ER-Targeted PET for Initial Staging and Suspected Recurrence in ER-Positive Breast Cancer
Mené sur 124 patientes atteintes d'un cancer du sein ER+ (âge médian : 52 ans ou 66 ans selon la cohorte), cet essai de phase 2 compare la performance, du point de vue du taux de détection de métastases distantes, d'une tomographie numérique par émission de positrons à base de 16 alpha-18F-fluoro-17 bêta-estradiol par rapport à des examens d'imagerie standards
Importance : There are insufficient data comparing 16
α-18F-fluoro-17β-estradiol (FES) positron emission tomography (PET) computed tomography (CT) with standard-of-care imaging (SOC) for staging locally advanced breast cancer (LABC) or evaluating suspected recurrence.
Objective
:
To determine the detection rate of FES PET/CT and SOC for distant metastases in patients with estrogen receptor (ER)-positive LABC and recurrences in patients with ER-positive BC and suspected recurrence.
Design, Setting, and Participants
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This diagnostic study was conducted as a single-center phase 2 trial, from January 2021 to September 2023. The study design provided 80% power to find a 20% detection rate difference. Participants included patients with ER-positive LABC (cohort 1) or suspected recurrence (cohort 2). Data were analyzed from September 2023 to February 2024.
Exposure
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Participants underwent both SOC imaging and experimental FES PET/CT. When there were suspicious lesions on imaging, 1 was biopsied for histopathological reference standard to confirm presence (true positive) or absence (false positive) of malignant neoplasm.
Main Outcomes and Measures
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The outcome of interest was the detection rate of FES PET CT vs SOC for distant metastases and recurrences.
Results
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A total of 124 patients were accrued, with 62 in cohort 1 (median [IQR] age, 52 [32-84] years) and 62 in cohort 2 (median [IQR] age, 66 [30-93] years). In cohort 1, of 14 true-positive findings, SOC imaging detected 12 and FES detected 11 (P
> .99). In cohort 2, of 23 true-positive findings, SOC detected 16 and FES detected 18 (P = .77). In 30 patients with lobular histology, of 11 true-positive findings, SOC detected 5 and FES detected 9 (P = .29). There were 6 false-positive findings on SOC and 1 false-positive finding on FES PET/CT (P = .13).
Conclusions and Relevance : In this diagnostic study with pathological findings as the reference standard, no difference was found between FES PET/CT and current SOC imaging for detecting distant metastases in patients with ER-positive LABC or recurrences in patients with ER-positive tumors and suspected recurrence. FES PET/CT could be considered for both clinical indications, which are not part of current Appropriate Use Criteria for FES PET. The findings regarding FES PET/CT in patients with lobular tumors, and for lower false positives than current SOC imaging, warrant further investigation.
JAMA Network Open , article en libre accès, 2023