Neoadjuvant therapy in renal cell carcinoma with tumor thrombus: A systematic review and meta-analysis

To evaluate the efficacy, feasibility and safety of neoadjuvant therapy (NAT) for renal cell carcinoma with tumor thrombus (RCC-TT) in terms of response, perioperative and oncological outcomes, and compare the results between neoadjuvant and non-neoadjuvant groups. Overall, 29 single-arm studies and 5 cohort studies were included. Of the 204 patients undergoing NAT, 16.2% were level I, 35.3% level II, 24.0% level III and 18.6% level IV thrombus. Most of patients underwent preoperative targeted therapy, immunotherapy-based combination therapy was applied in 5.4% patients. The total reduction rate of thrombus level was 29.4%. NAT is associated with a shorter operative time, less blood loss (p<0.05 for both). Rate of complications and oncological outcomes were similar between two groups. Overall, 32.1% (34/106) >= grade 3 adverse events occurred in patients undergoing NAT. Neoadjuvant therapy is safe and feasible with acceptable perioperative outcomes in RCC-TT.