Does the addition of targeted biological agents to first-line chemotherapy for advanced colorectal cancer increase complete response? A systematic review and meta-analysis

Aim The study assessed whether the addition of monoclonal antibodies (MoAbs) to first-line chemotherapy for advanced colorectal cancer (CRC) increases the complete response (CR) compared with controls. Method PubMed was reviewed for randomized clinical trials (RCTs) with approved MoAbs (bevacizumab, cetuximab and panitumumab) vs non-MoAbs as first-line therapy for patients with advanced CRC. The incidence and ratio of CR events were calculated in patients assigned to MoAbs compared with controls. Results A total of 3790 patients from nine RCTs were included for analysis. The overall incidence of CR in patients treated with MoAbs was 2.4% (95% CI: 1.7-3.3%) compared with 1.3% (95% CI: 0.8-2.2%) in controls. Comparison of the different types of MoAbs showed that the incidence of CR was higher for bevacizumab (3.1%, 95% CI: 2.1-4.3%) than for cetuximab (0.8%, 95% CI: 0.4-1.8%). The addition of MoAbs to chemotherapy significantly increased the OR of obtaining a CR compared with controls (OR = 1.96; 95% CI: 1.12-3.46; P = 0.02). No significant differences in the OR were observed in any of the subgroups. Conclusion The CR is a rare event in advanced CRC; however, the addition of MoAbs to first-line chemotherapy significantly increases the curative rate of metastatic disease compared with controls.