Prognostic impact of ER-staining patterns and heterogeneity of ER positive HER2 negative breast cancer.

ABSTRACT:

Background

Estrogen receptor (ER) expression is critical in breast cancer treatment. While low ER (1-9%) resembles triple-negative cancer with chemotherapy efficacy, the significance of "intermediate expression" (≥ 10%) and the therapeutic efficacy remain unclear. This study explores the differences in staining patterns and molecular characteristics of ER-low to intermediate expression to guide treatment.

Methods

A total of 104 breast cancer patients treated between January 2008 and July 2024 with an Allred Proportion Score (PS) of 2-4 were included. PS2 (n = 21) was classified as ER-low, while PS3 (n = 26) and PS4 (n = 57) as ER-intermediate (ER-int). ER-int was further divided by ER staining pattern: "Island" (heterogeneous) and "Scatter," (uniform) subgroups. The prognosi

SUBMITTER: Akita Y 

PROVIDER: S-EPMC12394359 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature