ONE HUNDRED MILLION women use daily oral contraceptives. Previously published work has shown a reduced risk of developing ovarian cancer following the use of combined (oestrogen and progesterone) products, much of the data concerns older products containing higher hormone levels. Following the development of new contraceptives, the effect of these drugs was investigated at the University of Copenhagen, Copenhagen, Denmark, in collaboration with researchers from the University of Aberdeen, Aberdeen, UK, discovering that new contraceptives decrease the risk of ovarian cancers.
Nearly 1.9 million Danish women aged 15–49 years old were divided into three groups of contraceptive use: never users (no record of hormonal contraceptive usage), current or recent users (up to 1 year after stopping use), or former users (>1 year after stopping use). Classification of the women was based on data collected from national prescribing and cancer registries dating between 1995 and 2014.
Combined oral products were used by 86% of the the women included in the study. Several factors, including age and parity, were considered before a comparison between combined contractive users and non-users was conducted. Analysis of ovarian cancer risk showed that the use of oral contraceptives resulted in 3.2 cases per 100,000-person years; on the other hand, never-users had a cancer risk of 7.5 cases per 100,000-person hours.
No solid conclusions can be drawn from this observational study, which was limited by the exclusion of older women, in whom most cases of ovarian cancer occur. However, the results support older studies considering the previous generation of contraceptives. The authors estimated that hormonal contraceptives prevented approximately 21% of ovarian cancers in the study group and concluded: “…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[…]”