WHI researchers defend their findings on HRT. (Workshop on Women's Health Initiative).

BETHESDA, MD. -- Women yearning for a simple, straightforward "yes" or "no" as to whether they should take hormone replacement therapy aren't going to get one from researchers in the Women's Health Initiative clinical trial.

The only firm conclusion that can be drawn from the WHI study so far is that combined estrogen-progestin HRT should not be taken solely to prevent cardiovascular disease, osteoporosis, or other chronic diseases because the risks outweigh the benefits in those cases, WHI investigators said at a conference sponsored by the National Institutes of Health.

But few women take HRT for those reasons alone. This leaves the remaining millions who use HRT to alleviate menopausal symptoms and forestall the effects of aging to puzzle out individually, along with their physicians, whether the risks revealed in the WHI trial outweigh the benefits in their particular case.

The study has found no increased risks for women who have had a hysterectomy and take unopposed estrogen, so the safety of that regimen is unquestioned at present.

The 2-day workshop, which featured some 60 speakers and elicited the often contentious opinions of dozens of audience members, provided a forum for the WHI investigators to review their findings and answer questions from physicians and others. The workshop was held because of "the tremendous reaction, and in many cases the overreaction," to the July 9 announcement that a component of the WHI study involving more than 16,000 women was halted early and the subjects were instructed to stop taking their study medications, said Dr. Elias A. Zerhouni, NIH director.

An interim analysis of the WHI data had shown that the number of invasive breast cancer cases in women taking combined HRT had crossed a predetermined threshold of excess risk. Compared with women taking placebo, those taking combined HRT for an average of 5.2 years had a 26% higher risk of developing breast cancer, a doubling of the risk of pulmonary emboli and deep vein thrombosis, a 41% increased risk of stroke, a 29% increased risk of MI, and a 22% increased risk of total cardiovascular disease.

In practical terms, this translates into 8 more breast cancers, 7 more cases of coronary heart disease, 8 more strokes, 8 more pulmonary embolisms, and 10 more deep vein thromboses per year for every 10,000 women using combined HRT, compared with those not taking the hormones.