Study: Colonoscopy alternative effective but far from perfect

A LONG-AWAITED US federal study of an X-ray alternative to the dreaded colonoscopy confirms its effectiveness at spotting most cancers but points out it is far from perfect.

Some experts believe this potentially cheaper, less intrusive option may boost the 50% screening rate for a cancer that is the country’s second-biggest killer.

“We’re talking about, for the first time really, screening the population,” said Dr Carl Jaffe, an imaging expert at the National Cancer Institute who was not involved in the research.

In the study, the largest of its kind, the so-called “virtual colonoscopy” identified nine out of 10 people who had cancers and large growths seen by regular colonoscopies.

But there were flaws, too. Among them: The radiologists sometimes misread the X-ray, leading them to spot polyps that weren’t there. That lead to unnecessary follow-up testing.

The X-ray test’s real value may be in showing who really needs a regular colonoscopy — it was better at ruling cancer out than it was at detecting it, suggests the report in yesterday’s New England Journal of Medi-cine.

Colorectal cancer will claim about 50,000 lives in the US this year. The point of screening, widely recommended at age 50, is to find growths before they turn cancerous.

The gold standard is colonoscopy, in which a long, thin tube equipped with a small video camera is snaked through the large intestine to view the lining. Any growth can be removed during the procedure.

It involves sedation and a missed day of work, not to mention preparation that uses pills or liquids to clean out the bowel.

The study focused on CT colonography, also known as virtual colonoscopy. It’s a super-X-ray of the colon that is quicker, cheaper and easier on the patient than traditional colonoscopies.

It, too, requires the bowel clean-out and has a potentially serious drawback — radiation.

Colonoscopies cost up to $3,000 (€2,085). The X-ray test costs $300 (€208) to $800 (€556); most insurers don’t cover it so far, but Medicare is considering it.

Insurers would probably weigh the study heavily in their coverage decisions, said Dr Durado Brooks of the American Cancer Society.