Non-specific invasive breast cancer with low-grade ductal carcinoma in situ is relatively more serious. Non-specific invasive breast cancer is the most common type of breast cancer, including invasive ductal carcinoma, invasive lobular carcinoma, sclerocarcinoma, simple carcinoma and so on, with a lower degree of differentiation. Cancer cells are more likely to infiltrate and widely invade the surrounding tissues, and are prone to metastasis, invading the lungs, bones as well as the liver. In addition, non-specific invasive breast cancer is easy to recur after treatment, and needs adjuvant chemotherapy, radiotherapy or endocrine therapy after surgery, etc. The prognosis is poorer than other types of breast cancer. However, low-grade ductal carcinoma in situ suggests that the malignancy degree of tumor cells is low, and the lesion is relatively limited without lymph node and distant metastasis, which is still in the early stage of the disease. Through radical breast cancer surgery, combined with postoperative radiotherapy, chemotherapy, endocrine targeted therapy, etc., the postoperative survival and cure rate can be improved; if the disease progresses due to the lack of active treatment, then the survival rate will be greatly reduced. Therefore, non-specific invasive breast cancer should be detected, diagnosed and treated early.