Detecting diminutive colorectal lesions at colonoscopy: a randomised controlled trial of pan-colonic versus targeted chromoscopy. Chromoendoscopy detects more adenomas than colonoscopy using intensive inspection without dye spraying. Does chromoendoscopy with structure enhancement improve the colonoscopic adenoma detection rate? Postoperative surveillance in patients with colorectal cancer who have undergone curative resection: a prospective, multicenter, randomized, controlled trial. High resolution colonoscopy with chromoscopy versus standard colonoscopy for the detection of colonic neoplasia: a randomized study.
Diminutive and flat colorectal lesions can be difficult to detect using conventional colonoscopic techniques. Previous data have suggested that pan-chromoscopy may improve detection rates. No randomised control trial has been performed examining detection rates of such lesions while controlling for extubation time and lavage effect.
                We conducted a randomised controlled trial of pan-colonic chromoscopic colonoscopy for the detection of diminutive and flat colorectal lesions while controlling for extubation time and lavage effect.
                Consecutive patients attending for routine colonoscopy were randomised to either pan-chromoscopy using 0.5% indigo carmine (IC) or targeted chromoscopy (control group). A minimum diagnostic extubation time was set at eight minutes with controls undergoing a matched volume of saline wash.
                A total of 260 patients were randomised; 132 controls and 128 to pan-colonic chromoscopy. Extubation times did not differ significantly between the control (median 15 minutes (range 8-41)) and chromoscopy (median 17 minutes (range 8-39)) groups. The volume of IC used in the pan-chromoscopy group (median 68 ml (range 65-90)) and normal saline used in the control group (69 ml (range 60-93)) did not differ significantly. There was a statistically significant difference between the groups regarding the total number of adenomas detected (p<0.05) with significantly more diminutive (<4 mm) adenomas detected in the pan-chromoscopy group (p = 0.03). Pan-chromoscopy diagnosed more diminutive and flat lesions in the right colon compared with controls (p<0.05), with more patients with multiple adenomas (>3) detected using pan-chromoscopy (p<0.01). Hyperplastic lesions were more commonly detected in the pan-chromoscopy group compared with controls (p<0.001). More hyperplastic polyps were detected in the left colon (86% rectosigmoid) using chromoscopy compared with controls.
                Chromoscopy improves the total number of adenomas detected and enhances the detection of diminutive and flat lesions. Importantly, eight diminutive lesions had foci of high grade dysplasia. Chromoscopy may benefit patients, assuming a high risk of colorectal cancer, and help in risk stratification and planning follow up colonoscopy intervals. Conventional colonoscopy misses some neoplastic lesions. We compared the sensitivity of chromoendoscopy and colonoscopy with intensive inspection for detecting adenomatous polyps missed by conventional colonoscopy. Fifty subjects with a history of colorectal cancer or adenomas underwent tandem colonoscopies at one of five centers of the Great Lakes New England Clinical Epidemiology and Validation Center of the Early Detection Research Network. The first exam was a conventional colonoscopy with removal of all visualized polyps. The second exam was randomly assigned as either pan-colonic indigocarmine chromoendoscopy or standard colonoscopy with intensive inspection lasting >20 minutes. Size, histology, and numbers of polyps detected on each exam were recorded. Twenty-seven subjects were randomized to a second exam with chromoendoscopy and 23 underwent intensive inspection. Forty adenomas were identified on the first standard colonoscopies. The second colonoscopies detected 24 additional adenomas: 19 were found using chromoendoscopy and 5 were found using intensive inspection. Chromoendoscopy found additional adenomas in more subjects than did intensive inspection (44% versus 17%) and identified significantly more missed adenomas per subject (0.7 versus 0.2, P < 0.01). Adenomas detected with chromoendoscopy were significantly smaller (mean size 2.66 +/- 0.97 mm) and were more often right-sided. Chromoendoscopy was associated with more normal tissue biopsies and longer procedure times than intensive inspection. After controlling for procedure time, chromoendoscopy detected more adenomas and hyperplastic polyps compared with colonoscopy using intensive inspection alone. Chromoendoscopy detected more polyps missed by standard colonoscopy than did intensive inspection. The clinical significance of these small missed lesions warrants further study. Colonoscopy is still considered the standard investigation for the detection of colorectal adenomas, but the miss rate, especially for small and flat lesions, remains unacceptably high. Chromoscopy has been shown to increase the yield for lesion detection in inflammatory bowel disease. The aim of this randomized prospective study was to determine whether a combination of chromoscopy and structure enhancement could increase the adenoma detection rate in high-risk patients.
