New Colorectal Cancer Screening Test Has Fewer False Positives

A new screening test under development for colorectal cancer has the potential to detect 43 percent more cancers than the fecal occult blood test when used as a first-line screen, according to researchers.

The ColorectAlert test detects a cancer-associated sugar in a sample of rectal mucus collected by a doctor using a digital rectal exam. The sample is placed on a small card and treated with chemicals that produce a color-change reaction. The color change is read with a highly sensitive spectrophotometer, which produces a number indicating the presence or absence of the sugar.

Two clinical trials using ColorectAlert are underway involving 1,250
individuals. An earlier study of 669 patients compared ColorectAlert with the fecal occult blood test, and showed that ColorectAlert produces significantly fewer false-positive results without compromising sensitivity.

"ColorectAlert produces fewer false positive results, so fewer people go on to have unnecessary colonoscopies," said Elaine McKenzie, Principal Consultant with Applied Management Consultants Ltd., who presented results of a comparative study of the two screening approaches to the Canadian Association for Population Therapeutics.

"FOBT looks for blood in the stool, but blood is often present in
stool for reasons other than cancer. These false-positive results require a follow-up colonoscopy to confirm the absence of colorectal cancer," McKenzie added.

Other sources: International Medical Innovations