Adjuvant therapy in renal cell carcinoma: is it the right strategy to inhibit VEGF?

Despite several clinical trials have assessed different agents in the adjuvant setting, renal cell carcinoma (RCC) still remains a disease orphan of an effective adjuvant treatment. In fact, systemic therapies targeting angiogenesis that have been observed to be effective in metastatic setting failed to show an improvement in terms of clinical outcomes when used ad adjuvant treatments. In this study, we performed a meta-analysis of 5 randomized clinical trials to assess the impact of tyrosine kinase inhibitors (TKIs) targeting angiogenesis after surgery: ASSURE, S-TRAC, PROTECT, ATLAS, SORCE. Among the 6,531 patients assessed, we confirmed the lack of efficacy of adjuvant treatments in terms of disease-free survival (DFS) (pooled-HR 0.93, 95% CI, 0.84-1.02, P=0.16) and overall survival (OS) (pooled-HR 0.98, 95% CI, 0.88-1.09, P=0.54). To the best of our knowledge, we still ignore why some treatments active in the metastatic setting do not show similar efficacy as adjuvant treatment. Exploring possible reasons of this apparently conflicting results is important as it may offer new insights that should be evaluated in next generation adjuvant trials. Immune checkpoint inhibitors (ICIs) have reported significant results-as monotherapy or in combinations with other anticancer agents-in metastatic setting, and the results of trials evaluating these agents in the adjuvant setting are awaited.