Invasive breast cancer stage I, II and III usually refers to pTNM staging, which needs to refer to the infiltration and growth of the tumor, lymph node invasion and distant metastasis. 1. Stage I: the maximum diameter of the tumor is less than 20mm, no lymphatic metastasis, no distant metastasis. If the above three conditions are satisfied at the same time, it is considered as stage I. 2. Stage II: Stage II if any of the following two conditions are met. (1) The maximum diameter of the tumor is more than 20mm, but there is no lymphatic or distant metastasis. (2) The maximum diameter of the tumor is less than 50mm, accompanied by 1~3 lymph nodes metastasis or sentinel lymph node metastasis, but no distant metastasis. 3. Stage III: If any one of the following three conditions is met, it is stage III. (1) The maximum diameter of the tumor is less than 50mm with 4~9 axillary lymph nodes metastasis but no distant metastasis. (2) The maximum diameter of the tumor is more than 50mm with 1~3 lymph nodes metastasis or sentinel lymph nodes metastasis but no lymphatic metastasis. (3) Tumor directly invades the chest wall and or skin to form an ulcer or mass with no lymphatic metastasis or only 4-9 axillary lymph nodes metastasis but no distant metastasis. Regardless of the staging, aggressive treatment is recommended.