Frontiers in Molecular Biosciences (Apr 2023)

Pathological identification of HER2-low breast cancer: Tips, tricks, and troubleshooting for the optimal test

  • Elham Sajjadi,
  • Elham Sajjadi,
  • Elena Guerini-Rocco,
  • Elena Guerini-Rocco,
  • Elisa De Camilli,
  • Oriana Pala,
  • Giovanni Mazzarol,
  • Konstantinos Venetis,
  • Mariia Ivanova,
  • Nicola Fusco,
  • Nicola Fusco

DOI
https://doi.org/10.3389/fmolb.2023.1176309
Journal volume & issue
Vol. 10

Abstract

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The introduction of novel anti-HER2 antibody-drug conjugates (ADC) for the treatment of HER2-low breast cancers has transformed the traditional dichotomy of HER2 status to an expanded spectrum. However, the identification of HER2-low (i.e., immunohistochemistry (IHC) score 1 + or IHC score 2+, without gene amplification) tumors is challenged by methodological and analytical variables that might influence the sensitivity and reproducibility of HER2 testing. To open all possible therapeutic opportunities for HER2-low breast cancer patients the implementation of more accurate and reproducible testing strategies is mandatory. Here, we provide an overview of the existing barriers that may trouble HER2-low identification in breast cancer and discuss practical solutions that could enhance HER-low assessment.

Keywords