Review Question - QID 210688

A 62-year-old woman makes an appointment with her primary care physician because she recently started experiencing post-menopausal bleeding. She states that she suffered from anorexia as a young adult and has been thin throughout her life. She says that this nutritional deficit is likely what caused her to not experience menarche until age 15. She used oral contraceptive pills for many years, has never been pregnant, and experienced menopause at age 50. A biopsy of tissue inside the uterus reveals foci of both benign and malignant squamous cells. Which of the following was a risk factor for the development of the most likely cause of her symptoms?