Study Finds Possible Genetic Indicator of Colorec...(l of the National Cancer Institute rese...),Health

"The gene-based tests are based on the assumption that a tumor will shed cells into the stool," said Dr. Gad Rennert, who wrote a commentary on the study.

"These cells, when isolated from the stool which is collected at home, have genetic characteristics which can be identified and suggest that there is risk," said Rennert, director of the CHS National Israeli Cancer Control Center.

The researchers found that one genetic red flag indicated colon cancer 53 percent of the time in stool samples.

That may sound like a promising number. But it isn't strong enough to turn the test into a useful screening tool and is no better than current methods of testing for blood in the stool, Kopetz said.

In the future, however, genetic tests hold promise because they are cheaper and easier on patients than colonoscopies, Kopetz said. "If the stool-based test came back abnormal, then a patient would be referred for a colonoscopy," he said.

More information

The American Cancer Society has more on colorectal cancer.

SOURCES: Jerald Wishner, M.D., director, colorectal cancer program and colorectal surgery, Northern Westchester Hospital, Mount Kisco, N.Y.; Scott Kopetz, M.D., assistant professor, Department of Gastrointestinal Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston; Gad Rennert, M.D., Ph.D., director, CHS National Israeli Cancer Control Center, Haifa, Israel; June 17, 2009, Journal of the National Cancer Institute