Outcomes of endoscopic submucosal dissection for esophageal cancer with segmental absence of intestinal musculature.

BACKGROUND AND AIMS: Perforation during esophageal endoscopic submucosal dissection (ESD) typically results from electrical damage. However, there are cases in which perforation occurs because of segmental absence of intestinal musculature (SAIM) without iatrogenic muscular injury. We investigated the occurrence rate and clinical course of SAIM during esophageal ESD. METHODS: We conducted a retrospective review of esophageal ESDs performed between 2013 and 2019 at 10 centers in Japan. RESULTS: Five of 1708 (0.29%) patients received ESD for esophageal cancer and had SAIM. The median muscular defect size was 20 mm. All lesions were resected without discontinuation. After resection, 3 patients were closed with Endoloop. Four patients had mediastinal emphysema. All patients were managed conservatively. CONCLUSIONS: SAIM is a very rare condition that is usually only diagnosed during ESD. Physicians performing esophageal ESD should be aware of SAIM. When SAIM is detected, the ESD technique should be modified to prevent full-thickness perforation.

A Multicenter Prospective Validation Study on Selective Endoscopic Resection of Sessile Serrated Lesions Using Magnifying Colonoscopy in Clinical Practice.

INTRODUCTION: Sessile serrated lesions (SSLs) have malignant potential for colorectal cancer in the serrated pathway. Selective endoscopic resection of SSLs would reduce medical costs and procedure-related accidents, but the accurate endoscopic differentiation of SSLs from hyperplastic polyps (HPs) is challenging. To explore the differential diagnostic performance of magnifying colonoscopy in distinguishing SSLs from HPs, we conducted a multicenter prospective validation study in clinical practice. METHODS: Considering the rarity of diminutive SSLs, all lesions ≥6 mm that were detected during colonoscopy and diagnosed as type 1 based on the Japan narrow-band imaging expert team (JNET) classification were included in this study. Twenty expert endoscopists were asked to differentiate between SSLs and HPs with high or low confidence level after conventional and magnifying NBI observation. To examine the validity of selective endoscopic resection of SSLs using magnifying colonoscopy in clinical practice, we calculated the sensitivity of endoscopic diagnosis of SSLs with histopathological findings as comparable reference. RESULTS: A total of 217 JNET type 1 lesions from 162 patients were analyzed, and 114 lesions were diagnosed with high confidence. The sensitivity of magnifying colonoscopy in detecting SSLs was 79.8% (95% confidence interval [CI]: 74.7-84.4%) overall, and 82.4% (95% CI: 76.1-87.7%) in the high-confidence group. These results showed that the sensitivity of this study was not high enough, even limited in the high-confidence group. CONCLUSIONS: Accurate differential diagnosis of SSLs and HPs using magnifying colonoscopy was challenging even for experts. JNET type 1 lesions ≥6 mm are recommended to be resected because selective endoscopic resection has a disadvantage of leaving approximately 20% of SSLs on site.

Long-Term Outcomes of Endoscopic Submucosal Dissection for Early Remnant Gastric Cancer: A Retrospective Multicenter Study.

INTRODUCTION: Favorable long-term outcomes of endoscopic submucosal dissection (ESD) for early remnant gastric cancer (ERGC) have been reported in single-center studies from advanced institutions. However, no studies have examined the long-term outcomes using a multicenter database. This study aimed to investigate the long-term outcomes of the aforementioned approach using a large multicenter database. METHODS: This retrospective multicenter cohort study included 242 cases with 256 lesions that underwent ESD for ERGC between April 2009 and March 2019 across 12 centers. We investigated the long-term outcomes of these patients with the Kaplan-Meier method, and the relationship between curability, additional treatment, or hospital category, and the survival time was evaluated using the log-rank test. RESULTS: During the median follow-up period of 48.4 months, the 5-year overall survival rate was 81.3%, and the 5-year gastric cancer-specific survival rate was 98.1%. The survival time of patients of endoscopic curability (eCura) C-2 without additional surgery was significantly shorter than the corresponding of patients of eCura A/B/C-1 and eCura C-2 with additional surgery. There was no significant difference in either overall survival or gastric cancer-specific survival rate between the high-volume and non-high-volume hospitals. CONCLUSION: The gastric cancer-specific survival of ESD for ERGC using a multicenter database was favorable. ESD for ERGC is widely applicable regardless of the hospital case volume. Management in accordance with the latest guidelines will lead to long-term survival.

