In an extensive study of 46,000 women over a span of 44 years, researchers from the University of Aberdeen found that the contraceptive pill protects against some cancers and is safe in the long run.

Established by the Royal College of General Practitioners in 1968, seven years after the introduction of the pill in Britain, the Oral Contraception Study was the longest research that delved into health implications of prolonged use of the pill.

According to lead author Dr Lisa Iversen, “pill users don’t have an overall increased risk of cancer over their lifetime and that the protective effects of some specific cancers last for at least 30 years.”

The pill lowers risk of bowel, endometrial and ovarian cancer

Taking the pill for any length of time lowered the cases of bowel cancer by 19%, endometrial cancer by 34%, and ovarian cancer by 33%.

“Previous large studies have shown that the pill reduces the risk of ovarian and womb cancer but increases the risk of cervical and breast cancer,” said Emma Shields, Cancer Research UK’s health information officer.

“But, we also know that once a woman stops using the pill, these increased risks start to fall back down while the reduced risk of ovarian and womb cancer continues,” she added.

This means that for every three women who would have developed ovarian or endometrial cancer, one has been protected by the pill. For bowel cancer, around one fifth of cases were prevented through oral contraception. Each year, it is estimated that around 35,000 women suffered from these conditions.

Referring to the massive results that were culled from 44 years of tracking pill users, Iversen said, “They provide strong evidence that most women do not expose themselves to long-term cancer harm if they choose to use oral contraception; indeed, many are likely to be protected.”

Review points to long-term protection in cancer

A 2015 review by Oxford University highlighted that women in their 70s were still being protected against endometrial cancer due to taking the pill earlier in life.

“Protection lasted for at least 30 years,” said Professor Valerie Beral. “It is time to start saying that not only does it prevent pregnancy, which is why people take it, but you should know you are less likely to get cancer than women who don’t take the pill.”

Still, many are concerned about the long term effects that come with age, especially with last year’s grim statistics showing a 60% increase in cancer deaths among women.

Dispelling the fears, Iversen said, “Because the study has been going for such a long time, we are able to look at the very long term effects, if there are any, associated with the pill.”

“We were also interested in what the overall balance of all types of cancer is amongst women who have used the pill as they enter the later stages of their life,” she added.

“We did not find any evidence of new cancer risks appearing later in life as women get older. These results from the longest-running study in the world into oral contraceptive use are reassuring.”

Benefits of contraceptive pill outweigh the risks

Contraceptive pills contain a low dose of oestrogen which is known to raise the risk of cancer. However, the combined pill also has progesterone, a protection against endometrial cancer. The study also found that although women taking the pill have a 4% increased risk in breast cancer, this risk will have decreased five years after stopping the contraception.

Professor Helen Stokes-Lampard, Chair of the Royal College of GPs, said, “Millions of women who use the combined oral contraceptive pill should be reassured by this comprehensive research that they are not at increased risk of cancer as a result – and that taking the pill might actually decrease their risk of certain cancers.”

Health information officer Shields advised women to consult their doctor before starting or stopping the pill. According to the National Health System (NHS), “for most women, the benefits of the pill outweigh the risks”. However, some may need to find alternative forms of contraception as oestrogen contributes to a slight increased risk of stroke.

“Ultimately decisions to prescribe the pill need to be made on a patient by patient basis, but this research will be useful to inform the conversations we have with our patients when discussing various contraceptive options that are available,” said Stokes-Lampard. MIMS

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