Patients with ER+/HER2+ advanced breast cancer are planned to be enrolled. Patients will receive first-line endocrine therapy combined with anti-HER2 therapy. The main purpose is to evaluate whether disease-free intervals can guide first-line endocrine combined targeted therapy for ER+/HER2+ advanced breast cancer.
This study is a prospective, single-arm, phase II clinical study for patients with ER+/HER2+ advanced breast cancer.