Pathologic response rates in HER2-low versus HER2-zero early breast cancer patients receiving neoadjuvant therapy: a systematic review and meta-analysis.

ABSTRACT:

Background

Currently, the primary methods for detecting HER2 expression levels are immunohistochemistry (IHC) and in situ hybridization (ISH), with the traditional standard being a HER2-positive score of 3 + accompanied by ERBB2 gene amplification detected through ISH. However, a new entity has recently emerged: HER2-low, defined as HER2 IHC 1 + or 2 + with negative ISH. HER2-low breast cancer, representing 45-60% of all HER2-negative tumors, has distinct biological characteristics and uncertain responses to conventional HER2-targeted therapies. Recent studies suggest varied clinical outcomes, highlighting the need for further investigation into the impact of HER2-low status on treatment efficacy and prognosis.

Objective

This meta-analysis evaluates the difference in complet

SUBMITTER: de Moraes FCA 

PROVIDER: S-EPMC11909821 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature