New large-scale European research has found that young women who take the new type of combined oral contraceptive pills, which contain lower doses of estrogens, may benefit from a reduced risk of ovarian cancer.
Carried out by researchers at the University of Aberdeen in Scotland and the University of Copenhagen in Denmark and published by The BMJ on Wednesday, the new study used national registers to gather data from nearly 1.9 million Danish women aged 15 to 49 years between 1995 and 2014.
The women were categorized into three different groups; never users of the pill, with no record of being dispensed hormonal contraception; current or recent users, who had stopped use up to one year ago; and former users, who had stopped the pill more than one year ago. The majority of the women, 86%, used a combined oral contraceptive pill.
The findings showed that the number of cases of ovarian cancer were highest in women who had never used hormonal contraception and lower among the women who were current or former users of hormonal contraception.
The reduced risk of ovarian cancer among current users was also stronger the longer they used a hormonal contraceptive.
In addition, the team also found that after stopping the pill the reduced risk of ovarian cancer decreased with time, and was no longer significant by 10 years after last use.
The researchers failed to find evidence that progestogen-only products had a protective effect, although they added that the number of women using these products was small, making it more difficult to detect an effect.
The findings are in line with previous research which has found that women who take the older combined oral contraceptives, which contain higher levels of estrogen, and older progestogens also show a reduced risk of ovarian cancer.
However, as an observational study the researchers point out that no firm conclusions can be made about cause and effect, and the study did not look at the effect of the pill on older women, a group which has the most cases of ovarian cancer occur.
“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,” commented the authors.
“The reduced risk seems to persist after stopping use, although the duration of benefit is uncertain. Presently, there is insufficient evidence to suggest similar protection among exclusive users of progestogen-only products,” they conclude.