WASHINGTON, March 13: A simple blood test may be able to predict who is at risk of colon cancer — offering a way to avoid the embarrassing ordeal of a colonoscopy, U.S. researchers said on Thursday.

They found a single genetic change that was much more common in people with a family history of colon cancer — and extremely common in people diagnosed with colon cancer.

The researchers said more studies must be done to ensure results are consistent, but they hope they have found a simple and accurate way to screen a healthy population for colon cancer.

“There are screening tests for cancers with rare family syndromes,” Dr. Andrew Feinberg of Johns Hopkins University in Baltimore, who led the study team, said in a telephone interview. An example is the breast cancer gene BRCA1, which causes perhaps 5 percent of all inherited breast cancers.

“And there are tests to screen for the presence of cancer, like the PSA test, for example,” he added — referring to the prostate specific antigen test that can show prostate cancer.

“But there are no tests for just screening the population to identify people who have a genetic risk of cancer.”—Reuters