[18F]FES PET/CT in Endocrine Refractory Breast Cancer

Study Overview
=================
Brief Summary
-----------------
In this study, positron emission tomography (PET/CT) imaging will be used to evaluate estrogen receptor (ER) activity in sites of metastatic disease using the investigational radiotracer [18F]fluoroestradiol (FES).

Detailed Description
-----------------
This study will evaluate [18F]FES PET/CT uptake as a predictor of progression free survival in endocrine refractory recurrent or metastatic breast cancer patients starting a new therapy regimen including endocrine targeted therapy. Imaging will occur prior to starting new therapy. Some patients may also undergo a second FES PET/CT scan at the time of suspected progression of disease to compare for changes in FES uptake measures. This is an observational study in that [18F]FES PET/CT will not be used to direct therapy decisions.

Official Title
-----------------
[18F]Fluoroestradiol (FES) PET/CT Imaging to Evaluate in Vivo ER in Endocrine Refractory Metastatic Breast Cancer

Conditions
-----------------
Estrogen Receptor Positive Breast Cancer, Breast Neoplasm, Metastatic Breast Cancer

Intervention / Treatment
-----------------
* Drug: [18F]FES


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: At least 18 years of age Recurrent or metastatic cancer that is of known or suspected breast origin - may be biopsy proven or identified on standard imaging (e.g. CT, bone scan, MRI, FDG PET/CT) History of ER+ pathology (ER+ may be confirmed from surgery or biopsy of primary breast cancer or lymph nodes, and/or surgery or biopsy of a metastatic site, metastatic biopsy is not required) At least one site of disease outside of the liver that is seen on standard imaging (e.g. CT, bone scan, MRI, FDG PET/CT); patients with measurable or nonmeasurable disease are allowed. History of progression or recurrence of disease while on an endocrine targeted therapy containing regimen as assessed by medical record review of breast cancer history at screening Participants must be informed of the investigational nature of this study and be willing to provide written informed consent and participate in this study in accordance with institutional and federal guidelines prior to study-specific procedures Exclusion Criteria: Females who are pregnant at the time of screening will not be eligible for this study, urine pregnancy test will be performed at screening in women of child-bearing potential. Inability to tolerate imaging procedures in the opinion of an investigator or treating physician Serious or unstable medical or psychological conditions that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study. History of HER2/neu positive cancer (IHC 3+ and/or FISH positive) as assessed by medical record review at screening

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FES PET/CT<br>All subjects will receive an [18F]FES PET/CT scan. | Drug: [18F]FES<br>* [18F]FES PET/CT scan<br>* Other names: Fluoroestradiol;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate [18F]FES PET/CT Uptake | Evaluate [18F]FES PET/CT uptake as a predictor of progression free survival in endocrine refractory recurrent or metastatic breast cancer patients starting a new therapy regimen including endocrine targeted therapy | 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlate [18F]FES Uptake Measures with Standard Immunohistochemistry | Correlate [18F]FES uptake measures with standard immunohistochemistry (IHC) (e.g. ER, PR, HER2-neu) and experimental pathology markers available from primary and/or metastatic tissue | 4 years | 
| Evaluate the utility of combined [18F]FES PET/CT and FDG PET/CT | Evaluate the utility of combined [18F]FES PET/CT and FDG PET/CT in identifying heterogeneity of estrogen receptor expression and functionality in metastatic breast cancer | 4 years | 
| Evaluate Overall Survival in Patients | Evaluate overall survival in patients receiving regimens containing endocrine targeted therapy | 4 years | 
| Compare FES Uptake Measures at Baseline and Progression | Compare FES uptake measures at baseline and progression in patients receiving additional endocrine targeted therapy | 4 years | 
| Correlate FES uptake measures with number of ER+ Circulating Tumor Cells | Correlate FES uptake measures with number of ER+ Circulating Tumor Cells (CTCs) and ratio of ER+ to ER- CTCs | 4 years |