Scientists Detect Unique Marker for Triple-Negative Breast Cancer
TUESDAY Sept. 28, 2010 -- In an effort to improve the prognosis of patients battling triple-negative breast cancer, scientists have identified a unique biomarker that may eventually allow some to receive a more targeted treatment.
Although relatively uncommon, triple negative breast cancer is notoriously difficult to treat because receptor targeted therapies don't work. The disease's name refers to breast cancers that test negative for estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2(HER2), all of which fuel most breast cancer growth.
"Triple-negative breast cancers currently lack therapeutic targets and are managed with conventional chemotherapy," study author Dr. Agnieszka K. Witkiewicz, an associate professor of pathology at Thomas Jefferson University Hospital in Philadelphia, explained in a news release.
In search of new treatment targets, the study's research team analyzed expression levels of a particular protein called IGF-1R (insulin-like growth factor) among 97 patients diagnosed with triple-negative breast cancer. Seventy-three of the patients were white, and 24 were black.
Witkiewicz and her colleagues found that when it came to IGF-1R, more is better. High expression of the protein was tied to a lower risk for lymph node metastasis (spread of the cancer) and had a borderline association with smaller tumor size. High expression levels were also linked to longer survival rates among patients younger than 55.
Among the study patients, about one in four demonstrated IGF-1R over-expression.
Noting that IGF-IR has already proven to be a successful target in sarcoma treatment, Witkiewicz said it might ultimately prove to be a good target for triple-negative breast cancer as well.
"For now, we know that it is there and we know it is a marker of better prognosis," said Witkiewicz. "The next step is to learn if triple-negative breast cancer patients benefit from targeting IGF-1R."
Witkiewicz and her colleagues are slated to present their findings Tuesday at the American Association for Cancer Research International Conference on Molecular Diagnostics in Cancer Therapeutic Development in Denver.
For more on triple-negative breast cancer, visit the Triple Negative Breast Cancer Foundation.
Posted: September 2010
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