Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histological diagnosis of invasive breast carcinoma

- Cytological proof of malignancy alone is not sufficient

- Early stage disease (T0-3, N0-2, M0) without clinical suspicion or evidence of
distant metastases on routine staging

- No locally advanced breast cancer (T4 and/or N3 disease)

- Completely resected disease by breast-conserving surgery with axillary node clearance
or modified radical mastectomy within the past 4-8 weeks

- Negative surgical margins required, unless either of the following are true:

- Deep surgical margins after full thickness resection

- Noninvasive cancer at surgical margins for which a mastectomy is planned
after completion of study chemotherapy

- No contraindication for or refusal of postoperative radiotherapy in patients who
underwent prior breast-conserving surgery

- Definite indication for adjuvant chemotherapy

- No prior or current invasive breast cancer or bilateral breast cancer

- Prior surgically-treated ductal carcinoma in situ or lobular carcinoma in situ
allowed

- Hormone receptor status:

- Estrogen receptor- and/or progesterone receptor-positive or -negative tumor

PATIENT CHARACTERISTICS:

- Sex: male or female

- Menopausal status: premenopausal or postmenopausal

- No previous malignancy except basal cell carcinoma, carcinoma in situ of the cervix,
or any cancer from which the patient has been disease-free for 10 years and for which
treatment consisted solely of resection

- ECOG status 0 or 1

- Hemoglobin > 9 g/dL

- WBC > 3,000/mm³

- Platelet count > 10,000/mm³

- Bilirubin normal (unless due to known Gilbert's disease)

- AST and ALT ≤ 1.5 times upper limit of normal (ULN)

- Albumin normal

- Creatinine ≤ 1.5 times ULN

- Creatinine clearance > 50 mL/min

- No active, uncontrolled infection

- Not pregnant or nursing

- Fertile patients must use effective contraception

- No concurrent medical, psychiatric, or geographic problems that might prevent
completion of treatment or follow-up

- Available for a minimum of 5 years' follow-up

- No known serious viral infection such as active hepatitis B, hepatitis C, or HIV

- No significant cardiac disease, such as impaired left ventricular function or active
angina requiring regular anti-anginal medication and/or resulting in restricted
physical activity

- No history of significant renal impairment or disease

PRIOR CONCURRENT THERAPY:

- No simultaneous participation in the active intervention phase of another treatment
trial

- Not being approached or recruited for another trial within 2 months of study entry

- No previous chemotherapy, hormonal therapy or radiotherapy for the treatment of
pre-invasive or invasive cancer except for either of the following:

- Previous radiotherapy for basal cell carcinoma

- Previous preoperative endocrine therapy, provided there was no evidence of
progression during this therapy, it lasted for less than 6 weeks in duration,
and it was stopped at least one month prior to trial entry

- Concurrent luteinizing hormone-releasing hormone analog therapy allowed for
premenopausal patients

- More than 4 weeks since prior hormone replacement therapy (HRT) or pre-operative
endocrine therapy

- No prior breast conserving surgery if there is a contradiction for or refusal of
postoperative radiotherapy