[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100659717":3},{"organization":4,"outcomesModule":7,"designInfo":48,"detailedDescription":52,"studyPopulation":53,"armGroups":54,"interventions":60,"overallOfficials":66,"centralContacts":70,"locations":80,"responsibleParty":92,"collaborators":49,"id":94,"slug":95,"hasResults":96,"nctId":97,"briefTitle":98,"officialTitle":99,"acronym":49,"eligibilityCriteria":100,"healthyVolunteers":96,"sex":101,"minAge":102,"maxAge":49,"enrollmentInfo":103,"targetDuration":49,"studyType":106,"phases":49,"briefSummary":107,"conditions":108,"keywords":110,"overallStatus":117,"whyStopped":49,"lastUpdateSubmitDate":118,"lastUpdatePostDateStruct":119,"startDateStruct":122,"completionDateStruct":124,"leadSponsor":126,"locationsCount":127},{"fullName":5,"class":6},"Asan Medical Center","OTHER",{"primaryOutcomes":8,"secondaryOutcomes":13,"otherOutcomes":28},[9],{"measure":10,"description":11,"timeFrame":12},"Prognostic value of baseline [18F]FES and [18F]FDG PET\u002FCT-derived molecular imaging biomarkers for progression-free survival","Association of baseline molecular imaging biomarkers derived from \\[18F\\]FES and \\[18F\\]FDG PET\u002FCT with progression-free survival (PFS) during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor","From initiation of first-line endocrine therapy until the date of first documented disease progression or death from any cause, whichever occurs first, assessed up to 48 months.",[14,17,20,24],{"measure":15,"description":16,"timeFrame":12},"Prognostic value of baseline ctDNA-based liquid biopsy biomarkers for progression-free survival","Association of baseline ctDNA-based liquid biopsy biomarkers with progression-free survival during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor",{"measure":18,"description":19,"timeFrame":12},"Prognostic value of baseline tumor tissue NGS findings for progression-free survival","Association of baseline tumor tissue NGS findings with progression-free survival during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor",{"measure":21,"description":22,"timeFrame":23},"Prognostic value of changes in ctDNA-based liquid biopsy biomarkers at 12 weeks for progression-free survival","Association of changes in ctDNA-based liquid biopsy biomarkers from baseline to approximately 12 weeks after treatment initiation with progression-free survival during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor.","From 12 weeks after treatment initiation until the date of first documented disease progression or death from any cause, whichever occurs first, assessed up to 48 months after treatment initiation.",{"measure":25,"description":26,"timeFrame":27},"Association among baseline molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings","Association among molecular imaging biomarkers derived from baseline \\[18F\\]FES and \\[18F\\]FDG PET\u002FCT, baseline ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings","At baseline, before initiation of first-line endocrine therapy.",[29,32,36,40,44],{"measure":30,"description":31,"timeFrame":23},"Prognostic value of changes in [18F]FDG PET\u002FCT at 12 weeks for progression-free survival","Association of changes in \\[18F\\]FDG PET\u002FCT findings at approximately 12 weeks after treatment initiation with progression-free survival during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor",{"measure":33,"description":34,"timeFrame":35},"Association between changes in [18F]FDG PET\u002FCT and changes in ctDNA-based liquid biopsy biomarkers at 12 weeks","Association between changes in \\[18F\\]FDG PET\u002FCT findings and changes in ctDNA-based liquid biopsy biomarkers from baseline to approximately 12 weeks after treatment initiation.","From baseline to approximately 12 weeks after treatment initiation.",{"measure":37,"description":38,"timeFrame":39},"Association among molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings at disease progression","Association among molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings assessed at the time of disease progression","At the time of first documented disease progression, assessed up to 48 months after initiation of first-line endocrine therapy.",{"measure":41,"description":42,"timeFrame":43},"Changes in molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings from baseline to disease progression","Changes in molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings between baseline and the time of disease progression","From baseline to the time of first documented disease progression, assessed up to 48 months after initiation of first-line