SHIELD: Surveillance of HR+/HER2- : Implementing ESR1m Long-term Monitoring and Detection in 1L aBC

연구 개요

This is a multicountry, multicenter, observational study in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer receiving first-line endocrine-based therapy with an aromatase inhibitor in combination with a CDK4/6 inhibitor. The study aims to describe the prevalence of ESR1 mutations at baseline and the emergence of ESR1 mutations over time using circulating tumor DNA testing in routine clinical practice. Patients receiving first-line treatment for at least 6 months and no more than 18 months, without evidence of disease progression at study entry, may undergo baseline ESR1 mutation testing. Patients with a negative baseline result may undergo longitudinal monitoring approximately every 3 months, for up to 18 months or 6 testing timepoints, to assess emergence of ESR1 mutations. The study will also describe mutation subtypes, testing methods used in routine practice, selected clinical characteristics, and treatment patterns across participating countries.