Clinical Research Directory

Inclusion Criteria: 1. Age over 40(include 40 years old), or before 60, female 2. Primary invasive breast cancer diagnosed by histopathology, except of occult breast cancer, inflammatory breast cancer and Paget's disease 3. Operable patients with no distant metastases at diagnosis (stage T1-T3, any N, M0) 4. The patient was at premenopausal status when first diagnosed (had menstruation in the last 12 months or hormone levels not reached menopause when diagnosed, E2 \> 30ng/L, FSH≤30U/L) 5. The patient has used chemotherapy (neoadjuvant chemotherapy or adjuvant chemotherapy) after diagnosis Exclusion Criteria: 1. Age before 40, or over 60(include 60 years old) 2. Patient who accepted bilateral ovariectomy or ovarian radiotherapy 3. Patient who used gonadotropin-releasing hormone agonist ( GnRHa) 4. Stage IV (metastatic) breast cancer 5. The patient was at postmenopausal status when first diagnosed (no menstruation in the past 12 months or hormone levels reached menopause when diagnosed, E2≤30ng/L, FSH \> 30U/L) 6. The patient has not used chemotherapy (neoadjuvant or adjuvant chemotherapy) since diagnosis 7. The investigator determines that the patient has any other condition that make her unfit to participate in the study