Breast cancer patients are not certain that they will always have back pain. If pain is felt, it may be back and shoulder pain corresponding to breast cancer on the same side. For example, if there are bone metastases, the shoulder blade or spine and rib metastases will have pain in the corresponding area of the back, but not all breast cancer patients have pain. Breast cancer may begin with a painless breast lump, which is one of the most common malignant tumors in women, and may occur in a very small number of men. It is not usually possible to diagnose breast cancer or determine the severity of breast cancer based on the presence or absence of pain in the back, but usually depends on the presence or absence of lymph node metastasis in the armpit. Surgery is the main treatment for breast cancer, and because it is a systemic disease, radiotherapy and other comprehensive treatments are also needed.