Dr. Gandhi and Dr. Clifton explore the prevalence and mechanisms of resistance to first-line endocrine therapy combined with CDK4/6 inhibitors in hormone receptor–positive/HER2-negative (HR+/HER2–) breast cancer.
What proportion of patients with HR+/HER2– breast cancer experience resistance to first-line endocrine therapy plus CDK4/6 inhibitor?
What are some of the mechanisms of resistance that can emerge following endocrine therapy and CDK4/6 inhibitors in HR+/HER2– breast cancer?
How you think about endocrine resistance in the post-CDK4/6 setting? What signals—clinical, molecular, or otherwise—influence your treatment sequencing decisions?
How does treatment resistance after first-line treatment create challenges in selecting second-line therapies?