In recent years, the incidence of breast cancer has been gradually increasing and the age of onset is decreasing. What do we need to know about breast cancer and what can we do to prevent it? How far is breast cancer from us? What are the early symptoms of breast cancer? Early breast cancer often does not have typical signs and symptoms, which is not easy to pay attention to, and is often found through physical examination or breast cancer screening, the following are typical signs of breast cancer. 1. Breast lumps 80% of breast cancer patients are first diagnosed with breast lumps. Patients often find breast lumps unintentionally, which are mostly single, hard, with irregular edges and less smooth surface. Most of the breast cancer is painless lumps, only a few of them are accompanied by different degrees of hidden pain or tingling. 2. Nipple overflow If blood, plasma, milk or pus flows from the nipple during non-pregnancy period, or if milk still flows even after stopping breastfeeding for more than half a year, it is called nipple overflow. There are many causes of nipple discharge, and common diseases include intraductal papilloma, breast hyperplasia, ductal dilatation and breast cancer. Unilateral hemorrhagic overflow from a single orifice should be further examined, and more attention should be paid to it if it is accompanied by a breast lump. 3. Skin changes Skin changes caused by breast cancer can show various signs, the most common one is that the tumor invades the ligament connecting the breast skin and deep pectoral muscle fascia, making it shorten and lose elasticity, pulling the skin in the corresponding area, and the breast skin will appear a small depression, like a small dimple. If the cancer cells block the lymphatic vessels, there will be “orange peel-like changes”, i.e. the breast skin will have many small dots of dimples, just like an orange peel. In the advanced stage of breast cancer, the cancer cells infiltrate into the skin along lymphatic ducts, glandular ducts or fibrous tissues and grow into the skin, forming hard nodules scattered in the skin around the main cancer foci, which is so-called “skin satellite nodules”. 4. Abnormalities of nipple and areola If the tumor is located in or close to the deep nipple, it can cause nipple retraction. If the tumor is far away from the nipple, and the large ducts in the breast are invaded and shortened, it can also cause nipple retraction or elevation. Eczema-like nipple cancer, i.e. mammary gland disease, manifested as itching, erosion, ulceration, crusting, flaking and burning pain of nipple skin, which may lead to nipple retraction. 5. Axillary lymph node swelling More than 1/3 of breast cancer patients admitted in big hospitals have axillary lymph node metastasis. At the initial stage, the lymph nodes in the axilla of the same side may be enlarged, and the enlarged lymph nodes are hard, scattered and pushable. As the disease progresses, the lymph nodes gradually merge and become adherent and fixed to the skin and surrounding tissues. In the advanced stage, metastatic lymph nodes can be felt on the clavicle and in the opposite axilla.