Evaluation of Hypertension as a Marker of Bevacizumab Efficacy

Predictive factors for efficacy of vascular endothelial growth factor pathway-targeted therapies have not been identified or confirmed. Hypertension has been observed as a side effect to anti-vascular endothelial growth factor therapy. The goal of our study was to retrospectively assess if hypertension induced during treatment with bevacizumab was associated with clinical outcome in metastatic colorectal cancer patients treated with bevacizumab.

We conducted a retrospective chart review of patients with colorectal cancer treated with bevacizumab at Lombardi Comprehensive Cancer Center from 2004 to 2008.

Eighty-four patients with metastatic colorectal cancer were eligible. Eighteen patients (21%) developed grades 3 hypertension. Twelve patients (14%) developed grade 2 hypertension. Six patients (7%) developed grade 1 hypertension. Median overall survival (OS) was 29 months and progression-free survival (PFS) was 10 months. Patients with any grade hypertension while on bevacizumab had an adjusted hazard ratio for death of 0.32 (p = 0.03) and adjusted risk of progression of 51% (p = 0.02) compared to those without hypertension (HTN). When stratified by metastatic disease, patients presenting with metastases who developed HTN had better OS and PFS (p = 0.03 and 0.01.) Among patients without metastases at diagnosis, those with HTN on bevacizumab had better OS and PFS but results were not statistically significant (p = 0.60 and 0.62, respectively).

Our data indicate that bevacizumab-induced hypertension may represent an interesting prognostic factor for clinical outcome in advanced colorectal cancer patients receiving bevacizumab.