Liposomal Doxorubicin Compared With Observation or Cyclophosphamide and Methotrexate in Treating Older Women Who Have Undergone Surgery for Breast Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed breast cancer * Disease must be confined to the breast and axillary nodes without detected masses elsewhere * No history of prior ipsilateral or contralateral invasive breast cancer * Resected disease * No more than 16 weeks since last surgery to remove the tumor * No known clinical residual locoregional disease * Margins must be negative for invasive breast cancer and ductal carcinoma in situ * No locally advanced, inoperable breast cancer including any of the following: * Inflammatory breast cancer * Supraclavicular node involvement * Enlarged internal mammary nodes unless pathologically negative * Synchronous bilateral invasive breast cancer (diagnosed in the past 2 months) allowed if all tumors are hormone receptor-negative * Must not be a candidate for endocrine therapy or standard chemotherapy * Hormone receptor-negative disease PATIENT CHARACTERISTICS: * Female * Menopausal status: postmenopausal * ECOG performance status 0-2 * Platelet count ≥ 100,000/mm\^3 * Granulocyte count ≥ 1,500/mm\^3 * WBC ≥ 3,000/mm\^3 * AST and ALT ≤ 1.5 times upper limit of normal (ULN) * Bilirubin normal * Creatinine clearance ≥ 50 mL/min * Creatinine \< 1.35 mg/dL * No significant malabsorption syndrome or disease affecting gastrointestinal tract function * No myocardial infarction within the past 6 months * No pulmonary embolism within the past 6 months * No deep vein thrombosis within the past 6 months * No New York Heart Association class III or IV heart disease * LVEF ≥ 50% by echocardiography, radionucleotide ventriculography, or MUGA * No evidence of acute ischemia by ECG * No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix or bladder, or ipsilateral or contralateral breast carcinoma in situ * No active, uncontrolled infection * No active hepatitis B or C virus infection * No other chronic infection * Patients must not have any of the following "geriatric syndromes": * Dementia * Delirium * Major depression (as diagnosed by a psychiatrist) * Recent falls * Spontaneous bone fractures * Neglect * Abuse * No evidence of medically relevant conduction system abnormalities that would preclude study entry * No other nonmalignant, uncontrolled systemic diseases, psychiatric illness, or addictive or cognitive disorder that would preclude study participation or compliance PRIOR CONCURRENT THERAPY: * At least 4 weeks since prior raloxifene, tamoxifen citrate, or other selective estrogen receptor modulators (SERMs) * No concurrent recombinant human epoetin alfa or pegfilgrastim * No prior neoadjuvant or adjuvant therapy for breast cancer except radiotherapy * Concurrent trastuzumab (Herceptin®) allowed * No concurrent hormonal replacement therapy * No other concurrent hormonal therapy (including estrogen, progesterone, androgens, tamoxifen citrate, SERMs, or aromatase inhibitors) except for the following: * Steroids for adrenal failure * Hormones for non-disease-related conditions (e.g., insulin for diabetes) * Intermittent dexamethasone as an antiemetic * No other concurrent investigational agents * No concurrent bisphosphonates, except for the treatment of osteoporosis * For patients who received prior anthracyclines, the following criteria must be met: * Cumulative dose ≤ 240 mg/m² for conventional doxorubicin * ≤ 140 mg/m² in case of prior doxorubicin and left chest radiotherapy (LCRT) * Cumulative dose ≤ 400 mg/m² for epirubicin * ≤ 230 mg/m² in case of prior epirubicin and LCRT