Ovarian cancer. Ovarian cancer causes the most deaths from all types of gynecologic cancers. Head of this study, Dr. Michael L Leitzman from the National Cancer Institute United States in Bethesda, Maryland, and University of Regensburg in Germany, said that women who are obese have a higher chance for ovarian cancer. It is not clear why obesity has contributed to ovarian cancer. Possibility this related to the effects of excess body fat to levels of estrogen in the body of a woman. This also often can create irregular menstrual cycles, he added.