Introduction and Treatment Considerations in HR+/HER2-Negative Advanced Breast Cancer

Dr. Paolo Tarantino introduces the discussion on practical approaches to managing treatment-related toxicities in patients with hormone receptor-positive, HER2-negative advanced breast cancer whose disease progresses following first-line CDK4/6 inhibitor plus endocrine therapy. He outlines the importance of anticipating, monitoring, and managing adverse events associated with pathway-directed therapies, including hyperglycemia, diarrhea, rash, and oral toxicities, to support patients in remaining on treatment. Dr. Tarantino then introduces the clinical considerations involved in selecting subsequent-line therapy for these patients. He emphasizes evaluating the tumor's sensitivity to prior endocrine therapy, noting that progression after at least 1 year of first-line treatment is generally considered indicative of endocrine sensitivity, while also accounting for individual patient characteristics. In addition to the clinical scenario, he highlights the importance of understanding the tumor's molecular landscape and identifying mutations that may contribute to disease progression and inform treatment selection.