Breast cancer has become the most prevalent malignant tumor among women worldwide, with about 1.2 million women suffering from breast cancer each year, and in developed countries, on average, one out of every eight to nine women may suffer from breast cancer. In China, the incidence of breast cancer among women in large and medium-sized cities is the highest, and the incidence rate continues to rise. In 2005, the incidence rate in Beijing increased by 31.7% compared with that before 1996, and the incidence rate in Shanghai increased from 17.7/100,000 in 1972 to 37/100,000 in 2000, ranking first among female malignant tumors in Shanghai. The incidence trend is younger, with the peak age of the disease at 45~55 years old, 10~15 years earlier than women in western countries, and the consultation time is quite late. Before surgery in economically underdeveloped areas of China, about 30% of patients already belong to late stage III and IV, while in the United States this percentage is only 15%. Regular screening is the most effective way to reduce the risk of breast cancer, and regular breast cancer screening is recommended from the age of 40; those with a family history of genetic predisposition and other high-risk factors are advised to attend screening earlier (the starting age of screening is advanced to 20 years old). Early detection and treatment is currently the most effective strategy to reduce breast cancer mortality. Encourage monthly breast self-examination: Self-examination can be done on the fifth day after menstruation. Method: Touch the entire breast with the fingertips of the middle and index fingers in a tapping motion, gently touching any lumps or changes under the skin. Look in the mirror and check both breasts for any changes in shape or contour, including nipple discharge, folds, dimpling or changes in the texture of the breast skin. Note: Not finger grasping. Hospital physical examination: Breast physical examination every 1-3 years for the average woman under 40 years old; breast physical examination and mammogram and breast ultrasound once a year for the average woman between 40 and 59 years old; breast physical examination and mammogram and breast ultrasound every 1-2 years for the average woman between 60 and 69 years old; breast physical examination and mammogram and breast ultrasound once every 2 years for women over 70 years old.