Breast Cancer Armored Chest, also known as Breast Armored Chest, is a skin change resulting from localized infiltration and metastasis in advanced stages of breast cancer. Breast cancer is a malignant tumor caused by genetic factors, estrogen or progesterone, and genetic mutations. When the tumor progresses to an advanced stage, metastasis and infiltration of the pectoral muscles, chest wall and subcutaneous lymph nodes can occur. As a result of the tumor, the skin may be dark red, the tumor may spread into plaques, and when the tumor spreads to the back and contralateral chest skin, it forms an armor-like shape known as armored chest. At this time, the patient may have respiratory difficulties, skin ulcers, bleeding, local odor, and formation of exogenous tumors due to chest skin infiltration, which is one of the characteristic manifestations of advanced breast cancer. For breast cancer patients who have formed armored chest, it means that they can no longer be treated surgically. They can only choose comprehensive treatment measures such as chemotherapy, radiotherapy and endocrine therapy under the guidance of doctors according to their physical conditions in order to reduce pain and improve the quality of life.