Real-world analysis of HER2-ultralow in HR+/HER2- metastatic breast cancer: prevalence and first-line chemotherapy outcomes.

ABSTRACT:

Background

HER2-ultralow is an emerging subgroup of metastatic breast cancer (mBC). However, despite an increasing interest, limited data exist on its prevalence and outcomes, especially among patients receiving standard first-line chemotherapy.

Objectives

This study assessed the prevalence and outcomes of HER2-ultralow mBC in a real-world cohort of hormone receptor-positive (HR+)/HER2-negative patients receiving first-line standard-of-care (SOC) chemotherapy.

Design

A retrospective, single-center cohort study.

Methods

We included HR+/HER2-negative mBC patients treated with SOC between January 2016 and February 2023. Patient data were reviewed from electronic health records. HER2-zero tumors (immunohistochemistry 0) were rescored by expert pathologists using th

SUBMITTER: Mathiot L 

PROVIDER: S-EPMC12477358 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature