Chromoendoscopy Technique Research Articles

Virtual indigo carmine dyeing: New artificial intelligence-based chromoendoscopy technique.

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How to assess endoscopic disease activity in ulcerative colitis in 2022.

Endoscopic remission currently represents an important therapeutic goal to reach in the management of patients with ulcerative colitis (UC). The diagnostic and prognostic role of endoscopy, which remains the gold standard for the assessment of disease activity, has been widely reported. Despite being unvalidated and suboptimal at measuring remission, the most widely used scoring system is the Mayo endoscopic subscore (MES). The UC Endoscopic Index of Severity and the UC Colonoscopic Index of Severity represent recent performing indices for the assessment of endoscopic disease activity in the field of white-light endoscopy. However, their use is still very limited, both in trials and clinical practice. The most recent Paddington international virtual chromoendoscopy score was the first validated index to assess vascular and mucosal features in UC using a virtual chromoendoscopy technique and showed good performance. This narrative review aims to describe these validated endoscopic scoring indices, focusing on the development methodology, and the strengths and weaknesses of each one in comparison with the MES for the assessment of UC activity.

Sa2044 DEVELOPMENT AND INITIAL EVALUATION OF THE VALID-CLASSIFICATION FOR PREDICTION OF COLORECTAL POLYP HISTOLOGY – A MULTICENTER INTERNATIONAL TRIAL

The recently introduced VIST chromoendoscopy technique allows for detailed analysis of surface and vascular pattern morphology. The aim of this study was to create a new and unique classification for differentiating colorectal polyps using the VIST technology and to assess its interobserver concordance. In addition, we aimed to evaluate the accuracy of the new classification for optical diagnosis and histology prediction of colon polyps. A digital library containing 26 videos/still images from 26 histologically confirmed polyps with VIST was first evaluated by seven endoscopists from five different countries in order to identify possible descriptors. In the second step, the descriptors were categorized using a modified Delphi methodology to propose the VALID-classification. In the third step, the seven endoscopists independently reviewed a new dataset comprising of 45 videos/still images, and provided for each a diagnosis based on the VALID-classification. The interobserver agreement of the VALID-classification’s individual descriptor was then assessed, and its accuracy in predicting colorectal polyp histology was evaluated. Using a modified Delphi process, the endoscopists agreed on summarizing 8 descriptors into three main domains. Those include polyp surface pattern morphology (regular, yes/no; irregular, yes/no; ulcerated, yes/no), and pit pattern morphology (regular, yes/no; tubular appearance, yes/no; villous appearance, yes/no; tubulovillous appearance, yes/no, no pits visible yes/no). Interobserver reliability calculated in Gwet’s AC1 for the polyp surface and pit pattern morphology were 0.78 (0.57,0.82, 95%CI, the same as below) and 0.56 (0.46,0.67) respectively. The accuracy of the classification in predicting diagnosis (Non-neoplasia, Adenoma and Cancer) was 0.90 (0.84, 0.94), while the one in predicting the histology type (Hyperplastic Polyp, Tubular Adenoma, Tubulovillous Adenoma, Villous Adenoma and Cancer) was 0.70 (0.63, 0.77). The new VALID-classification was developed allowing for prediction of colorectal polyp histology using the newly introduced VIST-chromoendoscopy technique. A good concordance was shown among the observers and a rather high accuracy of the VALID-classification has also been demonstrated in the initial video/still-image evaluation. Further in vivo trials are required to validate this new classification in a clinical setting.

Clinical Validation of BASIC Classification for the Resect and Discard Strategy for Diminutive Colorectal Polyps

Blue-light imaging (BLI) is a chromoendoscopy technique that uses direct (not filtered) emission of blue light with short wavelength (410 nm) to increase visibility of microvascular pattern and superficial mucosa. A BLI-based classification system for colorectal polyps (also called BLI Adenomas Serrated International Classification, BASIC) has been created and was validated using still images or short videos. We aimed to validate BASIC in a clinical practice setting, using thresholds recommended by the American Society for Gastrointestinal Endoscopy for the resect and discard strategy as the reference standard. We studied 333 patients (mean age, 62.7±8.1 y; 176 men) who underwent screening colonoscopy from January through July 2019. Six endoscopists trained in BASIC participated in the study. All detected diminutive polyps were characterized by real-time BLI and categorized as adenoma or non-adenoma according to BASIC. All polyps were removed and evaluated by histopathology. The BLI-directed surveillance intervals (based on high-confidence characterization of polyps 5 mm or smaller and pathology feature for others) were compared with histology-directed surveillance intervals, according to United States Multi-society Task Force and European Society of Gastrointestinal Endoscopy recommendations. We calculated negative-predictive values of optical real-time analysis of diminutive rectosigmoid adenomas. When we applied BASIC, 748 polyps smaller than 5 mm were categorized with 89% accuracy (95% CI, 85.9%-90.6%). BLI-directed surveillance was correct for 90% of patients according to the United States Multi-society task force criteria (95% CI, 86%-93%) and for 96% of patients according to European Society of Gastrointestinal Endoscopy criteria (95% CI, 93%-97%). The negative-predictive value for 302 polyps smaller than 5 mm, located in the rectosigmoid colon and evaluated with high confidence, based on histologic features of adenomatous polyps, was 91% (95% CI, 85%-95%). Our analysis of data from 333 patients undergoing screen colonoscopies supports the validity of BASIC discriminating diminutive colorectal polyps with histologic features of adenomas from non-adenomas. This allows for the implementation of the resect and discard strategy based on BLI in clinical practice. ClinicalTrials.gov no: NCT03746171.

Blue-light imaging compared with high-definition white light for real-time histology prediction of colorectal polyps less than 1 centimeter: a prospective randomized study

Blue-light imaging (BLI) is a new chromoendoscopy technique, potentially useful for differentiating neoplastic from nonneoplastic lesions. The present study was aimed at comparing BLI with high-definition white light (HDWL) in the real-time histology prediction of colon polyps<10mm. Consecutive outpatients undergoing colonoscopy with the ELUXEO 7000 endoscopy platform and 760 series video colonoscopes (Fujifilm Co, Tokyo, Japan) who had at least 1 polyp<10mm were randomized to BLI or HDWL for polyp characterization. The accuracy of high-confidence real-time histology prediction (adenoma vs not adenoma) by either BLI or HDWL for polyps<10mm (primary end-point) and diminutive (≤5mm) polyps was calculated, along with sensitivity, specificity, and positive and negative predictive values, with histopathology as the reference standard. A total of 483 polyps were detected in 245 randomized patients (125 and 120 in the BLI and HDWL arms, respectively). A total of 358 were diminutive, and 283 were adenomas. Overall, 222 (85.7%) and 193 (86.1%) polyps were characterized with high confidence by BLI and HDWL, respectively (P= .887), with an overall accuracy of 92% and 84%, respectively (P= .011). The accuracy was significantly higher by BLIthan HDWL, also for diminutive polyps (92% vs 83%; P= .008). When BLI was used, the negative predictive value for diminutive rectosigmoid polyps was 88%, and the post-polypectomy surveillance interval wascorrectly attributed in 85.7% and 93.7% of patients, respectively, according to U.S. and European guidelines. BLI was superior to HDWL for the real-time prediction of histology in polyps<10mm. A BLI-dedicated classification might further improve the endoscopist performance. (Clinical trial registration number: NCT03274115.).

Chromoendoscopy for Dysplasia Surveillance in Inflammatory Bowel Disease.

Long-standing ulcerative colitis (UC) and extensive Crohn's colitis confer increased risk for development of colorectal cancer. Screening and surveillance colonoscopy programs aim to identify, resect, or detect dysplasia or colorectal cancer. Dysplastic lesions can be removed by endoscopic resection and patients with unresectable lesions can be referred for colectomy at an earlier stage, with the goal of reducing overall morbidity and mortality from colorectal cancer. Surveillance colonoscopy for patients with inflammatory bowel disease (IBD) is endorsed by multiple specialty societies. High-definition endoscopy systems provide improved image resolution, and application of dilute indigo carmine or methylene blue for chromoendoscopy can provide increased contrast. International specialty society guidelines differ in their recommendations regarding use of chromoendoscopy for dysplasia surveillance, with some guidelines advocating a risk-stratified surveillance strategy. In this review, we discuss chromoendoscopy technique, training, implementation, yield as compared with standard-definition and high-definition white light colonoscopy, and positioning of this technique in clinical practice.

Optimizing the quality of endoscopy in inflammatory bowel disease: focus on surveillance and management of colorectal dysplasia using interactive image- and video-based teaching

Varying recommendations regarding the detection and management of dysplasia can lead to uncertainty and may impede the uptake of strategies that could improve surveillance in patients with inflammatory bowel disease (IBD). An educational event was held to assist in disseminating the recently published Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients: International Consensus Recommendations (SCENIC). Specialists in IBD and endoscopy led the Optimizing Quality of Endoscopy in IBD course. The American Society for Gastrointestinal Endoscopy (ASGE) organized the course, and the Crohn's and Colitis Foundation of America (CCFA) provided endorsement. One was held in March 2015 at the ASGE Institute for Training and Technology in Chicago, Illinois, and the second in September 2016 preceding the ASGE Endofest in Chandler, Arizona. The program included interactive case-based discussions and didactic presentations on topics including the rationale and current approach of surveillance in IBD; endoscopic characterization and nomenclature of active and quiescent disease; detection of dysplasia during IBD surveillance; role of image-enhanced endoscopy in IBD surveillance, with a focus on chromoendoscopy technique; and management of dysplasia in IBD. Participants were surveyed before and after the course to assess their perspectives and practice. Eighteen presenters or panel members and approximately 92 IBD and endoscopist physician leaders attended the meeting. Most attendees were aged 30 to 49 years (88.1%), had been in practice less than 10 years (89.7%), were from academic medical centers (90.7%), and spent >50% of their time caring for patients with IBD (59.7%). Recommended quality improvements for endoscopy in IBD included the use of endoscopic scoring systems to describe disease activity, the use of a modified Paris classification to characterize visible dysplastic lesions (polypoid, nonpolypoid with description of presence of ulcer and distinct or indistinct borders), the use of chromoendoscopy for dysplasia detection, and the endoscopic removal of visible dysplastic lesions. In the follow-up survey, participants were asked to indicate whether they had changed their practice as a result of attending the course. Ninety-three percent (93%) indicated they had changed their practice. For dysplasia detection, the use of chromoendoscopy increased: 51.7% of respondents reported using chromoendoscopy in most surveillance colonoscopies compared with 34.3% before the course. For dysplasia management, the use of EMR increased for polypoid and nonpolypoid lesions 10 to 20mm in size; and the referral of dysplastic lesions 20mm or larger that appeared endoscopically resectable shifted toward removal by an experienced endoscopist. Evidence-based advances in endoscopy have occurred in the characterization and nomenclature of active and quiescent disease, polypoid and nonpolypoid dysplasia in IBD, and in the detection and management of dysplasia in colonic IBD. Implementation of updated guidelines and recommendations into clinical practice may be facilitated by interactive image- and video-based courses on the topic.

Efficacy Evaluation of SAVE for the Diagnosis of Superficial Neoplastic Lesion.

