Q: When should I start endocrine drugs (tamoxifen, letrozole, anastrozole, exemestane, Norelide, etc.) for anti-cancer treatment after breast cancer surgery? Can I continue to take the drugs during radiotherapy? A: Once chemotherapy is completed, or chemotherapy is not necessary, and there is no contraindication to take the drugs, it can be started. Once endocrine drugs are started for anti-cancer treatment, they should be taken without interruption and for a long time, and the treating physician should be consulted for the specific number of years. Of course, if intolerable side effects occur after the drug is administered, corresponding adjustments should be made, such as changing the drug, reducing the dosage, adding adjuvant drugs and so on. It can be said that endocrine therapy for breast cancer is the pioneer of drug-targeted therapy, which has saved the lives of many breast cancer patients with low cost and high efficiency, and still occupies an irreplaceable position in the comprehensive treatment of breast cancer. However, the aforementioned endocrine drugs may affect the glow of the anticancer effect of chemotherapy drugs, and are generally not applied at the same time as chemotherapy. According to European and American studies, endocrine therapy for breast cancer does not conflict with radiotherapy and can be administered simultaneously. Of course, simultaneous application should pay more attention to cardiopulmonary protection in order to reduce the effects of synergistic effects of endocrine therapy and radiotherapy on the heart and lungs.