Biomarkers and Clinical Features of Metastatic Breast Cancer in Patients Treated With CDK4/6 Inhibitors

PRIMARY OBJECTIVES: I. Delineate clinical features of disease progression and responses to subsequent therapy following progression on ciclib-based therapy. II. Define pharmacogenomics relationships that could provide a more precise approach to drug dosing. III. Interrogate biomarkers related to response and acquired resistance in standard clinical practice. IV. Develop patient-derived models from resistant disease to functionally assess the mechanisms occurring with resistance. V. Elucidate the socio-demographic features related to the use of ciclibs clinically in the Roswell Park catchment area. OUTLINE: Patients electronic medical records are reviewed to capture clinical information, and patients undergo collection of blood, tissue, ascites or pleural effusions, and fresh body fluids or fresh biopsy samples for diagnosis/treatment decision, biomarker assessments, and description of mechanisms of resistance/response related to ciclib-therapy.