The detection of non-polypoid superficial neoplastic lesions using current standard of white light endoscopy surveillance and random biopsy is associated with high miss rate. The subtle changes in mucosa caused by the flat and depressed neoplasms often go undetected and do not qualify for further investigation, e.g., biopsy and resection, thus increasing the risk of cancer advancement. This paper presents a screening tool named the saliency-aided visual enhancement (SAVE) method, with an objective of highlighting abnormalities in endoscopic images to detect early lesions. SAVE is a hybrid system combining image enhancement and saliency detection. The method provides both qualitative enhancement and quantitative suspicion index for endoscopic image regions. A study to evaluate the efficacy of SAVE to localize superficial neoplastic lesion was performed. Experimental results for average overlap index >0.7 indicated that SAVE was successful to localize the lesion areas. The area under the receiver-operating characteristic curve obtained for SAVE was 94.91%. A very high sensitivity (100%) was achieved with a moderate specificity (65.45%). Visual inspection showed a comparable performance of SAVE with chromoendoscopy to highlight mucosal irregularities. This paper suggests that SAVE could be a potential screening tool that can substitute the application of burdensome chromoendoscopy technique. SAVE method, as a simple, easy-to-use, highly sensitive, and consistent red flag technology, will be useful for early detection of neoplasm in clinical applications.

Importance of Chromoendoscopy and ESD Technique in an IBD Patient: 2016 ACG Presidential Poster Award

Importance of Chromoendoscopy and ESD Technique in an IBD Patient: 2016 ACG Presidential Poster Award

Virtual chromoendoscopy improves the diagnostic yield of small bowel capsule endoscopy in obscure gastrointestinal bleeding

BackgroundSmall bowel capsule endoscopy represents the initial investigation for obscure gastrointestinal bleeding. Flexible spectral imaging colour enhancement (FICE) is a virtual chromoendoscopy technique designed to enhance mucosal lesions, available in different settings according to light wavelength – FICE1, 2 and 3. AimsTo compare the diagnostic yield of FICE1 and white light during capsule endoscopy in patients with obscure gastrointestinal bleeding. MethodsRetrospective single-centre study including 60 consecutive patients referred for small bowel capsule endoscopy for obscure gastrointestinal bleeding. Endoscopies were independently reviewed in FICE1 and white light; findings were then reviewed by another researcher, establishing a gold standard. Diagnostic yield was defined as the presence of lesions with high bleeding potential (P2) angioectasias, ulcers or tumours. ResultsDiagnostic yield using FICE1 was significantly higher than white light (55% vs 42%, p=0.021). A superior number of P2 lesions was detected with FICE1 (74 vs 44, p=0.003), particularly angioectasias (54 vs 26, p=0.002), but not ulcers or tumours. ConclusionsFICE1 was significantly superior to white light, resulting in a 13% improvement in diagnostic yield, and potentially bleeding lesions particularly angioectasias were more often observed. Our results support the use of FICE1 while reviewing small bowel capsule endoscopy for obscure gastrointestinal bleeding.

Present and future perspectives of virtual chromoendoscopy with i‐scan and optical enhancement technology

Despite being the current gold standard, white-light endoscopy may miss a significant proportion of lesions within the colorectum, thus leading to a misinterpretation of various disease findings. Traditionally, dye-based chromoendoscopy is used to improve both detection and characterization of lesions during luminal gastrointestinal (GI) endoscopy. Recently introduced dye-less chromoendoscopy (DLC) techniques have overcome many of the limitations of dye-based chromoendoscopy, thereby potentially improving lesion recognition and characterization. In detail, DLC techniques allow for better detection of esophageal lesions, gastric cancer and colorectal pathologies including colorectal polyps and inflammatory bowel diseases. Moreover, DLC techniques enable a more precise characterization of lesions throughout the whole luminal GI tract, thereby potentially enabling more accurate endoscopic therapies. In the present review we focus on the newly introduced dye-less chromoendoscopy technique i-scan and give an additional outlook on the recent development of optical enhancement technology.

