Trastuzumab deruxtecan (DS-8201) plus bevacizumab for HER2-low metastatic breast cancer with malignant pleural effusion: a case report and literature review.

ABSTRACT:

Introduction

HER2-low breast cancer has emerged as a distinct molecular subtype with unique biological features and therapeutic significance. Trastuzumab deruxtecan, an antibody-drug conjugate, has shown promising efficacy in both HER2-high and HER2-low disease.

Case description

We report the case of a 69-year-old woman with a 17-year history of breast cancer, initially diagnosed in 2007 with invasive ductal carcinoma and lymph node metastasis. After multiple lines of systemic therapy, the disease progressed with dynamic reduction of HER2 expression from 3+ to 1+, ultimately confirming HER2-low advanced breast cancer. Recurrent malignant pleural effusion became the predominant manifestation, severely impairing quality of life.

Intervention and outcomes

DS-8201 monothe

SUBMITTER: Han H 

PROVIDER: S-EPMC12832279 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature