http://thinkprogress.org/health/2015/08/06/3688609/birth-control-cancer-study/
"The birth control pill has prevented hundreds of thousands of cases of endometrial cancer, and can help reduce women’s risk of developing cancer even long after they stop using it, according to a new research that analyzes data collected between 1965 to 2014.
Endometrial cancer — sometimes also called “cancer of the womb” — begins in the inner lining of the uterus. Mainly affecting older women who have gone through menopause, it’s the most common gynecologic cancer in the United States. An estimated 10,000 American women will die from this condition in 2015.
But the statistics would be much worse without the pill, according to research published this week in the prestigious Lancet journal. After examining data from 36 different studies conducted in several high-income countries around the world, researchers from the University of Oxford concluded that taking birth control pills for just five years can reduce a woman’s risk of developing this type of cancer by 25 percent. They estimate oral contraceptives have prevented about 400,000 cases of endometrial cancer since 1965 — including 200,000 cases in the last decade alone."
