Does the Timing of Cytoreductive Nephrectomy Impact Outcomes? Analysis of REMARCC Registry Data for Patients Receiving Tyrosine Kinase Inhibitor Versus Immune Checkpoint Inhibitor Therapy.

Background and objective: The role of cytoreductive nephrectomy (CN) in the treatment of metastatic renal cell carcinoma (mRCC) has been called into question on the basis of clinical trial data from the tyrosine kinase inhibitor (TKI) era. Comparative analyses of CN for patients treated with immuno-oncology (IO) versus TKI agents are sparse. Our objective was to compare CN timing and outcomes among patients who received TKI versus IO therapy. Methods: This was a multicenter retrospective analysis of patients who underwent CN using data from the REMARCC (Registry of Metastatic RCC) database. The cohort was divided into TKI versus IO first-line therapy groups. The primary outcome was all-cause mortality (ACM). Secondary outcomes included cancer-specific mortality (CSM). Multivariable analysis was used to identify factors predictive for ACM and CSM. The Kaplan-Meier method was used to analyze 5-yr overall survival (OS) and cancer-specific survival (CSS) with stratification by primary systemic therapy and timing in relation to CN. Key findings and limitations: We analyzed data for 189 patients (148 TKI + CN, 41 IO +CN; median follow-up 23.2 mo). Multivariable analysis revealed that a greater number of metastases (hazard ratio [HR] 1.06; p = 0.015), greater primary tumor size (HR 1.10; p = 0.043), TKI receipt (HR 2.36; p = 0.015), and initiation of systemic therapy after CN (HR 1.49; p = 0.039) were associated with worse ACM. A greater number of metastases at diagnosis (HR 1.07; p = 0.011), greater primary tumor size (HR 1.12; p = 0.018), TKI receipt (HR 5.43; p = 0.004), and initiation of systemic therapy after CN (HR 2.04; p < 0.001) were associated with worse CSM. Kaplan-Meier analyses revealed greater 5-yr rates for OS (51% vs 27%; p < 0.001) and CSS (83% vs 30%; p < 0.001) for IO +CN versus TKI + CN. This difference persisted in a subgroup analysis for patients with intermediate or poor risk, with 5-yr OS rates of 50% for IO + CN versus 30% for TKI + CN (p < 0.001). A subanalysis stratified by CN timing revealed better 5-yr rates for OS (50% vs 30%; p = 0.042) and CSS (90% vs 30%, p = 0.019) for delayed CN after IO therapy, but not after TKI therapy. Conclusions and clinical implications: For patients who underwent CN, systemic therapy before CN was associated with better outcomes. In addition, IO therapy was associated with better survival outcomes in comparison to TKI therapy. Our findings question the applicability of clinical trial data from the TKI era to CN in the IO era for mRCC. Patient summary: For patients with metastatic kidney cancer treated with surgery, better survival outcomes were observed for those who also received immunotherapy in comparison to therapy targeting specific proteins in the body (tyrosine kinase inhibitors, TKIs). Immunotherapy or TKI treatment resulted in better outcomes if it was received before rather than after surgery.

Development of a Novel Risk Score to Select the Optimal Candidate for Cytoreductive Nephrectomy Among Patients with Metastatic Renal Cell Carcinoma. Results from a Multi-institutional Registry (REMARCC).

BACKGROUND: Selection of patients for upfront cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) has to be improved. OBJECTIVE: To evaluate a new scoring system for the prediction of overall mortality (OM) in mRCC patients undergoing CN. DESIGN, SETTING, AND PARTICIPANTS: We identified a total of 519 patients with synchronous mRCC undergoing CN between 2005 and 2019 from a multi-institutional registry (Registry for Metastatic RCC [REMARCC]). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cox proportional hazard regression was used to test the main predictors of OM. Restricted mean survival time was estimated as a measure of the average overall survival time up to 36 mo of follow-up. The concordance index (C-index) was used to determine the model's discrimination. Decision curve analyses were used to compare the net benefit from the REMARCC model with International mRCC Database Consortium (IMDC) or Memorial Sloan Kettering Cancer Center (MSKCC) risk scores. RESULTS AND LIMITATIONS: The median follow-up period was 18 mo (interquartile range: 5.9-39.7). Our models showed lower mortality rates in obese patients (p = 0.007). Higher OM rates were recorded in those with bone (p = 0.010), liver (p = 0.002), and lung metastases (p < 0.001). Those with poor performance status (<80%) and those with more than three metastases had also higher OM rates (p = 0.026 and 0.040, respectively). The C-index of the REMARCC model was higher than that of the MSKCC and IMDC models (66.4% vs 60.4% vs 60.3%). After stratification, 113 (22.0%) patients were classified to have a favorable (no risk factors), 202 (39.5%) an intermediate (one or two risk factors), and 197 (38.5%) a poor (more than two risk factors) prognosis. Moreover, 72 (17.2%) and 51 (13.9%) patients classified as having an intermediate and a poor prognosis according to MSKCC and IMDC categories, respectively, would be reclassified as having a good prognosis according to the REMARCC score. CONCLUSIONS: Our findings confirm the relevance of tumor and patient features for the risk stratification of mRCC patients and clinical decision-making regarding CN. Further prospective external validations are required for the scoring system proposed herein. PATIENT SUMMARY: Current stratification systems for selecting patients for kidney removal when metastatic disease is shown are controversial. We suggest a system that includes tumor and patient features besides the systems already in use, which are based on blood tests.