Impact of Human Epidermal Growth Factor Receptor 2 in Patients With Metastatic Colorectal Cancer Treated With

Marco Maria Germani1, Beatrice Borelli2, Tadayoshi Hashimoto3

  • 1Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy.

Abstract

Insights

Human epidermal growth factor receptor 2 (HER2) amplification/overexpression (HER2-pos) and mutations (HER2-mut) are negative prognostic factors in metastatic colorectal cancer (mCRC). HER2-pos and HER2-mut do not predict benefit from anti-EGFR/bevacizumab therapies.

Area of Science:

  • Oncology
  • Gastroenterology
  • Molecular Biology

Background:

  • HER2 amplification/overexpression (HER2-pos) occurs in 5% of RAS/BRAF wild-type metastatic colorectal cancers (mCRC).
  • The prognostic and predictive roles of HER2-pos and HER2 mutations (HER2-mut) in mCRC treated with anti-EGFR/bevacizumab (bev) remain unclear.

Purpose of the Study:

  • To evaluate the prognostic and predictive value of HER2 amplification/expression and HER2 mutations in untreated mCRC.
  • To assess the efficacy of anti-EGFR/bevacizumab therapies in relation to HER2 status.

Main Methods:

  • Individual patient data from 1,604 patients with pMMR/MSS RAS/BRAF wild-type mCRC across eight randomized clinical trials were analyzed.
  • Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were assessed based on HER2 status (amplification/expression and mutation) and treatment regimens.

Main Results:

  • HER2-pos patients (5%) had significantly shorter PFS and OS compared to HER2-negative (HER2-neg) patients, irrespective of treatment.
  • No interaction was observed between HER2 status and the efficacy of anti-EGFR/bevacizumab therapies for PFS, OS, or ORR.
  • HER2-mutant tumors (2%) were associated with shorter OS, with no differential benefit from anti-EGFR/bevacizumab.

Conclusions:

  • HER2-pos and HER2-mut are negative prognostic factors in pMMR/MSS RAS/BRAF wild-type mCRC.
  • Current anti-EGFR/bevacizumab therapies do not offer differential benefit in patients with HER2-pos or HER2-mut tumors.
  • Further research into targeted HER2-directed therapies is warranted for these patient subgroups.