Indigo Carmine Staining Increases the Yield for Dysplasia in Ulcerative Colitis among Inexperienced Endoscopists: Implementation of a Chromo-endoscopy Program

Purpose: Previous studies have shown that chromoendoscopy increases the yield for dysplasia in ulcerative colitis (UC) among experienced endoscopists. The aim of this study was to determine if the yield of dysplasia in patients with longstanding UC could be increased among endoscopists with no experience in this technique through the introduction of a chromoendoscopy program. Methods: Patients with longstanding UC presenting for routine surveillance colonoscopy were enrolled at 3 sites with visualization of the colon by white light endoscopy (WLE) followed by indigo carmine staining (IC). Prior to study initiation, 6 endoscopists who performed the colonoscopies were instructed on chromoendoscopy technique and image interpretation. Lesion size, morphology (pedunculated, flat or sessile), location, histology and modality that detected the abnormality (WLE or IC) were recorded. Standard surveillance biopsies were also obtained. Incremental yield of IC staining for all dysplastic lesions and flat dysplastic lesions on a per-patient and per-lesion basis was calculated. We set a clinically important incremental increase in dysplasia detection with IC of over 20% for statistical comparisons. Results: Seventy-five patients were enrolled across three sites (Florida: 38, Arizona: 24, Minnesota: 13). A total of 157 lesions were identified (WLE: 78, IC: 79), the majority of which were non-dysplastic (85%). Non-dysplastic lesions consisted of 89 pseudopolyps (57%) and 45 hyperplastic polyps (29%). Under WLE, 7 patients (9.3%) had at least 1 dysplastic lesion and with IC, 9 additional patients (12%) had at least 1 dysplastic lesion resulting in 16 patients (21%) having a dysplastic lesion. Among the 75 patients, 10 dysplastic lesions were detected with WLE (LGD, 3; HGD, 2; adenoma, 5) and an additional 12 dysplastic lesions were found with IC (LGD, 3; adenoma, 9) resulting in 22 dysplastic lesions found. Only 1 flat dysplastic lesion was identified with WLE, yet an additional 7 flat dysplastic lesions were found with IC resulting in 8 found overall. For all dysplastic lesions detected through WLE and IC the median size was 4.5 mm. IC staining resulted in a significant increase in detection of all dysplastic lesions and flat dysplastic lesions well in excess of what would be expected from a repeat WLE (Table).Table: Increase in UC dysplasia detection with chromoendscopyConclusion: Implementation of chromoendoscopy among endoscopists previously inexperienced with this technique resulted in higher dysplasia detection compared to white light endoscopy alone in patients with longstanding UC. These rates are similar to the published literature from experienced centers and are encouraging for implementation of chromoendoscopy programs for UC surveillance.

504 Virtual Chromoendoscopy With I-Scan for Diagnosis of Mucosal Healing in Patients With Inflammatory Bowel Disease - a Randomized Double-Blind Controlled Study

Increased vascular permeability and angiogenesis plays a crucial role in the pathogenesis of inflammatory bowel diseases (IBD). Previously, magnifying endoscopy and chromoendoscopy have been shown to be reliable tools for predicting histological assessment of disease severity in patients with mild or even inactive disease. i-scan was recently introduced as a novel computed virtual chromoendoscopy technique which enables a clear visualization of the mucosal vascular pattern within the gastrointestinal tract.

Su1456 The Learning Curve of Virtual Chromoendoscopy With I-SCAN for Prediction of Hyperplastic and Adenomatous Colorectal Lesions - a Multicenter Study

I-scan was recently introduced as a new computed virtual chromoendoscopy technique which enables high-definition imaging of lesions with improved tissue contrast. Previous studies have shown that i-scan yield in an improved detection rate of colorectal lesions. The learning curve for interpretation of i-scan images is unknown.

