RecruitingPhase 2NCT07314073

[18F]FES PET/CT for the Detection of Distant Metastasis in Low-grade ER-positive Stage III Breast Cancer

A Phase 2, Open-label, Non-randomized, Single Center Study Evaluating 18F-Fluoroestradiol Positron Emission Tomography/Computed Tomography for the Detection of Distant Metastases in Low-grade, Estrogen Receptor-positive Stage III Breast Cancer

Sponsor

Asan Medical Center

Enrollment

85 participants

Start Date

Dec 24, 2025

Study Type

INTERVENTIONAL

Conditions

Stage III Breast Cancer

Summary

This study aims to evaluate the detection rate of distant metastases using \[18F\]FES PET/CT in patients with low-grade, ER-positive stage III breast cancer.

Eligibility

Min Age: 19 Years

Inclusion Criteria6

Male or female patients aged ≥19 years, regardless of race/ethnicity
Patients newly diagnosed with invasive breast cancer within 90 days prior to screening, with documented histopathological confirmation.
Patients diagnosed with histologically confirmed estrogen receptor-positive, histologic grade 1 or 2 primary breast cancer
Patients with clinical stage IIIA-IIIC disease according to the 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system
Patients who have undergone, or are scheduled to undergo chest computed tomography (CT), abdominal CT, and bone scintigraphy within 90 days prior to screening before the 18F-FES PET/CT scan
Patients with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of ≤2

Exclusion Criteria9

The subject or the subject's legally authorized representative has not signed the informed consent form
Subjects who are currently receiving systemic therapy for breast cancer (e.g., neoadjuvant chemotherapy, hormonal therapy)
Subjects with a history of another invasive malignancy within the past 2 years (except for non-melanoma skin cancer)
Subjects diagnosed with distant metastases on chest CT, abdominal CT, or bone scintigraphy performed within 90 days prior to screening or before the 18F-FES PET/CT scan
Subjects for whom neither biopsy nor ≥6 months of follow-up imaging has been performed for lesions suspicious for distant metastases
Pregnant or breastfeeding women. The following cases are considered not at risk of pregnancy: (1) physiologically postmenopausal (no menses for ≥2 years), (2) surgically sterile (history of bilateral oophorectomy or hysterectomy), (3) women of childbearing potential with a documented negative serum or urine pregnancy test within 24 hours prior to 18F-FES administration, and who agree to use effective contraception during the trial.
Subjects with serious and/or uncontrolled and/or unstable medical conditions (e.g., congestive heart failure, acute myocardial infarction, severe pulmonary disease, chronic kidney disease, or chronic liver disease)
Subjects who are relatives or students of the investigator, or otherwise in a dependent relationship with the investigator
Subjects who, in the judgment of the investigator, are unable to provide complete data for the clinical trial due to personal circumstances or other reasons