Combined contraceptive pill linked to reduced risk of ovarian cancer

The combined contraceptive pill decreases the risk of ovarian cancer for users when compared with non-users, suggests research undertaken by scientists from the Universities of Aberdeen and Copenhagen.

The combined contraceptive pill contains synthetic forms of the hormones oestrogen and progestin and is used regularly by over 100 million women worldwide. It works by preventing the release of an egg cell from the ovaries, and both reducing the ability of sperm cells to penetrate the womb, and by thinning the lining of the womb to reduce the chance of a fertilised egg implanting itself into the wall of the womb. When used correctly, it is over 99% effective at preventing pregnancy.

The combined contraceptive pill contains synthetic forms of the hormones oestrogen and progestin and is used regularly by over 100 million women worldwide

This new research suggests that the combined pill may be useful for more than just preventing unwanted pregnancies. It found that for current users of the combined pill, it reduced the risk of ovarian cancer by 42% compared to those who do not use it. It also reduces the risk by 34% for those had used the combined pill at some point in their lives. They also concluded that the decrease in risk was greater for those women who had been using the pill for a longer period. All in all, the researchers believe that the combined pill has reduced the incidence of recorded cases of ovarian cancer by 21%.

The study found that the reduction in risk only occurred in women using the combined pill. The progestin-only pill, an alternative contraceptive pill, had no effect on the incidence rate of ovarian cancer. This research draws from a Danish database of 1.8 million women, who between the years 1995 and 2014 were aged 15-49, as this is considered to include most women of reproductive age.

The progestin-only pill, an alternative contraceptive pill, had no effect on the incidence rate of ovarian cancer

Ovarian cancer has a poor survival rate when compared with other types of cancer, with somewhere between 30-40% of patients surviving five years after diagnosis, depending on where in the world the case occurs. Therefore, finding ways to prevent the occurrence of this cancer is paramount to decreasing the number of deaths that occur because of it. Perhaps the conclusions of this research may one day be a part of the conversation women have with their GP when deciding on a contraception method that is right for them.

However, the combined pill also has its downsides and is generally viewed as a contraception method that comes with certain risks. For example, it has been shown that women using hormonal contraceptives, including the combined pill, are at higher risk of being diagnosed with depression. It is also noteworthy that the combined pill has in fact previously been linked to a slight increase in the occurrence of breast cancer.

Ovarian cancer has a poor survival rate when compared with other types of cancer, with somewhere between 30-40% of patients surviving five years after diagnosis

The study was not without its limitations, however. For example, only women between the ages of 14-49 were considered. Data from Cancer Research UK suggests 53% of ovarian cancers occur in those over the age of 65. By excluding the older cohort of women, the insight into long-term effects of the reduction in ovarian cancer risk is diminished, and the claims of reduced ovarian cancer risk only apply to those women in this age bracket. Perhaps most importantly, the study did not identify a causal link between the combined pill and a reduction in ovarian cancer occurrence, it merely identified a strong correlation, and as the mantra goes: “correlation does not imply causation”.

Of course, this study is only preliminary, and experts always recommend that you talk to your doctor before changing contraception methods. But perhaps one day, we may recognise the combined pill as a useful tool in our battle against cancer.