SAN DIEGO — High-definition chromocolonoscopy did not significantly increase detection of adenomas, compared with high-definition white light colonoscopy, in a randomized, multicenter study of 660 patients.
In average-risk patients aged 50 years or older undergoing first-time screening colonoscopy, at least one adenoma was seen in 55.5% of 321 patients using chromocolonoscopy and in 48.4% of 339 patients using white light colonoscopy. The 7.1 percentage point increase in the detection rate did not reach statistical significance (P value, 0.07), Dr. Charles J. Kahi and his associates reported at the annual meeting of the American College of Gastroenterology.
Chromocolonoscopy detected an average of 1.3 adenomas per patient, and white light colonoscopy detected an average of 1.1 adenomas per patient, a difference that again was not statistically significant (P value, 0.07), said Dr. Kahi of Indiana University, Bloomington.
There was a modest, statistically significant increase in detection of small (less than 5 mm) or flat adenomas and detection of non-neoplastic lesions using chromocolonoscopy. High-definition chromocolonoscopy detected an average of 0.6 flat adenomas per patient, 0.8 small adenomas per patient, and 1.8 non-neoplastic lesions per patient, compared with 0.4 flat adenomas, 0.7 small adenomas, and 1.0 non-neoplastic lesions per patient with high-definition white light colonoscopy (P values, 0.01, 0.03, and less than 0.0001, respectively).
The two techniques did not differ significantly in detection of advanced adenomas (0.06 per patient with chromocolonoscopy and 0.04 per patient with white-light colonoscopy) or detection of advanced adenomas smaller than 10 mm in size (0.02 per patient with chromocolonoscopy and 0.01 per patient with white light colonoscopy).
Overall, these findings do not support the routine use of high-definition chromocolonoscopy for colorectal cancer screening in average-risk patients, Dr. Kahi said.
In general, flat and depressed colon neoplasms are easy to miss on colonoscopy, he noted, but awareness is increasing that they are precursors for colorectal cancer in Western populations. Flat or depressed lesions are more difficult to visualize than polypoid lesions with conventional colonoscopy and are more likely to contain high-grade dysplasia or invasive carcinoma.
The mean procedure time was significantly longer in the chromocolonoscopy group (31 minutes) compared with the white light colonoscopy group (22 minutes), and the mean dose of the sedative propofol was significantly higher in the chromocolonoscopy group (345 mg) than with white light (297 mg).
Dr. Kahi reported having no conflicts of interest related to this study.
Chromocolonoscopy detected an average of 1.3 adenomas per patient; white light colonoscopy detected 1.1.
Source DR. KAHI