Risk Factors 2. Some gynecologic diseases Long-term endogenous estrogen exposure polycystic ovary syndrome functioning ovarian tumors anovulating dysfunctional bleeding Infertility, NulliparityRisk Factors 2. Some gynecologic diseases ( Long-term endogenous estrogen exposure ) - polycystic ovary syndrome - functioning ovarian tumors - anovulating dysfunctional bleeding - Infertility, Nulliparity