Accuracy of human epidermal growth factor receptor 2 (HER2) immunohistochemistry scoring by pathologists in breast cancer, including the HER2-low cutoff : HER2 IHC scoring concordance in breast cancer.

ABSTRACT:

Background

Breast cancer was previously categorized as human epidermal growth factor receptor 2 (HER2)-positive (immunohistochemistry [IHC] 3+, IHC 2+ / in situ hybridization [ISH]-positive) or HER2-negative (IHC 0, IHC 1+, IHC 2+/ISH-). Recent studies of trastuzumab deruxtecan, a HER2-directed antibody-drug conjugate, have explored the spectrum of HER2 expression in tumors categorized as HER2-negative, including HER2-low (IHC 1+, IHC 2+/ISH-) and HER2-ultralow (IHC 0 with membrane staining). Clinical relevance of HER2-low and HER2-ultralow is reinforced by encouraging efficacy findings in these populations.

Objective

To assess HER2-low and HER2-ultralow scoring performance by pathologists, and compare real-world HER2-low scoring with centralized scoring by trained pathologi

SUBMITTER: Wrobel A 

PROVIDER: S-EPMC11969812 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature