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

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.