I et større antal epidemiologiske studier og et randomiseret placebokontrolleret studie, WHI (the Women’ s Health Initiative) er det evident, at den samlede risiko for brystcancer øges med stigende behandlingsvarighed hos kvinder, som er eller lige har været i HRT - behandling.
According to evidence from a large number of epidemiological studies and one randomised placebo- controlled trial, the Women’s Health Initiative (WHI), the overall risk of breast cancer increases with increasing duration of HRT use in current or recent HRT users.