Adjuvant endocrine therapy for premenopausal breast cancer: 1.TAM for 5 years. 2.TAM treatment for 2~3 years into menopause can be changed to AI treatment for a total of 5 years; TAM treatment for 5 years into menopause can be changed to AI intensive treatment for 2~5 years. 3. Young patients with high-risk recurrence factors can be considered for ovarian function suppression plus TAM or AI therapy. 4. For some of those who are not suitable for TAM treatment, ovarian function suppression plus AI treatment can be considered. Adjuvant endocrine therapy for postmenopausal breast cancer: 1. Switch to AI for 3~2 years after TAM therapy for 2~3 years. 2.For high-risk or HER2-positive patients, start with AI for 5 years. 3. For patients who have completed 5 years of TAM therapy, those with positive lymph nodes should receive AI for another 2~5 years.