Within-center age and sex-stratified randomization assigned women to either a control arm, where they were asked to follow their usual medical care, or an intervention arm, where they were offered screening at regular intervals . Participants completed a self-administered risk factor questionnaire at entry, which queried information on demographics, smoking, history of cancer in firstdegree relatives, anthropometry, personal medical and medication use history, and personal history of cancer screening tests. Reproductive history covered menarche and menopause, parity and age at first pregnancy, and gynecologic surgeries, including hysterectomy, oophorectomy, and tubal ligation. The questionnaire ascertained age at first use and total duration of use of oral contraceptives. For menopausal hormone therapy, the question-naire asked about ever-use, current use, and duration of use but did not differentiate estrogen-only formulations from estrogen plus progestin.