Breast cancer with Ki67 of 40% is salvageable, Ki67 of 40% is relatively low, the malignancy of this cancer is relatively low, the risk of metastasis and recurrence is relatively small, as long as active and effective treatment, the disease can be improved. Patients can undergo surgery at early stage, and after surgery, they can cooperate with targeted drug therapy, radiotherapy, chemotherapy, stem cell transplantation therapy and bio-immunotherapy to control the spread of cancer cells, prevent the disease from recurring, and prolong the survival period of patients. The higher the Ki67 positive rate is, the faster the tumor grows, the higher the malignant degree and the higher the chance of recurrence. The higher the Ki67 value of breast cancer, the more difficult the treatment will be, and it is necessary to cooperate with the comprehensive treatment method to improve the condition, and the prognosis is also poorer. Breast cancer is a malignant tumor and should be treated as soon as possible to avoid delaying the best treatment period.