Study of Elacestrant Treatment in Postmenopausal Women With ER HER2- ESR1-mutated Locally Advanced or Metastatic Breast Cancer

What this Trial Is About

Researchers are investigating the prevalence of ESR1 mutation after endocrine therapy and evaluating quality of life, tolerability, safety, and treatment details in postmenopausal women with locally advanced or metastatic estrogen receptor-positive ER HER2-negative breast cancer that has ESR1 mutations. This observational study focuses on women receiving second-line treatment with elacestrant in routine clinical settings, aiming to understand real-world outcomes and adverse event management. Participants receive elacestrant according to its Summary of Product Characteristics SmPC, with treatment decisions guided by the investigator. The study includes two groups patients with ESR1 mutated tumors and those with ESR1 wildtype tumors. ESR1 mutation testing may occur after inclusion, and patients with proven ESR1 mutations must be enrolled within two weeks after starting elacestrant treatment. During the study, participants undergo assessments including evaluations of global health, functional and symptom scores, and quality of life measures using tools like the EORTC QLQ-C30 and EQ-5D-5L from enrollment up to 11 months. Safety monitoring includes tracking adverse events and liver function tests from treatment start until 30 days after stopping elacestrant, for up to 24 months. Additional data collected covers patient and disease characteristics, treatment details, dose modifications, and subsequent therapies, providing comprehensive real-world insights.

Elacestrant in Patients With ER+ HER2- ESR1-mutated Locally Advanced or Metastatic Breast Cancer