The pill gives long-lasting protection against ovarian cancer

Cancer Research UK

The contraceptive Pill gives women substantial and long-lasting protection against ovarian cancer, according to a new report by Cancer Research UK scientists in The Lancet today (Friday Jan 25th).

The researchers found that the protection against ovarian cancer lasted for more than 30 years after women had stopped taking the Pill. They also found that the longer the Pill was used the greater the protection and that taking the Pill for 15 years halved the risk of ovarian cancer.

Researchers estimated that, in high income countries, using oral contraceptives for ten years reduces the risk of developing ovarian cancer before the age of 75 from 12 down to 8 per 1000 women, and reduces the risk of death from ovarian cancer before age 75 from 7 down to 5 per 1000 women.

The new report* brings together worldwide evidence from 45 epidemiological studies of ovarian cancer in 21 countries. These include 23,257 women with ovarian cancer of whom 7,308 (31 per cent) had used oral contraceptives and 87,303 women without ovarian cancer of whom 32,717 (37 per cent) had used oral contraceptives.

Lead author Professor Valerie Beral, director of the Cancer Research UK Epidemiology Unit at Oxford University, said: "Worldwide, the Pill has already prevented 200,000 women from developing cancer of the ovary and has prevented 100,000 deaths from the disease. More than 100 million women are now taking the Pill, so the number of ovarian cancers prevented will rise over the next few decades to about 30,000 per year."

The Pill also causes long-lasting protection against endometrial cancer (cancer or the lining of the womb) but causes a short-lived increase in breast cancer and in cervical cancer (cancer of the neck of the womb). Co-author Sir Richard Peto, Professor of Epidemiology at Oxford University, said: "Young women don’t have to worry about cancer from taking the Pill because the eventual reduction in ovarian cancer is bigger than any increase in other types of cancer caused by the Pill."

Young women take the Pill mostly for contraceptive purposes. There are known to be some definite health risks among current or recent users. But these are outweighed by the long-term protective effects against the devastation of ovarian cancer - one of the most dangerous types of cancer.

Dr Lesley Walker, Cancer Research UK's director of cancer information, said: "All women who have taken the Pill or are currently taking it should be reassured by this study. Any woman with concerns about taking the contraceptive Pill should discuss them with her GP or local Family Planning Clinic."

Ends

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Notes to Editor

*This study, led by Oxford University researchers, was conducted by the Collaborative Group on Epidemiological Studies of Ovarian Cancer, a collaboration involving 120 researchers from around the world. The work was supported by Cancer Research UK and the Medical Research Council.

In the UK 1.2 per cent of women develop ovarian cancer before they are 75 years old. 6,615 women were diagnosed with cancer of the ovary in the UK in 2004, with 85 per cent diagnosed in women aged 50 and older.

In the UK 0.7 per cent of women die from ovarian cancer before they are 75 years old; 4,447 women died from the disease in the UK in 2005.

The contraceptive Pill has also been shown to provide long-lasting protection against endometrial cancer.

In this paper researchers found that the protection against ovarian cancer did not vary much by the type of Pill that had been used. Although the oestrogen dose in Pills typically used in the 1960s was more than double the dose typically used in the 1980s, this study found that the reduction in risk did not vary substantially for Pill use during the 1960s, 1970s or 1980s.

A re-analysis of the worldwide data from 24 studies has shown that there is an increased risk of cervical cancer while women are on the Pill and for a short time afterwards. But 10 years after women stopped taking the Pill the cervical cancer risk reverts to that of a woman who has never taken it (Lancet, 2007, 370: p1609-21).

A re-analysis of the worldwide data from 54 studies has shown that there is a small increased risk of breast cancer while women are on the Pill and for a short time afterwards. But 10 years after women stopped taking the Pill, the breast cancer risk reverts to that of a woman who has never taken it. (Lancet,1996, 347: p1713-27).

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