Outcomes of Patients With Advanced Renal Cell Carcinoma With Non-Clear Cell Histology Treated With Systemic Therapy

Patients with nonclear cell renal cell carcinoma (RCC) and RCC with sarcomatoid differentiation have been under-represented in clinical trials. This study evaluates the outcomes and treatment patterns of patients with non-clear cell RCC and RCC with sarcomatoid features compared to those with clear cell RCC receiving systemic therapy.

A single-center retrospective analysis of patients with advanced or metastatic RCC receiving systemic therapy was conducted. Patients were divided into groups based on histology: nonclear cell RCC, clear cell RCC, and RCC with and without sarcomatoid features. The primary endpoint was overall survival (OS) for each group calculated from the date of diagnosis of advanced or metastatic RCC to the date of last follow-up or death. Additionally, an exploratory analysis was conducted by nonclear cell type and type of first-line treatment.

Overall, 251 patients were included, with most treated before 2018. First-line therapies included vascular endothelial growth factor monotherapy (68.5%), immunotherapy monotherapy (7.6%), immunotherapy combination therapy (16.7%), or other treatments (7.2%). Overall survival was shorter for patients with nonclear cell RCC compared to clear cell RCC (39.2 months vs. 81.1 months, hazard ratio (HR), 1.60, 95% Confidence Interval 1.0, 2.6, P = .04). Additionally, OS for patients with sarcomatoid differentiation was shorter compared to patients without sarcomatoid differentiation (43.4 vs. 75.0 months, HR 1.5, 95% CI 0.8, 2.6, P = .20).

We demonstrate inferior outcomes among patients with advanced or metastatic nonclear cell RCC and RCC with sarcomatoid differentiation receiving systemic treatment. Further prospective studies are warranted testing immunotherapy combinations and novel treatments in patients with nonclear cell RCC.