Scappaticci FA et al. (2007) Arterial thromboembolic events in patients with metastatic carcinoma treated with chemotherapy and bevacizumab. J Natl Cancer Inst 99: 1232–1239

The combination of bevacizumab and chemotherapy has been shown to improve survival in patients with various metastatic carcinomas; however, trials have reported an increased occurrence of arterial thromboembolism (ATE) in patients receiving this combination. A study by Scappaticci et al. has determined the risk of ATE versus venous thromboembolism (VTE) in patients treated with bevacizumab and chemotherapy.

This retrospective study analyzed the results of five randomized controlled trials that included 1,745 patients with metastatic breast, colorectal, or non-small-cell lung cancer. Of these patients, 963 received bevacizumab plus chemotherapy (group A) and 782 received chemotherapy only (group B). The incidence of ATE was higher in group A than group B (hazard ratio 2.0; P = 0.031), but the development of VTE was not significantly associated with bevacizumab administration (hazard ratio 0.89; P = 0.44). The absolute rates of developing an ATE per 100 person-years of exposure were 5.5 and 3.1 events for groups A and B, respectively (rate ratio 1.8; P = 0.076). Incidence of ATE events was associated with exposure to bevacizumab (P = 0.04), prior ATE event (P <0.001), and age 65 years or older (P = 0.01). Some patients in these trials also received low-dose aspirin; use of this agent was associated with moderate increases in grade 3 and 4 bleeding events in both treatment groups (from 3.6% to 4.7% in group A, and from 1.7% to 2.2% in group B).

This study shows that bevacizumab in combination with chemotherapy increases the risk of ATE but not VTE in patients with metastatic cancer.