Efficacy and Toxicity of Panitumumab After Progression on Cetuximab and Predictive Value of MiR-31-5p in Metastatic Wild-type KRAS Colorectal Cancer Patients

Anticancer Res. 2016 Sep;36(9):4955-9. doi: 10.21873/anticanres.11063.


Background: In metastatic colorectal cancer (mCRC), panitumumab is generally considered to be ineffective after the progression on cetuximab therapy. However, few studies have demonstrated that a small subset of mCRC patients may benefit from panitumumab in this setting.

Patients and methods: In our study, wild-type KRAS mCRC patients, enrolled into the nationwide Czech registry CORECT between January 2007 and December 2012, were screened for panitumumab therapy after progression on cetuximab.

Results: We identified 26 mCRC in the registry with well documented progression on cetuximab in combination with irinotecan-based chemotherapy (FOLFIRI or irinotecan alone) who received panitumumab monotherapy. Partial response (PR) was achieved in 3 (11.5%) patients and stable disease (SD) in 7 (26.9%) patients after 8 weeks of therapy. Thirteen (50.0%) patients had evidence of progressive disease (PD) and in 3 (11.5%) cases response was not available. Furthermore, we confirmed that higher expression levels of newly described biomarker, miR-31-5p, in tumor are significantly associated with shorter progression-free survival (PFS) in patients treated with cetuximab (p=0.038); however, we did not observe association between miR-31-5p and response to panitumumab in mCRC patients after progression on cetuximab.

Conclusion: It remains possible that a subset of mCRC patients may benefit from panitumumab after progression on cetuximab.

Keywords: KRAS; Metastatic colorectal cancer; cetuximab; miR-31-5p; microRNA; panitumumab.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal / administration & dosage*
  • Antibodies, Monoclonal, Humanized
  • Biomarkers, Tumor / biosynthesis
  • Biomarkers, Tumor / genetics*
  • Cetuximab / administration & dosage
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / pathology
  • Disease Progression
  • Disease-Free Survival
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Male
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • Middle Aged
  • Mutation
  • Panitumumab
  • Prognosis
  • Proto-Oncogene Proteins p21(ras) / genetics


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Biomarkers, Tumor
  • KRAS protein, human
  • MIRN31 microRNA, human
  • MicroRNAs
  • Panitumumab
  • Proto-Oncogene Proteins p21(ras)
  • Cetuximab