Featured Research

from universities, journals, and other organizations

Hormone therapy begun at menopause may pose risk for breast cancer

Date:
January 31, 2011
Source:
Journal of the National Cancer Institute
Summary:
Starting hormone therapy at around the time of menopause is associated with a greater risk of breast cancer compared to starting after a longer gap, according to a new study.

Starting hormone therapy at around the time of menopause is associated with a greater risk of breast cancer compared to starting after a longer gap, according to a study published online Jan. 28 in The Journal of the National Cancer Institute. In this large, prospectively followed cohort of women, those who started hormone therapy five years or more after menopause had little or no increased risk, regardless of the type of hormone therapy used, how long they used it, and whether they were overweight or obese.

Related Articles


Many studies have established that breast cancer incidence increases in users of hormonal therapy, in particular among women who use an estrogen-progestin combination as opposed to estrogen-alone. Few studies have looked at the timing of hormone therapy as a risk factor, although two previous studies suggested the interval between menopause and initiating hormone therapy may influence breast cancer risk.

To investigate this question, Valerie Beral, FRS, of Oxford University and colleagues, used data from the Million Women Study (MWS) in the UK. The researchers estimated the adjusted relative risks of breast cancer in hormone therapy users and past users compared to non-users in 1.13 million women in the study. They also compared women on different types of hormone therapy.

They found that women starting hormone therapy at the time of menopause were at greater risk of breast cancer than those starting it later. They write, "A new finding of this study, which has been little investigated previously, is that the interval between menopause and starting hormonal therapy has a substantial effect on breast cancer risk."

Two previous studies have suggested this association but only in certain subgroups. "In this large study, we found greater risks of breast cancer if hormonal therapy use began either before or soon after menopause than after a longer gap; and this pattern of risk was seen across different types of hormonal therapy, among women who used hormonal therapy for either short of long durations, and also in lean and in overweight and obese women."

In an accompanying editorial, Rowan T. Chlebowski, M.D., Ph.D., of Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center and Garnet Anderson from the Fred Hutchinson Cancer Research Center note the study provides substantial support for similar findings from the Women's Health Initiative (WHI) in the U.S. They add that the similarities between the patterns of breast cancer risk in these two large studies increase the likely validity of the results, especially since the methodologies of the two studies were quite different.

The editorialists also discuss discrepancies in the two studies' findings regarding the risk of estrogen-only hormone therapy; the WHI found little risk associated with estrogen alone while the MWS found a statistically significant increased risk, except in overweight and obese women. They conclude that "the question of the effect of estrogen-only formulation use on breast cancer risk in postmenopausal women, even with longer-term hormone use, still stands unanswered."


Story Source:

The above story is based on materials provided by Journal of the National Cancer Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. V. Beral, G. Reeves, D. Bull, J. Green. Breast Cancer Risk in Relation to the Interval Between Menopause and Starting Hormone Therapy. JNCI Journal of the National Cancer Institute, 2011; DOI: 10.1093/jnci/djq527

Cite This Page:

Journal of the National Cancer Institute. "Hormone therapy begun at menopause may pose risk for breast cancer." ScienceDaily. ScienceDaily, 31 January 2011. <www.sciencedaily.com/releases/2011/01/110129081524.htm>.
Journal of the National Cancer Institute. (2011, January 31). Hormone therapy begun at menopause may pose risk for breast cancer. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2011/01/110129081524.htm
Journal of the National Cancer Institute. "Hormone therapy begun at menopause may pose risk for breast cancer." ScienceDaily. www.sciencedaily.com/releases/2011/01/110129081524.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins