[Mammographic breast density and breast cancer risk during HRT]

Higher breast density leads to a higher risk of breast-cancer coming along with a reduced sensitivity of mammography, the most important method for early diagnosis of breast cancer. HRT leads to an increase in breast density in up to (1/3) of treated women. Combined regimes of estrogen-progestin show a stronger influence than estrogen only. Changes of breast density appear almost entirely within the first year of administration and seem to be reversible after suspension of treatment within a few weeks. A possible solution of the dilemma is to perform mammography in asymptomatic premenopausal women during the first half of the menstrual cycle. In women with increased breast density using HRT it is recommended to modify the combination of hormones, change the application mode, or suspend HRT for a short period of 3 weeks prior to mammography. In symptomatic women with dense breasts, additive breast ultrasound is strongly recommended to reduce the otherwise high rate of missed breast cancers.