Breast Cancer, Hormone Link Clarified
Breast Cancer, Hormone Link Clarified
Individual Risk Is Widely Overestimated, Researchers Say
Aug. 4, 2005 - Breast cancer risk associated with the use of hormone therapy is much smaller than most women have been led to believe, according to researchers in Australia who have calculated the risk in a new way.
Widely reported studies suggest that compared to nonhormone users, women who take hormones for many years have anywhere from a 50% higher risk of developing breast cancer to double the risk.
While that sounds pretty scary, the new research indicates that the real risk is actually quite small, says John Boyages, MD, who is executive director of the New South Wales Breast Cancer Institute.
Boyages and colleagues used a mathematical formula to estimate the excess risk of breast cancer due to exposure from hormone therapy use over time. This is known as the cumulative absolute risk.
They found only a slightly higher risk in women who took a combination of estrogen and progestin for up to five years.
Far from doubling the risk, the researchers suggest that the risk in a 50-year-old woman increased from 6.1% to 6.7% if she took combined hormones for five years. The risk for the same woman who took hormones for a decade was estimated to be 7.7%.
The findings are reported in the Aug. 6 issue of the British Medical Journal.
"We are not saying that there is no risk associated with taking hormones," Boyages tells WebMD. "But I do think that women have been unnecessarily scared by the figures they have seen in the media. We have to work harder to communicate risk in ways that women can understand."
Up until three years ago, hormone therapy was widely prescribed to menopausal women in the belief that the treatment would protect against heart disease and other conditions associated with aging.
The early halting of the U.S. government-sponsored Women's Health Initiative prevention trial in July of 2002 caused millions of women to abandon the treatment. Researchers initially reported a "small but unacceptable" increase in breast cancers associated with hormone therapy, as well as increases in heart attacks, strokes, and blood clots.
Breast Cancer, Hormone Link Clarified
Individual Risk Is Widely Overestimated, Researchers Say
Aug. 4, 2005 - Breast cancer risk associated with the use of hormone therapy is much smaller than most women have been led to believe, according to researchers in Australia who have calculated the risk in a new way.
Widely reported studies suggest that compared to nonhormone users, women who take hormones for many years have anywhere from a 50% higher risk of developing breast cancer to double the risk.
While that sounds pretty scary, the new research indicates that the real risk is actually quite small, says John Boyages, MD, who is executive director of the New South Wales Breast Cancer Institute.
Absolute Risk Low
Boyages and colleagues used a mathematical formula to estimate the excess risk of breast cancer due to exposure from hormone therapy use over time. This is known as the cumulative absolute risk.
They found only a slightly higher risk in women who took a combination of estrogen and progestin for up to five years.
Far from doubling the risk, the researchers suggest that the risk in a 50-year-old woman increased from 6.1% to 6.7% if she took combined hormones for five years. The risk for the same woman who took hormones for a decade was estimated to be 7.7%.
The findings are reported in the Aug. 6 issue of the British Medical Journal.
"We are not saying that there is no risk associated with taking hormones," Boyages tells WebMD. "But I do think that women have been unnecessarily scared by the figures they have seen in the media. We have to work harder to communicate risk in ways that women can understand."
Measuring Risk
Up until three years ago, hormone therapy was widely prescribed to menopausal women in the belief that the treatment would protect against heart disease and other conditions associated with aging.
The early halting of the U.S. government-sponsored Women's Health Initiative prevention trial in July of 2002 caused millions of women to abandon the treatment. Researchers initially reported a "small but unacceptable" increase in breast cancers associated with hormone therapy, as well as increases in heart attacks, strokes, and blood clots.
Source...