Virtual biopsy may identify between harmless and precancerous bowel lesions

In collaboration with the Press Association

It may soon be possible for doctors to investigate potentially pre-cancerous bowel lesions or 'polyps' without removing them, scientists have said.

A team at Florida's Mayo Clinic have published preliminary work suggesting that a probe system - called 'high resolution confocal endomicroscopy' - appears to be able to tell whether or not a polyp is likely to develop into cancer, without having to remove the growth for examination.

Currently, people who show symptoms of bowel cancer are referred for a colonoscopy, and any suspicious looking polyps are removed surgically for laboratory examination.

Study author Dr Michael Wallace, professor of medicine at Mayo Clinic, said that, although the system's accuracy needed fine-tuning, it could potentially be used during a colonoscopy so that harmless polyps are not removed unnecessarily.

"Today, half of all polyps surgically removed during colonoscopy procedures are benign, and so this virtual biopsy will save time and expense and reduce complications that can occur," he explained.

"This will shift our role from one of going in and getting tissue for a pathologist to examine to one in which we can do the pathology ourselves. This is instantaneous, real time pathology."

The device consists of a tiny imaging tool that can be attached to an endoscope during a colonoscopy.

Polyps that look suspicious can be illuminated and magnified by 1,000 times, enabling doctors to observe the polyp so closely that they would be able to see a single red blood cell moving through a blood vessel.

When tested on 37 polyps within 25 patients, the probe was found to be 98 per cent accurate in identifying lesions that were not cancerous and did not need to be removed.

Lead research fellow Dr Anna Buchner, who is due to present the findings at the Digestive Disease Week meeting in San Diego, commented: "That is what you want in a device like this.

"Removing a polyp that looks precancerous, but turns out to be benign, is okay, but you don't want to leave polyps intact in the colon that are actually cancerous," she explained.

"This probe is almost perfectly reliable in that regard and with more experience I am sure we can improve accuracy to nearly 100 per cent."