The Grapevine

Preventing Ovarian Cancer Could Be Side-Effect Of New Oral Contraceptive

Long-term research from the past has revealed a link between the use of birth control pills and the lowered risk of certain cancers including colorectal, endometrial, and ovarian.

But since these studies examined decades' worth of data, they often involved older forms of oral contraceptives. Researchers decided to find out if a similar risk reduction could be linked to newer pills which come in different combinations and hormones levels.

The paper titled "Association between contemporary hormonal contraception and ovarian cancer in women of reproductive age in Denmark: prospective, nationwide cohort study" was published in the British Medical Journal on Sept. 26.

The research team looked at data on more than 1.8 million Danish women aged 15 to 49 between 1995 and 2014. They were categorized into one of the following three: women who never used hormonal contraceptives, women who currently use them or did so recently for up to one year, and women who formerly used them for more than a year.

The risk of ovarian cancer was found to be highest in the first group who had never used hormonal birth control. Meanwhile, the risk was much lower among women who, at some point, used combination pills with both estrogen and progestin.

This protective effect was not observed in women who used progestin-only birth control. But this may have been a result of inadequate data since most of the participants used combination pills.

"[For] women who are currently of reproductive age who are using contemporary hormonal products, this [study’s] findings are reassuring because it is continuing to show a reduced risk of ovarian cancer associated with combined oral contraceptives," said Dr. Lisa Iversen, first author of the study. 

However, she does note that the study could not establish causality, only an association. If the pill does help in preventing cancer, the authors estimate that their use prevented 21 percent of ovarian cancers in the group of Danish women who participated in the study. 

Another limitation of the research is that women were no longer tracked after they turned 50, which means the potential diagnoses of cancer after this age were not included.

The finding "reaffirms that potential benefit" of newer birth control pills, said Dr. Jennifer Wu, an obstetrician/gynecologist at Lenox Hill Hospital in New York City who was not involved in the study.

Ovarian cancer is particularly dangerous since symptoms are not apparent until later stages when it has spread. According to the American Cancer Society, only around 47 percent of women survive five years post-diagnosis.

"Ovarian cancer has such a delayed time to diagnosis and such poor long-term survival that prevention is essential," Wu explained, adding, "when counseling patients on birth control options, the reduction in ovarian cancer must be considered."