Concordance of HER2-low scoring in breast carcinoma among expert pathologists in the United Kingdom and the republic of Ireland -on behalf of the UK national coordinating committee for breast pathology.

ABSTRACT:

Background

Recent clinical evidence showed that breast cancer with low HER2 expression levels responded to trastuzumab deruxtecan therapy. The HER2-low cancers comprise immunohistochemistry (IHC) score 1+ and 2+ ISH non-amplified tumours, currently classified as HER2 negative. Little data exists on the reproducibility of pathologists reporting of HER2-low cancer.

Patient and methods

Sixteen expert pathologists of the UK National Coordinating Committee for Breast Pathology scored 50 digitally scanned HER2 IHC slides. The overall level of agreement, Fleiss multiple-rater kappa statistics and Cohen's Kappa were calculated. Cases with low concordance were re-scored by the same pathologists after a washout period.

Results

Absolute agreement was achieved in 6% of cases, all

SUBMITTER: Zaakouk M 

PROVIDER: S-EPMC10382984 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature