March 21, 2023

Hormonal contraceptives and breast cancer incidence

While there is substantial evidence suggesting an association between the use of combined oral contraceptives, containing both oestrogen and progestogen, and a small increase in breast cancer incidence, there is limited data on the risk associated with progestogen-only hormonal contraceptive use. The use of progestogen-only contraceptives has increased substantially in recent years, with almost as many prescriptions in England for oral progestogen-only contraceptives as for combined oral contraceptives in 2020.

This analysis, published in PLOS Medicine, presents new data looking at the association between progestogen-only hormonal contraceptives and combined oral contraceptives with breast cancer risk. The study also combines this new data with previously published data on combined oral contraceptives to assess breast cancer risk associated with current or recent use of different types of hormonal contraceptives.

Journalists came along to this briefing and hear the authors of this study discuss:

• What is the associated risk of developing breast cancer for women using progestogen-only hormonal contraceptives?
• How do the associated risks of developing breast cancer compare between women using progestogen-only hormonal contraceptives and combined oral contraceptives?
• How does the associated risk of developing breast cancer vary with different forms/modes of delivery of hormonal contraceptives?
• How does the associated risk of developing breast cancer from hormonal contraceptive use change with age?
• Weighing up the risks vs benefits of hormonal contraceptive use in women.

Speakers included:

Prof Gillian Reeves, Professor of Statistical Epidemiology and Director of Cancer Epidemiology Unit, Oxford Population Health, University of Oxford

Dr Danielle Fitzpatrick, Infectious Diseases Advanced Trainee, Alfred Health, previously Researcher in the Cancer Epidemiology Unit, Oxford Population Health, University of Oxford

Kirstin Pirie, Statistical Programmer, Cancer Epidemiology Unit, Oxford Population Health, University of Oxford

This Briefing accompanied an SMC Roundup of Comments.