Gene-Based Blood Test for Colon Cancer Shows Promise

Early trial supports accuracy of the screening, which could be a boon in preventing the disease

By Robert Preidt

HealthDay Reporter

WEDNESDAY, June 19 (HealthDay News) -- Could screening for colon cancer someday be as easy as having a blood test? Researchers say just such a test is showing early promise in trials.

The screening checks for levels of miR-21 -- a piece of DNA known as microRNA. Researchers in the gastrointestinal cancer research lab at the Baylor Research Institute in Dallas studied several hundred patients with either colorectal polyps (noncancerous growths that often precede cancer) or full-blown cancer.

They found that measuring levels of miR-21 in the blood accurately spotted up to 92 percent of patients with colorectal cancer.

The test also accurately identified up to 82 percent of patients with advanced colorectal polyps -- growths that put people at high risk of developing colorectal cancer.

The study was published June 19 in the Journal of the National Cancer Institute.

"This blood-based test could be transformative in how we screen patients for colorectal cancer; it would save lives and could result in major savings of health care dollars," Dr. Michael Ramsay, president of Baylor Research Institute, said in an institute news release.

Other experts were cautiously optimistic.

"These results are very promising for the future of cancer screening and treatment," said Dr. Jerald Wishner, director of colorectal surgery at Northern Westchester Hospital in Mount Kisco, N.Y.

"Colonoscopy screening is the current gold standard to detect colon cancer. However, less than 50 percent of Americans who should be screened get screened," Wishner said. "The blood test is a less invasive screening method that will eliminate barriers to colonoscopies, including embarrassment and possible discomfort in preparation for the test."

Dr. David Robbins, associate chief of endoscopy at Lenox Hill Hospital in New York City, agreed that it is "only a matter of time before we can screen for the most common, and most lethal, cancers using a simple blood test."

"This well-designed study brings us one step closer to the holy grail of colon cancer eradication by identifying those at high risk for developing colon cancer by measuring a pretty straightforward genetic signature," Robbins said.

According to the American Cancer Society, colon cancer is the second leading cancer killer, after lung cancer. More than 102,000 new cases of the disease will be diagnosed among Americans this year, and almost 51,000 people will die from the disease in 2013.

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