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

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.