Breast invasive cancer grade 3 can be early stage I-II cancer or late stage III-IV cancer. The grading of invasive cancer is a kind of pathological histological grading, which essentially reflects the differentiation of cancer cells into 3 grades. The higher the grade, the worse the differentiation, which means the more malignant the cancer is. The stage of cancer refers to the stage of cancer, which is divided into clinical stage and pathological stage, essentially reflecting the spread of cancer. To know which stage of invasive breast cancer grade 3 belongs to, other information must be provided, such as the patient’s CT or MRI results, and the relevant results of pathological examinations performed after surgery. In conclusion, the grading and staging of invasive breast cancer is an assessment of the characteristics of the cancer from different perspectives and therefore requires more detailed information from the patient for accurate grading and staging.