AFP and breast cancer: An increase in the levels of estradiol, testosterone, progesterone, human chorionic gonadotropin and alpha-fetoprotein hormones has been observed and proven in pregnancy, and it seems the increase in human chorionic gonadotropin and fetoprotein progesterone can have a protective effect against breast cancer due to its anti-estrogenic properties effective on the breast tissue, but the association between the higher incidence of breast cancer and the birth of twins or multiples was first established in the 1980s [46].