Reishi Mushroom Extract for Fatigue and/or Arthralgias/Myalgias in Patients With Breast Cancer on Aromatase Inhibitors

This phase II trial tests how well Reishi mushroom extract works in treating fatigue and/or joint/muscle pain (arthralgias/myalgias) in patients with breast cancer on aromatase inhibitors. Fatigue and arthralgias/myalgias are common symptoms in breast cancer patients taking aromatase inhibitors (AI). Given the long duration of AI treatment for some women (up to 10 years), these symptoms can significantly impact quality of life and premature discontinuation of AIs, a beneficial medication. Reishi mushrooms are among several medicinal mushrooms that have been used for hundreds of years, mainly in Asian countries, to help enhance the immune system, reduce stress, improve sleep, and lessen fatigue. Reishi mushroom extracts have not been studied explicitly for treatment-induced arthralgias/myalgias, but have been shown to improve quality of life, muscular strength, pain, and flexibility. Information from this study may help researchers determine the effect of Reishi mushroom extract on fatigue and arthralgias/myalgias in breast cancer patients receiving an AI.

PRIMARY OBJECTIVE: I. To evaluate the efficacy of 1,000 mg three times daily (TID) of Reishi mushroom extracts as therapy for cancer-related fatigue measured by uniscale measurement at the end of four weeks. SECONDARY OBJECTIVES: I. To evaluate the efficacy of Reishi mushroom extracts as therapy for cancer-related arthralgias at the end of four weeks and four weeks after cross-over as measured by the Brief Pain index (BPI)-adapted for AI associated arthralgias. II. To evaluate the effect of Reishi mushroom extracts on cancer-related quality of life (QOL), as measured by uniscale, at the end of four weeks and four weeks after cross-over. III. To evaluate the efficacy of Reishi mushroom extracts on mood, as assessed by the World Health Organization Five Well-Being Index (WHO-5) item well-being scale, at the end of four weeks and four weeks after cross-over. IV. To evaluate treatment toxicity between the two treatment arms, as measured by a patient symptom experience diary and weekly calls from the study team. V. To evaluate the interest, knowledge, and acceptance of integrative treatments for cancer-related symptoms. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive Reishi mushroom extract orally (PO) TID on days 1-28 for weeks 1-4 and then placebo PO TID on days 1-28 for weeks 5-8 in the absence of disease progression or unacceptable toxicity. ARM II: Patients receive placebo PO TID on days 1-28 for weeks 1-4 and Reishi mushroom extract PO TID on days 1-28 for weeks 5-8 in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days.