                All patients included in the trial had a personal history of colorectal adenomas and/or a family history of colorectal cancer (but excluding genetic syndromes). They were randomized to one of two tandem colonoscopy groups, with the first pass consisting of conventional colonoscopy for both groups, followed by either chromoscopy and structure enhancement (the "study" group) or a second conventional colonoscopy (the control group) for the second-pass colonoscopy. All detected lesions was examined histopathologically after endoscopic resection or biopsy. The principal outcome parameter was the adenoma detection rate; the number, histopathology, and location of lesions was also recorded.
                A total of 292 patients were included in the study (146 patients in each group). The patients' demographic characteristics, the indications for colonoscopy, and the quality of bowel preparation were similar in the two groups. There was a significant difference between the two groups with respect to the median duration of the examination (18.9 minutes in the control group vs. 27.1 minutes for the study group, P < 0.001). Although more hyperplastic lesions were detected throughout the colon in the study group ( P = 0.033), there was no difference between the two groups in either the proportion of patients with at least one adenoma or in the total number of adenomas detected. Chromoscopy and structure enhancement diagnosed significantly more diminutive adenomas (< 5mm) in the right colon, compared with controls ( P = 0.039).
                On the basis of our results we cannot generally recommend the systematic use of chromoscopy and structure enhancement in a high-risk patient population, although the detection of small adenomas in the proximal colon was improved. Although systematic postoperative surveillance of patients with colorectal cancer has been demonstrated to improve survival, it remains unknown whether a more intensive strategy provides any significant advantage. This prospective, multicenter, randomized, controlled trial was aimed at comparing the efficacy of two different surveillance strategies in terms of both survival and recurrence resectability.
                Patients with stage II or III colorectal cancer were allocated randomly to either a simple surveillance strategy including clinical evaluation and serum carcinoembryonic antigen monitoring, or an intensive strategy in which abdominal computed tomography or ultrasonography, chest radiograph, and colonoscopy were added.
                A total of 259 patients were included: 132 were observed according to the simple strategy and 127 were observed according to the intensive strategy. Both groups were similar with respect to baseline characteristics and rate and type of tumor recurrence. After a median follow-up of 48 months, there was no difference in the probability of overall survival in the whole series (hazard ratio [HR] = 0.87; 95% CI, 0.49 to 1.54; P = .62). However, the intensive strategy was associated with higher overall survival in patients with stage II tumors (HR = 0.34; 95% CI, 0.12 to 0.98; P = .045) and in those with rectal lesions (HR = 0.09; 95% CI, 0.01 to 0.81; P = .03), mainly due to higher rate of resectability for recurrent tumors. Colonoscopy was responsible for the detection of the highest proportion (44%) of resectable tumor recurrence in the intensive arm.
                A more intensive surveillance strategy improves the prognosis of patients with stage II colorectal cancer or those with rectal tumors. Inclusion of regular performance of colonoscopy seems justified up to the fifth year of follow-up, at least. High-resolution colonoscopy with chromoscopy (HRC) is a technique designed to improve the detection of colonic neoplasias. We prospectively compared standard colonoscopy (SC) and HRC in a randomized multicenter trial.
                Patients (n = 203; age, 58 +/- 10 years; sex ratio, 1) were recruited according to the following criteria: (1) a history of either familial or personal colonic neoplasia or (2) alarm symptoms after the age of 60 years. After randomization, an SC was performed in 100 patients (resolution, < or = 410,000 pixels) and a HRC in 103 patients (Fujinon EC485ZW, 850,000 pixels). In the HRC group, each colonic segment was examined before and after spraying with indigo carmine 0.4%.
                Two hundred seventy-six polyps were detected in 198 patients. One hundred sixty of them were hyperplastic polyps, 116 were adenomas, and 2 were carcinomas. The numbers of hyperplastic polyps and purely flat adenomas were significantly higher in the HRC group than in the SC group (1.1 +/- 1.6 vs 0.5 +/- 1.4 and 0.22 +/- 0.68 vs 0.07 +/- 0.29, respectively; P = .01 and P = .04), but there was no significant difference in the total number of adenomas per patient (primary end point) detected between the HRC and the SC groups (0.6 +/- 1.0 vs 0.5 +/- 0.9, respectively).
                Although HRC improves detection of purely flat adenomas and hyperplastic polyps, the overall detection of colonic adenomas in a population at increased risk of neoplasia is not significantly improved. These findings do not support the routine use of HRC in clinical practice.
There appears to be strong evidence that chromoscopy enhances the detection of neoplasia in the colon and rectum. Patients with neoplastic polyps, particularly those with multiple polyps, are at increased risk of developing colorectal cancer. Such lesions, which presumably would be missed with conventional colonoscopy, could contribute to the interval cancer numbers on any surveillance programme.