Hormonal contraception and breast cancer, what more do we need to know?

Abstract

Most women use hormonal contraception for more than 30 years and for many, this may involve exposure in their older reproductive years when baseline breast cancer risk rises steeply. Overall, the risk of breast cancer diagnosis with exposure to hormonal contraception is very small and outweighed by its contraceptive benefits but despite this, there are still outstanding questions for all methods used in clinical practice due to paucity of available evidence, lack of which should not be taken to imply safety. This is exemplified by the following assumptions: the progestogen-only pill and long-acting reversible contraceptives are 'breast-safe' options in peri-menopausal women, use of the levonorgestrel intrauterine system for the management of endometrial pathology in breast cancer survivors is less likely to promote disease recurrence and the benefit all hormonal contraceptive methods confer in reducing unplanned pregnancy in women at high familial risk outweigh the risk of breast cancer diagnosis. There is no data on risk with the concurrent prescription of hormone replacement therapy in women exhibiting climacteric symptoms who are still menstruating. Advice of GPs and Community Sexual & Reproductive Health specialists will inevitably be sought about some or all these issues and in the absence of conclusive evidence from clinical studies, caution should be applied and women counselled appropriately.