Ovarian cancer risk reduced among women taking modern combined oral contraceptive pills

By Dr. Ananya Mandal, MDSep 27 2018

According to a new study women of reproductive age who are using the modern oral contraceptive pills or patches and rings that contain a combination of estrogen and progesterone are at a reduced risk for ovarian cancer. The study was published in the recent issue of the British Medical Journal (BMJ).

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The older forms of birth control pills were higher on estrogen and progesterone and were widely used in the 1980s. These pills had also been seen to be protective against ovarian cancer. This new study looked at the modern low dose birth control pills. Authors wrote, “Based on our results, contemporary combined hormonal contraceptives are still associated with a reduced risk of ovarian cancer in women of reproductive age, with patterns similar to those seen with older combined oral products.” These pills protect against almost all forms of ovarian cancer, explained the team led by Dr Lisa Iversen, a researcher at the University of Aberdeen in Scotland.

At present nearly 100 million women globally use hormonal birth control says the United Nations. In 2012, 238,000 women were diagnosed with ovarian cancer found the International Agency for Research on Cancer killing 150,000.

The study looked at data from the Danish Sex Hormone Register Study. This database contained records of Danish women aged between 15 and 79 and followed them up from 1995 to 2014. The team then eliminated women who have undergone treatments for infertility or cancers or for blood clots, thrombosis etc. and included the rest of the women. Women aged between 15 and 49 years – or those in their reproductive age were only included in the study. This whittling down the database resulted in over two million women who were included in the analysis.

Now these women were divided into three groups;

• Those who had never used birth control pills or other hormonal contraception,
• Those who were either using it at present or within the last one year
• Those who were using these contraceptive methods earlier but had stopped now

The results showed that the risk of ovarian cancer was greatest among women who had never used hormonal contraception and lower among women who had used these methods of contraception in the past. They noted that longer the women were using hormonal birth control, the stronger was the protection against the cancer. The protection seemed to reduce once the hormonal contraceptives were stopped they noted. The study found that using hormonal contraceptives prevented around 21 percent of ovarian cancers in the study population. Women who are presently taking any form of hormonal contraceptive are at a 42 per cent lower cancer risk, the study found. The researchers further looked at women who were using progestin only pills and found that no similar protection was offered.

Source: https://www.bmj.com/content/362/bmj.k3609