Breast cancer tends to target several groups of people, including early age at menarche, late age at menopause, infertility, age at first full-term delivery, first-degree relatives with a history of breast cancer, over-nutrition, obesity, and high-fat diets. The mammary gland is a target organ for the action of many hormones, such as estrogen and progesterone. Therefore, early age at menarche, late age at menopause, lifelong infertility, low age at first full-term labor, and high age at first full-term labor are factors that predispose to breast cancer. First-degree relatives with a history of breast cancer are 2-3 times more likely to develop the disease than the general population, which is also a susceptibility factor for breast cancer. Over-nutrition, over-obesity, and high-fat diets can enhance or prolong the stimulation of breast epithelial cells by estrogen, thereby increasing the incidence of breast cancer. People with breast cancer susceptibility factors can go to the hospital for regular screening every year, so as to achieve early detection and early treatment of any disease.