Effects of GnRHa on Ovarian Function Against Chemotherapy-induced-gonadotoxicity

Inclusion Criteria: * Premenopausal women 18 to 49 years of age are eligible for enrollment * Patients have operable stage I to IIIA breast cancer for which treatment with adjuvant or neoadjuvant cyclophosphamide-containing chemotherapy was planned. * Eligible participants had taken no estrogens, antiestrogens, selective estrogen-receptor modulators, aromatase inhibitors, or hormonal contraceptives within the month before enrollment. * Human chorionic gonadotropin negative by urine test before entering the group. * Informed consent, understanding and compliance with the requirements of the study. * No significant chronic disease and any organ dysfunction. Exclusion Criteria: * Exceptions were made for the use of hormonal contraception in women younger than 35 years of age that was discontinued before randomization. * Use of hormonal treatment for up to 2 months for the purposes of in vitro fertilization and cryopreservation of embryos or oocytes before randomization. * Patients with metastatic lesions or history of bilateral ovariectomy,ovarian radiation were excluded. * Patients received previous adjuvant endocrine therapy for breast cancer are not suitable to this trial. * Patients with uterine and/or adnexal diseases needing medical or surgical treatment are not suitable. * Allergic to active or inactive excipients of GnRHa is an exclusion criterion.