In recent years, the incidence of breast cancer among Asian women has increased significantly. In Beijing, for example, the incidence of breast cancer in the urban area of the city has risen by 91% over the past 20 years, with an average annual increase of 4.6%. At the same time, the occurrence of breast cancer has a younger development trend, patients under the age of 40 years old accounted for an increase in cases, many of which are “single aristocrats”. Breast cancer is caused by infertility. Because not having children and not breastfeeding have a great impact on the reproductive hormones in a woman’s body. The cyclical changes in hormones cause physiological changes in the breast tissue. Estrogen stimulates the proliferation of milk ducts and connective tissue and promotes breast development; progesterone mainly promotes the development of breast follicles. Scientists at the University of Oxford, in a project called the Million Women Breast Cancer Study, have concluded that the more children a woman has and the longer she breastfeeds, the lower her risk of developing breast cancer. If a woman has five children in her lifetime, one every two years, and breastfeeds each child, the incidence of breast cancer in that woman will drop by 50 percent or more. Breast Cancer Triggers, Sexlessness. Studies claim that sex reduces the incidence of breast cancer. Oxytocin and dehydroepiandrosterone in the human body will be fully released during orgasm and high arousal, and play a role in protecting the breast. Especially for women who have never been pregnant, high quality and regular sex can make up for never having children. To be single and still stay away from breast cancer. Then, it is recommended to drink less alcohol, prohibit late nights and exercise.