P111 “EARS” (Erlanger Activity Related Score) of IBD: A new tool that allows accurate in vivo assessment of inflammatory activity in ulcerative colitis

Background: Increased vascular permeability and angiogenesis play a crucial role in the pathogenesis of inflammatory bowel disease (IBD). Previously, magnifying endoscopy and chromoendoscopy have been shown to be reliable tools for predicting histological assessment of severity in patients with mild or even inactive disease. i-scan (Pentax, Tokyo, Japan) was recently introduced as a novel computed virtual chromoendoscopy technique which enables a clear visualization of the mucosal vascular pattern within the gastrointestinal tract. Aim was to determine whether i-scan has the potential to enhance assessment of disease severity and extent in patients with mild or inactive IBD in comparison to high-definition white light endoscopy (HD-WL). Methods: Consecutive patients with IBD were randomly assigned at a 1:1 ratio to undergo colonoscopy with HD-WL (Group 1) or i-scan (Group 2). The mucosal vascular pattern and any mucosal abnormalities were recorded. Inflammation in ulcerative colitis was recorded according to Mayo ulcerative endoscopic score and in Crohn’s disease according to Crohn’s Disease Endoscopic Index of Severity (CDEIS). Subsequent to endoscopic characterization targeted biopsies were obtained from every segment for subsequent histopathological analysis of disease activity. Results: Overall, 100 patients were screened to participate in this study of whom 78 patients (HD white light, n = 39; i-scan, n = 39) completed the study protocol thereby matching the previously calculated sample size. Average duration of the examination was 18 minutes in group A and 20.5 minutes in group B which was not statistically significant. When comparing the endoscopic prediction of inflammatory extent and activity with the histological results an overall agreement of 51.28% and 56.41% (group A) and 92.31% and 89.74% (group B) was found, respectively. These differences were statistically significant (p = 0.0009 and p = 0.011). Conclusions: The present study indicates that i-scan significantly improves the diagnosis of the severity and extent of mucosal inflammation in patients with IBD. This newly developed imaging technique will therefore have important implications for diagnostic and therapeutic interventions in patients with IBD.

The endoscopic diagnosis of nonerosive reflux disease using flexible spectral imaging color enhancement image: a feasibility trial

Nonerosive reflux disease (NERD) is classified into grade M (minimal change, endoscopically; erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings) and grade N (normal) in the modified Los Angeles classification system in Japan. However, the classification of grades M and N NERD is not included in the original Los Angeles system because interobserver agreement for the conventional endoscopic diagnosis of grades M or N NERD is poor. Flexible spectral imaging color enhancement (FICE) is a virtual chromoendoscopy technique that enhances mucosal and vascular visibility. The aim of this study is to evaluate whether the endoscopic diagnosis of grades M or N NERD using FICE images is feasible. Between April 2006 and May 2008, 26 NERD patients and 31 controls were enrolled in the present study. First, an experienced endoscopist assessed the color pattern of minimal change in FICE images using conventional endoscopic images and FICE images side-by-side and comparing the proportion of minimal change between the two groups. Second, three blinded endoscopists assessed the presence or absence of minimal change in both groups using conventional endoscopic images and FICE images separately. Intraobserver variability was compared using McNemar's test, and interobserver agreement was described using the kappa value. Minimal changes, such as erythema and whitish turbidity, which were detected using conventional endoscopic images, showed up as navy blue and pink-white, respectively, in color using FICE images in the present FICE mode. The NERD group had a higher proportion of minimal change, compared with the control group (77% and 48%, respectively) (P= 0.033). In all three readers, the detection rates of minimal change using FICE images were greater than those using conventional endoscopic images (P= 0.025, <0.0001, and 0.034 for readers A, B, and C, respectively). The kappa values for all pairs of three readers using FICE images were between 0.683 and 0.812, while those using conventional endoscopic images were between 0.364 and 0.624. Thus, the endoscopic diagnosis of grades M or N NERD using FICE images is feasible and may improve interobserver agreement.

Double-balloon enteroscopy-assisted virtual chromoendoscopy for small-bowel disorders – a case series

The Fujinon intelligent color enhancement (FICE) system is a new, virtual chromoendoscopy technique that enhances mucosal visibility. The aim of this study was to assess the utility of double-balloon enteroscopy (DBE) with FICE technology (EPX-4400 processor, Japan) for the characterization of various small-bowel diseases. Overall, a total of 574 endoscopic pictures were obtained and analyzed. FICE was found to be a helpful method for the evaluation of adenomatous small-bowel polyps and angiodysplasias. Its use for the characterization of celiac and Crohn's disease appears to be limited. Overall, FICE may become a useful method that aids in characterization and provides new insights to small-bowel pathologies.

