Real-world experience with CDK4-6 inhibition in the old and oldest old with a diagnosis of breast cancer.

This study describes characteristics, toxicity and survival in old patients with HR+/HER2-breast cancer (BC) treated with CDK4/6 inhibitors. Retrospective observational study that included patients ≥ 75 years with HR+/HER2-BC treated with CDK4/6 inhibitors between 2017 and 2021. Patients' general and cancer-related data were collected.