Comparison of tumors with HER2 overexpression versus HER2 amplification in HER2-positive breast cancer patients.

ABSTRACT:

Background

Human epidermal growth factor receptor 2 (HER2)-positive tumors are defined by protein overexpression (3+) or gene amplification using immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH), respectively. HER2-positive tumors have historically included both IHC(3+) and IHC(2+, equivocal)/FISH(+) tumors and received the same treatment. Differences in biology between these two tumor types, however, are poorly understood. Considering anti-HER2 drugs bind directly to HER2 protein on the cell surface, we hypothesized anti-HER2 therapies would be less effective in IHC(2+)/FISH(+) tumors than in IHC(3+) tumors, leading to differences in patient outcomes.

Methods

A total of 447 patients with HER2-positive invasive carcinoma who underwent curative surgery

SUBMITTER: Horimoto Y 

PROVIDER: S-EPMC8897871 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature