Adjuvant Vascular Endothelial Growth Factor-targeted Therapy in Renal Cell Carcinoma: A Systematic Review and Pooled Analysis

Abstract

Context: Contradictory data exist with regard to adjuvant vascular endothelial growth factor receptor (VEGFR)-targeted therapy in surgically managed patients for localized renal cell carcinoma (RCC).

Objective: To systematically evaluate the current evidence regarding the therapeutic benefit (disease-free survival [DFS] and overall survival [OS]) and grade 3-4 adverse events (AEs) for adjuvant VEGFR-targeted therapy for resected localized RCC.

Evidence acquisition: A critical review of PubMed/Medline, Embase, and the Cochrane Library in January 2018 according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement was performed. We identified reports and reviewed them according to the Consolidated Standards of Reporting Trials and Standards for the Reporting of Diagnostic Accuracy Studies criteria. Of eight full-text articles that were eligible for inclusion, five studies (two of five were updated analyses) were retained in the final synthesis. Study characteristics were abstracted and the number needed to treat (NNT) per trial was estimated.

Evidence synthesis: The three randomized controlled phase III trials included the following comparisons: sunitinib versus placebo or sorafenib versus placebo (Adjuvant Sorafenib or Sunitinib for Unfavorable Renal Carcinoma [ASSURE] study, n=1943), sunitinib versus placebo (S-TRAC, n=615), and pazopanib versus placebo (Pazopanib As Adjuvant Therapy in Localized/Locally Advanced RCC After Nephrectomy study, n=1135). The NNT ranged from 10 (S-TRAC) to 137 (ASSURE study). The pooled analysis showed that VEGFR-targeted therapy was not statistically significantly associated with improved DFS (hazard ratio [HR_random]: 0.92, 95% confidence interval [CI]: 0.82-1.03, p=0.16) or OS (HR_random: 0.98, 95% CI: 0.84-1.15, p=0.84) compared with the control group. The adjuvant therapy group experienced significantly higher odds of grade 3-4 AEs (OR_random: 5.89, 95% CI: 4.85-7.15, p<0.001). In exploratory analyses focusing on patients who started on the full-dose regimen, DFS was improved in patients who received adjuvant therapy (HR_random: 0.83, 95% CI: 0.73-0.95, p=0.005).

Conclusions: This pooled analysis of reported randomized trials did not reveal a statistically significant effect between adjuvant VEGFR-targeted therapy and improved DFS or OS in patients with intermediate/high-risk local or regional fully resected RCC. Improvement in DFS may be more likely with the use of full-dose regimens, pending further results. However, adjuvant treatment was associated with high-grade AEs.

Patient summary: Vascular endothelial growth factor receptor-targeted therapy after nephrectomy for localized kidney cancer is not associated with consistent improvements in delaying cancer recurrence or prolonging life and comes at the expense of potentially significant side effects.

Keywords: Adjuvant therapy; Meta-analysis; Metastatic renal cell carcinoma; Systemic therapy; Targeted therapy.