You’d think there wouldn’t be room for another nail to be hammered into the coffin of postmenopausal hormone therapy (HT). After all, HT has been linked to heart attack, stroke, blood clots, breast cancer and colon cancer.

But then along comes this finding from a Danish study published today in the Journal of the American Medical Association (JAMA):

Women who take HT to relieve their hot flashes and night sweats may be as much as 38 percent more likely to develop ovarian cancer than women who never took the hormones.

Actually, the link between HT and ovarian cancer isn’t all that new. Earlier studies also found an association between taking postmenopausal hormones and an increased risk of ovarian cancer. But some people questioned whether those findings were true for all types of hormone therapy.

This new study answers that question with a resounding "Yes." Its analysis of medical data from more than 900,000 women aged 50 and older found an increased risk of ovarian cancer among HT users “regardless of the duration of use, the formulation, estrogen dose, regimen, progestin type, and route of administration.”

It's important to point out that the absolute risk of developing ovarian cancer from HT was small in this study: About 1 extra case of ovarian cancer developed for every 8,300 women taking the hormones. That was about 5 percent (140 cases) of the ovarian cancers that showed up during the study’s eight years of follow up. But because ovarian cancer is so often fatal, women should give that small risk weighty consideration when deciding whether or not to use HT, noted the study's authors.