The main reason is that many people ignore the early symptoms of breast cancer, so what will happen in the early stage of breast cancer? Some early symptoms of breast cancer patients can not yet touch a clear lump in the breast, but they often have local discomfort, especially postmenopausal women who sometimes feel mild pain and discomfort in one breast, or sinking and soreness in the back of one shoulder, even involving the upper arm of that side. 2, early in the breast can be touched in the size of a bean lump, hard, movable. Generally there is no obvious pain, a few have paroxysmal hidden pain, dull pain or stabbing pain and other symptoms. 3.Changes in breast appearance: the skin at the lump is seen to be elevated, some local skin is orange peel-like, or even edema, discoloration, eczema-like changes, etc. 4. Near the center of the nipple with nipple retraction. There is mild indentation of the breast skin, nipple erosion, nipple asymmetry, or the skin of the breast is thickened and coarsened, and the pores are enlarged. 5, nipple overflow: special attention should be paid to further examination when the overflow is bloody or plasma blood. 6. Regional lymph node enlargement, with the most common being ipsilateral axillary lymph node enlargement. If the supraclavicular lymph node is enlarged, it is already in advanced stage. In addition, estrogen is one of the prerequisites for the development of breast tumor. The onset of breast cancer ranges from 18 to 70 years old, mostly between 30 and 60 years old. Especially, the reproductive period and menopause are the high incidence stages of female breast cancer, and women who have used estrogen replacement therapy for more than 10 years should be closely monitored and genetic screening should be performed if available. Because of the small size of the breasts and the small area exposed to estrogen, people with small breasts are relatively less likely to get this disease, but there is no shortage of such cases, and it is inaccurate to say that only plump people will get breast cancer. Breast cancer is one of the most common malignant tumors in women, accounting for 7-10% of all malignant tumors in the body and is second only to uterine cancer in women. Its incidence is often related to heredity, and the incidence is higher in women around menopause. It is one of the most common malignant tumors that usually occurs in the glandular epithelial tissues of the breasts and seriously affects women’s physical and mental health and even endangers their lives. Breast cancer is rare in men, and only about 1-2% of breast patients are male.