• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Study: Estrogen Not a Breast Cancer Threat

Posted on: Tuesday, 11 April 2006, 18:00 CDT

By CHRISTINE DELL'AMORE

Estrogen does not increase risk of breast cancer in post-menopausal women with hysterectomies, according to a new study that may simmer down a heated debate on estrogen.

The study, part of the federal Women's Health Initiative, a 15-year project of 161,808 women, confirms previous research that shows estrogen does not put women in danger of breast cancer.

For women who have had a hysterectomy -- which is the majority of women taking menopause medicine -- now they don't have this fear factor of breast cancer looming over their heads, said lead author Dr. Marcia Stefanick, principal investigator at the Stanford Clinical Center and the chair of the WHI's Steering and Executive Committees.

The study will appear in this week's issue of the Journal of the American Medical Association.

Stefanick and colleagues looked at 10,739 women aged 50 to 79 -- all with hysterectomies, or without uteruses -- between 1993 and 1998. The study was meant to explore mixed findings that came out of the WHI's previous Estrogen-Alone trial, which gave women with past hysterectomies estrogen therapy.

In general, women with uteruses take a combination therapy, as progestin protects against harm to the uterus. Women without uteruses typically take estrogen alone.

But the Estrogen-Alone trial was halted in 2004, a year earlier than intended, due to increased incidence of stroke and a lack of impact on coronary heart disease.

The primary findings, published in the April 2004 Journal of the American Medical Association, concluded that after almost seven years of follow-up, estrogen provided no overall benefit, yet offered a glimmer of hope: The women on estrogen had statistically nonsignificant drops in breast cancer.

Stefanick and colleagues' recent study confirms the reductions were insignificant. The study also reported women on estrogen needed more follow-up mammograms due to breast abnormalities.

To tease out further research topics, the authors conducted exploratory analyses of certain subgroups of women, including women with an estimated five-year breast cancer risk; a history of benign breast disease, or cysts; and those who had first-degree relatives with breast cancer.

In these analyses, estrogen apparently provided a protective effect on breast cancer incidence, although Stefanick warns these results aren't yet solidified. The study shouldn't be a green light for women to take estrogen, she said.

Combined therapies, such as estrogen and progestin, may still be harmful in some cases. Another WHI study, published in JAMA in July 2002, found a combination therapy of estrogen plus progestin in women with their uteruses increased their chance of breast cancer. This trial also stopped early, after 5.6 years of follow-up.

In 2002, approximately 8 million women used estrogen therapy alone, according to NIH, and although estrogen's somewhat tainted reputation has led to a decline in prescriptions for hormones in past years, doctors still feel it is a valid choice for women.

This (study) is really wonderful for women, especially for those entering menopause, said Dr. Hugh Taylor, director of Yale University's Menopause Program.

We've seen so much confusing and conflicting information about estrogen, it will be very reassuring.

Millions suffer needlessly from hot flashes and other menopause symptoms, opting to battle through instead of take estrogen, Taylor said.

And for those women with uteruses intact, Taylor said future research will target how to administer progestin in smaller quantities, or find alternatives for the hormone.

Women with incapacitating menopause symptoms may find the benefit of hormone therapy overshadows its risks, said Dr. John H. Glick, a medical oncologist who directs the Abramson Cancer Center of the University of Pennsylvania.

For instance, a woman whose daily activities are disrupted by hot flashes may look at estrogen's effects -- a slight increased risk of stroke, no effect on coronary heart disease -- and decide to go for it. Ultimately, it's a quality of life issue, Glick said, and the decision should be made with the aid of her doctor.

The hooplah over estrogen has caused an exaggerated sense of risk, Taylor said.

When we really look beyond the surface of the confusion that's been so prevalent, there really is a lot of good news there. We've unnecessarily frightened women in this country, he said.

E-mail: consumerhealth@upi.com

Source: United Press International

More News in this Category