FSRH CEU statement: study on contemporary hormonal contraception and the risk of breast cancer

An observational study published in the New England Journal of Medicine reports that, in the Danish study population, women who were currently using any method of hormonal contraception (HC) or had done so within the last 6 months were 20% more likely to be diagnosed with breast cancer than those who had never used HC.

Another main finding is that the absolute increase in breast cancers diagnosed among current and recent HC users was small. Among women aged 15-49 who had never used HC, 55 incident breast cancers were observed per 100,000 woman-years. Among current or recent HC users, 13 additional breast cancers (95% CI, 10 to 16) were observed per 100,000 woman-years - approximately 1 extra breast cancer for every 7,690 women using HC for 1 year.

What does the study add to what we already know?

In line with the findings of this study, previous large observational studies have identified an increased breast cancer risk in current and recent COC users which disappears over time.

Implications for clinical practice

The findings of this study do not alter existing FSRH advice to UK prescribers. Women should be informed of the small apparent increase in breast cancer risk associated with current or recent use of HC. They should be advised that risk reduces with time after stopping HC. This risk must be weighed against the benefit of effective contraception and non-contraceptive benefits including management of heavy menstrual bleeding and menstruation-related symptoms. Combined oral contraception has the additional significant benefit of long-lasting reduced risk of ovarian, endometrial, and perhaps colorectal cancer. Details of the benefits and risks associated with contraceptive methods can found in FSRH Clinical Guidelines and UK MEC, available on the FSRH website.

Study: Mørch LS, Skovlund CW, Hannaford PC, et al. Contemporary Hormonal Contraception and the Risk of Breast Cancer. N Engl J Med 2017;377:2228-2239. Available at: http://www.nejm.org/doi/full/10.1056/NEJMoa1700732

You can download the statement here