DISEASE CHARACTERISTICS:

• Histologically confirmed invasive breast cancer meeting the following criteria:

  • 1-3 node-positive disease (pN1mi, pN1a, pN1b, or pN1c) by sentinel node biopsy or axillary lymph node dissection

    • Patients with positive sentinel node are not required to undergo full axillary lymph node dissection, at the discretion of the treating physician

  • Positive estrogen receptor (ER) and/or progesterone receptor (PR) status according to American Society of Clinical Research/College of American Pathologists (ASCO/CAP) guidelines

    • Considered positive if ≥ 1% positive tumor nuclei in the sample on testing in the presence of expected reactivity of internal [normal epithelial elements] and external controls

  • Negative HER-2 as determined by IHC or non-amplified fluorescence in situ hybridization (FISH) or chromogen in situ hybridization (CISH) for screening

    • If HER2 is 2+ by IHC, FISH/CISH must be performed and must not be positive (must be a ratio of ≤ 2.2)
    • If IHC is 0 or 1+ by institutional standards, FISH/CISH is not required
    • Patients with FISH/CISH in the indeterminate range (a ratio of 1.8 to 2.2) allowed provided they are not planning to receive treatment with trastuzumab

  • Recurrence Score (RS) by Oncotype DX® ≤ 25

    • Submission of tissue (paraffin block from primary tumor, positive and negative lymph node block) from surgery required

• Patients with multifocal, multicentric, or synchronous bilateral breast cancers are allowed

  • Multifocal disease is defined as more than one invasive cancer < 2 cm from the largest lesion within the same breast quadrant (The Oncotype DX® testing must be completed on the largest lesion)
  • Multicentric disease is defined as more than one invasive cancer ≥ 2 cm from the largest lesion within the same breast quadrant or more than one lesion in different quadrants (Oncotype DX® testing should be completed on all tumors and the determination for eligibility should be made on the highest recurrence score)
  • Synchronous bilateral disease is defined as invasive breast cancer in both breasts, diagnosed within 30 days of each other (The Oncotype DX® testing should be completed on the node-positive breast)
• Prior diagnosis of DCIS allowed provided it was treated with mastectomy alone (no therapeutic radiation or endocrine therapy)
• No inflammatory breast cancer or metastatic disease
• Must have had breast-conserving surgery with planned radiotherapy or total mastectomy (with or without planned postmastectomy radiation) with clear margins within the past 56 days

PATIENT CHARACTERISTICS:

• Menopausal status: pre- or post-menopausal
• Zubrod performance status 0-2
• Not pregnant or nursing
• Fertile patients must use an effective non-hormonal contraception method while on treatment and for ≥ 3 months after completion of protocol treatment
• No other prior malignancy except adequately treated basal cell or squamous cell skin cancer; in situ cervical cancer; adequately treated stage 0, I, or II cancer from which the patient is currently in complete remission; or any other cancer from which the patient has been disease-free for the past 5 years
• LVEF ≥ 50% if an anthracycline-based regimen is planned

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior chemotherapy or endocrine therapy for breast cancer
• No prior preventive tamoxifen or raloxifene
• No prior therapeutic breast radiotherapy
• Not requiring concurrent chronic treatment with systemic steroids or other immunosuppressive agents
• Patients randomized to either arm may also co-enroll in Phase III trials that compare local therapies or compare systemic therapies (not including chemotherapy)
• Patients randomized to chemotherapy may also co-enroll in Phase III trials that compare chemotherapies