Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
In Reply: In response to Dr Utian, we acknowledged
that the estimated effects of estrogen plus progestin on endometrial cancer
and ovarian cancer did not reach statistical significance. The fact that these
data arose from the only randomized, double-blind, placebo-controlled trial
of sufficient size and duration to examine effects on these rare gynecologic
cancers makes them a unique, although still not definitive, contribution to
The comparison of the cancer rates within the Women's Health Initiative
trial to population-based rates is irrelevant to understanding intervention
effects. Participants in randomized trials typically have lower event rates
than the general population—the so-called healthy-volunteer effect.
In this case, the comparison is further confounded by many other factors including
considerable exposure to hormone therapy in the general population.
Anderson GL, Judd HL, Kaunitz AM, McNeeley SG, Barad DH, Liu J, Lopez AM, Beresford SAA, Pettinger M. Hormone Therapy and Risk of Gynecologic Cancers—Reply. JAMA. 2004;291(1):42. doi:10.1001/jama.291.1.43-a