Featured Research

from universities, journals, and other organizations

Breastfeeding, Other Factors May Affect Risk Of Breast Cancer Type

Date:
August 26, 2008
Source:
American Cancer Society
Summary:
Factors such as age at menopause as well as a woman's breastfeeding practices can influence her risk of developing certain types of breast cancer.

Factors such as age at menopause as well as a woman's breastfeeding practices can influence her risk of developing certain types of breast cancer. That was the conclusion of a new study published in the October 1, 2008 issue of CANCER, a peer-reviewed journal of the American Cancer Society. The study's results suggest that there are distinct and separate hormonal risk factors associated with different subtypes of breast cancer.

Related Articles


Clinical differences among breast cancer subtypes have been well-described, but researchers have limited data on how the various subtypes arise and which individuals are at greatest risk. Having this information could help physicians identify which women are more likely to develop certain subtypes of breast cancer, which respond differently to different anti-cancer therapies and have very different survival rates.

Amanda Phipps, a predoctoral research associate at the Fred Hutchinson Cancer Research Center in Seattle, and her colleagues conducted a study to better understand the specific risk factors for the subtypes of breast cancer, which are classified by expression of the estrogen receptor, the progesterone receptor, and the HER2 receptor. Some breast cancer types express one or more of these proteins on their cell surface, while others express none. The research team suspected that reproductive or hormonal factors may play a significant role in a woman's risk of developing different subtypes because these cell receptors are influenced by endogenous sex hormones.

For their study, the scientists pooled two population-based studies of breast cancer in women aged 55-79 years. Their analysis included 1,023 women with breast cancer whose cells express the estrogen and progesterone receptors (called luminal cancers), 39 women with HER2-overexpressing breast cancer, and 78 triple-negative cases (no expression of estrogen, progesterone, or HER2 receptors). The study also included 1,476 women without breast cancer.

The investigators found that reproductive risk factors varied considerably by breast cancer subtype. For example, early age at menarche was associated with risk of HER2-overexpressing disease but not with any other subtype. Breastfeeding for 6 months or longer was associated with a lower risk of luminal cancer as well as triple-negative cancer, a type that can be particularly aggressive and difficult to treat. Both late age at menopause and use of estrogen plus progestin hormone therapy were associated with an increased risk of luminal disease. Finally, no differences in risks associated with number of children or the age when a woman first gave birth were observed by subtype.

The study authors concluded that their results indicate that "certain reproductive factors may have a greater impact on risk of certain molecular subtypes of disease compared to others." They added that additional studies on the causes of breast cancer subtypes are needed to better understand the biology of the disease.


Story Source:

The above story is based on materials provided by American Cancer Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amanda I. Phipps, Kathleen E. Malone, Peggy L. Porter, Janet R. Daling, and Christopher I. Li. Reproductive and hormonal factors for postmenopausal luminal, HER2-overexpressing, and triple-negative breast cancer. CANCER, Published Online: August 25, 2008 DOI: 10.1002/cncr.23786

Cite This Page:

American Cancer Society. "Breastfeeding, Other Factors May Affect Risk Of Breast Cancer Type." ScienceDaily. ScienceDaily, 26 August 2008. <www.sciencedaily.com/releases/2008/08/080825092343.htm>.
American Cancer Society. (2008, August 26). Breastfeeding, Other Factors May Affect Risk Of Breast Cancer Type. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2008/08/080825092343.htm
American Cancer Society. "Breastfeeding, Other Factors May Affect Risk Of Breast Cancer Type." ScienceDaily. www.sciencedaily.com/releases/2008/08/080825092343.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Malnutrition on the Rise as Violence Flares in C. Africa

Malnutrition on the Rise as Violence Flares in C. Africa

AFP (Jan. 28, 2015) Violence can flare up at any moment in Bambari with only a bridge separating Muslims and Christians. Malnutrition is on the rise and lack of water means simple cooking fires threaten to destroy makeshift camps where people are living. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Poultry Culled in Taiwan to Thwart Bird Flu

Poultry Culled in Taiwan to Thwart Bird Flu

Reuters - News Video Online (Jan. 28, 2015) Taiwan culls over a million poultry in efforts to halt various strains of avian flu. Julie Noce reports. Video provided by Reuters
Powered by NewsLook.com
Media Criticizing Parents For Not Vaccinating Children

Media Criticizing Parents For Not Vaccinating Children

Newsy (Jan. 28, 2015) As the Disneyland measles outbreak continues to spread, the media says parents who choose not to vaccinate their children are part of the cause. Video provided by Newsy
Powered by NewsLook.com
Shark Bite Victim Making Amazing Recovery

Shark Bite Victim Making Amazing Recovery

AP (Jan. 27, 2015) A Texas woman who lost more than five pounds of flesh to a shark in the Bahamas earlier this month could be released from a Florida hospital soon. Experts believe she was bitten by a bull shark while snorkeling. (Jan. 27) Video provided by AP
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