Journal of the National Cancer Institute
-
J. Natl. Cancer Inst. · Feb 2011
Breast cancer risk in relation to the interval between menopause and starting hormone therapy.
Although breast cancer risk is greater in users of estrogen-progestin than estrogen-only formulations of menopausal hormonal therapy, reports on their effects have been somewhat inconsistent. We investigated whether the timing of these therapies affected breast cancer incidence. ⋯ There was substantial heterogeneity in breast cancer risk among current users of hormonal therapy. Risks were greater among users of estrogen-progestin than estrogen-only formulations and if hormonal therapy started at around the time of menopause than later.