Breast cancer staging should be combined with the diameter size of the tumor, as well as with the situation of axillary lymph node metastasis and with whether the patient has distant metastasis. If the tumor is within 2cm and there is no axillary lymph node metastasis, it should belong to stage I. If the tumor is between 2-5cm and there is lymph node metastasis in the axilla but it has not fused into a cluster, it should be in stage II; if the tumor is more than 5cm and there is lymph node metastasis in the axilla and it has fused into a cluster, it should be in stage III; if the tumor is bigger or even inflammatory breast cancer with distant metastasis, it is stage IV breast cancer. Pathological staging of breast cancer should be combined with immunohistochemistry at the same time, which is the result of molecular typing to decide the next treatment plan. If it is er-positive, Pr-negative and Her2-negative, endocrine therapy is generally considered as an option; if it is triple-negative breast cancer, chemotherapy generally needs to be considered, but the effect is not very good in general; if it is er- and Pr-negative, and Her2-positive, targeted therapy and so on should be considered.