Analysis of adverse events of bevacizumab-containing systemic chemotherapy for metastatic colorectal cancer in Japan

Background: Bevacizumab (BV) is widely used in chemotherapy for metastatic colorectal cancer (mCRC). Although specific adverse events have been observed, their risk factors have not been clarified. Patients and Methods: 178 mCRC patients who underwent chemotherapy were retrospectively examined and correlations between possible risk factors and adverse events were analyzed. Results: 87 out of 178 patients were treated with BV-containing chemotherapy. Possible risk factors for BV-related adverse events were: remaining primary tumor, current bleeding, history of arterial thromboembolism (ATE), hypertension, and proteinuria, and these were observed in 22%, 2%, 7%, 16%, and 8% of patients, respectively. Patients with hypertension prior to chemotherapy developed significantly worse hypertension (p=0.018). Gastrointestinal bleeding occurred in 3 out of 18 patients with residual primary tumor (16.7%) and 6 out of 63 patients with no primary tumor (8.7%) (p=0.385). Conclusion: Pre-existing hypertension appears to be a risk factor for BV-related deterioration of hypertension.