The patients are being asked to take part in this study because they have a hormone receptor-positive breast cancer (contains estrogen and/or progesterone receptors) and their doctor has told them that they have an option to receive chemotherapy or hormonal therapy before surgery. The purpose of this study is to assess if chemotherapy using docetaxel and cytoxan (TC) or hormonal therapy using exemestane can shrink the size of their breast tumor and allow them to preserve the breast or have less extensive surgery on their breast.

The purpose of this study is to assess if chemotherapy using docetaxel and cytoxan (TC) or hormonal therapy using exemestane can shrink the size of your breast tumor and allow you to preserve your breast or have less extensive surgery on your breast. Additionally, by receiving chemotherapy or hormonal therapy before surgery, we will be able to determine if the treatment you receive is effective in treating your cancer. Prior to entering this study, a special test, called the Oncotype DX assay, will be performed on a small amount of your cancer from the biopsy you had at the time you were diagnosed with breast cancer, to determine the likelihood that your cancer will benefit from and shrink with chemotherapy and hormonal therapy. You will only be eligible to enter this study if the recurrence score of your cancer determined using the Oncotype DX assay is less than or equal to 24. Patients with hormone receptor-positive breast cancers with recurrence scores less than or equal to 24 have been previously demonstrated to obtain a larger benefit from hormonal therapy, compared to chemotherapy, when these agents are given after surgery. The ability of hormonal agents and chemotherapy to shrink cancers prior to surgery has not been specifically examined in hormone receptor-positive cancers with recurrence scores less than or equal to 24.

Inclusion Criteria:

• Signed informed consent.

• Histologically or cytologically confirmed breast carcinoma.

• Early stage breast cancer (T1c-3, clinically node-negative-3 [cN0-3], CM0).

• Pre-treatment biopsy with the following characteristics:

  • Hormone receptor-positive cancer as defined as ER and/or progesterone receptor (PR)-positive by standard immunohistochemistry (IHC)
  • HER2-negative (HER2 ≤ 2 by IHC; if HER2 2+ by IHC must be fluorescent in situ hybridization [FISH] non-amplified)
  • Recurrence score < 25 using Oncotype DX 21-gene recurrence score assay

• Patients must have measurable disease as defined by palpable lesion with both diameters ≥ 1 cm measurable with caliper or a positive mammogram or ultrasound with at least one dimension ≥ 1 cm. Screening mammogram of the contralateral breast must be performed within past 12 months per standard practice guidelines. Clip placement is required for study entry.

• Baseline measurements of the indicator lesions must be recorded on the Patient Registration Form. To be valid for baseline, the measurements must have been made within 14 days of study enrollment if palpable. If not palpable, a mammogram or MRI must be done within 14 days. If palpable, a diagnostic mammogram of the affected breast or MRI must be done within 2 months prior to study enrollment, defined as date of signed, informed consent. If clinically indicated, staging xrays and scans must be done within 28 days of study entry.

• Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2.

• Adequate organ function within 14 days of study entry:

  • Bone marrow function: absolute neutrophil count (ANC) ≥ 1500/mm³, Hgb > 8.0 g/dl and platelet count ≥ 100,000/mm³.
  • Hepatic function: total bilirubin < upper limit of normal (ULN). Serum glutamic oxaloacetic transaminase (SGOT) (AST) or serum glutamic pyruvic transaminase (SGPT) (ALT) and alkaline phosphatase ≤ 1.5 x ULN).
  • Renal function: calculated creatinine clearance (CrCl) ≥ 30 mL/min using the Cockcroft Gault equation.

• Patients must be at least 18 years of age.

Exclusion Criteria:

• Evidence of disease outside the breast or chest wall, except ipsilateral axillary or internal mammary lymph nodes.
• Prior chemotherapy, hormonal therapy, biologic therapy or radiation therapy for breast cancer.
• Pregnant or lactating women are not eligible. Women of childbearing potential must have a negative serum pregnancy test completed within 7 days of study entry, and use an appropriate form of birth control throughout the trial period.
• Medical, psychological or surgical condition which the investigator feels might compromise study participation.
• Patients with history within the last 5 years of previous or current malignancy at other sites with the exception of adequately treated carcinoma in-situ of the cervix or basal or squamous cell carcinoma of the skin. Patients with a history of other malignancies who remain disease free for greater than five years are eligible.
• Evidence of peripheral or sensory neuropathy.
• Patients with a history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80 are excluded from participation.
• Serious, uncontrolled, concurrent infection(s).
• Clinically significant cardiac disease (e.g. congestive heart failure, symptomatic coronary artery disease and cardiac arrhythmias not well controlled with medication) or myocardial infarction within the last 12 months prior to study entry.
• Major surgery within 28 days of study entry.
• Evidence of central nervous system (CNS) metastases.