Impact Of Ki67 And Progesterone Receptor On Pfs With Cyclin-Dependent Kinase 4/6 Inhibitors In Her2-Negative Advanced Breast Cancer: A Real World Mono-Institutional Experience

Introduction: Current guidelines recommend the use of hormone therapy plus CDK 4/6 inhibitors (CDK4/6i) as initial treatments in patients (pts) with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer (ABC). The subgroup analyses of phase III studies of CDK4/6i did not identify any predictive marker that could help the clinicians to address the therapeutic choice.