Adjuvant therapy in patients with sarcomatoid renal cell carcinoma: post hoc analysis from Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) E2805

Objectives: To study the effects of adjuvant therapy in patients with sarcomatoid renal cell carcinoma (sRCC) enrolled in the randomised phase III clinical trial E2805. Patients and Methods: The original trial (E2805) was a randomised, double-blinded phase III clinical trial comparing outcomes in 1943 patients with RCC accrued between 2006 and 2010 and treated with up to 1 year of adjuvant placebo, sunitinib, or sorafenib. The present study analyses the cohort of patients with sRCC that participated in E2805. Results: A total of 171 patients (8.8%) had sarcomatoid features. Of these, 52 patients received sunitinib, 58 received sorafenib, and 61 received placebo. Most patients were pT3–4 (71.1%, 63.7%, and 70.5%, respectively); 17.3%, 19.0%, and 27.9% had pathologically positive lymph nodes; and 59.6%, 62.1%, and 62.3% of the patients were University of California Los Angeles (UCLA) Integrated Staging System (UISS) very-high risk. In 49% of patients with subsequent development of metastatic disease, recurrence occurred in the lung, followed by 30% in the lymph nodes, and 13% in the liver. There was a high local recurrence rate in the renal bed (16%, 29%, and 18%, respectively). The 5-year disease-free survival (DFS) rates were 33.6%, 36.0%, and 27.8%, for sunitinib, sorafenib and placebo, respectively (hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.45–1.20 for sunitinib vs placebo, and HR 0.82, 95% CI 0.53–1.28 for sorafenib vs placebo). Conclusions: Adjuvant therapy with sunitinib or sorafenib did not show an improvement in DFS or OS in patients with sRCC.