Even low-androgen triple-negative breast cancer responds to anti-androgen therapy

February 24, 2015, University of Colorado Denver

A University of Colorado Cancer Center study published today in the journal Molecular Cancer Therapeutics shows that only about 1 percent of triple-negative breast cancer cells in a tumor must be "androgen-receptor-positive" to show benefit from anti-androgen therapies. There are no FDA-approved targeted therapies for triple-negative breast cancer. Clinical trials currently underway are showing promising preliminary results of anti-androgen-receptor therapies against triple-negative breast cancers expressing a higher percentage of androgen-receptor-positive cells.

"What we're showing is that the threshold for benefit from anti-androgen-receptor therapies in triple-negative may be far lower than we previously thought. This is an extremely optimistic finding for many people who have been without options for targeted cancer therapy," says Valerie Barton, the study's first author and PhD candidate in the lab of CU Cancer Center investigator Jennifer Richer, PhD.

Triple-negative breast cancers are those without known hormone or genetic drivers - specifically, breast cancers that do not drive their growth with the hormones estrogen or progesterone, or with the gene HER2. Without a known driver, there has been no "target" in triple-negative breast cancer to treat with targeted therapies, and the triple-negative subtype has the worst five-year survival rate of any breast cancer. The current study is the most recent in an extremely promising line of work at the CU Cancer Center and elsewhere that aims to prove as an additional driver and target in breast cancer.

"We're getting closer to being able to call some triple-negative breast cancers, androgen-receptor-positive breast cancers. And we may have to start referring to the remaining triple-negative breast cancers that are completely without androgen receptors as quadruple-negative breast cancers," Barton says.

The current study treated triple-negative breast with the anti-androgen-receptor drug Enzalutamide, currently FDA approved for use as an anti-androgen against prostate cancer. It has been previously shown that Enzalutamide is active against "luminal" triple-negative breast cancer cells that tend to have abundant androgen receptors. Barton and colleagues tested Enzalutamide against non-luminal cell lines that have far fewer androgen receptors.

"Even in these cells and in mouse models of tumors with low percentage of androgen receptor positive , we observed that Enzalutamide was significantly effective at reducing proliferation, growth, migration and invasion of cancer cells," Barton says.

"Our results suggest that anti-androgen receptor therapy may benefit a larger percentage of triple negative breast cancers than previously thought," Barton says.

Explore further: Three San Antonio studies target androgen in breast cancer

Related Stories

Three San Antonio studies target androgen in breast cancer

December 11, 2014
Three studies presented by University of Colorado Cancer Center researchers at the San Antonio Breast Cancer Symposium 2014 demonstrate the effects of blocking androgen receptors in breast cancer. One shows that, counterintuitively, ...

Possible new weapon found for fighting some types of breast cancer

June 23, 2014
Researchers believe they have discovered one reason why some women with estrogen receptor-positive breast cancer may respond poorly or only temporarily to estrogen-blocking drugs such as tamoxifen. Results of a new study, ...

New target, new drug in breast cancer

June 4, 2012
Many breast cancers depend on hormones including estrogen or progesterone for their survival and proliferation. Eight years of lab work at the University of Colorado Cancer Center and elsewhere suggest that the androgen (AR) ...

Studies show increasing evidence that androgen drives breast cancer

April 10, 2013
Estrogen and progesterone receptors, and the gene HER2 – these are the big three markers and/or targets in breast cancer. Evidence presented at the AACR Annual Meeting 2013 adds a fourth: androgen receptors.

Clinical trial hits new target in war on breast cancer

December 3, 2012
Breast cancers are defined by their drivers – estrogen and progesterone receptors (ER and PR) and HER2 are the most common, and there are drugs targeting each. When breast cancer has an unknown driver, it also has fewer ...

Novel breast cancer gene found

January 9, 2015
A new study identifies a gene that is especially active in aggressive subtypes of breast cancer. The research suggests that an overactive BCL11A gene drives triple-negative breast cancer development and progression.

Recommended for you

Researchers find a way to 'starve' cancer

January 18, 2018
Researchers at Vanderbilt University Medical Center (VUMC) have demonstrated for the first time that it is possible to starve a tumor and stop its growth with a newly discovered small compound that blocks uptake of the vital ...

Modular gene enhancer promotes leukemia and regulates effectiveness of chemotherapy

January 18, 2018
Every day, billions of new blood cells are generated in the bone marrow. The gene Myc is known to play an important role in this process, and is also known to play a role in cancer. Scientists from the German Cancer Research ...

Researchers develop swallowable test to detect pre-cancerous Barrett's esophagus

January 17, 2018
Investigators at Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center have developed a simple, swallowable test for early detection of Barrett's esophagus that offers promise ...

Scientists zoom in to watch DNA code being read

January 17, 2018
Scientists have unveiled incredible images of how the DNA code is read and interpreted—revealing new detail about one of the fundamental processes of life.

Presurgical targeted therapy delays relapse of high-risk stage 3 melanoma

January 17, 2018
A pair of targeted therapies given before and after surgery for melanoma produced at least a six-fold increase in time to progression compared to standard-of-care surgery for patients with stage 3 disease, researchers at ...

Dulling cancer therapy's double-edged sword

January 17, 2018
Researchers have discovered that killing cancer cells can actually have the unintended effect of fueling the proliferation of residual, living cancer cells, ultimately leading to aggressive tumor progression.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.