Association between bevacizumab-related hypertension and response to treatment in patients with metastatic colorectal cancer

BACKGROUND: Bevacizumab has become standard of care as first-line treatment of metastatic colorectal cancer (mCRC), after proving increased response rates and improvement in survival outcomes. Hypertension (HTN) is a common complication of the treatment with bevacizumab and, owing to its close relation with antiangiogenic mechanism, may represent a clinical biomarker to predict the efficacy of the treatment. The aim of this study was to retrospectively evaluate if HTN grades 2 to 3 were correlated with response to treatment with bevacizumab in first line, as well as with improved progression-free survival (PFS) and overall survival (OS), in a series of patients with mCRC. METHODS: Retrospective evaluation of clinical records of patients with histologically proven mCRC, treated with bevacizumab as first-line treatment, between January 2008 and December 2013. RESULTS: 79 patients were evaluated. 51.9% of patients developed HTN G2-G3 during chemotherapy-bevacizumab treatment. In the group of patients who developed bevacizumab-related HTN, 73.2% showed response to treatment (complete response (CR)+ partial response (PR)) and 97.6% achieved disease control (CR, PR or stable disease) compared to 18.4% of patients with response and 63.2% with disease control in the group that did not (OR 12.08; 95% CI 4.13 to 35.29; p<0.001 responders vs non-responders; OR 20.8; 95% CI 2.56 to 168.91; p 0.005 controlled vs non controlled disease). The median OS was 28 months (22.7–33.3). Significant statistical difference was obtained in PFS between the two groups (p<0.001). In the group that developed bevacizumab-related HTN, the median OS was 33 months (25.7–40.3), and in the group that did not, it was 21 months (16.5–25.5) with no significant statistical difference between the two groups (p 0.114). CONCLUSIONS: In this subset of patients, HTN G2-3 was predictive of response to treatment with bevacizumab and of PFS but not of OS.