AR and ER Imaging in Metastatic Breast Cancer

Study Overview
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Brief Summary
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Knowledge of breast cancer estrogen receptor (ER) expression is of major importance in treatment-decision making. Patients with ER-positive tumors can be treated with anti-oestrogen therapy, which has relatively few side effects compared to chemotherapy. Whole-body tumor ER-expression can be visualized by 18F-fluoroestradiol PET imaging (FES-PET). In addition to ER, the androgen receptor (AR) is a potential new target in breast cancer. PET imaging with 18F-fluorodihydrotestosterone (18F-FDHT) may allow visualization of tumor AR-expression. In the current study we will perform FES-PET and FDHT-PET in metastatic breast cancer patients and evaluate the concordance with concurrent biopsies. Molecular imaging of tumor AR- and ER-expression may well be of value for future treatment decision-making.

Official Title
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Androgen Receptor and Estrogen Receptor Imaging in Metastatic Breast Cancer Patients

Conditions
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Metastatic Breast Cancer

Intervention / Treatment
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* Other: FDHT-PET scan
* Other: FES-PET scan
* Other: CT-scan
* Other: Bone scintigraphy
* Other: Tumor biopsy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Metastatic breast cancer, with at least one known metastasis outside of the liver Presence of a lesion that is safely accessible for tumor biopsy (may be liver lesion) Postmenopausal status defined as one of the following: age ≥60 years previous bilateral oophorectomy age <60 years and amenorrhea for >12 months in the absence of interfering hormonal therapies (such as LH-RH agonists and ER-antagonists) patients age <60 years using an ER-antagonist should have amenorrhea for > 12 months and FSH >24 U/L and LH >14 U/L e. patient age <60 years using LH-RH agonists should continue LH-RH-agonists until after the PET procedures Initially ER-positive tumor histology. ECOG performance status 0-2. Signed written informed consent Able to comply with the protocol Exclusion Criteria: Use of estrogen receptor ligands, including tamoxifen, fulvestrant or estrogens, or androgen receptor ligands, during the 6 weeks before entry into the study Life-expectancy ≤ 3 months

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FES/FDHT-PET<br> | Other: FDHT-PET scan<br> <br> Other: FES-PET scan<br> <br> Other: CT-scan<br> <br> Other: Bone scintigraphy<br> <br> Other: Tumor biopsy<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity/ specificity | The concordance between PET (with 18F-FDHT and 18F-FES), and immunohistochemistry (for AR and ER) on concurrent (within 8 weeks) tumor biopsy will be evaluated. | within two months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy | The number of lesions detected on PET imaging compared to CT-scan and bone scintigraphy. | within six weeks | 
| Inter- and intra-patient variation | Inter- and intra-patient variation in tumor FDHT and FES-uptake will be calculated. | within six weeks | 
| Inter-observer variation | Inter-observer variation in FES PET and FDHT PET results in two independent observers. | approximately two months |