(HealthDay News) — Use of oral contraceptives, even for just a few years, offers significant long-term protection against endometrial cancer, and longer use is associated with greater risk reduction, according to research published online Aug. 4 in The Lancet Oncology.
Valerie Beral, of the University of Oxford in the United Kingdom, and colleagues analyzed data from 36 studies involving a total of 27,276 women with endometrial cancer around the world. They estimated that over the past 50 years, oral contraceptives have prevented about 400,000 cases of endometrial cancer among women before age 75 in wealthy nations, including about 200,000 between 2005 and 2014 alone.
The team found that every five years of oral contraceptive use cut the odds of endometrial cancer by about one-quarter. In high-income nations, 10 years of oral contraceptive use lowered the risk of developing the disease before age 75 from 2.3 to 1.3 cases per 100 users. The researchers also found that a woman’s reproductive history, amount of body fat, alcohol and tobacco use, or ethnicity had little effect on the amount of protection oral contraceptives provide against endometrial cancer.
“The strong protective effect of oral contraceptives against endometrial cancer — which persists for decades after stopping the pill — means that women who use it when they are in their 20s or even younger continue to benefit into their 50s and older, when cancer becomes more common,” Beral said in a journal news release.