Featured Research

from universities, journals, and other organizations

Analysis Of Tamoxifen Studies Reveals Slight Increase Of Stroke Risk

Date:
October 12, 2004
Source:
American Academy Of Neurology
Summary:
A recent analysis of tamoxifen studies completed since 1980 revealed an increased risk of stroke in women who were randomized to tamoxifen versus placebo or other therapies. Details of the analysis and the researchers’ conclusions are reported in the October 12 issue of Neurology, the scientific journal of the American Academy of Neurology.

St. Paul, Minn. – A recent analysis of tamoxifen studies completed since 1980 revealed an increased risk of stroke in women who were randomized to tamoxifen versus placebo or other therapies. Details of the analysis and the researchers’ conclusions are reported in the October 12 issue of Neurology, the scientific journal of the American Academy of Neurology.

More than 250,000 U.S. women are diagnosed with breast cancer each year. Breast cancer accounts for nearly one in three cancers diagnosed in the U.S. and is the second leading cause of death for women. Fortunately, 90 percent of breast cancers are now diagnosed at localized and regional stages, for which five-year survival rates are 97 percent and 79 percent, respectively. Tamoxifen, a medication in pill form that interferes with the activity of estrogen, has been used for more than 20 years to treat patients with advanced breast cancer. It is used as adjuvant, or additional, therapy following primary treatment for early stage breast cancer. In women at high risk of developing breast cancer, tamoxifen reduces the chance of developing the disease.

In addition to its effects on breast cancer, the benefits of tamoxifen include increased bone mineral density, reduced risk of hip fractures, and lower levels of cholesterol. While tamoxifen is known to increase the risk of blood clotting in women with cancer, its relationship to stroke risk has been unclear. Because tamoxifen increases the risk of thromboembolism (a blood clot that has traveled from its site of origin to another vessel), its use could be associated with a higher risk of ischemic stroke (arterial obstruction) as compared to hemorrhagic (bleeding) stroke.

Researchers from Duke University Medical Center sought to determine the overall risk of both ischemic stroke and all strokes associated with tamoxifen. They conducted a systematic review of all clinical trials of tamoxifen published since 1980 using MEDLINE.

Nine trials met their inclusion criteria, with 39,601 total subjects enrolled, 19,954 of whom were randomized to tamoxifen. Six of the trials specifically reported ischemic stroke events. All trials used a standard dose of tamoxifen (20 mg daily).

“With tamoxifen, we found the frequency of all strokes was 1.06 percent and for ischemic stroke was 0.71 percent, versus 0.39 percent with controls,” reported study author Cheryl Bushnell, MD, MHS. The risk of ischemic stroke increased by 82 percent and risk of all strokes by 29 percent in women randomized to tamoxifen versus placebo or other therapies. Bushnell concluded, “The absolute increase in risk was small.”

“The results of this analysis support the practice of careful screening of women who are being considered for tamoxifen therapy,” noted Bushnell, “although physicians and their patients should be reassured that the absolute risk of stroke may be very low. In many women, this risk of stroke with tamoxifen may be outweighed by the benefit of treating or preventing breast cancer. In addition, women should not stop their prescribed therapy based on this study.”

Results of this analysis should be interpreted with some caution. Among other variables, specific stroke risk factors of the women in these studies were not reported, and the methods of determining ischemic or other types of stroke were not documented in any of the trials. Ongoing studies of tamoxifen that are designed to carefully track stroke events will further clarify this risk.

The study was supported by a grant from the National Institutes of Health and a National Stroke Association Research Fellowship.

The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer's disease, epilepsy, Parkinson's disease, autism and multiple sclerosis.

For more information about the American Academy of Neurology, visit its web site at http://www.aan.com.


Story Source:

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


Cite This Page:

American Academy Of Neurology. "Analysis Of Tamoxifen Studies Reveals Slight Increase Of Stroke Risk." ScienceDaily. ScienceDaily, 12 October 2004. <www.sciencedaily.com/releases/2004/10/041012090021.htm>.
American Academy Of Neurology. (2004, October 12). Analysis Of Tamoxifen Studies Reveals Slight Increase Of Stroke Risk. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2004/10/041012090021.htm
American Academy Of Neurology. "Analysis Of Tamoxifen Studies Reveals Slight Increase Of Stroke Risk." ScienceDaily. www.sciencedaily.com/releases/2004/10/041012090021.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
CDC Calls for New Ebola Safety Guidelines

CDC Calls for New Ebola Safety Guidelines

AP (Oct. 20, 2014) Centers for Disease Control and Prevention Director Dr. Tom Frieden laid out new guidelines for health care workers when dealing with the deadly Ebola virus including new precautions when taking off personal protective equipment. (Oct. 20) 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