The purpose of this observational study is to learn about the HER2 heterogeneity and its impact on benefit from trastuzumab deruxtecan in metastatic breast cancer. The main question it aims to answer is: \- Does the heterogeneity of HER2 expression level and spatial distribution in different tissues affect the efficacy of trastuzumab deruxtecan in metastatic breast cancer?
Age range
18 Years – 80 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Progression-free survival (PFS)
Timeframe: From date of T-DXd treatment initiation until the date of first documented disease progression or date of death from any cause, whichever came first, assessed up to 60 months.