NEW YORK -- Screening patients for colon cancer using a special type of endoscope -- a flexible lighted tube -- that magnifies the bowel may be better than using the standard approach, according to a recent report.

A more accurate assessment of risk could potentially eliminate many unneeded colonoscopies, resulting in major cost savings.

Magnification endoscopy allows the detection of clusters of abnormal cells -- dysplastic aberrant crypt foci (ACF) -- a marker for colon cancer not seen with standard colonoscopy. Adding the ACF findings to standard results could, in theory, improve risk assessment and surveillance recommendations.

The special type of colonoscopy, which is offered at only a few centers worldwide, uses a combination of optical and digital techniques to magnify the colon 70 times. Although a special preparatory regimen is needed, the actual procedure takes about the same time as standard colonoscopy. "The magnification allows us to see things at almost the cellular level," Dr. Richard Benya, an internist who is using the device at the University of Illinois at Chicago, told Reuters Health. "This allows us to see structures that really haven't been visualized before -- that's the real value of it."

"The current paradigm for colorectal cancer screening is to evaluate for the presence of polyps and remove them," Dr. Benya noted. "The problem is that less than 5% of all polyps go on to become cancer." However, once patients have a polyp removed, they are advised to return every 3 to 5 years for repeat evaluation.

"I'm not entirely convinced that this is the best way or the most cost-effective way to do business," he emphasized. Evaluation with a magnification endoscope could potentially improve the screening process, eliminating unneeded exams, Dr. Benya noted. "For example, someone with very little ACF probably needs minimal surveillance, while someone with a lot of ACF probably needs close surveillance." Because this approach is relatively new, there are no long-term studies that assess how well it predicts cancer, Benya said. "Still, based on pathologic findings, we know that ACFs are increased in patients whose colon was removed for cancer rather than for other reasons."

Dr. Benya added that, with further testing, magnification endoscopy could become the gold standard for determining a person's colon cancer risk.