1.What is breast cancer? Breast cancer is a malignant tumor that occurs from the ductal epithelium of the breast. In many western countries, the incidence of breast cancer is the first of all cancers in women. In China, breast cancer accounts for the top two malignant tumors in women. According to relevant data, its incidence rate is 23 per 100,000 population in women and only 0.49 per 100,000 population in men. Breast cancer in men accounts for about 1% of all breast cancers. Breast cancer mostly occurs in women between 40 and 60 years old, or around menopause, especially between 45 and 49 years old and between 60 and 64 years old. 2. What are the causes of breast cancer? From the analysis of clinical practice and animal experiments, the occurrence of breast cancer is related to the following factors: (1) Hormonal disorders. Hormonal disorders mainly refer to the disorder of estrogen secretion. Because the high incidence of breast cancer is between 40 and 60 years old, this is the period when estrogen secretion is disordered and estrogen level is high in women. Due to the increased secretion of estrogen in the body, the ductal epithelial cells of the breast become overproliferated and cancer occurs. (2) Childbirth and breastfeeding. In recent years, a large number of surveys have proved that women who have not given birth or have given birth but rarely breastfeeding have a higher chance of breast cancer than women who have breastfed many times or breastfed for a long time. This indicates that having more children and breastfeeding can reduce the chance of breast cancer. (3) Genetic factors. It is mainly manifested in having a family history of breast cancer. According to foreign data, there are two forms of positive family history: one is that the mother has breast cancer and her daughter also has breast cancer, which mostly occurs before menopause and is often bilateral; the other is that the mother has not had breast cancer, but at least two sisters in a family have breast cancer, the incidence of breast cancer in such families is two to three times higher than that in families without family history, and this kind of breast cancer mostly occurs after menopause. The incidence of breast cancer in such families is 2 to 3 times higher than that in families without family history, and this kind of breast cancer mostly occurs after menopause and is often unilateral. 3. What are the early clinical manifestations of breast cancer? (1) Breast lumps. The main manifestation of breast cancer is a lump on the breast, which is often the early symptom of breast cancer. Most patients do not feel any pain, only less than 1/3 of them feel some stabbing pain or dull pain, but it is not very obvious. In early stage, the cancer tissue is not infiltrated and the lump can still move. However, since the lump of breast cancer is very similar to benign breast tumor in many aspects, it is inaccurate to determine its nature by touching the lump alone and must be examined in hospital. (2) Unilateral nipple overflow night. The sudden appearance of nipple flow (milk-like, blood-like or water-like fluid) in non-lactating women should be noted as it may be breast cancer. (3) Routine checkups reveal breast occupations such as echogenic nodules and calcified foci through ultrasound and X-ray. 4.Risk factors for breast cancer? (1) Family history. (2) Menstrual factors. If the age of menarche is earlier than 12 years old, the risk of breast cancer is 2.2 times greater than that of menarche at 17 years old; if menopause is later than 50 years old, the risk of breast cancer is 1 times greater than that of menopause after 45 years old. (3) Excessive miscarriage. Normal abortion does not increase the risk of breast cancer, but repeated abortions or multiple abortions before the age of 18 are likely to cause breast diseases and increase the risk of breast cancer. (4) Breastfeeding. Breastfeeding is one of the best natural means to prevent breast cancer. Breastfeeding can reduce the risk of breast cancer by 20% to 30%, while non-breastfeeding infants after delivery will greatly increase the chance of breast cancer. (5) Poor quality of sex life. Breast disease and sex life are closely related, and sexual repression in women can increase the incidence of lobular hyperplasia and breast tumors. Domestic survey shows that 86% of women with lobular hyperplasia have never reached orgasm during sex. The older the age of first marriage, the higher the incidence of breast cancer. (6) Depressive mood. The incidence of breast cancer is also higher among single women, women who stay behind, PR girls, retired female workers and some secondary school teachers who suffer from breast diseases. This will lead to imbalance of internal environment and decrease of immunity, which will make cancer easily occur.