Neoadjuvant chemotherapy (NCT) plus targeted agents versus NCT alone in colorectal liver metastases patients: A systematic review and meta-analysis

PURPOSE: To assess the efficacy of neoadjuvant chemotherapy (NCT) plus targeted agents versus NCT alone for the treatment of colorectal liver metastases (CRLM) patients. METHODS: Trials published between 1994 and 2015 were identified by an electronic search of public databases (MEDLINE, EMBASE, Cochrane library). All clinical studies were independently identified by two authors for inclusion. Demographic data, treatment regimens, objective response rate (ORR), hepatic resection and R0 hepatic resection rate were extracted and analyzed using Comprehensive MetaAnalysis software (Version 2.0). RESULTS: A total of 40 cohorts with 2099 CRLM patients were included: 962 patients were treated with NCT alone, 602 with NCT plus anti-epidermal growth-factor receptor (EGFR)-monoclonal antibodies (MoAbs) and 535 with NCT plus bevacizumab. Pooled ORR was significantly higher for NCT plus bevacizumab or anti-EGFR-MoAbs than NCT alone [relative risk (RR) 1.53, 95% CI 1.30–1.80; p < 0.001; RR 1.53, 95% CI: 1.27–1.83, p < 0.001; respectively]. NCT plus bevacizumab significantly improved R0 hepatic resection rate (RR 1.61, 95% CI: 1.27–2.04, p < 0.001), but not for overall hepatic resection rate (RR 1.26, 95% CI: 0.81–1.94, p = 0.30). While hepatic resection and R0 hepatic resection rate was comparable between NCT plus anti-EGFR-MoAbs and NCT alone (p = 0.42 and p = 0.37, respectively). CONCLUSIONS: In comparison with NCT alone, NCT plus bevacizumab significantly improve ORR and R0 hepatic resection rate but not for hepatic resection rate. Our findings support the need to compare NCT plus bevacizumab with NCT alone in the neoadjuvant setting in large prospective trials due to its higher hepatic resection rate and R0 hepatic resection rate in CRLM patients.