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