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Hormone Therapy

Therapeutic Estradiol for Breast Cancer

Phase 2
Waitlist Available
Led By Matthew P. Goetz, M.D.
Research Sponsored by Mayo Clinic
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Women must be postmenopausal
Presence of moderate or strong nuclear ERbeta staining in > 25% of cells in specimen submitted during Pre-Screening Step
Screening 3 weeks
Treatment Varies
Follow Up 5 years
Awards & highlights

Study Summary

This trial is studying how well estradiol works in treating patients with a certain type of breast cancer that has spread.

Who is the study for?
This trial is for postmenopausal women with a specific breast cancer type that's spread within the body or to nearby areas. Participants must have ER beta positive, triple negative tumors and be in good general health (ECOG status 0 or 1). They should not have had more than three prior chemo treatments for metastatic breast cancer and must agree to undergo necessary biopsies.Check my eligibility
What is being tested?
The study tests how effective estradiol, a form of estrogen, is on patients whose tumor cells overexpress ER beta but lack other hormone receptors. The goal is to see if estradiol can shrink these specific types of tumor cells. Various imaging techniques like CT scans will monitor the results.See study design
What are the potential side effects?
Potential side effects from therapeutic estradiol may include an increased risk of blood clots, changes in mood or sex drive, nausea, headaches, high blood pressure, and vaginal irritation or discharge. Each person might experience side effects differently.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
I have gone through menopause.
My cancer cells show a certain level of ERbeta protein.
I agree to provide a biopsy sample for testing.
I am fully active or restricted in physically strenuous activity but can do light work.
My tumor is negative for both ER and HER2.
I have had 3 or fewer chemotherapy treatments for my metastatic breast cancer.
I can take pills by mouth.
My breast cancer is not driven by estrogen or HER2.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~5 years
This trial's timeline: 3 weeks for screening, Varies for treatment, and 5 years for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Clinical benefit rate
Secondary outcome measures
Changes in phospho-ERbeta, cystatins 1, 2, 4 and 5, phospho-Smad2/3 and Ki-67
Incidence of adverse events
Overall survival distribution
+2 more
Other outcome measures
Changes in serum cystatin levels in response to treatment

Trial Design

1Treatment groups
Experimental Treatment
Group I: Treatment (estradiol)Experimental Treatment5 Interventions
Patients receive estradiol PO TID for days 1-28. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo a tissue biopsy at the end of cycle 1, collection of blood samples on C1D1, at the end of cycle 1, and at the end of treatment. In addition, patients undergo CT, MRI, or PET scans at baseline, at the end of cycles 2, 4, and 6, and then every 8 weeks until disease progression.
First Studied
Drug Approval Stage
How many patients have taken this drug
Magnetic Resonance Imaging
Completed Phase 3
Completed Phase 4
Computed Tomography
Completed Phase 2
Positron Emission Tomography
Completed Phase 2

Find a Location

Who is running the clinical trial?

Mayo ClinicLead Sponsor
3,253 Previous Clinical Trials
3,835,393 Total Patients Enrolled
83 Trials studying Breast Cancer
13,796 Patients Enrolled for Breast Cancer
National Cancer Institute (NCI)NIH
13,741 Previous Clinical Trials
40,957,821 Total Patients Enrolled
944 Trials studying Breast Cancer
1,544,008 Patients Enrolled for Breast Cancer
Matthew P. Goetz, M.D.Principal InvestigatorMayo Clinic
4 Previous Clinical Trials
592 Total Patients Enrolled
2 Trials studying Breast Cancer
192 Patients Enrolled for Breast Cancer

Media Library

Estradiol (Hormone Therapy) Clinical Trial Eligibility Overview. Trial Name: NCT03941730 — Phase 2
Breast Cancer Research Study Groups: Treatment (estradiol)
Breast Cancer Clinical Trial 2023: Estradiol Highlights & Side Effects. Trial Name: NCT03941730 — Phase 2
Estradiol (Hormone Therapy) 2023 Treatment Timeline for Medical Study. Trial Name: NCT03941730 — Phase 2
~11 spots leftby Jul 2026