Inclusion Criteria

• Women ≥ 18 years of age.
• Histological confirmation of ER+, HER2- breast cancer, newly diagnosed and slides available for central confirmation of ki 67 measurement.
• Detectable disease as defined by mammography, breast ultrasound of greater than 5mm in size:
  • NOTE: Tumor lesions in a previously irradiated area are not considered measurable disease; Disease that is measurable by physical examination only is not eligible.    
• Not taking aromatase inhibitor.
• ECOG Performance Status (PS) 0, 1 or 2 (Appendix I).
• The following laboratory values obtained within ≤ 90 days of registration:
  • Platelet count ≥ 100,000/mm^3;
  • Absolute neutrophil count (ANC) ≥ 1,000/mm^3;
  • Hemoglobin ≥ 11 g/dL;
  • Serum transaminase [ALT or AST] ≤ 1.2 x upper limit of normal (ULN);
  • Alkaline phosphatase ≤ 1.2 x ULN;
  • Serum creatinine ≤ 1.2 x ULN.
• Negative pregnancy test done ≤ 7 days prior to registration, for persons of childbearing potential only:
  • If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.
• Provide written informed consent.
• Ability to complete questionnaires by themselves or with assistance.

Exclusion Criteria:

• Current use of any medicinal mushrooms.
• Metastatic cancer.
• Currently on chemotherapy.      
• Concurrent Endocrine therapy (Selective Estrogen receptor Modifiers or Aromatase Inhibitors).
• Allergy to mushrooms.
• Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens.
• Immunocompromised patients and patients known to be HIV positive and currently receiving antiretroviral therapy:
• NOTE: Patients known to be HIV positive, but without clinical evidence of an immunocompromised state, are eligible for this trial.
• Uncontrolled intercurrent illness including, but not limited to:
• • ongoing or active infection;
  • symptomatic congestive heart failure;
  • unstable angina pectoris;
  • cardiac arrhythmia;
  • or psychiatric illness/social situations that would limit compliance with study requirements.
• Receiving any other investigational agent which would be considered as a treatment for the primary neoplasm.
• Other active malignancy 3 years prior to registration:
  • EXCEPTIONS: Non-melanotic skin cancer or carcinoma-in-situ of the cervix;
  • NOTE: If there is a history of prior malignancy, they must not be receiving chemotherapy treatment for their cancer.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 3/21/2024. Questions regarding updates should be directed to the study team contact.