There was a sense of deja vu surrounding the announcement by the National Institutes of Health (NIH) last week that it had called a halt to a major study of the health effects of long-term estrogen use. Didn't we already know that hormone-replacement therapy, when administered for more than a couple of years, was a bad idea?
Well, yes and no. Two years ago, the NIH cut short the part of the Women's Health Initiative (WHI) study that looked at the long-term use of a combination treatment including estrogen and progestin. Reason: women in the study were showing increased risk of...