ABSTRACT
Objective This study assessed whether the best overall response rate(ORR) of cetuximab combined with oxaliplatin,leucovorin and fluorouracil/Xeloda was superior to that of this method alone as first-line treatment for metastatic colorectal cancer.The influence of KRAS mutation status was investigated.Methods Patients received cetuximab(400mg/m2 initial dose followed by 250mg/m2,wk thereafter)less than 2 times plus chemotherapy(oxaliplatin 130mg/m2 on day 1,plus leucovorin 200mg/m2 and fluorouracil as a 400mg/m2 bolus followed by a 600mg/m2 infusion during 22 hours on days 1 and 2) or chemotherapy alone.Treatment was continued until disease progression or unacceptable toxicity.KRAS mutation status was assessed in the subset of patients with assessable tumor samples.Results The confirmed ORR for cetuximab plus oxaliplatin,leucovorin and fluorouracil/Xeloda was higher than that with alone(42.86% vs 21.74%).A statistically significant increase in the odds for a response with the addition of cetuximab to oxaliplatin,leucovorin and fluorouracil/Xeloda could be established.In patients with KRAS wild-type tumors,the addition of cetuximab to oxaliplatin,leucovorin and fluorouracil/Xeloda was associated with a clinically significant increased chance of response(ORR 54.55% vs 21.74%) and a lower risk as compared with chemothrapy alone.Cetuximab plus oxaliplatin,leucovorin and fluorouracil/Xeloda was generally well tolerated.Conclusion The clinical effcacy of chemothrapy(oxaliplatin,leucovorin and fluorouracil/Xeloda) plus cetuximab is better than only chemothrapy.KRAS mutational status was shown to be a highly predictive selection criterion in the treatment decision regarding the addition of cetuximab to oxaliplatin,leucovorin and fluorouracil/Xeloda for previously untreated patients with metastatic colorectal cancer.