Featured Research

from universities, journals, and other organizations

Neither Abortion Nor Miscarriage Associated With Breast Cancer Risk

Date:
April 24, 2007
Source:
JAMA and Archives Journals
Summary:
Neither induced abortion nor spontaneous abortion (miscarriage) appears to be associated with breast cancer risk in premenopausal women, according to a recent report.

Neither induced abortion nor spontaneous abortion (miscarriage) appears to be associated with breast cancer risk in premenopausal women, according to a report in the April 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Related Articles


Women younger than age 35 who carry a pregnancy to term appear to have a reduced lifetime risk of breast cancer, according to background information in the article. Pregnancy may accelerate breast cell differentiation, the process by which cells take on specialized roles. "An incomplete pregnancy may not result in sufficient differentiation to counter the high levels of pregnancy hormones that may foster proliferation," the rapid growth and division typical of cancer cells, the authors write. "However, these biological mechanisms are uncertain, and a prematurely terminated pregnancy may not affect breast cancer risk at all."

Karin B. Michels, Sc.D., Ph.D., and colleagues at Brigham and Women's Hospital, Harvard Medical School and Harvard School of Public Health, Boston, examined the association between abortion and breast cancer in 105,716 women who were part of the Nurses' Health Study II (NHSII). The women were between age 29 and 46 at the beginning of the study in 1993. At that time, and again every two years through 2003, they answered questions about whether and at what age they had had miscarriages or induced abortions and provided information about breast cancer risk factors and diagnoses.

A total of 16,118 participants (15 percent) reported having a history of induced abortion and 21,753 (21 percent) had a history of spontaneous abortion. Between 1993 and 2003, 1,458 new cases of breast cancer occurred among the women. "In this cohort study of young women, we found no association between induced abortion and breast cancer incidence and a suggestion of an inverse association between spontaneous abortion and breast cancer incidence during 10 years of follow-up," the authors write.

"We observed associations in two subgroups, an association between induced abortion and progesterone receptor--negative breast cancer [cancer that does not respond to the hormone progesterone] and an inverse association between spontaneous abortion before the age of 20 years and breast cancer incidence," they continue. However, they caution that these secondary analyses are based on small numbers of women. "No obvious mechanisms can be provided for these subgroup findings; thus, chance has to be considered as a possible explanation."

A 2003 international expert panel convened by the National Cancer Institute reviewed and assessed research regarding reproductive events and the risk of breast cancer, and concluded that based on existing evidence, induced abortion is not associated with an increased risk of breast cancer. "The data from the NHSII provide further evidence of a lack of an important overall association between induced or spontaneous abortions and risk of breast cancer," the authors conclude. "Among this predominantly pre-menopausal population, neither induced nor spontaneous abortion was associated with the incidence of breast cancer."

The NHSII is supported by a Public Health Service grant from the National Cancer Institute, National Institutes of Health, U.S. Department of Health and Human Services.


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Cite This Page:

JAMA and Archives Journals. "Neither Abortion Nor Miscarriage Associated With Breast Cancer Risk." ScienceDaily. ScienceDaily, 24 April 2007. <www.sciencedaily.com/releases/2007/04/070423185607.htm>.
JAMA and Archives Journals. (2007, April 24). Neither Abortion Nor Miscarriage Associated With Breast Cancer Risk. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2007/04/070423185607.htm
JAMA and Archives Journals. "Neither Abortion Nor Miscarriage Associated With Breast Cancer Risk." ScienceDaily. www.sciencedaily.com/releases/2007/04/070423185607.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) 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