Surgery vs. No Surgery for Primary Tumor in De Novo Stage IV Breast Cancer With Solitary Bone Metastases

This is a national multicenter, prospective, randomized controlled trial. The study aims to compare the 5-year overall survival (OS) between patients receiving primary tumor surgery followed by systemic therapy (surgery group) and those receiving systemic therapy alone (non-surgery group) in patients with de novo Stage IV breast cancer who have solitary bone metastases. Secondary objectives include comparing progression-free survival (PFS), breast cancer-specific survival (BCSS), local control rates, patient-reported outcomes (BREAST-Q, QLQ-C30), safety (surgical complications and systemic therapy toxicities), and cost-effectiveness.