Which is false: oxaliplatin or fluoropyrimidine? An analysis of patients with KRAS wild-type metastatic colorectal cancer treated with first-line epidermal growth factor receptor monoclonal antibody.

This meta-analysis was performed to determine whether the addition of monoclonal antibodies (mAbs) of epidermal growth factor receptor (EGFR) to oxaliplatin-based chemotherapy treatment improves efficacy in KRAS wild-type metastatic colorectal cancer (mCRC), and whether infusional 5-fluorouracil (5-FU) and oxaliplatin is a preferred combination for EGFR mAbs. Oxaliplatin (including treatment), EGFR mAbs, first-line treatment, KRAS wild-type, and mCRC were used as key words. The PRIME, OPUS, COIN, and NORDIC VII trials were identified by two independent authors. Time-to-event outcomes of overall survival (OS) and progression-free survival (PFS) were analyzed using HRs (hazard ratios) with fixed effect, and response rate (RR) using odd ratios (OR) with fixed effect. A total of 1767 patients who were KRAS wild-type were included in this meta-analysis, with 866 patients in the mAbs and chemotherapy combination group and 901 patients in the chemotherapy alone group. The addition of mAbs to oxaliplatin-based chemotherapy in patients with KRAS wild-type mCRC as first-line treatment resulted in significant improvements in PFS (HR = 0.88; 95% confidence interval (CI), 0.79-0.99; P = 0.03) and response rate (RR) (OR = 1.38; 95% CI, 1.14-1.66; P = 0.009) compared with chemotherapy alone, but the difference in OS was not significant (HR = 0.96; 95% CI, 0.85-1.08; P = 0.48). However, the differences in OS and PFS were not significant when mAbs were added to bolus 5-FU or capecitabine-based regimens compared with chemotherapy alone, whereas PFS improved with an infusional 5-FU and oxaliplatin combination (P = 0.06; PFS, HR = 0.76; 95% CI, 0.65-0.86; P = 0.0002), and even OS was marginally significant, which was consistent with the subgroup analysis of cetuximab and panitumumab. EGFR mAbs combined with oxaliplatin and an infusional 5-FU regimen was associated with significantly improved RR, PFS and OS as first-line treatment in KRAS wild-type mCRC.