Oral contraceptive pills protect against ovarian and endometrial cancer, study finds

A study involving more than 250,000 women has shown that the use of oral contraceptives can protect women against ovarian and endometrial cancer. The protective effect remains for several decades after discontinuing the use. 

The team, from Uppsala University, Sweden, say that oral contraceptives include oestrogen and progestin, which are synthetic forms of female sex hormones. The oestrogen and progestin in oral contraceptives prevent ovulation and thereby protect against pregnancy.

In the current study, the scientists compared the incidence of breast, ovarian and endometrial cancers between women that had used oral contraceptive pills and never users.

“It was clear that women who had used oral contraceptive pills had a much lower risk of developing both ovarian and endometrial cancer. Fifteen years after discontinuing with oral contraceptives, the risk was about 50 percent lower. However, a decreased risk was still detected up to 30-35 years after discontinuation,” said Åsa Johansson, one of the leading researchers behind the study.

However, the researcher highlight that oral contraceptive pills have previously been associated with an increased risk of breast cancer.

“Surprisingly, we only found a small increased risk of breast cancer among oral contraceptive users and the increased risk disappeared within a few years after discontinuation,” said Johansson. “Our results suggest that the lifetime risk of breast cancer might not differ between ever and never users, even if there is an increased short-term risk.”

“In addition to protecting against pregnancy, we have shown that oral contraceptive pills also have other positive effects,” said Therese Johansson, one of the PhD students behind the study.

The study is published in Cancer Research.