Bevacizumab increases the incidence of cardiovascular events in patients with metastatic breast or colorectal cancer.

INTRODUCTION: The effect of systemic administration of bevacizumab in cancer patients over a 5-year period after the beginning of chemotherapy treatment and comparison with a control group.

METHODS: The study population consists of adult patients with metastatic breast or colorectal cancer who had not previously received antineoplasmatic treatment. Patients were stratified into two groups according to treatment: one group was treated with conventional chemotherapy plus bevacizumab and the other group was treated with conventional chemotherapy alone. The two groups did not differ in their cardiovascular history or demographic characteristics.

RESULTS: Fatal outcomes were more frequent in the bevacizumab group in total as well as in different periods of follow up. However, a statistically significant difference was noted at 12 months (P-value 0.007) for new deaths and at 24 (p-value 0.001) and 60 months (p-value 0.004) for all deaths. Moreover, patients who experienced a cardiovascular or thromboembolic event belonged exclusively to the bevacizumab group. At the 5-year follow-up, five patients in the bevacizumab group developed coronary artery disease (19.23%), four experienced an acute myocardial infarction (14.81%) and five patients suffered from a thromboembolic event (17.86%).

CONCLUSIONS: The addition of bevacizumab to conventional chemotherapy for metastatic breast or colorectal cancer increases the incidence of cardiovascular events, which is mainly due to the increased prevalence of myocardial infarction and thromboembolic events.