RATIONALE: Goserelin may help prevent early menopause in patients undergoing chemotherapy for breast cancer. It is not yet known whether goserelin is effective in preventing early menopause in women undergoing chemotherapy for breast cancer. PURPOSE: This randomized phase III trial is studying goserelin to see how well it works compared with no goserelin in preventing early menopause in premenopausal women undergoing chemotherapy for stage I, stage II, or stage III breast cancer.

OBJECTIVES: Primary * Compare the incidence of premature ovarian failure after chemotherapy in premenopausal women with stage I-III breast cancer treated with goserelin vs no goserelin . Secondary * Compare the quality of life of patients treated with these regimens. * Compare menopausal symptoms in patients treated with these regimens. * Compare bone mineral density loss in patients treated with these regimens. * Compare hormone levels in patients treated with these regimens. * Compare menstruation in patients treated with these regimens. * Compare the incidence of pregnancy in patients treated with these regimens. OUTLINE: This is a randomized, open-label, prospective, parallel group, multicenter study. Patients are stratified according to age (≤ 40 years vs \> 40 years) and participating center. Patients are randomized to 1 of 2 treatment arms. Arm I (chemotherapy alone): Patients receive neoadjuvant or adjuvant cyclophosphamide- and/or anthracycline-containing chemotherapy. Treatment continues for 6-8 courses in the absence of disease progression or unacceptable toxicity. Arm II (chemotherapy plus goserelin for ovarian function suppression): Patients receive neoadjuvant or adjuvant chemotherapy as in arm I. Patients also receive goserelin subcutaneously every 3-4 weeks beginning 1-3 weeks before the start of chemotherapy. Treatment with goserelin repeats every 3-4 weeks until completion of chemotherapy. Quality of life is assessed at baseline, at 3, 6, 12, 18, and 24 months, and then annually for up to 5 years. After completion of study therapy, patients are followed periodically for 5 years. Peer Reviewed and Funded or Endorsed by Cancer Research UK PROJECTED ACCRUAL: A total of 400 patients will be accrued for this study.