Triptorelin in Preventing Early Menopause in Premenopausal Women Who Are Receiving Chemotherapy for Stage I, Stage II, or Stage III Breast Cancer That Has Been Removed By Surgery

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed breast cancer resected at time of original diagnosis Stage I-III disease Candidate for 1 of the following adjuvant chemotherapy regimens: FEC (fluorouracil, epirubicin hydrochloride, and cyclophosphamide) every 21 or 28 days CMF (cyclophosphamide, methotrexate, and fluorouracil) every 28 days A→CMF (doxorubicin hydrochloride followed by CMF) EC→P (epirubicin hydrochloride and cyclophosphamide every 21 days followed by paclitaxel every 21 days) FEC→P (FEC every 21 days followed by paclitaxel every 21 days) EC→D (EC every 21 days followed by docetaxel every 21 days) AC (doxorubicin hydrochloride and cyclophosphamide) every 21 days AC→P (AC every 21 days followed by paclitaxel every 21 days) E→CMF (epirubicin hydrochloride followed by CMF every 28 days) No evidence of metastases or localized or distant recurrence Investigation to exclude metastases required for any suspicious manifestation Premenopausal, defined as the presence of active menstrual cycles or normal menses within six weeks before initiation of chemotherapy Hormone receptor status not specified PATIENT CHARACTERISTICS: Female No other malignancy within the past 5 years except basal cell or squamous cell skin cancer or adequately treated in situ carcinoma of the cervix No history of noncompliance to medical regimens or patients who are considered potentially unreliable Not pregnant or nursing Negative pregnancy test PRIOR CONCURRENT THERAPY: See Disease Characteristics No prior chemotherapy and/or radiotherapy for cancer or non-neoplastic disease No other concurrent hormonal therapy except for tamoxifen