(RxWiki News) Hormone replacement therapy is often considered for treatment of menopause symptoms. Could it potentially treat more serious conditions?
A recent review looked at the results of two previous menopausal hormone therapy trials to compare the risks and benefits of using hormone therapy for chronic disease prevention.
The researchers found that both hormone regimens carried an increased risk for both coronary heart disease and breast cancer in women. The findings also showed that there was an increased risk of stroke, gallbladder disease, and urinary incontinence (leakage) in both hormone regimens.
The researchers concluded that the hormone therapies used in the study may be reasonable for the treatment of menopausal symptoms in some women, but the potential risks of using hormone therapy to treat or prevent chronic disease outweigh the potential benefits.
"Discuss the risks and benefits of hormone therapy with your doctor."
The lead author of this study was JoAnn E. Manson, MD, DrPH, from the Brigham and Women's Hospital of the Harvard Medical School in Boston, Massachusetts.
The researchers used data from two previous menopausal hormone therapy trials called the Women's Health Initiative Randomized Trials (WHI). The study population consisted of 27,347 postmenopausal women between the ages of 50 to 79 who were recruited for the previous studies between 1993 and 1998 from 40 different medical centers from around the US.
The WHI consisted of two trials.
In the first, 16,608 women with a uterus (those who had not undergone hysterectomy) were randomly given conjugated equine estrogens (CEE) plus medroxyprogesterone acetate (MPA) or a placebo. In the second, 10,739 women who had previously undergone hysterectomy (no uterus) were randomly given CEE alone or a placebo.
The current researchers wanted to determine the risks versus benefits of using hormone therapy to treat or prevent coronary heart disease (CHD) and breast cancer. The researchers also considered the risk of stroke, pulmonary embolism (blocked artery), colorectal cancer (cancer of the colon and rectum), hip fractures, endometrial (lining of the uterus) cancer, and death from other causes.
The researchers found that the CEE plus MPA group had an 18 percent increased risk of having CHD compared to the placebo group. However, the risk ratio increased to 80 percent after one year.
For the women in the CEE alone group, the researchers found a 6 percent decreased risk of having CHD compared with the placebo group. The risk did not change after a year.
The researchers found that in the CEE plus MPA trial, women who were at least 20 years past onset of menopause were more at risk for CHD compared with the placebo group; in the CEE alone trial, younger women were found to face a moderately decreased risk compared to the placebo.
For breast cancer, the researchers found that the women in the CEE plus MPA group were 24 percent more at risk for breast cancer compared to the placebo group. The risk increased over time for this trial with the cases of cancer becoming more advanced.
The researchers discovered that the women in the CEE alone group had a 21 percent decreased risk of breast cancer compared to the placebo. The risk did not change over time.
In the CEE plus MPA group, the researchers found a 37 percent increased risk of stroke, and in the CEE alone group, there was a 35 percent increased risk of stroke compared to both placebos.
In the CEE plus MPA group, the researchers found a 98 percent increased risk of pulmonary embolism compared to the placebo. In the CEE alone group, there was only a 35 percent increased risk compared to the placebo.
For colorectal cancer, the CEE plus MPA group had a decreased risk of 38 percent compared to the placebo. In the CEE alone group, the researchers found an increased risk of 15 percent compared to the placebo.
The women in the in the CEE plus MPA group had a 17 percent decreased risk for endometrial cancer compared to the placebo. The researchers found this risk to decrease over time. The women in the other trial were not tested for this since they did not have a uterus.
The researchers found that the women in both trials experienced a 33 percent decrease in hip fractures compared to the placebo groups. This risk was found to decrease over time, especially for women in the CEE alone group who were farther from the onset of menopause.
Neither of the trials specifically affected all-cause mortality (death from any cause). However, researchers found that younger women had a decreased risk compared to the older women.
The researchers found that the effects of hormone therapy were sometimes due to age or length of time since onset of menopause. However, both hormone regimens were linked to increased risk of stroke, blood clots, gallbladder disease, and urinary incontinence at any age.
Overall, the researchers found that the risks of both hormone regimens outweigh the benefits. The researchers believe that hormone therapy can successfully help women treat menopausal symptoms, but hormone therapy should not be used for the treatment or prevention of chronic disease.
The authors noted a couple limitations.
First, the participants of the WHI were only given one dose of the hormones, all the same formula, and all given orally; therefore the results of this study may not be applicable to a general population. Second, a portion of the initial study population did not participate in follow-up assessment.
This study was published in the October edition of JAMA.
The National Heart, Lung, and Blood Institute, National Institutes of Health, US Department of Health and Human Services funded the Women’s Health Initiative.