Common Gene Variant May Help Spur Cancer

TUESDAY, Oct. 4 (HealthDay News) -- Researchers at Northwestern University say they''ve learned more about how a relatively common gene variant, called TGFBR1*6A, contributes to tumor development.

Previous research found that this variant increases cancer risk by about 24 percent but it''s not clear exactly how TGFBR1*6A -- which is found in 13.7 percent of the general population -- contributes to cancer development. The gene has been thought to play a role in colorectal cancers, and perhaps other forms of cancer as well.

TGFBR1*6A is a variant of transforming growth factor beta (TGF-beta), a powerful, naturally occurring inhibitor of cell growth.

This study of 531 patients with head and neck cancer, colorectal cancer, and breast cancer found TGFBR1*6A to be frequently acquired in metastatic lesions from colorectal cancer and may give these malignant cells a growth advantage in the presence of TGF-beta.

People who have the TGFBR1*6A variant are at greater likelihood of developing metastases than people who don''t have this variant, the researchers found. That means that TGFBR1*6A may serve as a useful "biomarker" for those at risk, the study authors said.

"Since 13.7 percent of the general population and 17.1 percent of patients with a diagnosis of cancer carry at least one copy of the *6A allele, our findings may have substantial public health importance," the researchers said.

"The results [also] highlight a new facet of TGF-beta signaling in cancer and suggest that TGFBR1*6A may represent a potential therapeutic target," they noted.

The study appears in the Oct. 5 issue of the Journal of the American Medical Association.

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The U.S. National Cancer Institute has more about cancer and genetics.

-- Robert Preidt

SOURCE: Journal of the American Medical Association, news release, Oct. 4, 2005

Last Updated: Oct. 4, 2005