If non-hormonal options are not effective and symptoms are debilitating, short-term topical estrogen at the lowest effective vaginal dose may be considered following specialist advice (including for estrogen receptorpositive breast cancer with a good prognosis).59,60 Professional bodies have suggested that vaginal estrogen should be given with tamoxifen and not aromatase inhibitors.53,61,62 The effect of any systemic estrogen absorption may be counteracted by tamoxifen’s mode of action at the receptor level in breast tissue. This evidence concerns the gene CYP19A1 and breast cancer.