Incidence and risk of thromboembolism associated with bevacizumab in patients with non-small cell lung carcinoma

Background: Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF), is effective for the treatment of advanced non-small cell lung cancer (NSCLC). However, severe adverse events (AEs) have been reported in NSCLC patients treated with bevacizumab. Currently, the contribution of Bevacizumab to thromiboemibolism is still controversial. We conducted a study to determine the overall risk and incidence of thromboembolism with bevacizumab in NSCLC patients. Methods: Electronic databases such as the PubMed, Web of Science and Cochrane Library were searched for related trials. Statistical analyses were conducted to calculate the overall incidence rates, odds ratios (ORs), and 95% confidence intervals (CIs) by using either random-effect or fixed-effect models depending on the heterogeneity. We also used trial sequence analysis (TSA) to verify the pooled result. Results: A total of 3,555 subjects from nine studies were included. The overall incidence of thromboembolism events in NSCLC patients treated with bevacizumab was 4.8% (95% CI: 1.9-7.7%). Without bevacizumab, this incidence was 2.9% (95% CI: 0.6-5.1%). Bevacizumab use was associated with a significantly increased risk in thromboembolism events (OR =1.74; 95% CI: 1.15-2.62; P=0.008). Subgroup analysis based on the doses showed that bevacizumab administered at 15 mg/kg (OR =1.81; 95% CI: 1.14-2.86; P=0.012), but not 7.5 mg/kg (OR =1.32; 95% CI: 0.78-2.24; P=0.296), increased the risk of thromboembolism. Conclusions: Bevacizumab is associated with a significantly increased risk of thromboembolism development in NSCLC patients. It may have dose-toxicity relationship and low dose of bevacizumab may be a better choice for NSCLC patients, with equal efficacy and low hazard of thromboembolism events.