Classified Treatment Strategy for De-novo Metastatic Breast Cancer After Systemic Adjuvant Therapy

For patients with de novo stage IV breast cancer, the current debate is whether local surgery can improve the survival of patients. There is no clinical study on the classification after systemic treatment of de novo stage IV breast cancer patients. In fact, the clinical stage of tumor can change with the change of treatment. For example, the stage Ⅲ of locally advanced breast cancer can down-staging to the stage Ⅱ after systemic treatment. Similarly, patients with stage Ⅳ can down-staging to stage Ⅱ or stage Ⅲ after systemic treatment. At this time, the patient can receive surgical treatment. Therefore, this study is to first treat de novo stage IV breast cancer patients with systemic treatment, according to the response after systemic treatment to give different treatment measures（surgery or continued systemic treatment）. The investigators hope that this study will provide new ideas for the treatment of de novo stage IV breast cancer and other de novo stage IV cancers.