Assessment of predictive factors associated with the technical difficulty of endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma: Japanese multicenter retrospective study.

OBJECTIVES: Endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma (ESCC) is performed for the treatment of lesions with varied backgrounds and factors. However, the predictive factors associated with the technical difficulty of ESD remain unknown in patients with varied lesions. Therefore, this study aimed to identify the predictive factors associated with the technical difficulty of ESD for ESCC using a retrospective cohort. METHODS: This multicenter, retrospective study was conducted in 10 hospitals in Japan. Consecutive patients who underwent esophageal ESD between January 2013 and December 2019 were enrolled. Lesions of subepithelial tumors, adenocarcinoma, and adenoma were excluded. Difficult lesions were defined as ESD requiring a long procedure time (≥120 min), perforation development, piecemeal resection, or discontinued ESD. In the present study, the clinical factors were assessed to identify the technical difficulty of ESD using univariate and multivariate analyses. RESULTS: Among 1708 lesions treated with esophageal ESD, eight subepithelial tumors, 44 adenocarcinomas, and two adenomas were excluded. Finally, 1505 patients with 1654 lesions were analyzed, and 217 patients with 217 lesions (13.1%) were classified as patients with difficult lesions. In multivariate analysis, the predictive factors associated with the technical difficulty of ESD were as follows: tumors with varices, tumors with diverticulum, antiplatelet use (discontinued), circumference of tumor (≥1/2), preoperative tumor size ≥30 mm, trainee, and nonhigh-volume center. CONCLUSION: This multicenter retrospective study identified the predictive factors associated with the technical difficulty of ESD for ESCC with varied backgrounds and factors.

Safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices.

BACKGROUND: Heavy drinking is associated with esophageal cancer and esophageal varices. However, there are limited reports of endoscopic resection for esophageal cancer with esophageal varices. In this multicenter study, we clarified the safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices. METHODS: In this multicenter, retrospective, observational study, patients underwent esophageal endoscopic submucosal dissection at 10 referral centers in Japan from January 2013 to December 2019. We analyzed characteristics including backgrounds and varices, treatment outcomes, and adverse events in cases with esophageal varices. RESULTS: A total of 1708 patients were evaluated, 27 (1.6%) of whom had esophageal varices. In patients with esophageal varices, the en bloc resection rate and R0 resection rate were 100% and 77.8%, respectively. Patients with esophageal varices had longer procedure times than patients without esophageal varices (p = 0.015). There was no significant difference in adverse events. There was no significant difference in procedure time and number of adverse events between patients who underwent pretreatment and those who did not. There was no significant difference in these outcomes for patients with lesions on varices compared to those without. Child-Pugh classification and location of the lesions also did not affect these outcomes. CONCLUSIONS: Esophageal cancer with esophageal varices could be treated endoscopically safely and effectively.

The risk scoring system for assessing the technical difficulty of endoscopic submucosal dissection in cases of remnant gastric cancer after distal gastrectomy.

BACKGROUND: Endoscopic submucosal dissection (ESD) for remnant gastric cancer (RGC) after distal gastrectomy (DG) is considered technically challenging due to the narrow working space, and severe fibrosis and staples from the previous surgery. Technical difficulties of ESD for RGC after DG have not been thoroughly investigated. This study aimed to develop and validate a risk-scoring system for assessing the technical difficulty of ESD for RGC after DG in a large multicenter cohort. METHODS: We investigated patients who underwent ESD for RGC after DG in 10 institutions between April 2008 and March 2018. A difficult case was defined as ESD lasting ≥ 120 min, involving piecemeal resection, or the occurrence of perforation during the procedure. A risk-scoring system for the technical difficulty of the procedure was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: A total of 197 consecutive patients with 201 lesions were analyzed. There were 90 and 111 difficult and non-difficult cases, respectively. The scoring model consisted of four independent risk factors and points of risk scores were assigned for each as follows: tumor size > 20 mm: 2 points; anastomosis site: 2 points; suture line: 1 point; and non-expert endoscopist: 2 points. The C-statistics of the scoring system for technical difficulty was 0.72. CONCLUSIONS: We developed a validated risk-scoring model for predicting the technical difficulty of ESD for RGC after DG that can contribute to its safer and more reliable performance.

