Blood test could reduce colonoscopies

Johns Hopkins University researchers are developing a simple blood test that can help doctors determine who needs a colonoscopy, a screening procedure for colon cancer recommended for all adults over 50 – but one considered so unpleasant that many avoid it.

The new test, which looks for cancer-related proteins in the blood, identifies colon cancer and precancerous polyps almost as well as a colonoscopy, according to a study published in the journal Cancer Research.

The authors say their test won’t replace colonoscopies but might provide a noninvasive means of identifying high-risk patients – and an incentive for them to undergo the more invasive procedure.

“Part of what we are trying to do here is use blood markers for cancer like we do cholesterol levels to predict heart disease risk,” said Robert H. Getzenberg, a cancer researcher at the Johns Hopkins School of Medicine. “If I could tell you you have a 92 percent chance of having colon cancer, you might be more willing to undergo a colonoscopy.”

The blood test might also reduce the overall number of people who need a colonoscopy by screening out low-risk patients.