Clinical Value of Next Generation Sequencing in Endocrine Therapy for Advanced Hormone Receptor Positive/HER-2 Negative Breast Cancer

To determine the landscape of gene mutation before and after endocrine therapy, to search for molecular markers of endocrine therapy efficacy, and to explore the clinical value of using NGS detection of ctDNA to guide precise endocrine therapy in patients with advanced breast cancer. The primary endpoints were progression-free survival (PFS), and the secondary endpoints included overall survival time (OS), adverse events (AE), and severe adverse events (SAE).