Reishi Mushroom Extract for Fatigue and/or Arthralgias/myalgias in Patients with Breast Cancer on Aromatase Inhibitors, MNCCTN Trial

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