To the Editor: Dr Chlebowski and colleagues, in their follow-up of the Women's Health Initiative (WHI),1 showed an increase in breast cancer mortality for women randomized to estrogen plus progestin compared with placebo of 1.3 per 10 000 women per year. Also, longer follow-up data on de novo hormone therapy users in the trial confirmed no increased risk of breast cancer incidence. The WHI commenced in the 1990s and ceased in 2002, and the risks and benefits described relate to a regimen of hormone therapy rarely used in the United States in 2010. Lower doses, different estrogens and progestins, and different regimens are now more commonly prescribed. As Dr Bach2 points out in the accompanying Editorial, more evidence is needed, but on outcomes related to newer regimens.
Baber R. Breast Cancer in Postmenopausal Women After Hormone Therapy. JAMA. 2011;305(5):466-467. doi:10.1001/jama.2011.74