endocrine therapy.",{"measure":45,"description":46,"timeFrame":47},"Prognostic value of imaging, ctDNA, and tumor tissue NGS biomarkers at disease progression for progression-free survival during second-line therapy","Association of molecular imaging biomarkers, ctDNA-based liquid biopsy biomarkers, and tumor tissue NGS findings at disease progression with progression-free survival during second-line therapy","From initiation of second-line therapy until the date of subsequent documented disease progression or death from any cause, whichever occurs first, assessed up to 48 months after initiation of second-line therapy.",{"allocation":49,"interventionModel":49,"interventionModelDescription":49,"primaryPurpose":49,"observationalModel":50,"timePerspective":51,"maskingInfo":49},null,"COHORT","PROSPECTIVE","Endocrine therapy combined with CDK4\u002F6 inhibitors is a standard first-line treatment for patients with ER-positive, HER2-negative metastatic breast cancer. However, treatment response varies among patients, and both de novo and acquired endocrine resistance remain major causes of disease progression. Changes in ER expression and molecular alterations such as ESR1 mutations and alterations in the PI3K-AKT pathway have been implicated in the development of endocrine resistance.\n\n\\[18F\\]FES PET\u002FCT enables noninvasive whole-body assessment of ER expression in lesions, and may provide information on spatial heterogeneity of ER expression across metastatic lesions. In combination with \\[18F\\]FDG PET\u002FCT, which reflects tumor glucose metabolism, molecular imaging may provide complementary information regarding tumor biology and treatment resistance. Imaging biomarkers reflecting inter-lesional heterogeneity in FES uptake and quantitative FDG metabolic activity may therefore be useful for predicting outcomes during endocrine therapy.\n\nCirculating tumor DNA (ctDNA) provides a minimally invasive method for detecting tumor-derived genomic alterations, including mutations associated with endocrine resistance. Integrating ctDNA and tumor tissue genomic findings with molecular imaging may provide a more comprehensive assessment of the molecular and spatial heterogeneity of metastatic breast cancer.\n\nThis single-center, prospective observational cohort study will enroll patients with ER-positive, HER2-negative metastatic breast cancer who are scheduled to receive first-line endocrine therapy with an aromatase inhibitor combined with a CDK4\u002F6 inhibitor. Baseline molecular imaging biomarkers will be derived from \\[18F\\]FES and \\[18F\\]FDG PET\u002FCT. The primary objective is to evaluate the prognostic value of these imaging biomarkers for progression-free survival during first-line endocrine therapy combined with a CDK4\u002F6 inhibitor.\n\nIn a subset of participants with adequate tumor tissue available, paired ctDNA analysis and tumor tissue next-generation sequencing will also be performed to investigate their associations with progression-free survival and molecular imaging biomarkers. Changes in \\[18F\\]FDG PET\u002FCT findings during treatment and molecular and imaging characteristics associated with disease progression will also be explored.","Patients with ER-positive, HER2-negative metastatic breast cancer who are scheduled to initiate first-line endocrine therapy with an aromatase inhibitor in combination with a CDK4\u002F6 inhibitor at Asan Medical Center. Potentially eligible patients will be identified from the medical oncology outpatient clinic or inpatient wards and prospectively enrolled according to the predefined eligibility criteria.",[55],{"label":56,"type":49,"description":57,"interventionNames":58},"ER-Positive, HER2-Negative Metastatic Breast Cancer","Participants with ER-positive, HER2-negative metastatic breast cancer who are scheduled to receive first-line endocrine therapy with an aromatase inhibitor in combination with a CDK4\u002F6 inhibitor.",[59],"Diagnostic Test: [18F] FES",[61],{"type":62,"name":63,"description":64,"armGroupLabels":65,"otherNames":49},"DIAGNOSTIC_TEST","[18F] FES","Participants will undergo baseline 18F-fluoroestradiol (\\[18F\\]FES) PET\u002FCT before initiation of first-line endocrine therapy combined with a CDK4\u002F6 inhibitor. \\[18F\\]FES (111-222 MBq) will be administered intravenously, and whole-body PET\u002FCT imaging will be performed according to the institutional imaging protocol. \\[18F\\]FES PET\u002FCT will be used to assess estrogen receptor expression and heterogeneity across metastatic lesions.",[56],[67],{"name":68,"affiliation":5,"role":69},"Sangwon Han, Clinical