CHICAGO -- Long-term use of combined hormone replacement therapy was associated with a 70% increased risk of uterine leiomyoma in peri- and postmenopausal patients in a recent case-control study.
The study--said to be the first to look specifically at the association between leiomyoma formation and prior HRT use--involved 256 women with a confirmed first case of leiomyoma and 276 control patients in the same age range who had no previous diagnosis of leiomyoma. Long-term use of HRT was defined as at least 5 years, Dr. Susan D. Reed reported at the annual meeting of the North American Menopause Society.
The association between use of HRT and leiomyoma development was restricted to those with lower adiposity as measured by body mass index, noted Dr. Reed of the University of Washington, Seattle.
Among case patients with a BMI of less than 24 kg/[m.sup.2], the risk of leiomyoma development increased fourfold compared with controls; among those who were heavier, no increase in risk was noted (odds ratio 1).
The findings were not entirely surprising; leiomyomas are known to be stimulated by estrogen and progestins in vitro, and agents such as GnRH agonists and mifepristone have been shown to shrink fibroids, Dr. Reed told this newspaper.
But aside from the suggestion that exogenous sources of estrogen and progestins might contribute to leiomyoma development in women with low adiposity, the implications of these findings for women considering HRT remain unclear. Studies of the initiation of HRT in women with known fibroids, for example, have been poorly designed and resulted in conflicting findings.
COPYRIGHT 2002 International Medical News Group
COPYRIGHT 2002 Gale Group