Association between age and sex and mortality after adjuvant therapy for renal cancer

Background In phase 3 trials of patients with resected high-risk renal cell carcinoma, adjuvant sunitinib has demonstrated no overall survival (OS) benefit, an uncertain disease-free survival (DFS) benefit, and increased toxicity versus placebo. To identify patients who may derive benefit or harm from adjuvant therapy, the authors assessed the effects of age and sex on treatment outcomes in the phase 3 Adjuvant Sorafenib or Sunitinib for Unfavorable Renal Cancer (ASSURE) trial. Methods The authors conducted a post hoc subgroup analysis of age and sex among patients in the ASSURE trial. Adjusted hazard ratios (HRs) for OS and DFS were evaluated with sunitinib or sorafenib versus placebo in 4 patient subgroups defined by sex and median age at the time of the study. Results Sunitinib treatment was associated with decreased OS (HR, 2.21; 95% confidence interval, 1.29-3.80) among women aged >56 years, but not in women aged <= 56 years or men of any age. Similar associations with age and sex were observed for DFS, but these were not statistically significant (women aged >56 years: HR, 1.41 [95% confidence interval, 0.94-2.10]). No such association was found for sorafenib. The interaction by age and sex on mortality was found to be statistically significant for sunitinib (P = .01), but not sorafenib (P = .10). Conclusions Adjuvant sunitinib may increase mortality among older women with renal cell carcinoma. Given the recent approval of adjuvant sunitinib for patients with high-risk resected renal cell carcinoma, additional studies are needed to confirm these findings.