assistant professor","PRINCIPAL_INVESTIGATOR",[71,76],{"name":72,"role":73,"phone":74,"phoneExt":49,"email":75},"Sangwon Han","CONTACT","+82-2-3010-0657","hswon87@amc.seoul.kr",{"name":77,"role":73,"phone":78,"phoneExt":49,"email":79},"Jaeeun Kim","+82-2-3010-4572","kje0216@amc.seoul.kr",[81],{"facility":5,"status":49,"city":82,"state":49,"zip":49,"country":83,"countryCode":49,"cosmosGeoPoint":84,"geoPoint":89,"contacts":90},"Seoul","South Korea",{"type":85,"coordinates":86},"Point",[87,88],126.9784,37.566,{"lat":88,"lon":87},[91],{"name":72,"role":73,"phone":74,"phoneExt":49,"email":75},{"type":69,"investigatorFullName":72,"investigatorTitle":93,"investigatorAffiliation":5,"oldNameTitle":49,"oldOrganization":49},"Clinical assistant professor","100659717","predicting-endocrine-resistance-using-molecular-imaging-and-liquid-biopsy-in-metastatic-breast-cancer-100659717",false,"NCT07867925","Predicting Endocrine Resistance Using Molecular Imaging and Liquid Biopsy in Metastatic Breast Cancer","PREDICTion of Endocrine Resistance Using Molecular Imaging and Liquid Biopsy in Metastatic Breast Cancer (PREDICT-ER)","Inclusion Criteria:\n\n* Male or female participants aged 19 years or older, regardless of race or ethnicity.\n* Histologically confirmed invasive breast cancer that is ER-positive and HER2-negative by immunohistochemistry.\n* Scheduled to initiate first-line systemic endocrine therapy with an aromatase inhibitor in combination with a CDK4\u002F6 inhibitor for metastatic breast cancer within 60 days of screening.\n* Have undergone or be scheduled to undergo \\[18F\\]FDG PET\u002FCT before initiation of endocrine therapy combined with a CDK4\u002F6 inhibitor.\n* Have measurable or clinically evaluable metastatic disease on standard-of-care imaging.\n* Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.\n\nExclusion Criteria:\n\n* Failure of the participant or the participant's legally authorized representative to provide written informed consent.\n* History of another invasive malignancy within the previous 2 years, except for non-melanoma skin cancer.\n* Absence of lesions with significant uptake on \\[18F\\]FDG PET\u002FCT, or inability to quantitatively evaluate major lesions because of lesion location (e.g., brain or other sites with high physiologic uptake), severe motion artifacts, reconstruction errors, or other technical limitations.\n* Metastatic disease confined exclusively to the liver on imaging.\n* Previous systemic treatment for metastatic breast cancer, including endocrine therapy, targeted therapy, or anticancer chemotherapy including antibody-drug conjugates (ADCs).\n* Pregnancy or breastfeeding. Participants are considered not to be of childbearing potential if they are physiologically postmenopausal (amenorrhea for at least 2 years) or surgically sterile (documented bilateral oophorectomy or hysterectomy). Participants of childbearing potential must have a negative serum or urine pregnancy test within 24 hours before \\[18F\\]FES administration and must use contraception during the study period.\n* Serious, uncontrolled, and\u002For unstable medical conditions, including but not limited to congestive heart failure, acute myocardial infarction, severe pulmonary disease, chronic kidney disease, or chronic liver disease.\n* Being a relative or student of an investigator or otherwise having a dependent relationship with an investigator.\n* Any personal circumstances or other conditions that, in the investigator's judgment, are likely to prevent complete collection of study data.","ALL","19 Years",{"count":104,"type":105},100,"ESTIMATED","OBSERVATIONAL","This prospective observational study aims to evaluate the prognostic value of molecular imaging biomarkers derived from baseline \\[18F\\]FES and \\[18F\\]FDG PET\u002FCT for progression-free survival in patients with estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer receiving first-line endocrine therapy combined with a CDK4\u002F6 inhibitor. In a subset of patients with available tumor tissue, paired tumor tissue next-generation sequencing (NGS) and circulating tumor DNA (ctDNA) analysis will also be performed to investigate their associations with imaging biomarkers, treatment response, and clinical outcomes.",[109],"Metastatic Breast Cancer (HR+\u002F HER2-)",[111,112,113,114,115,116],"breast cancer","[18F]FES PET\u002FCT","[18F]FDG PET\u002FCT","Endocrine therapy","Endocrine resistance","ctDNA","NOT_YET_RECRUITING","2026-10-05",{"date":120,"type":121},"2026-10-09","ACTUAL",{"date":123,"type":105},"2026-10-13",{"date":125,"type":105},"2030-12-31",{"name":5,"class":6},1]