More Results from WHI on Breast Cancer Risk with Combined Hormone Therapy

Significantly more (and larger) breast cancers occurred among HT recipients than among placebo recipients in the WHI.

Previous results from the Women's Health Initiative (WHI) showed that increased risk for breast cancer was associated with combined estrogen and progesterone hormone therapy (HT; Journal Watch Jul 26 2002). Now, the WHI researchers present further details on breast cancer outcomes.

In the WHI, 16,608 women (age range, 50-79) without breast disease were randomized to daily conjugated equine estrogen (0.625 mg) plus medroxyprogesterone acetate (2.5 mg) or placebo; participants were followed for a mean of 5 years with annual mammography and breast exams.

Significantly more total breast cancers (245 vs. 185 cases; hazard ratio, 1.24) and invasive breast cancers (199 vs. 150 cases; HR, 1.24) were reported in the HT group than in the placebo group.…

Reviewing Author

Thomas L. Schwenk, MD