Longitudinal change of genetic variations in cetuximab-treated metastatic colorectal cancer

Cancer Genet. 2021 Nov:258-259:27-36. doi: 10.1016/j.cancergen.2021.06.007. Epub 2021 Jul 11.


Recurrent gene mutations and copy number alterations in cancer patients are presumably associated with resistance to targeted therapy. In the present study, we assessed the gene mutations and copy number alterations that recurrently occurred in cetuximab-treated patients with metastatic colorectal cancer (mCRC). Targeted next-generation sequencing was performed in the tumor samples obtained pre- and postcetuximab treatment to assess the variations that occurred during cetuximab treatment. Moreover, we identified the emergent gene mutations (CDK6, EPHA3, ERCC2, MYC, PCMTD1, PIK3CA, PRIM2, RICTOR, and ZNRF3) and copy number alterations (ARAF, BCL2, BRCA2, EGFR, MYC, and SMAD4) that were recurrently observed only in postprogression samples and not in pretreatment or posttreatment samples from patients revealing clinical response. Furthermore, to identify the feasible candidate variations implicated in treatment resistance, we examined the variants with clonal expansion during treatment and discovered PCBP1 as a variant associated with posttreatment progression. Various recurrent mutations were enriched in the TGF-beta signaling pathway. Collectively, we identified recurrent variations in mCRC samples exhibiting post-cetuximab progression. Additionally, future studies are required to evaluate the therapeutic potential of these variations.

Keywords: Cetuximab; Colorectal cancer; PCBP1; TGF-beta.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents, Immunological / therapeutic use*
  • Biomarkers, Tumor / genetics*
  • Cetuximab / therapeutic use*
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / pathology
  • Female
  • Follow-Up Studies
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Mutation*
  • Neoplasm Metastasis
  • Neoplasm Recurrence, Local / drug therapy*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / pathology
  • Prognosis
  • Survival Rate


  • Antineoplastic Agents, Immunological
  • Biomarkers, Tumor
  • Cetuximab