18F-fluoroestradiol (18F-FES) PET/CT Guided First-line Treatment for HR+/HER2- Metastatic Breast Cancer Patients

A Single-center, Real-world Study Exploring the Guidance of FES-PET for First-line Treatment of HR Positive, HER2 Negative Unresectable or Metastatic Breast Cancer Patients

A single-center, real world study to evaluate the role of FES-PET in guiding the first-line treatment of HR+/HER2- MBC patients.

Inclusion Criteria:

1. age >= 18 years old;
2. Patients who were diagnosed as HR Positive, HER2 Negative recurrent unresectable (local or regional) or stage IV (M1) breast cancer between January 2020 to February 2024;
3. Received CDK4/6 inhibitor plus endocrine treatment or chemotherapy as first-line therapy for at least one cycle;
4. Complete medical history was available.

Exclusion Criteria:

1. Medical history was incomplete.