AC chemotherapy regimen is only one kind of breast cancer chemotherapy regimen. The choice of breast cancer chemotherapy regimen is based on tumor size, menstrual status, postoperative pathological results of staging and immunohistochemistry results, etc. The severity of breast cancer cannot be judged according to chemotherapy regimen, and there is no such thing as the chemotherapy regimen being the lightest. AC chemotherapy regimen is one of the most commonly used regimens for adjuvant chemotherapy of breast cancer, in which A stands for drugs such as adriamycin and epirubicin, and C stands for cyclophosphamide. Anthracycline combined with paclitaxel combination chemotherapy regimens, such as EC (epirubicin, cyclophosphamide)-T (docetaxel or paclitaxel) regimen, are commonly used for breast cancer patients with poorly differentiated and late-staged tumors. For patients with better tumor differentiation and earlier staging, paclitaxel-based regimens such as TC regimen (docetaxel or paclitaxel, cyclophosphamide) can be used. Breast cancer patients should follow the doctor’s instructions in choosing chemotherapy regimens, and in the course of chemotherapy, they should have timely rechecks, and consult the doctor in case of discomfort.