The most common clinical protocol is to start chemotherapy within 2-4 weeks after the patient’s surgery. Chemotherapy is one of the five major treatments for breast cancer and is also an effective way of systemic treatment for breast cancer. The timing of chemotherapy after surgery needs to be combined with the patient’s post-operative recovery and the type of disease. Chemotherapy should not be given too early or too late after surgery. If systemic chemotherapy is administered early after surgery, it will affect the healing of the surgical incision and prolong the recovery time of breast cancer patients. If chemotherapy is administered later after surgery, it can cause a loss of chemotherapy effect. Studies have shown that starting chemotherapy after breast cancer surgery too late decreases the survival rate of patients compared to starting chemotherapy 6-8 weeks after surgery and chemotherapy within 4 weeks after surgery. Therefore, the most common protocol in clinical practice is to start chemotherapy within 2-4 weeks after the patient’s surgery.