Further information on the known increased risk of breast cancer with HRT and its persistence after stopping
(Source: Medicines & Healthcare Products Regulatory Agency (MHRA))
The risk of breast cancer is increased during use of all types of HRT, except vaginal estrogens, and some excess risk of breast cancer persists for longer than previously thought after stopping HRT.
Actions for prescribers
- Inform women who use HRT or are considering starting HRT of new information on the risks of breast cancer at their next routine appointment (see patient resources in the Drug Safety Update)
- Only prescribe HRT for relief of menopause symptoms that adversely affect the quality of life, and regularly review patients to ensure HRT is used for the shortest time at the lowest dose
- Remind current and past HRT users to be vigilant for signs of breast cancer and encourage them to attend for breast screening when invited
A new study confirms knowledge of breast cancer risk
An important new study* has confirmed and extended knowledge on the risk of breast cancer with the use of systemic HRT (oral or applied under or to the skin as gels or patches [transdermal]).
The risk of breast cancer falls after stopping HRT, but the new analysis shows some excess risk of breast cancer persists for more than 10 years after stopping HRT. This means the total number of additional HRT-related cases diagnosed in the period after stopping HRT up to age 69 years is higher than previously thought.
Other key study findings are:
- All types of systemic HRT are associated with a significant excess incidence of breast cancer, irrespective of the type of estrogen or progestogen or route (oral or transdermal)
- There is little or no increase in risk of breast cancer with current or previous use of HRT for less than 1 year; however, there is an increased risk with HRT use for longer than 1 year
- Risk of breast cancer increases further with longer durations of HRT use
- Risk of breast cancer is higher for combined estrogen-progestogen HRT than estrogen-only HRT
- For women who use HRT for similar durations, the total number of HRT-related breast cancers by age 69 years is similar whether HRT is started in her 40s or in her 50s
- The study found no evidence of an effect on breast cancer risk with the use of low doses of estrogen applied directly via the vagina to treat local symptoms
What can an individual woman do to reduce her risk?
- Using HRT for as short a time as possible will help to reduce overall risk
- There are no medical risks with stopping HRT, but symptoms may return especially if HRT is stopped suddenly. Gradually stopping treatment may help to reduce the chances of this
- Low-dose vaginal estrogens do not appear to increase breast cancer risk for women in whom this is a therapeutic option