The use of birth control pills decreases the risk of developing endometrial cancer by half.

At Significantly Higher Risk 
• Postmenopausal women. 
• Menopause after age 52 (2.4 times as likely).
• Lack of children (twice as likely). 
• Women with hypertension (twice as likely).
• Diabetics (2.8 times as likely). 
• Women who do not ovulate, in other words those with polycystic ovaries (Stein-Leventhal syndrome).
• Estrogen replacement therapy without supplemental progesterone (seven times as likely).
• History of pelvic radiation therapy (eight times as likely).
• Obesity greater than 23 kg (50 pounds) over ideal body weight (10 times as likely).