Featured Research

from universities, journals, and other organizations

Cancer Treatment: Selecting Patients Based On Genotype May Increase Efficacy Of Tamoxifen, Study Suggests

Date:
April 30, 2008
Source:
Journal of the National Cancer Institute
Summary:
Breast cancer patients who carry the wild-type gene required for tamoxifen metabolism may have comparable risk of recurrence when taking tamoxifen or an aromatase inhibitor, according to modeling data. Cytochrome P450 2D6 (CYP2D6) converts tamoxifen into its metabolically active form called endoxifen.

Breast cancer patients who carry the wild-type gene required for tamoxifen metabolism may have comparable risk of recurrence when taking tamoxifen or an aromatase inhibitor, according to modeling data.

Cytochrome P450 2D6 (CYP2D6) converts tamoxifen into its metabolically active form called endoxifen. The enzymes encoded by different variants of the CYP2D6 gene metabolize tamoxifen at different rates. For example, women who carry two copies of the CYP2D6*4 allele have less endoxifen in their blood than women who carry two copies of the wild-type allele for CYP2D6. The lower serum concentration of endoxifen may make tamoxifen less effective for the women with the CYP2D6 *4 allele. However, two large randomized trials, which did not test women for their CYP2D6 genotype, showed that breast cancer survivors who take aromatase inhibitors reduce their risk of recurrence more than those taking tamoxifen.

To estimate whether women with wild-type CYP2D6 might derive more clinical benefit from tamoxifen than from aromatase inhibitors, Rinaa Punglia, M.D., of the Dana-Farber Cancer Institute in Boston and colleagues created a mathematical model. The researchers used estimates about the risk of recurrence from past randomized trials.

Punglia and colleagues calculated that women with wild-type CYP2D6 who take tamoxifen would have approximately the same reduction in the risk of recurrence as was seen for the whole population of women who took aromatase inhibitors in the clinical trial. Therefore, women with wild-type CYP2D6 genotype may derive as much benefit from tamoxifen as from aromatase inhibitors.

"Our model raises the possibility that tailored therapy based on pharmacogenomics could be considered for such women," the authors write.

In an accompanying editorial, Daniel Hayes, M.D., of the University of Michigan Comprehensive Cancer Center in Ann Arbor and colleagues review what is known about tamoxifen metabolism and CYP2D6 allele types and their impact on the risk of recurrence for breast cancer patients.

The editorialists comment that the conclusions by Punglia and colleagues are important because they have brought the field of pharmacogenomics to the attention of breast cancer physicians. However, the analysis was based on limited data and on modeling assumptions and must be viewed with caution. "We do not recommend routine CYP2D6 genotyping for all patients who are considering tamoxifen, although we recognize that there are already selected circumstances in which such knowledge might be helpful," they write.

This research was reported April 29 in the Journal of the National Cancer Institute.


Story Source:

The above story is based on materials provided by Journal of the National Cancer Institute. Note: Materials may be edited for content and length.


Cite This Page:

Journal of the National Cancer Institute. "Cancer Treatment: Selecting Patients Based On Genotype May Increase Efficacy Of Tamoxifen, Study Suggests." ScienceDaily. ScienceDaily, 30 April 2008. <www.sciencedaily.com/releases/2008/04/080429170256.htm>.
Journal of the National Cancer Institute. (2008, April 30). Cancer Treatment: Selecting Patients Based On Genotype May Increase Efficacy Of Tamoxifen, Study Suggests. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2008/04/080429170256.htm
Journal of the National Cancer Institute. "Cancer Treatment: Selecting Patients Based On Genotype May Increase Efficacy Of Tamoxifen, Study Suggests." ScienceDaily. www.sciencedaily.com/releases/2008/04/080429170256.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) 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:
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