The goal of this study is to evaluate changes in body composition among patients who are treated with cyclin-dependent kinase (CDK) 4/6 inhibitors (abemaciclib, ribociclib, or palbociclib). There is preliminary data suggesting that these drugs have more effect on body fat mass than body muscle mass. These drugs have already been approved by U.S Food and Drug Administration (FDA) to treat ER+/HER2- metastatic breast cancer. The investigators will follow up body composition changes among patients who receive CDK 4/6 inhibitors as part of their standard of care. Body composition changes will be measured from CT or PET/CT scans that are part of standard of care treatment, and from DEXA scans (as part of proposed study). The investigators will also conduct body measurements with measuring tape, and will draw blood tests to assess for fat biomarkers.
The goal of this study is to evaluate changes in body composition among patients who are treated with cyclin-dependent kinase (CDK) 4/6 inhibitors (abemaciclib, ribociclib, or palbociclib).