NEW YORK (Reuters Health) - In a nationwide study, Finnish researchers found a slightly elevated risk of breast cancer in women who used estrogen-only hormone therapy for 5 years or longer. Use of estrogen for less than 5 years was not associated with breast cancer risk.
Estrogen for 5 years or more, either in pill or patch form "means 2 to 3 extra cases of breast cancer per 1,000 women who are followed for 10 years," Dr. Olavi Ylikorkala from Helsinki University Central Hospital and colleagues report in the December issue of Obstetrics and Gynecology.
The risk of breast cancer was similar with oral and patch (transdermal) estrogen. It's been suggested that patch estrogen may be safer than pill estrogen with regard to risk of breast cancer, "but in our study a transdermal route did not vary from the oral one in this regard," the researchers note.
The findings are based on all Finnish women older than 50 years using estrogen-only therapy for at least 6 months during 1994 and 2001 who were followed for breast cancer until the end of 2002.
In a commentary, Dr. John Collins notes that women suffering hot flashes and other distressing symptoms related to menopause "can be reassured that short-term (less than 5 years) use of either combined estrogen-progestin therapy or estrogen alone will have little appreciable effect on their personal breast cancer risk."
"Longer use of combined estrogen-progestin therapy undeniably increases their breast cancer risk, likely to a greater extent than exposure to estrogen alone," Collins writes. "However, the level of risk remains similar to risks that many women accept through lifestyles that expose them to daily alcohol ingestion, lack of regular exercise, and postmenopausal obesity."
SOURCE: Obstetrics and Gynecology, December 2006.
Recent news about a dramatic decrease in new breast cancer cases has added to information on how hormone replacement therapy (HRT) might increase breast cancer risk.
But there are different kinds of hormone replacement therapy treatments. Some contain only estrogen, while others contain both estrogen and progesterone (known as combined HRT). Doctors thought that the different types of HRT would affect breast cancer risk differently. Doctors also thought that HRT in pill form might increase risk more than HRT given as a patch (transdermal therapy).
The study reviewed here found that taking estrogen-only HRT for fewer than five years—as a pill OR a patch—was NOT associated with an increased risk of breast cancer in women living in Finland. When estrogen-only HRT was used for more than five years, breast cancer risk increased slightly.
A strong public health system in Finland makes it relatively easy to study and compare large populations of women over a long period of time. Usually more people in a study and longer follow-up time means more accurate results. In this study, more than 18,000 women who received estrogen-only HRT for at least six months were followed, some for as long as eight years (1994-2002). About 2,200 women in the study were diagnosed with breast cancer. The breast cancer rate of these women were compared to breast cancer rates in women who did not receive HRT.
The concerns about HRT and breast cancer risk are very real. But for some women, the side effects of menopause severely reduce their quality of life. They have to weigh the benefits of HRT against the risks. If you're experiencing severe menopausal side effects and are considering HRT, talk to your doctor about the results of this study. Together, you can decide which type of HRT, if any, might be right for you.
Breastcancer.org 7 East Lancaster Avenue, 3rd Floor Ardmore, PA 19003
Learn more about our commmitment to your privacy
© 2008 Breastcancer.org - All rights reserved.
Breastcancer.org is a non-profit organization dedicated to providing information and community to those touched by this disease. Learn more about our commitment to providing complete, accurate, and private breast cancer information.