Bleeding after Bevacizumab Treatment in Patients with Metastatic Colorectal Cancer

AIMS AND BACKGROUND: To evaluate the adverse events (AEs) of bleeding caused by bevacizumab/5-fluorouracil/leucovorin (5-FU/LV) combination chemotherapy with addition of irinotecan or oxaliplatin in patients with metastatic colorectal cancer (mCRC). METHODS: A retrospective study was conducted to evaluate the bleeding AEs associated with bevacizumab and to explore potential associations between bleeding and baseline patient characteristics. The National Cancer Institute Common Terminology Criteria for Adverse Events v4.0 were used to classify the severity of AEs. AEs were divided into five grades: grade 1, mild: intervention not indicated; grade 2, moderate: medical intervention or minor cauterization indicated; grade 3, severe: transfusion, radiological, endoscopic or elective surgical intervention indicated; grade 4, life threatening: urgent intervention indicated; and grade 5, death. RESULTS: Sixty-two patients were evaluated. Bleeding occurred in 26 (41%) patients; the incidence of grade 3 bleeding was 1.6% while no grade 4-5 bleeding occurred. Grade 1 epistaxis and grade 2 hemoptysis events were observed in 25.8% and 3.2% of patients, respectively. Hematochezia events occurred in 12 (19.4%) patients, one (1.6%) of whom required bevacizumab discontinuation. The incidence of hematochezia was higher in patients with unresected primary tumors, prior intestinal bleeding, and tumor response (p<0.05). CONCLUSIONS: These data provide important information about the incidence of clinically significant bleeding AEs, including minor mucocutaneous hemorrhage and major tumor-related bleeding such as hemoptysis and hematochezia in bevacizumab-treated mCRC patients. In addition, unresected primary tumor, prior bleeding, and tumor response were significant risk factors for hematochezia.