WEDNESDAY, May 23, 2007 (HealthDay News) -- Experience is key to successful colonoscopies, and doctors who perform these procedures need to do more than 150 before they become proficient.
So concludes of one of several studies on colon cancer, the results of which were outlined in a special news conference Wednesday at the annual Digestive Disease Week conference, in Washington, D.C.
Some other findings: Increased risk of colon cancer in men is linked with high levels of the blood inflammatory marker C-reactive protein; discomfort during colonoscopy among the elderly is a myth; newer high-resolution colonoscopes miss cancers at the same rate as standard scopes; and sedation and thorough bowel-cleansing make for a successful colonoscopy.
In the first study, Dr. S. Lee, from Soon Chun Hyang University, Cheonan, South Korea, and colleagues looked at the results of more than 3,700 colonoscopies.
They found that overall, more than 79 percent were completed successfully. However, for those doctors who had performed more than 150 colonoscopies, the success rate jumped to 97.1 percent.
Moreover, among those doctors who had done more than 150 procedures, the time needed to insert the colonoscope tube into the bowel dropped from 14.2 minutes to just under 10 minutes.
"We suggest that the minimum number of procedures to attain technical competency is more than 150," Lee said.
In another study, Dr. H. Chiu, from the Department of Internal Medicine at the National Taiwan University Hospital, and colleagues measured blood levels of C-reactive protein, an indication of inflammation, in almost 6,700 people who had undergone colonoscopy.
Chiu's team found that C-reactive protein levels were significantly higher in men with colon cancer than in men who did not have the illness. However, this association was found only among men.
"These data support the crucial role of chronic inflammation in the development of colorectal cancer," Chiu said. "We can use C-reactive protein as a biomarker to differentiate a higher-risk group from a lower-risk group," he added.
In a third presentation, Dr. K. P. Patel, from the gastroenterology unit at Hammersmith Hospital Campus, Imperial College Faculty of Medicine, London, reported that poor bowel preparation was the primary reason for failed colonoscopies among elderly patients -- not patient discomfort, as has been previously assumed.
Surveying the results of almost 2,000 colonoscopies, Patel's team found that 11.8 percent of patients under 75 had incomplete examinations. For those over 75, the rate of incomplete exams rose to 20.7 percent.
The main reason for the increased failure rate in the older patients was poor bowel preparation, which accounted for 42.5 percent of the unsuccessful exams. Before a colonoscopy, patients are required to fast and use laxatives to thoroughly clean the bowel.
Surprisingly, only 0.7 percent of colonoscopies in those over 75 were stopped due to discomfort, compared with 2.6 percent in the younger patients, Patel said.
"Contrary to popular belief, older patients tolerate the procedure better than younger patients," Patel said.
Dr. Berndt Birkner, a gastroenterologist from Munich, Germany, reported on the details of more than 145,000 colonoscopies. Two factors that made these procedures more successful include better bowel preparation and sedating patients, the researchers found.
"Our main message is that we have to control, and we have to secure, a good preparation for colonoscopy," Birkner said.
A final presentation compared the effectiveness of high-resolution colonoscopes with standard white light colonoscopes. Dr. R. M. Soetikno, and colleagues from Stanford University in Palo Alto, Calif., randomly assigned 240 patients to each procedure.
Soetikno's group found that the rate of missed cancers was the same whichever scope was used. The overall "miss rate" was 11 percent for tumors of any size and 3 percent for tumors 6 millimeters or larger.
"There was really no difference between the two arms of the study," Soetikno said "They were both the same."
For more information on colon cancer, visit the American Cancer Society.