Functional Imaging in Prediction of Response to Abemaciclib for Advanced Hormone Receptor-Positive, HER2-Negative Breast Cancer

This study is looking at whether special imaging scans (PET/CT) can predict how well a breast cancer drug called abemaciclib will work. Abemaciclib is a targeted pill used for hormone receptor-positive, HER2-negative breast cancer — a common type that is fueled by estrogen but not by the HER2 protein. **You may be eligible if...** - You have metastatic or locally advanced breast cancer that cannot be surgically removed - Your cancer is ER-positive and HER2-negative (your doctor can confirm this) - You are being considered for hormone therapy combined with abemaciclib - You are a man or woman (any age) **You may NOT be eligible if...** - Your breast cancer is HER2-positive or hormone receptor-negative (triple-negative) - You are not a candidate for the drug abemaciclib - You are unable to undergo imaging scans required for the study - You are pregnant Talk to your doctor to see if this trial is right for you.