Better choice of contraceptives can prevent breast cancer

Cathrin Brisken © Alain Herzog / EPFL There is a strong link between hormonal contraceptives and breast cancer risk. The main culprit are progestins, synthetic mimics of the pregnancy hormone progesterone that stimulate cell growth in the breast. An EPFL study into the distinct biological effects of different progestins on the breast shows that contraceptive-related breast cancer can be prevented by more informed choices about the composition of contraceptives. Hormonal contraceptives, e.g. the pill, the patch, and the vaginal ring, contain synthetic hormones that prevent pregnancy by either stopping ovulation, changing the cervical mucus to stop sperm from passing through the cervix and finding an egg, or changing the womb's lining to prevent a fertilized egg from being implanted in it. Despite their widespread use, hormonal contraceptives are known to increase the risk of breast cancer, which is the most common cause of cancer-related death among women worldwide, and also topped the list of most commonly diagnosed cancers in 2020. The main component of hormonal contraceptives are progestins, which, mimic the female sex hormone progesterone. Progesterone is involved in a number of biological processes, including the menstrual cycle, pregnancy, and various aspects of fetal development, like brain programming.