The Role of Cytoreductive Nephrectomy for Sarcomatoid Renal Cell Carcinoma: A 29-year Institutional Experience.

Abstract

To assess which patients respond best following cytoreductive nephrectomy for renal cell carcinoma (RCC) with sarcomatoid dedifferentiation (sRCC) and whether outcomes are improving over time. We identified 562 patients with metastatic RCC treated between 1989-2018 with cytoreductive nephrectomy. We reviewed baseline clinical and pathological characteristics, including the presence of sRCC, and metastatic sites at time of nephrectomy. The primary study endpoint was overall survival (OS). Univariate and multivariate Cox-regression analyses were used to identify significant predictors of OS. The study cohort had 192 sRCC patients, with a median age of 59 years. Frequently involved metastatic locations were lung (n=115), retroperitoneal nodes (n=63) and axial skeleton (n=43). Lung metastasis were more prevalent in clear cell histology (p=0.0017) whereas nodal involvement was associated with non-clear cell subtypes (p=0.0064). Median follow-up was 14 months. Estimated 2- and 5-year OS were 34.1% and 14.8%, respectively. On multivariate analysis, metastases to the liver (HR=1.64; 95% CI 1.02-2.63; p=0.04), lung (HR=1.50; 95% CI 1.05-2.14; p=0.03), retroperitoneal nodes (HR=1.52; 95% CI 1.03-2.25; p=0.04) and non-clear cell histology (HR=1.61; 95% CI 1.10-2.35; p=0.01) were associated with worse OS in the sRCC cohort. OS after cytoreductive nephrectomy for sRCC and non-sRCC is improving over time. In patients with sRCC, presentations with unifocal metastasis not involving the liver or lung, clear cell histology and node negative disease have better outcomes following cytoreductive nephrectomy and may yield greater benefit from the procedure.