Early, middle and late stages of triple-negative breast cancer are mainly based on the size of breast cancer foci, whether there is lymph node metastasis and whether there is distant metastasis. 1. Early stage: Early stage triple-negative breast cancer with the size of the cancerous foci in the breast usually <=2cm, and without metastasis to the lymph nodes around the breast or distant organs, according to TNM staging, it is stage I breast cancer. 2. Intermediate stage: the size of the cancer foci of triple-negative breast cancer in the intermediate stage ranges from 2 to 5 cm, and some cases may be larger than 5 cm, and this stage of breast cancer will be accompanied by metastasis of lymph nodes in the axilla of the same side, and it will be staged as stage Ⅱ – stage Ⅲ according to TNM staging. 3. Advanced stage: advanced triple-negative breast cancer does not focus on the size of the breast cancer foci or axillary lymph node metastasis, but mainly focuses on the existence of metastasis in distant organs, such as metastasis in lungs, liver, brain and other organs, which is stage Ⅳ according to TNM staging. Triple-negative breast cancer is limited by treatment methods, so if you have been diagnosed, please consult a doctor in time to determine the stage and treatment methods through professional pathological analysis.