Researchers in Saskatchewan are hoping to determine if a simple blood test can detect colorectal cancer risk.

A new screening research trial supported by the Saskatchewan Health Department is scheduled to begin in the next two weeks.

The Saskatchewan Cancer Agency and Phenomenome Discoveries have collaborated to develop a clinical trial protocol to evaluate the company's new serum test for colorectal cancer risk screening, discovered at Phenomenome's lab in Saskatoon.

Five thousand patients will be recruited for the two-year trial. All patients undergoing a colonoscopy procedure will be asked to volunteer some medical history and two blood samples, which will be analyzed at the Saskatchewan Disease Control Laboratory using Phenomenome's new risk screening test.

Results of the blood test and colonoscopy will be compared and the cancer agency will assess the utility of the blood test as a pre-colonoscopy screening tool. Results will be available in late 2009.

"This blood test gives great promise to be able to identify with great accuracy a segment of the population at high risk for development of colon cancer at a stage where intervention would either prevent or cure the cancer," said Dr. James McHattie, head of gastroenterology for the Regina Qu'Appelle Health Region and the lead clinical investigator on the trial.

Phenomenome's test detects a metabolite called gTA, which studies have shown is deficient in the blood of up to 90 per cent of people with colorectal cancer.

"It is through collaboration with the trial's sponsoring agencies that we've been able to undertake the most extensive evaluation of colon pathology and metabolic risk factors in history," said Dr. Dayan Goodenowe, president and CEO of Phenomenome Discoveries.

Ontario screens for colon cancer using a fecal occult blood test, which looks for minute amounts of blood in stool samples. The blood could signal the presence of polyps that are bleeding, which in turn could be early colorectal cancer.

Although the fecal occult blood test has a significant false-positive rate — meaning not all positive tests turn out to be cancer — the procedure is considered effective and cost-efficient enough to be a first step.

People who test positive go for diagnostic colonoscopies.