Comparison Between ER Loss and Triple-Negative Breast Cancer Guided by 18F-FES PET/CT in Metastatic Breast Cancer

Clinical Outcomes of ER-Positive to Negative Conversion Versus Triple-Negative Breast Cancer (TNBC): Evidence From a 18F-fluoroestradiol Positron Emission Tomography/Computed Tomography (18F-FES PET/CT) Guided Propensity-Score-Matched Study

This study aimed to compare survival outcomes and clinical characteristics between ER loss and metastatic triple-negative breast cancer (mTNBC) patients, exploring the prognostic implications of dynamic ER changes.

Inclusion Criteria:

• Patients diagnosed with breast cancer (according to International Classification of Diseases 10th Revision) with confirmed metastasis, regardless of being de novo diagnosed or progressed from a non-metastatic stage.
• MBC patients who underwent 18F-FES PET/CT at the Fudan University Shanghai Cancer Center between 2017 and 2023
• Patients diagnosed with primary ER-positive tumor and who were yet to receive any systemic therapy during the advanced stage
• Contemporaneous patients with metastatic TNBC at initial diagnosis

Exclusion Criteria:

• Patients with incomplete medical records and those diagnosed with secondary primary tumors