K-ras status and efficacy of cetuximab-containing regimen in the treatment of patients with metastatic colorectal cancer / 中国癌症杂志

ABSTRACT

Background and purpose: Cetuximab-containing regimen has been increasingly applied in the treatment of patients with metastatic colorectal cancer. Simultaneously, the predictive factors of outcome for cetuximab have been thoroughly researched. The aim of this study was to evaluate the relationship between K-ras status and efficacy of cetuximab containing regimen in the treatment of patients with metastatic eolorectal cancer. Methods: Between March 2006 and June 2008, twenty-seven patients with metastatic colorectal cancer were treated with cetuximab in combination with chemotherapy. The K-ras mutation status [wild-type (wt) or mutation (nat)] was examined by polymerase chain reaction (PCR) and direct sequencing. The influence of K-ras mutation status on efficacy of cetuximab-containing regimen was analyzed. Results: For 27 patiants in this cohort, K-ras wt was detected in 55.6% (15/27) cases and K-ras mt in 44.4% (12/27) cases. Statistically significant differences were found between the patients with K-ras wt and K-ras mt in terms of overall response rate (ORR) (66.7% vs 25.0%,P=0.035) and progression-free survival (PFS) (8 months vs 4 months, P=0.0028). However, there was no significant difference in overall survival (OS) (19 months vs 12 months, P>0.05). The most common treatment-related adverse effect was skin reaction, with incidence rate of 80.0% and 66.7% (P>0.05), respectively. No treatment related death was observed. Conclusion: K-ras mutation status is a predictive factor of good efficacy of cetuximab-containing regimen in the treatment of patients with metastatic colorectal cancer. Patients with K-ras wt could benefit from cetuximab in combination with chemotherapy.