Recently, I was shocked to hear that a good friend was admitted to the hospital for surgery for breast cancer, and I was sorry to hear that the magazine appointment day was approaching. Breast cancer is one of the most common malignant tumors in women, and according to statistics, its incidence accounts for 7-10% of all malignant tumors in the body. All expectant mothers, new mothers and unexpectant mothers must pay attention to their health and must not neglect breast examination. I remember one afternoon about three years ago, I was chatting with my old director who had just finished a mammography clinic, and I heard her say that the number of breast cancer patients during pregnancy and lactation had increased significantly in recent years. At that time, I was still a junior doctor at the International Peace Maternal and Child Health Hospital. The old director who had guided me in breast surgery had a daughter, only one year older than me, who was found to have a lump on her breast four months after giving birth to a baby boy by Caesarean section. The helplessness of sending the white hair to the black hair, not to mention the fact that there is a child who has not yet learned to speak, makes people see the kind of heartache, which cannot be expressed in words. As a result, I paid special attention to the information and research progress of breast cancer during pregnancy and lactation, and always took special care of it in my pre-marital and pre-pregnancy health guidance. Breast cancer during pregnancy or lactation refers to breast cancer that occurs during pregnancy and one year after delivery. Although the incidence of breast cancer during this period only accounts for 1% to 8% of all breast cancers, because it occurs during pregnancy or lactation, there are obvious changes in hormone levels in the body. The levels of estrone, estradiol, estriol and adrenocorticotropic hormone increase significantly during pregnancy, prolactin and growth hormone increase during lactation, T-cells in blood decrease, and immune function is low, thus leading to accelerated tumor growth, increased malignancy, and easy dissemination. In addition, the physiological enlargement and congestion of breast tissue make it difficult to detect the tumor and the misdiagnosis rate is high, so that patients often have lymph node metastasis at the time of consultation, which makes the follow-up treatment very difficult. Etiologically, there is no evidence to prove any causal relationship between pregnancy or breastfeeding and the development of breast cancer, but if we review the medical history, patients often find breast lumps or nipple overflowing with blood or fluid before and during early pregnancy, but due to insufficient attention, and it is not easy to distinguish between lumps and normal physiological growths, they do not consult the doctor until half a year or a year later, but unfortunately the best time for treatment has been missed. In recent years, due to environmental pollution, hormonal foods, stressful working life, late marriage and childbirth, reluctance to breastfeeding, etc., breast cancer has become the first malignant tumor among women in Shanghai, and the incidence rate is still on the rise, therefore, the prevention of this disease should not be neglected. According to recent survey data in Shanghai, breast cancer occurs mainly in the age group of 50-60 years old, while most women of childbearing age are between 24-35 years old, so this age group is not a high incidence group. According to data from China in previous years, the proportion of breast cancer in the age group of 30 to 39 years old was 21.4%, while those who developed before the age of 30 were less common. Because normal breast tissue in young adulthood often has nodular changes on clinical palpation and changes cyclically with the menstrual cycle, and fibrocystic changes in breast tissue are so common during this period that clinicians rarely suspect malignancy, and patients themselves neglect examination because many others around them have similar symptoms. According to a study, the clinical diagnosis rate of breast cancer in young adults is only 37%, and about half of them are diagnosed as benign, 30% of which are diagnosed as fibroadenoma. Therefore, on the one hand, we do not need to talk about “lumps” and cause unnecessary psychological burden, but on the other hand, we should not neglect breast examination before pregnancy, especially for those who have family history and have been diagnosed with fibroadenoma or other benign diseases, further definite diagnosis is necessary. Self-examination Early diagnosis and prevention are the main focus of breast disease care. Self-examination of the breast, physical examination by a physician, and mammography or ultrasound are the most common and primary modalities used today. However, radiography is not recommended because it may affect the quality of the embryo before conception. Self-examination of the breast is easy and simple, and about 90% of breast cancer symptoms are detected on their own, but research studies also show that although more than 96% of women already know about self-examination of the breast, only 40% of them do it in real life. After a thorough examination by your physician, further consultation with your doctor, learning the correct method of examination, and insisting on regular self-examination on the 9th to 11th day of each menstrual cycle, routine monthly breast self-examination combined with regular professional physician examination is still one of the most important means of early detection and prevention of breast cancer today. Eliminate Breast Cancer Attack Among the known risk factors for breast cancer, except for genetic predisposition which is beyond our control, many of them can be prevented by changing our lifestyle habits and environment. In terms of nutrition, we must control our body weight in an ideal state, limit the total daily calorie intake, consume foods with low fat and low cholesterol content and foods with high fiber such as fruits, vegetables and cereals, and pay attention to supplementing with appropriate micronutrients and vitamins with antioxidant effects in combination with our lifestyle, and reduce the intake of salt, food additives, smoked and preserved foods. Avoid smoking and alcohol and eliminate caffeine-containing foods. Maintain a harmonious sex life and avoid the use of any hormones and any unnecessary drugs. Keep the air, water and working environment clean, use filters if necessary, and avoid long-term use of various cleaning agents, pesticides, sterilizers and other chemicals. Try to avoid the interference of radiation, avoid household appliances, office equipment and electromagnetic fields and outdoor electric fields. Adhere to moderate daily physical exercise. Maintain a good state of mind and find out all the relaxation methods that help you to control and regulate your mental stress. Breastfeeding Health Protection As modern women’s demand for education and participation in social activities is greatly increased, late marriage and late childbirth are becoming more and more common in metropolitan cities like Shanghai, and even the phenomenon of “leftover men and women” has become a social problem in recent years. Delayed lactation, shortened breastfeeding period, or even no breastfeeding is also a high risk factor for breast cancer. I am glad that the majority of my follow up patients who received preconception counseling were able to breastfeed for more than 6 months after delivery, not only to nurture the next generation, but also to invest in an effective insurance policy for their health. There are more and more new mothers who want to keep breastfeeding. Be alert to cancer killers, make self-protection, change your lifestyle habits, adjust your mental stress, and be a healthy and confident mother-to-be.