (16%) had a level IV thrombus. Median overall survival was 1.7 years, cancer-specific survival was 2.2 years, and progression-free survival was 1.1 years. Systemic symptoms at diagnosis, larger preoperative tumor size, and adrenal metastases conferred a greater hazard of death (P<0.05). Brain metastasis conferred a greater hazard of cancer-specific death (P<0.05). CONCLUSIONS: Identification of patients most likely to benefit from cytoreductive nephrectomy with tumor thrombectomy remains elusive. Multiple patient specific factors could aid in prediction of survival postoperatively.