Cetuximab-based therapy for metastatic colorectal cancer: a meta-analysis of the effect of K-ras mutations

Int J Colorectal Dis. 2010 Jun;25(6):713-21. doi: 10.1007/s00384-010-0927-4. Epub 2010 Mar 23.


Background: Cetuximab has a favorable effect on patients with metastatic colorectal cancer harboring wild K-ras gene. This meta-analysis was planned to quantify the benefit.

Methods: A meta-analysis of clinical studies that have used cetuximab-based therapy (CBT) for patients with known K-ras status.

Results: There were four randomized studies (RS) that compared CBT versus non-cetuximab control (NCC) in 2,292 patients, and six non-randomized studies (NRS) included patients received cetuximab after failure of prior chemotherapy (411 patients). Patients in RS with wild K-ras tumor gained more benefit from CBT vs. NCC. For response rate (RR), the odds ratio was 2.10 (p = 0.0002), while the hazard ratio (HR) for progression-free survival (PFS) was 0.64 (p = 0.04). On the other hand, CBT was associated with an adverse effect on RR and no effect on PFS in mutated K-ras. In all patients who received CBT in RS and NRS, those with wild vs. mutated K-ras demonstrated higher RR (odds ratio 3.72; p < 0.0001). Compared with NCC in three RS, CBT showed significant overall survival (OS) advantage in patients with wild K-ras (HR = 0.68; p = 0.01).

Conclusions: The significant clinical benefit of CBT concerning RR, PFS, and OS was restricted to patients with wild-type K-ras. There is a need to better define potential responders to CBT.

Publication types

  • Meta-Analysis

MeSH terms

  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents / therapeutic use*
  • Cetuximab
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / pathology
  • Disease-Free Survival
  • Humans
  • Mutation / genetics*
  • Neoplasm Metastasis
  • Odds Ratio
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins p21(ras)
  • Treatment Outcome
  • ras Proteins / genetics*


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents
  • KRAS protein, human
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins
  • Cetuximab