If successful, the test could be broadly applied to identify those who most need to be monitored with invasive but standard colonoscopy or who should make changes in their diet or in other factors to help lower their risk of developing colon cancer.

The researchers' test is based on the fact that five percent to 10 percent of people have improper control of a growth-promoting gene called insulin-like growth factor 2 or IGF-2. The Johns Hopkins scientists reported in February that, in mice, the double dose of IGF-2 protein sets the stage for cancer development -- by increasing the number of primitive cells found in the colon -- and that early evidence suggests the same could be true in people.

"If everything works out -- if IGF-2 status is tied to colon cancer risk in people and the blood test is workable -- then IGF-2 status could be the colon cancer equivalent of cholesterol levels as a risk factor for heart disease," says Andrew Feinberg, M.D., Ph.D., professor of medicine at Johns Hopkins and one of the leaders of the project. "We've never had a broad molecular screening tool like that for any cancer."

But there's a lot of work to do first. With the new Doris Duke Charitable Foundation grant, part of the foundation's Clinical Interfaces Award Program, Feinberg and his colleagues will develop and validate the blood test, study how IGF-2 status changes over time and evaluate whether IGF-2 status is a predictor of colon cancer. Patients will be enrolled at Johns Hopkins Hospital and at the Cleveland Clinic Foundation in Ft. Lauderdale, Fla.

"We've long suspected that genomic changes underlie cancer risk, but that knowledg
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Contact: Joanna Downer
jdowner1@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
9-Sep-2005