Breast cancer risk in women on HRT varies widely

Analysis of more than 1.6 million mammograms, including 9300 cases of breast cancer, showed HRT use conferred increased risk of breast cancer in white (21%), Hispanic (35%) and Asian (58%) women but not black women.

HRT use was linked to a greater risk of cancer in women with low or normal BMI and among those with low-normal BMI but more dense breasts. Obese women with less dense breasts had no increased risk, they found.

J Natl Cancer Inst 2013; online 3 Sept