Featured Research

from universities, journals, and other organizations

Fertility drugs do not increase breast cancer risk, study shows

Date:
April 3, 2014
Source:
American Association for Cancer Research (AACR)
Summary:
Women who took clomiphene citrate (brand name Clomid) or gonadotropins as a part of fertility treatment did not experience an increased risk for breast cancer over 30 years of follow-up, compared with women who were not treated with these medications, according to a study. This study was conducted using data from a cohort of more than 12,000 women evaluated for infertility between 1965 and 1988 at five different locations in the United States that retained detailed records of infertility evaluations and treatments.

Women who took clomiphene citrate (brand name Clomid) or gonadotropins as a part of fertility treatment did not experience an increased risk for breast cancer over 30 years of follow-up, compared with women who were not treated with these medications, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

"We wanted to evaluate the long-term relationship of fertility medications and breast cancer risk after controlling for other factors that have been shown to be correlated with both breast cancer risk and use of those drugs," said Louise A. Brinton, Ph.D., M.P.H., chief of the Hormonal and Reproductive Epidemiology Branch at the National Cancer Institute (NCI) in Bethesda, Md. "Overall, our data show that use of fertility drugs does not increase breast cancer risk in this population of women, which is reassuring."

An elevated risk for invasive breast cancer was observed for a small number of women who were exposed to 12 or more cycles of clomiphene, who had a little more than 1.5 times the risk of women in the study who never took fertility drugs. Women who were unable to become pregnant after taking gonadotropins and clomiphene citrate had nearly twice the risk of women in the study who never took either medication.

"The observed increase in risk for these small subsets of women may be related to persistent infertility rather than an effect of the medications," said Brinton. "Nevertheless, these findings stress the importance of continued monitoring of women who are exposed to fertility drugs."

Under current practices, clomiphene is usually limited to three to six cycles at doses up to 100 mg, which is far lower than in the past, including patients in this study who were prescribed doses up to 250 mg, oftentimes for many years, explained Brinton.

"Given the high doses of drugs received by our study participants and the lack of large increases in breast cancer risk many years after exposure, women previously exposed to such drugs should be reassured by these findings," said Brinton. "However, the women in our study who developed breast cancer were on average only 53 years old, which is still young in terms of when we usually expect breast cancers to develop.

"This cohort of women should continue to be monitored as they progress into a typical breast cancer age range; in addition, data are needed to assess the long-term effects of fertility drugs given in current practice, such as those used in conjunction with IVF," added Brinton.

This study was conducted using data from a cohort of more than 12,000 women evaluated for infertility between 1965 and 1988 at five different locations in the United States that retained detailed records of infertility evaluations and treatments. These patients were followed until 2010, and 9,892 were eligible for this study. Among them, 749 women developed breast cancer. The researchers were able to obtain medical documentation for 696 of these, and 536 were validated as having invasive breast cancers.


Story Source:

The above story is based on materials provided by American Association for Cancer Research (AACR). Note: Materials may be edited for content and length.


Journal Reference:

  1. L. A. Brinton, B. Scoccia, K. S. Moghissi, C. L. Westhoff, S. Niwa, D. Ruggieri, B. Trabert, E. J. Lamb. Long-term Relationship of Ovulation-Stimulating Drugs to Breast Cancer Risk. Cancer Epidemiology Biomarkers & Prevention, 2014; 23 (4): 584 DOI: 10.1158/1055-9965.EPI-13-0996

Cite This Page:

American Association for Cancer Research (AACR). "Fertility drugs do not increase breast cancer risk, study shows." ScienceDaily. ScienceDaily, 3 April 2014. <www.sciencedaily.com/releases/2014/04/140403084245.htm>.
American Association for Cancer Research (AACR). (2014, April 3). Fertility drugs do not increase breast cancer risk, study shows. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2014/04/140403084245.htm
American Association for Cancer Research (AACR). "Fertility drugs do not increase breast cancer risk, study shows." ScienceDaily. www.sciencedaily.com/releases/2014/04/140403084245.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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:
from the past week

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