Neoadjuvant Endocrine Therapy in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Node-Negative Breast Cancer
Condition: Breast Cancer; Invasive Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: Anastrozole; Letrozole; Exemestane; Tamoxifen
Intervention description: 1 mg once daily.; 2.5mg once daily.; 25 mg once daily.; 20 mg once daily.
Intervention MeSH terms: Tamoxifen; Letrozole; Anastrozole; Exemestane
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 37.0
Sex: Female
Minimum age: 18 Years
Healthy volunteers: No
Keywords: aromatase inhibitor; breast cancer; estrogen receptor; progesterone receptor; endocrine-targeted therapy; Anti-estrogen therapy; HR+; HER2-negative; Neoadjuvant Treatment

Summary:

      This is an exploratory interventional study that initiates standard-of-care anti-estrogen
      treatment preoperatively for four weeks.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Female; age ≥18 years.

          -  Pathologically proven diagnosis of invasive breast cancer, clinically stage I-II.

          -  Clinically lymph node negative, confirmed by clinical exam and/or ultrasound imaging.

          -  Estrogen- and/or progesterone-receptor-positive tumor, defined ≥1% positively staining
             cells by immunohistochemistry, according to the current American Society of Clinical
             Oncology (ASCO)/College of American Pathologists (CAP) guidelines.

          -  HER2/neu must be negative by immunohistochemistry (IHC) or fluorescence in situ
             hybridization (FISH).

          -  Eastern Cooperative Oncology Group (ECOG) performance status 0-2.

          -  Pretreatment evaluations (minimum diagnostic workup) within 28 days prior to study

          -  Qualify for anti-endocrine treatment (per medical oncologist).

          -  Informed consent provided.

          -  If history of contralateral breast cancer, patient completed all treatment two years
             prior

          -  No treatment for this breast cancer or any malignancy within two years (except
             non-melanomatous skin cancer, carcinoma in situ of the cervix and contralateral breast
             cancer)

          -  Using adequate methods of contraception; negative pregnancy test.

          -  No strong CYP2D6 inhibitors.

          -  Adequate organ function with baseline lab values.

               -  Absolute neutrophil count (ANC) ≥ 1500/µL.

               -  Hemoglobin (Hb) ≥ 9g/dL.

               -  Platelet count ≥ 100,000/µL.

               -  Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3x upper
                  limit of normal (ULN).

               -  Serum bilirubin within ≤ 1.5 x ULN.

        Exclusion Criteria:

          -  American Joint Committee on Cancer (AJCC) clinical T4, N1-3 or M1, breast cancer.

          -  Synchronous non-breast malignancy (exceptions include non-melanomatous skin cancer,
             carcinoma in situ of the cervix).

          -  Purely noninvasive breast cancer (i.e., ductal carcinoma in situ, lobular carcinoma in
             situ).

          -  Men with breast cancer.

          -  Medical, psychiatric or other condition that would prevent the patient from receiving
             the protocol therapy or providing informed consent.

          -  Pregnant or lactating women.