HRT & Breast cancer

Approximately 1 in 8 women will develop breast cancer during their lifetime in Ireland, regardless of whether they take HRT or not. Risk factors associated with a higher risk of breast cancer than HRT include being overweight, obesity and drinking a glass or more of wine per day.

Yet, HRT is synonymous with breast cancer to lots of women following the media reporting of the small increased risk of breast cancer seen in the American WHI (Women’s Health Initiative) study in 2002 in which women who were largely older than that of the average woman going through the menopause were given a combined synthetic HRT. This study is not representative of the usual cohort of women who take HRT.

Evidence from studies suggests a small increased risk of breast cancer with HRT use which increases with duration of use and reduces on
stopping. This risk needs to be acknowledged but the overall benefits of HRT also need to be taken into consideration. Women with an early menopause or premature ovarian insufficiency who take HRT up until the age of 51 are at no increased risk of breast cancer above their own genetic and environmental baseline risk.