Why Some Breast Tumors Resist Chemo

Breast cancer with four genes appears to resist taxane chemo

(RxWiki News) It's always been a mystery as to why some cancers don't respond to chemotherapies. Recent research has uncovered why a common chemo agent doesn't always work with breast cancers.

Researchers have found that a particular marker may be able to forecast that a woman's breast cancer won't respond to taxane chemotherapy.

"Find out about genetic testing."

A research team, led by Ing Swie Goping at the University of Alberta, has learned that tumors with low levels of particular genes appear not to respond well to chemotherapy agents commonly used to fight breast cancer.

"These tumors didn't shrink and were resistant to a common chemotherapy treatment. These results give us a strong incentive to continue our research," said Goping, who is a researcher in both the Department of Biochemistry and the Department of Oncology

In this small study, investigators looked at tumor samples from 24 women with breast cancer who underwent chemotherapy before surgery.

The medical scientists found alterations in four genes that are part of a cancer cell's "survival" system. These alterations weakened the system designed to help cells survive attacks.

But surprisingly, rather than the cancer's weakened survival system making the chemotherapy more effective, just the opposite occurred. The stronger the survival system, the better the chemo worked.

Anthony J. Berdis, Ph.D., assistant professor of pharmacology at Case Western Reserve University School of Medicine, told dailyRx, "This study provides new insight into how an existing anti-cancer agent causes cell death by inhibiting a cellular process normally associated with cell survival."

He continued, "This exciting data first provides a new way to attack cancer cells. Secondly, this information provides a way to screen patients in advance to see if they would benefit from this anti-cancer agent. Both features will provide better ways to treat patients with breast cancer," Berdis concluded.

Goping hopes to confirm these findings by examining thousands of samples over the next several years.

She noted, though, that it would be years before breast cancer patients could actually be tested for this marker.

Findings from this research were published in the March, 2012 issue of Oncogene.

This research was funded through grants from the Canadian Breast Cancer Foundation and Alberta Cancer Foundation/Alberta Innovates-Health Solutions

The authors declare no conflicts of interest.

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Review Date: 
March 28, 2012