Outcomes of Older Women With Hormone Receptor–Positive, Human Epidermal Growth Factor Receptor–Negative Metastatic Breast Cancer Treated With a CDK4/6 Inhibitor and an Aromatase Inhibitor: An FDA Pooled Analysis

There was similar efficacy with a CDK4/6 inhibitor in combination with an AI compared with AI alone for first-line treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer in older women compared with younger patients. Patients older than age 75 years experienced higher rates of toxicity, dose modifications, and a decrease from baseline in quality-of-life measures.