Using Reishi mushroom extract to treat fatigue and pain in breast cancer patients on aromatase inhibitors

Reishi Mushroom Extract for Fatigue and/or Arthralgias in Patients With Breast Cancer on Aromatase Inhibitors: A Randomized Phase II MNCCTN Trial

Phase 2 Interventional Mayo Clinic · NCT06028022

This study is testing whether Reishi mushroom extract can help reduce fatigue and pain in breast cancer patients who are taking aromatase inhibitors.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years and up
SexFemale
SponsorMayo Clinic Academic / other
Drugs / interventionschemotherapy
Locations23 sites (Albert Lea, Minnesota and 22 other locations)
Trial IDNCT06028022 on ClinicalTrials.gov

What this trial studies

This phase II trial evaluates the effectiveness of Reishi mushroom extract in alleviating fatigue and joint/muscle pain in patients with estrogen receptor-positive breast cancer who are undergoing treatment with aromatase inhibitors. Participants will be randomized into two groups, receiving either the mushroom extract or a placebo for four weeks, followed by a crossover period. The study aims to measure improvements in fatigue, pain, quality of life, and mood, while also monitoring any treatment-related side effects. The findings may provide insights into the potential benefits of integrative treatments for cancer-related symptoms.

Who should consider this trial

Good fit: Ideal candidates include post-menopausal women aged 18 and older with estrogen receptor-positive breast cancer who are currently taking aromatase inhibitors and experiencing significant fatigue.

Not a fit: Patients who are not post-menopausal, have not been diagnosed with breast cancer, or are not currently on aromatase inhibitors may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could offer a natural treatment option to improve the quality of life for breast cancer patients experiencing fatigue and pain from aromatase inhibitors.

How similar studies have performed: While Reishi mushroom extracts have been used traditionally for various health benefits, this specific application for cancer-related symptoms has not been extensively studied, making it a novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥ 18 years
* History of breast cancer, estrogen receptor positive (ER+), Her 2 positive or negative
* Fatigue ≥ 4/10
* Currently post-menopausal (as defined by National Comprehensive Cancer Network (version 4.2024), taking any aromatase inhibitor in the curative setting and planning to be on such for at least 8 weeks after registration. \[Patients on concurrent ovarian suppression (such as with leuprolide acetate, goserelin) are allowed\]; CDK 4/6 inhibitors abemaciclib, ribociclib ARE allowed
* Prior treatment: last chemotherapy ≥ 90 days prior to randomization (if treated with chemotherapy)
* On a stable dose of pain medications if pain medications are being regularly used. (i.e., no change in dosage in the past 30 days)
* If on supplements, must be on stable dose with no plan to change; not on or planning any acupuncture or other specific supportive modalities for fatigue or AI arthralgias
* Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2
* White blood cell count (WBC) ≥ 3,000/mm\^3 (obtained ≤ 30 days prior to randomization)
* Hemoglobin ≥ 10 g/dL (obtained ≤ 30 days prior to randomization)
* Platelet count ≥ 100,000/mm\^3 (obtained ≤ 30 days prior to randomization)
* Total bilirubin ≤ 1.5 x upper limit of normal (ULN) (obtained ≤ 30 days prior to randomization)
* Alanine aminotransferase (ALT) or aspartate transaminase (AST) ≤ 1.2 x ULN (obtained ≤ 30 days prior to randomization)
* Prothrombin time (PT)/activated partial thromboplastin time (aPTT) ≤ 1.5 x ULN (obtained ≤ 30 days prior to randomization)
* Negative pregnancy test done ≤ 7 days prior to registration, for persons on concurrent ovarian suppression only
* Provide informed consent
* Ability to complete questionnaires
* Willing to return to enrolling institution during the active monitoring phase of the study
* Patients who have had a recent surgery or procedure should be healed and cleared by their clinician and/or surgeon per local standards, prior to registration

Exclusion Criteria:

* Other known uncontrolled medical conditions causing fatigue such as untreated thyroid disease, depression, fibromyalgia, chronic fatigue syndrome, infection, autoimmune disease, or active/untreated hepatitis
* Allergy to mushrooms
* On anticoagulation medication or aspirin or having a known bleeding disorder
* On any specific medication for fatigue (e.g., methylphenidate)
* Metastatic cancer diagnosis (history of nodal metastases is allowed)
* Chronic steroid use, unless on physiologic replacement doses
* Current use of any medical mushrooms
* On medications for diabetes
* History of symptomatic hypotension
* Taking CYP3A4, CYP2D6 sensitive substrates which can be located at the following link:

https://www.fda.gov/drugs/drug-interactions-labeling/healthcare-professionals-fdas-examples-drugs-interact-cyp-enzymes-and-transporter-systems

* Drugs which exhibit either \>20% inhibition or \>20% induction of CYP2E1 in vivo, such as: Acetaminophen, Dapsone, Enflurane, Halothane, Isoflurane, \& Theophylline
* Taking olaparib
* Any of the following because this study involves an agent that has unknown genotoxic, mutagenic and teratogenic effects:

  * Pregnant persons
  * Nursing persons
  * Persons on concurrent ovarian suppression who are unwilling to employ adequate contraception (e.g., hormonal methods, barrier methods, intrauterine device, abstinence)
* Planned surgery or procedure during time on study and ≤ 14 days after last dose, due to bleeding risks

Where this trial is running

Albert Lea, Minnesota and 22 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Estrogen Receptor-Positive Breast Carcinoma
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.