Application of Multiband Imaging (MBI) in the Diagnosis of Non-Erosive Reflux Disease (NERD): A Case-Control Study

Background and Aim: White light, standard endoscopy allows to diagnose gastroesophageal reflux disease (GERD) in approximately 60% of symptomatic patients; optical chromoendoscopy (NBI) has been shown to improve the visualization of mucosal and microvascular patterns potentially caused by GERD. The aim of the present study was to evaluate a novel electronic chromoendoscopy technique (Multiband Imaging, Fujinon) for the endoscopic diagnosis of GERD. in a case-control study. Methods: At endoscopy we enrolled consecutive patients with GERD symptoms of >3 months duration, not taking PPI; controls were selected among those referred for GERD-unrelated conditions and without typical or atypical reflux symptoms.

Fuji Intelligent Chromo Endoscopy and staining technique for the diagnosis of colon tumor

Colon cancer is a common malignant tumor in the clinic with an incidence rate that is increasing in recent years. The key point for improving the survival rate is the diagnosis and treatment at an early stage. The purpose of this study was to compare the difference of the Fuji Intelligent Chromo Endoscopy (FICE) and staining technique for the diagnosis of colon tumors and non-tumor lesions. From March to November 2007, 654 patients were examined with ordinary colonoscopy. Among them 223 patients with colon neoplasm or polypoid lesion were included. The patients were examined with a magnifying ordinary colonoscopy, a magnifying FICE technique and magnifying staining technique. The pit pattern and blood capillary form of the lesion were examined, an endoscopic diagnosis was made and it was compared with the pathologic diagnosis. Four hundred and fifty-one neoplasms were detected in the 223 patients, among those 91.1% (411/451) were detected with the magnifying ordinary endoscopy while 99.1% (447/451) were detected with the FICE technique; there was a significant difference between the two methods. FICE could clearly show the structure and form of mucosal blood capillaries (P < 0.01) but there was no significant difference between the two methods for showing the pit pattern. The coincident rate of FICE for the diagnosis of tumor and non-tumor lesions was 91.6% (413/451), that of the magnifying staining technique was 82.0% (370/451) (P < 0.05). Magnifying FICE could show the mucosal microstructure and blood capillary form and it had a superiority of high coincident rate, high sensitivity and specificity when compared with ordinary magnifying colonoscopy and magnifying staining endoscopy. In addition, it was easy to operate and a biopsy could be taken from the target, so it has a satisfactory clinical practical value.

Proportion of De Novo Cancers Among Colorectal Cancers in Japan

Adenomatous polyps are main precursors of colorectal cancers (CRCs). In Japan, de novo cancers, which do not arise from preexisting adenomas, are considered to account for a substantial number of CRCs, but the relative importance of de novo carcinogenesis remains controversial. This study estimated the proportion of de novo cancers among CRCs in Japan. The subjects were persons 40-79 years of age who were relatively similar to those in the general population. The subjects underwent colonoscopy between 1997 and 2001. Early cancers among CRCs detected in this study were classified as de novo cancers or polyp cancers derived from adenomas. The age-specific incidence of the early CRCs was calculated, and the proportion of de novo cancers was estimated. The lifetime risk of early CRCs was estimated. The study group comprised 14,817 persons. CRCs were diagnosed in 189 subjects, including 83 early cancers. There were no differences with regard to size and location between de novo cancers and polyp cancers, but morphology differed. Eighty-four percent (16/19) of de novo cancers were flat elevated or depressed. The expected lifetime risk of developing early CRCs was 5.27% for men and 3.21% for women. Among persons with early cancers, the expected probabilities of developing de novo cancer were 18.6% for men, 27.4% for women. De novo cancers account for a considerable proportion in Japan. This information suggests that the recommended interval for colonoscopic examination in Japan should be shorter than that in the United States.