Turkey Tail Mushroom for Treating Post-Menopausal Women With HER2-Negative ER-Positive Breast Cancer Undergoing Surgery

March 26, 2026 updated by: Mayo Clinic

A Phase 2 Pilot Window of Opportunity Study Turkey Tail Mushrooms (TTM) (Trametes Versicolor) in Post-Menopausal Women With HER2 (-) ER (+) Breast Cancer Planning to Undergo Surgical Therapy

This phase II trial tests how well turkey tail mushroom (TTM) works in treating post-menopausal women with HER2-negative, estrogen receptor (ER)-positive breast cancer undergoing surgery. TTM is a common mushroom. In traditional Chinese medicine, it is used for enhancing function and removing toxins, as well as for cancer, hepatitis, and infections. There is previous evidence of significant tumor shrinkage occurring in the 2-month window between diagnosis and surgery in women who have taken TTM. Giving TTM may be effective in treating post-menopausal women with HER2-negative, ER-positive breast cancer undergoing surgery.

Study Overview

Detailed Description

PRIMARY OBJECTIVE:

I. To determine changes in proliferation (Ki-67) in ER+HER2- breast cancers that receive turkey tail administration.

SECONDARY OBJECTIVES:

I. To assess associated adverse effects of coriolus versicolor extract (TTM). II. To determine if quality of life (QOL), mood and energy levels change while taking TTM.

OUTLINE:

Patients receive TTM orally (PO) twice daily (BID) starting at the time of study registration and continuing up to the day prior to standard of care (SOC) surgery (up to 20-42 days) in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up 7-30 days after last dose.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Cancer Center Clinical Trials
  • Phone Number: 507-293-6386

Study Locations

    • Arizona
      • Scottsdale, Arizona, United States, 85259
        • Recruiting
        • Mayo Clinic in Arizona
        • Contact:
        • Principal Investigator:
          • Brenda J. Ernst, MD
        • Contact:
          • Cancer Center Clinical Trials
          • Phone Number: 507-293-6386

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Women ≥ 18 years of age
  • Histological confirmation of ER+, HER2- breast cancer, newly diagnosed and tissue available for central confirmation of Ki-67 measurement. Subjects are eligible if they have a Ki-67 of ≥10%. Ki-67 will be repeated for patients who have had this done externally.
  • Scheduled for definitive breast surgery
  • Detectable disease as defined by mammography, breast ultrasound of greater than 5mm in size.

    • NOTE: Tumor lesions in a previously irradiated area are not considered measurable disease; Disease that is measurable by physical examination only is not eligible
  • Post menopausal as defined by:

    • Self-reported last menstrual period greater than 12 months, or
    • Bilateral oophorectomy, or
    • Follicle stimulating hormone (FSH) >20 mIU/mL, and estradiol level ≤ 20 pg/mL
  • Not taking aromatase inhibitor or a selective estrogen receptor modifier
  • Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2 obtained ≤ 90 days prior to registration
  • Platelet count ≥ 100,000/mm^3 (obtained ≤ 90 days prior to registration)
  • Absolute neutrophil count (ANC) ≥ 1,000/mm^3 (obtained ≤ 90 days prior to registration)
  • Hemoglobin ≥ 11 g/dL (obtained ≤ 90 days prior to registration)
  • Serum transaminase [alanine aminotransferase (ALT) or aspartate aminotransferase (AST)] ≤ 1.2 x upper limit of normal (ULN) (obtained ≤ 90 days prior to registration)
  • Alkaline phosphatase ≤ 1.2 x ULN (obtained ≤ 90 days prior to registration)
  • Serum creatinine ≤ 1.2 x ULN (obtained ≤ 90 days prior to registration)
  • Provide written informed consent
  • Ability to complete the Symptom Experience Diary by themselves or with assistance

Exclusion Criteria:

  • Ki-67 of <10%
  • Current use of any medicinal mushrooms
  • Patient with locally advanced cancer who will require neoadjuvant therapy or metastatic cancer
  • Currently on systemic chemotherapy
  • Concurrent endocrine therapy (selective estrogen receptor modifiers or aromatase inhibitors)
  • Allergy to mushrooms
  • Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens
  • Immunocompromised patients
  • Patients known to be HIV positive and currently receiving antiretroviral therapy.

    • NOTE: Patients known to be HIV positive, but without clinical evidence of an immunocompromised state, are eligible for this trial
  • Uncontrolled intercurrent illness including, but not limited to:

    • Ongoing or active infection
    • Symptomatic congestive heart failure
    • Unstable angina pectoris
    • Cardiac arrhythmia
    • Or psychiatric illness/social situations that would limit compliance with study requirements
  • Receiving any other investigational agent which would be considered as a treatment for the primary neoplasm
  • Other active malignancy 3 years prior to registration

    • EXCEPTIONS: Non-melanotic skin cancer or carcinoma-in-situ of the cervix
    • NOTE: If there is a history of prior malignancy, they must not be receiving chemotherapy treatment for their cancer

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Treatment (TTM)
Patients receive TTM PO BID starting at the time of study registration and continuing up to the day prior to SOC surgery (up to 20-42 days) in the absence of disease progression or unacceptable toxicity.
Ancillary studies
Dietary Supplement Given PO
Other Names:
  • Turkey Tail Mushroom Extract
  • Yunzhi Extract

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Ki-67
Time Frame: Baseline; at the time of surgery
Change in Ki-67 from the time of enrollment (pre-treatment) to the time of surgery (post-treatment) will be recorded. Slides from the original biopsy at the time of diagnosis will be used to assess pre-treatment Ki-67. A tissue sample obtained at the time of surgery will be used to assess Ki-67 post-treatment.
Baseline; at the time of surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quality of life changes
Time Frame: Up to 10 weeks
Changes in quality of life will be assessed using the Symptom Experience Diary, which will be completed by study staff during weekly phone calls with participants. The Symptom Experience Diary consists of 2 yes/no questions and 10 questions answered on a scale of 0-10 where 0=none at all and 10=as bad as it can be.
Up to 10 weeks
Adverse effects of Turkey Tail Mushrooms (TTM)
Time Frame: Up to 10 weeks
Adverse effects of TTM will be assessed by the number of patients with grade 2 or higher toxicities.
Up to 10 weeks
Patient-reported outcomes
Time Frame: Up to 10 weeks
Patient reported outcomes will be assessed using the Symptom Experience Diary, which will be completed by study staff during weekly phone calls with participants. The Symptom Experience Diary consists of 2 yes/no questions and 10 questions answered on a scale of 0-10 where 0=none at all and 10=as bad as it can be.
Up to 10 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Brenda J. Ernst, MD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 25, 2024

Primary Completion (Estimated)

December 30, 2027

Study Completion (Estimated)

April 30, 2028

Study Registration Dates

First Submitted

June 4, 2024

First Submitted That Met QC Criteria

June 4, 2024

First Posted (Actual)

June 10, 2024

Study Record Updates

Last Update Posted (Actual)

March 31, 2026

Last Update Submitted That Met QC Criteria

March 26, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • MC220305 (Mayo Clinic)
  • 23-003846 (Other Identifier: Mayo Clinic Institutional Review Board)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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