Featured Research

from universities, journals, and other organizations

Tamoxifen Chemoprevention Tied To Early Detection Of Breast Cancer

Date:
October 12, 2008
Source:
University of Texas M. D. Anderson Cancer Center
Summary:
The drug tamoxifen does not prevent or treat estrogen receptor negative breast cancer, but it can make the disease easier to find, researchers report in the Oct. 1 Journal of the National Cancer Institute.

The drug tamoxifen does not prevent or treat estrogen receptor (ER) negative breast cancer, but it can make the disease easier to find, researchers report in the Oct. 1 Journal of the National Cancer Institute.

Women at high-risk for breast cancer who took tamoxifen as a preventive measure in a clinical trial and later developed ER-negative breast cancer had a median time to first diagnosis of 24 months, compared with 36 months for those who received placebo, according to a retrospective statistical analysis.

While long-term survival has not yet been observed for the trial, that one-year advanced diagnosis is an unexpected and significant finding, said study lead author Yu Shen, Ph.D., professor in The University of Texas M. D. Anderson Department of Biostatistics. "Based on our basic understanding of breast cancer, survival rate is higher when cancer is detected at an earlier stage. Our findings open up a new area of research."

"It's a good example of how innovative application of statistical analysis can make a great contribution to better understanding the biological mechanisms of cancer," Shen said.

Tamoxifen is an anti-hormonal therapy known to be effective against ER-positive breast cancer, which is driven by the hormone estrogen. In the Breast Cancer Prevention Trial, conducted at 300 centers, 13,388 women at high risk for breast cancer were randomized to either tamoxifen or placebo. Of those, 174 were diagnosed with ER-positive tumors and 69 with ER-negative tumors. This study found that the drug prevents the incidence of ER-positive breast cancer.

Shen and colleagues requested access to the trial data to illustrate a new statistical methodology and examine tamoxifen's effect on time to diagnosis of disease, which was not determined in the original trial. The more flexible statistical model allowed the team to separately estimate time to diagnosis among diseased cases and the incidence of disease among study participants in both the placebo and tamoxifen arms of the study.

They found that taking tamoxifen made no difference in the time to diagnosis of ER-positive breast cancer and reduced the incidence of ER-positive cancer. Tamoxifen had no effect on the incidence of ER-negative disease, while reducing the median time to diagnosis of ER-negative disease by a year.

The researchers discovered a few hints as to why tamoxifen treatment might make ER-negative cancers more detectable, but Shen cautions that pinpointing the biological factors behind the finding will require additional research. "As statisticians, we uncover the phenomenon, but we cannot explain why it happened," she said.

Other research has indicated that ER-negative breast cancer is less likely to be detected by mammography. In this study, mammography detected 77.4 percent of ER-negative tumors in the placebo group, compared with 94.7 percent in the tamoxifen group, however this finding fell short of statistical significance.

Taking tamoxifen alters breast density, which appears to be a major factor in the sensitivity of mammography screening, the authors note. By altering the density of normal tissue, tamoxifen may modify the contrast between normal tissue and tumors, which might increase the ability of mammography to detect disease. The BCPT trial did not collect breast density data, so this risk factor could not be evaluated.

Grants from the National Cancer Institute funded this research.

Co-authors with Shen are Joseph Constantino, Ph.D., of the Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh; and Jing Qin, Ph.D., of the Biostatistics Research Branch of the National Institute of Allergy and Infectious Diseases.


Story Source:

The above story is based on materials provided by University of Texas M. D. Anderson Cancer Center. Note: Materials may be edited for content and length.


Cite This Page:

University of Texas M. D. Anderson Cancer Center. "Tamoxifen Chemoprevention Tied To Early Detection Of Breast Cancer." ScienceDaily. ScienceDaily, 12 October 2008. <www.sciencedaily.com/releases/2008/10/081007172824.htm>.
University of Texas M. D. Anderson Cancer Center. (2008, October 12). Tamoxifen Chemoprevention Tied To Early Detection Of Breast Cancer. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/10/081007172824.htm
University of Texas M. D. Anderson Cancer Center. "Tamoxifen Chemoprevention Tied To Early Detection Of Breast Cancer." ScienceDaily. www.sciencedaily.com/releases/2008/10/081007172824.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