Contrary to popular myth, ‘the pill’ prevents womb cancer, study finds

The contraceptive Pill has helped to prevent 200,000 cases of womb cancer over the last ten years, according to Oxford University researchers.

In fact, they estimated that over the past 50 years, birth control pills 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.

Now United Kingdom researchers grouped together data from 27,276 women with endometrial cancer in 36 studies from North America, Europe, Asia, Australia, and South Africa to examine the effects of oral contraceptives on cancer risk.

The benefits increase the longer a woman is on the pill, and occur independently of a range of cancer risk factors including weight, use of menopause hormone therapy, smoking and whether or not she has had children.

They found that every five years on the Pill cut the chances of developing womb cancer by a quarter in high-income countries.

Use of the Pill is already known to offer a degree of protection against both womb and ovarian cancers.

But the researchers stopped short of suggesting that women start taking oral contraceptives as an anti-cancer measure.

The worldwide team of experts says widespread use of the pill in developed countries is likely to have saved hundreds of thousands of lives since the 1960s, and women should feel confident that the benefits of the drug outweigh its risks when it comes to cancer.

The study may surprise some as oestrogen levels in oral contraceptives have decreased markedly over the years.

The study noted that while earlier forms of the Pill contained a higher dose of the hormone oestrogen than at present, this did not affect the risk reduction properties in women as the decades went on.

They 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 birth control pills provide against uterine cancer. The study was funded by the Medical Research Council and Cancer Research UK.

Associate Professor Canfell said women should not decide to take the pill based on the research without speaking to their doctors, but should feel reassured of the pill’s safety given the findings.

“One of the most impressive aspects of the studies showed that the reduction in risk persists long after the patient ceases use of the pill, even up to 30 years later”, said Dr. Jennifer Wu, an obstetrician-gynecologist at Lenox Hill Hospital in New York City.