ER Positive

This study looks at whether a simple blood test can help predict how well a breast cancer treatment will work. It follows patients with advanced hormone receptor-positive breast cancer whose cancer has progressed after their first treatment. Researchers collect a blood sample when patients start a second hormone therapy treatment and may collect additional samples over time. By comparing blood test results with patient outcomes, the study aims to identify biomarkers that can predict which patients are most likely to benefit from treatment.