Estrogen HRT Linked to
Rare Breast Cancer
NEW YORK - A new study may let 40 million American women breathe a little easier.
Many of these women =97 those in the over 50 group =97 have been gambling = on their health by taking estrogen and other female hormones to replenish their dwindling natural supplies. Hormone replacement therapy provides protection against osteoporosis and heart disease, but a number of studies have also linked it to a troubling increase in breast cancer rates.
This news, however, indicates that those breast cancer risks may not be as ominous as previously thought, further tipping the balance in favor of HRT.
The study, published in Wednesday=92s Journal of the American Medical Association, found HRT was associated with a type of breast cancer tumors that are less common and have a more favorable outcome than other types.
"It=92s good news and it's good news," said Susan M. Gapstur, Ph.D., a Northwestern University Medical School epidemiologist and lead author of the study. "This study offers more information to say that the benefits [of HRT] continue to outweigh the risks."
The Study - Giving Iowa a Try
In the study, Gapstur and her colleagues analyzed data from a 10-year survey of over 37,000 post-menopausal women in Iowa who were selected at random from Iowa drivers' license records in 1986, and were followed through 1996.
Gapstur and her colleagues weeded out women who had reported a previous mastectomy or had already had cancer other than skin cancer and looked at the effect of HRT and other factors on the rest of the cancer-negative women. They were unable to look at specific types of HRT/estrogen-only or estrogen plus progesterone because the survey did not ask women which therapy they were using.
96 percent of women with localized breast cancer survive at least five years.
Women in the study who used HRT for five years or less had 1.81 times the number of invasive carcinomas with a favorable histology; those who had used HRT for over five years had 2.65 times the risk of these cancers than non-hormone users, while they did not have increased numbers of other types of breast cancer.
The researchers accounted for other factors influencing breast cancer rates such as body mass index, smoking, age of first childbirth and family history of cancer, but they found this increased tumor risk was independent of all these factors.