Evolution of HER2-low expression from primary to recurrent breast cancer.

ABSTRACT: About a half of HER2-negative breast cancer (BC) show HER2-low expression that can be targeted by new antibody-drug conjugates. The main aim of this study is to describe the evolution of HER2 expression from primary BC to relapse by including HER2-low category in both primary and recurrent BC samples. Patients with matched primary and relapse BC samples were included. HER2 was evaluated according to ASCO/CAP recommendations in place at the time of diagnosis. A cutoff of >10% cells staining for HER2-positivity was applied. HER2-negative cases were sub-classified as HER2-low (IHC = 1 + /2+ and ISH not amplified), or HER2-0 (IHC-0). 547 patients were included. The proportion of HER2-low cases was 34.2% on the primary tumor and 37.3% on the relapse samples. Among HER2-negative cases, HER2-low

SUBMITTER: Miglietta F 

PROVIDER: S-EPMC8511010 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature