DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the breast
• Hormone receptor status: estrogen and/or progesterone receptor positive tumor
• Her2/neu negative tumor by either fluorescent in situ hybridization (FISH) or immunohistochemistry (e.g., 0 or 1+ by DAKO Herceptest)

• Must have undergone surgery to remove the primary tumor by either a mastectomy or local excision plus an acceptable axillary procedure (i.e., sentinel lymph node biopsy and/or axillary dissection) within the past 84 days

  • Must have adequate (i.e., ≥ 1 mm, if margin width specified) tumor-free margins of resection for invasive and ductal carcinoma in situ

    • Lobular carcinoma in situ involving the resection margins are allowed
  • Negative axillary nodes as determined by a sentinel lymph node biopsy and/or axillary dissection as defined by the American Joint Committee on Cancer sixth edition staging system

• Tumor size 1.1-5.0 cm

  • Tumors that measure 5 mm-1.0 cm are allowed provided there are unfavorable histological features, defined as intermediate or poor nuclear and/or histologic grade or lymphovascular invasion

  • Pathologic tumor size should be used

    • If microscopic measurement is used and tumor includes ductal carcinoma in situ, the measurement should include only the invasive component of the tumor

• Tissue specimen from the primary tumor available for diagnostic testing with Oncotype DX to determine Oncotype Recurrence Score

  • No prior Oncotype DX Assay unless patient has a recurrence score of 11-25
• Patients who develop breast cancer while receiving a selective estrogen-receptor modulator (SERM) (e.g., tamoxifen, toremifene, or raloxifene) or an aromatase inhibitor (e.g., anastrazole, letrozole, or exemestane) for breast cancer prevention or a SERM for other indications (e.g., raloxifene for osteoporosis) are ineligible
• No prior ipsilateral or contralateral invasive breast cancer, bilateral synchronous cancers, or prior ipsilateral or contralateral ductal carcinoma in situ

PATIENT CHARACTERISTICS:

• Female only
• Any menopausal status allowed
• WBC count ≥ 3,500/mm^3
• Platelet count ≥ 100,000/mm^3
• Creatinine ≤ 1.5 mg/dL
• AST ≤ 3 times upper limit of normal
• Life expectancy ≥ 10 years
• No chronic obstructive pulmonary disease requiring treatment
• No chronic liver disease (e.g., cirrhosis or chronic active hepatitis)
• No history of cerebrovascular accident
• No history of congestive heart failure or other cardiac disease that would contradict the use of an anthracycline (e.g., doxorubicin hydrochloride or epirubicin)
• No chronic psychiatric condition or other condition that would preclude study compliance
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective nonhormonal contraception (e.g., intrauterine device, condoms, diaphragm, abstinence)
• No other invasive malignancies within the past 5 years except curatively treated basal cell or squamous cell carcinoma of the skin or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior chemotherapy or radiotherapy (including MammoSite^® brachytherapy radiotherapy) for this cancer
• Prior SERM or aromatase inhibitor therapy that was administered for up to 8 weeks for this cancer is allowed
• No concurrent radiotherapy with chemotherapy
• Concurrent enrollment on another CTSU study allowed provided patient is already enrolled on ECOG-PACCT-1 and the treatment options in the other study are consistent with PACCT-1-specified treatment assignment (i.e., chemohormonal therapy or hormonal therapy alone)