Does the Pill really reduce the onset of certain cancers?

A long-term study suggests a protective effect for women taking oral contraceptives

For many younger women the oral contraceptive pill (OCP) is the “go to” method to control fertility. It’s a reliable method of contraception, with an estimated 100 to 150 million women worldwide using the Pill at present.

While the short-term risks of taking a combined oestrogen and progesterone product, such as the chances of an individual developing a blood clot, will be the main focus of an initial consultation when deciding on the safest and most suitable form of contraception, there are other long-term health issues worth considering.

A recent study has looked at the very long-term cancer risks and benefits associated with the OCP. Researchers in the UK enrolled some 23,000 women using OCPs and 23,000 women with no past or current use of OCP in the study between 1968 and 1969. They were followed up for an average of 40 years and the incidence of different cancers in each group was calculated. The average duration women used the Pill for was 3.7 years.

Of the women who had ever used the OCP, some 4,661 were diagnosed with at least one cancer over the follow-up period. Among the never-users, 2,341 were diagnosed with cancer. Current or recent (within the past five years) users of the OCP were at an increased risk for cancer in general as well as for breast cancer and for cancer of the cervix. This significantly increased risk of breast and cervical cancer appeared to wane within about five years of stopping the Pill; nor was there any evidence of either cancer recurring at increased risk over time in “ever users”. And there was nothing to suggest that new cancer risks appeared later in life among women who had used the OCP.


The study, published in the American Journal of Obstetrics and Gynaecology, suggested some striking long-term benefits: use of the OCP was associated with a reduced risk of bowel cancer, ovarian cancer, cancer of the womb and blood cancers. This association lasted for many years after stopping the Pill.

Oestrogen and progesterone may influence cancer development and growth; this has been a concern ever since the introduction of hormonal contraception. But clearly the combination also has some benefits: we know the risk for ovarian cancer is reduced when the number of ovulations is fewer and when transport of potentially carcinogenic agents is reduced through the genital tract-mechanisms the OCP has a beneficial effect on.

The OCP is associated with many non-contraceptive benefits. Because of the precise and constant cyclical dosage of female hormones, it regulates periods and makes them less heavy. In premenopausal women with anaemia due to heavy periods, prescribing the Pill is a useful way to reverse the trend of excessive blood loss.

Severe premenstrual syndrome (PMS) can be hugely disabling. For some women the intense anxiety and irritability is similar to a brief bout of clinical depression; add bloating, fatigue and breast tenderness and it becomes quite difficult to function. Again the Pill can help by smoothing out hormonal highs and lows.

A less obvious role for the Pill is the treatment of acne in women. One particular Pill formulation is renowned for its ability to reduce oily skin which, combined with its anti-androgen properties, make it a good treatment for acne. Research suggests the combined pill is as effective at treating the skin condition as are oral antibiotics.

The OCP is a highly effective contraceptive method when used properly. In addition it is associated with many non-contraceptive benefits. There has been an understandable fear of cancer associated with the use of hormonal treatments. Yes, there is some increased risk with current or recent use of the Pill but the findings of this latest study are largely reassuring.

While any long -term  benefits of the OCP are unlikely to be the main factor for a young woman choosing contraception, they offer an additional dimension to that choice.

  •  @muirishouston