Abstract
OBJECTIVE: Tumor shrinkage of at least 10% after presurgical targeted molecular therapy (TMT) in renal cell carcinoma (RCC) patients has been associated with better overall survival (OS) outcomes. We characterized primary and metastatic tumor diameter response and OS in patients with metastatic clear cell RCC (ccRCC) who received preoperative TMT, immunotherapy, or both followed by deferred cytoreductive nephrectomy (dCN). MATERIALS AND METHODS: Patients with metastatic ccRCC (n = 198) who underwent preoperative therapy and dCN from 2005 to 2019 were identified retrospectively. Longest primary and metastatic tumor diameters were calculated using cross-sectional images obtained before systemic therapy and dCN using the Response Evaluation Criteria in Solid Tumors. Patients were stratified by tumor shrinkage of at least 10% in the primary and/or metastatic tumors after systemic therapy. The Kaplan-Meier method was used to estimate OS, and Cox proportional hazards models were used to assess the association of patient characteristics with OS. RESULTS: In total, 31.31% of patients had only metastatic tumor shrinkage (MTS) ≥ 10%, 8.08% had only primary tumor shrinkage (PTS) ≥ 10%, 32.32% had PTS and MTS ≥ 10%, and 28.28% had PTS/MTS < 10%. The median OS, number of patients with tumor shrinkage ≥ 10%, and International Metastatic Database Consortium (IMDC) scores were similar among the 3 systemic therapy groups (all P ≥ 0.80). Patients with MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% had significantly longer median OS compared to patients with PTS/MTS < 10% (P < 0.01). Patients with intermediate-risk IMDC scores had significantly longer median OS compared to patients in the poor-risk group. After adjusting for preoperative therapy and IMDC risk group, MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% were associated with better OS outcomes (HR 0.48 95% CI 0.32-0.73, P < 0.001; HR 0.48, 95% CI 0.23-0.98, P = 0.04; HR 0.44, 95% CI 0.29-0.67, P < 0.001, respectively). CONCLUSIONS: Intermediate risk score and shrinkage of at least 10% in the primary tumor, metastases, or both were associated with better OS outcomes in patients with metastatic ccRCC who underwent dCN independent of the type of preoperative systemic therapy.