Cytoreductive nephrectomy in metastatic papillary renal cell carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC).

Abstract

581 Background: There is evidence that cytoreductive nephrectomy (CN) may be beneficial in metastatic renal cell carcinoma (mRCC), but the role of CN in patients with papillary histology is unclear. Methods: Using the IMDC database, a retrospective analysis was performed on patients with papillary mRCC treated with or without CN. Baseline characteristics and IMDC risk factors were collected. Median overall survival (OS) was determined for both patient groups. Multivariable Cox regression analysis was performed to control for imbalances in individual IMDC risk factors. Results: In total, 353 patients with papillary mRCC with (n = 75) or without (n = 278) a component of clear cell histology were identified. Median follow-up time was 57.1 months (95% CI 32.9-77.8) and the OS from the start of first-line targeted therapy for the entire cohort was 13.2 months (95% CI 12.0-16.1). Baseline characteristics are in Table 1 and patients who had CN were more likely to be younger, with better KPS, and have sarcomatoid histology. Median OS in patients with CN was 16.3 months (95% CI 13.1-19.2), compared to 8.6 months (95% CI 6.1-12.2; 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). Conclusions: The use of CN in patients with mRCC and papillary histology appears to be associated with improved survival when compared to no CN after adjustment for risk criteria. A clinical trial in this rare population may not be possible but this data does corroborate with clear cell literature. [Table: see text]