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.
Keywords: Bevacizumab; Colorectal cancer; Hypertension.