Cytoreductive Nephrectomy in Metastatic Papillary Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium

BACKGROUND: There is evidence that cytoreductive nephrectomy (CN) may be beneficial in metastatic renal cell carcinoma (mRCC). This has been studied predominantly in clear-cell RCC, with more limited data on the role of CN in patients with papillary histology. OBJECTIVE: To determine the benefit of CN in synchronous metastatic papillary RCC. DESIGN, SETTING, AND PARTICIPANTS: Using the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) database, a retrospective analysis was performed for patients with papillary mRCC treated with or without CN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Median overall survival (OS) and progression-free survival (PFS) were determined for both patient groups. Cox regression analysis was performed to control for imbalances in individual IMDC risk factors. RESULTS AND LIMITATIONS: In total, 647 patients with papillary mRCC were identified, of whom 353 had synchronous metastatic disease. Of these, 109 patients were treated with CN and 244 were not. The median follow-up was 57.1mo (95% confidence interval [CI] 32.9-77.8) and the OS from the start of first-line targeted therapy for the entire cohort was 13.2mo (95% CI 12.0-16.1). Median OS for patients with CN was 16.3mo, compared to 8.6mo (p<0.0001) in the no-CN group. When adjusted for individual IMDC risk factors, the hazard ratio (HR) of death for CN was 0.62 (95% CI 0.45-0.85; p=0.0031). Limitations include the retrospective nature of the analysis. CONCLUSIONS: The use of CN in patients with mRCC and papillary histology appears to be associated with better survival compared to no CN after adjustment for risk criteria. Selection of appropriate candidates for CN is crucial. A clinical trial in this rare population may not be possible. PATIENT SUMMARY: In a population of patients with advanced papillary kidney cancer, we found that surgical removal of the primary kidney tumor was associated with better overall survival.