Blood test for colon cancer promising: study

A simple blood test correctly identified most colorectal cancers in an early trial of the technology, offering the possibility of a convenient screening test that could be done during routine checkups, the company which developed it said on Wednesday.

The test, being developed by Danish biotech company Exiqon, worked well at both identifying colon cancers and at ruling them out, the company said at an American Association for Cancer Research meeting in Denver.

"Our test has the potential to be safe, cheap, robust, accurate and of little or no inconvenience to the individual," Soren Nielsen, the company's scientific manager of diagnostic product development, said in a statement.

Nielsen said the company is not looking to replace colonoscopy, the current gold standard test for colon cancer.

Instead, they hope it will be used as an initial screening tool to identify people who need further testing.

Belgian biotech firm OncoMethylome also has a colon cancer blood test, as does Exact Sciences Corp.

Colon cancer is the second biggest cancer killer in most countries behind lung cancer.

In standard colonoscopies, a tiny camera is threaded up through the rectum. The device has a little pair of clippers on the end to remove suspicious-looking growths called polyps so they can be tested to see if they might become cancerous.

U.S. health experts recommend regular colonoscopies for people starting at age 50 and the practice is credited with helping to lower the number of deaths from colon cancer from around 52,000 in 2007 to just under 50,000 people in 2009 in the United States.

PATIENTS SHUN INVASIVE TEST

But only about half of those who should get tested do, in part because the procedure is embarrassing, uncomfortable and can, in rare cases, cause injury.

"The problem with colonoscopy and other invasive tests is that people tend not to use them unless they have symptoms," Nielsen said in a telephone interview.

He said there are other screening tests available now that are less invasive than colonoscopy, including tests that require people to collect a tiny sample of their stool and send it to a lab. But he said people often will not even do that.

"What we're aiming for is something that can tell you whether you are likely to have colorectal cancer from a blood sample," Nielsen said.

The company's test screens for microRNAs, tiny bits of genetic material from tumors in the blood.

In the study, the team examined blood from both early stage colorectal cancer patients and healthy donors of similar ages.

The company is starting a large clinical trial in people who have cancer symptoms and are undergoing a colonoscopy.