http://www.digitaljournal.com/life/health/birth-control-pills-have-prevented-thousands-of-cancer-cases/article/440264

Birth control pills have prevented thousands of cancer cases

Posted Aug 5, 2015 by Karen Graham
A new collaborative study has found that 400,000 cases of endometrial cancer, which develops in the uterine lining, have been prevented in the last 50 years. Almost half of those cancers were prevented in the last 10 years.
Different kinds of birth control pills.
Different kinds of birth control pills.
Ceridwen
British researchers say that taking birth control pills, even for just a few years, can offer significant protection for women against uterine cancer.
Doctors have known for a long time that women taking birth control pills have a lower risk of endometrial cancer, as well as ovarian and colorectal cancers. Earlier studies have shown that taking the Pill for 10 years also cut the risk of ovarian cancer by 50 percent, says JoAnn Manson, a Harvard Medical School professor who wasn’t involved in the new study.
But the British researchers found the Pill's benefits against endometrial cancer were dramatic. Women who took the Pill for five years had a 24 percent lower risk of developing uterine cancer, while those who took the Pill for 10 to 15 years cut their risk in half, according to the study.
The study, led by researchers at the University of Oxford in England, also showed that the longer women continued taking the Pill, the more their risk declined, and even after stopping this form of contraception the risks continued to be low for uterine cancer.
Manson, who’s also chief of preventive medicine at Brigham and Women’s Hospital in Boston, told USA Today the new British study's "primary message is to provide reassurance that for women who are using birth control pills to manage their family planning, the benefits are likely to balance out, if not outweigh, any risks."
According to Health.com, in a news release, lead author of the study, Valerie Beral of the University of Oxford, said, “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."
An interesting finding by the research team showed the lower level of estrogen used in contraceptive pills today has proven to be just as effective in reducing the risks of uterine cancer as those Pills used in the 1960s. The researchers also found that other factors, such as percent of body fat, tobacco or alcohol use, and ethnicity, had little to do with the amount of protection the Pill afforded women against uterine cancer.
The study was funded by the Medical Research Council and Cancer Research U.K. The study was published in the journal The Lancet Oncology on August 4, 2015, under the title: Endometrial cancer and oral contraceptives: an individual participant meta-analysis of 27 276 women with endometrial cancer from 36 epidemiological studies