Colonoscopy polyp detection benchmarks could be too low

Screening benchmarks for detecting polyps during colonoscopies may be too low, according to a study published online this month in the journal Gastrointestinal Endoscopy.

Current guidelines set the adenoma rate at 15 percent for women and 25 percent in men for those individuals with an average risk of colorectal cancer. In this study, however, researchers at the Mayo Clinic in Florida using high-definition endoscopic tools to screen 2,400 individuals achieved adenoma detection rates of 25 percent for women and 41 percent for men.

"Our study suggests that national benchmarks may be too low given our increasing ability to find polyps using the high-definition colonoscopy tools that a majority of physicians use today," Michael Wallace, M.D., chief of the division of gastroenterology and hepatology at Mayo Clinic in Florida, said in an announcement. "We want to be able to detect all polyps that may turn cancerous, and our study shows these polyps may be more prevalent than had been recognized at the time national standards were drafted.

"While many of the polyps we found were small, and we cannot say that they would have turned cancerous, our goal as gastroenterologists and physicians is to detect and remove all potentially precancerous polyps."

Researchers also found a higher rate of advanced polyps (larger than 1 centimeter in size or those with a more advanced pre-cancerous pathology) in both men and women. These advanced polyps were found in 8.7 percent of women and 15 percent of men.

"Studies using older, lower definition colonoscopy screening technology had put detection rates of those kinds of polyps at about 5 percent, so our findings suggest that rate should also be higher," Wallace said.

To learn more:
- see the study abstract
- read the announcement