Menopause is generally defined as the permanent termination of menstruation and is also used to describe the persistent reduction of estrogen synthesized by the ovaries during breast cancer treatment. There are several clear definitions of menopause: 1. post bilateral oophorectomy; 2. age ≥ 60 years; 3. age < 60 years, menopause ≥ 12 months, not receiving chemotherapy, endocrine therapy or treatment to suppress ovarian function, and follicle stimulating hormone and estradiol levels within the postmenopausal range; 4. age < 60 years, taking endocrine drugs, follicle stimulating hormone and estradiol levels should be within the postmenopausal range 5. Patients who are receiving luteinizing hormone-releasing hormone agonist or antagonist therapy cannot determine whether they are menopausal; 6. Premenopausal women who are receiving adjuvant chemotherapy, menopause cannot be used as a basis for determining menopause; 7. Because although patients may stop ovulating or experience menopause after chemotherapy, ovarian function may still be normal or have the potential to recover. In general, the criteria for menopause are E2 below 30 PG/ml and serum FSH > 40 U/l.