Hypertension as a predictive biomarker for efficacy of bevacizumab treatment in metastatic colorectal cancer: A meta-analysis

Purpose: Bevacizumab has demonstrated survival benefit in patients with metastatic colorectal cancer (in CRC) when combined with chemotherapy. However, no validated predictors currently exist for its efficacy. Hypertension has been evaluated as a surrogate marker for efficacy of bevacizumab, although analyses, to date, have yielded conflicting results. The aim of this meta-analysis was to dissect the association between hypertension and efficacy of bevacizumab treatment in mCRC. Methods: We searched PubMed, EMBASE, Chinese Biomedical Database (CBM), and Wan Fang Digital Journals before September, 2013. The primary clinical outcomes included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). Relative risk (RR) or summary hazard ratio (HR) were calculated using a fixed-effects or random-effects model, depending on the heterogeneity of the included studies. Studies meeting our search criteria were assessed. Results: Nine studies were considered eligible, with 1674 mCRC patients included. Six (308 patients, 104 with hypertension), 8 (1661 patients, 431 with hypertension) and 5 (1512 patients, 408 with hypertension) studies were eligible for the ORR, PFS and OS meta-analysis, respectively. Bevacizumab-related hypertension was associated with increased ORR (RR= 1.63; 95% CI 1.26-2.12; p=0.0002), improved PFS (HR =0.68; 95% CI 0.58-0.79; p<0.00001) and OS (HR=0.52; 95% CI 0.42-0.66; p<0.00001). There was no statistically significant difference between-study heterogeneity. Conclusion: These analyses suggest that hypertension may be a potential biomarker for efficacy of bevacizumab treatment in mCRC. Additional large prospective trials are required to confirm its predictive role.