New HRT data `reassuring`

WASHINGTON, DC, United States (UPI) -- A new analysis of data from the Women`s Health Initiative (WHI) -- which first cast an ominous light on the health risks of hormone replacement therapy (HRT) -- reveals that postmenopausal women who are candidates for HRT with estrogen alone because they no longer have a uterus are not at greater risk for breast cancer, provided they take the hormone for a limited period.

The new findings add a new and at least partially reassuring wrinkle to the unsettling results of a previous study -- the 2002 WHI`s Estrogen plus Progestin trial -- that found that the combination HRT of estrogen and progesterone had more health risks than benefits, including a higher incidence of breast cancer.

The latest study was dubbed the WHI Estrogen-Alone trial, which focused on 10,739 postmenopausal women, ages 50 to 79, who had previously undergone hysterectomies and did not need progesterone in their HRT regimen to combat the increased risk of uterine cancer that estrogen alone produces. The study took place at 40 U.S. clinical centers between 1993 and 1998.

The subjects were randomly given either 0.625 mg daily dose of oral conjugated equine estrogens(CEE), or placebo. Mammograms were performed when subjects entered the study and each year thereafter, and all breast cancers diagnosed through February 29, 2004 were included in the results.

After a mean follow-up of 7.1 years, subjects in the CEE arm had a slightly lower incidence of breast cancer than those in the placebo group, but had more benign changes in breast tissue that showed up on mammograms and required follow-up mammographic studies.

'This was very different from what we expected,' Garnet Anderson, co-principal investigator of the WHI told United Press International. 'Although the increased risk of stroke produced by taking estrogen alone mandated that the trial be stopped, some of us wanted to keep it going to see if the reduction in the incidence of breast cancer would continue and become statistically significant.'

Anderson told UPI that all the risks that emerged from taking estrogen alone were small but the clinical disease benefits were also small. Thus, hormone replacement therapy should not be used to prevent heart disease, colorectal cancer or osteoporosis, he said.

'However, if you have a woman with menopausal symptoms that need reduction, hormones are the most effective way to deal with them,' Anderson said. 'Nothing else compares. Now women who are eligible for HRT with estrogen alone can feel more comfortable with their decision.'

Eric Winer, director of the Breast Oncology Center at the Dana-Farber Cancer Institute, told UPI he found the new information 'reassuring.'

'The days when HRT would be recommended for long periods of time to produce general health benefits are long past,' Winer said. 'HRT doesn`t decrease the risk of heart disease and does increase the risk of stroke, and we have many other ways of addressing bone health that don`t involve hormones; but if a menopausal woman without a uterus chooses to take estrogen alone, this article says that decision will not increase her risk of developing breast cancer and that`s welcome news.'

Winer added that he thought the results were interesting because they suggest that estrogen and progesterone taken together daily increase the possibility of developing breast cancer, and this indicates that hormonal influences are more complicated than people believed in the past.

Anderson urged clinicians to use the information cautiously when recommending treatment because the data were not yet statistically significant.

'We saw a small, interesting reduction in breast cancer incidence that needs to be followed with research,' Anderson said. 'It`s not the level of evidence that can justify us saying that these hormones may prevent breast cancer.'

She also noted that WHI`s results contradict the findings from other well-run, respected studies, and attributed that contradiction in part to the fact that the previous studies were observational and based on reports from patients and their doctors rather than randomized clinical trials such as the one performed by the WHI.

'But the observational studies are valuable because they have the advantage of time,' Anderson stated. 'Our trial lasted around seven years. Some of the observational studies have data from 10, 15 or 20 years. They may be seeing longer term effects that we have not yet had the ability to observe.'

The results of the WHI study will be published in the April 12 issue of the Journal of the American Medical Association.

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