Efficacy of international web-based educational intervention in the detection of high-risk flat and depressed colorectal lesions higher (CATCH project) with a video: Randomized trial.

OBJECTIVES: Three subcategories of high-risk flat and depressed lesions (FDLs), laterally spreading tumors non-granular type (LST-NG), depressed lesions, and large sessile serrated lesions (SSLs), are highly attributable to post-colonoscopy colorectal cancer (CRC). Efficient and organized educational programs on detecting high-risk FDLs are lacking. We aimed to explore whether a web-based educational intervention with training on FIND clues (fold deformation, intensive stool/mucus attachment, no vessel visibility, and demarcated reddish area) may improve the ability to detect high-risk FDLs. METHODS: This was an international web-based randomized control trial that enrolled non-expert endoscopists in 13 Asian countries. The participants were randomized into either education or non-education group. All participants took the pre-test and post-test to read 60 endoscopic images (40 high-risk FDLs, five polypoid, 15 no lesions) and answered whether there was a lesion. Only the education group received a self-education program (video and training questions and answers) between the tests. The primary outcome was a detection rate of high-risk FDLs. RESULTS: In total, 284 participants were randomized. After excluding non-responders, the final data analyses were based on 139 participants in the education group and 130 in the non-education group. The detection rate of high-risk FDLs in the education group significantly improved by 14.7% (66.6-81.3%) compared with -0.8% (70.8-70.0%) in the non-education group. Similarly, the detection rate of LST-NG, depressed lesions, and large SSLs significantly increased only in the education group by 12.7%, 12.0%, and 21.6%, respectively. CONCLUSION: Short self-education focusing on detecting high-risk FDLs was effective for Asian non-expert endoscopists. (UMIN000042348).

Prophylactic Clipping After Colorectal Endoscopic Resection Prevents Bleeding of Large, Proximal Polyps: Meta-analysis of Randomized Trials.

BACKGROUND & AIMS: The benefits of prophylactic clipping to prevent bleeding after polypectomy are unclear. We conducted an updated meta-analysis of randomized trials to assess the efficacy of clipping in preventing bleeding after polypectomy, overall and according to polyp size and location. METHODS: We searched the MEDLINE/PubMed, Embase, and Scopus databases for randomized trials that compared the effects of clipping vs not clipping to prevent bleeding after polypectomy. We performed a random-effects meta-analysis to generate pooled relative risks (RRs) with 95% CIs. Multilevel random-effects metaregression analysis was used to combine data on bleeding after polypectomy and estimate associations between rates of bleeding and polyp characteristics. RESULTS: We analyzed data from 9 trials, comprising 71897 colorectal lesions (22.5% 20 mm or larger; 49.2% with proximal location). Clipping, compared with no clipping, did not significantly reduce the overall risk of postpolypectomy bleeding (2.2% with clipping vs 3.3% with no clipping; RR, 0.69; 95% confidence interval [CI], 0.45-1.08; P = .072). Clipping significantly reduced risk of bleeding after removal of polyps that were 20 mm or larger (4.3% had bleeding after clipping vs 7.6% had bleeding with no clipping; RR, 0.51; 95% CI, 0.33-0.78; P = .020) or that were in a proximal location (3.0% had bleeding after clipping vs 6.2% had bleeding with no clipping; RR, 0.53; 95% CI, 0.35-0.81; P < .001). In multilevel metaregression analysis that adjusted for polyp size and location, prophylactic clipping was significantly associated with reduced risk of bleeding after removal of large proximal polyps (RR, 0.37; 95% CI, 0.22-0.61; P = .021) but not small proximal lesions (RR, 0.88; 95% CI, 0.48-1.62; P = .581). CONCLUSIONS: In a meta-analysis of randomized trials, we found that routine use of prophylactic clipping does not reduce risk of postpolypectomy bleeding overall. However, clipping appeared to reduce bleeding after removal of large (more than 20 mm) proximal lesions.

Factors associated with inaccurate size estimation of colorectal polyps: A multicenter cross-sectional study.

BACKGROUND AND AIM: Accurate polyp size estimation is essential in deciding the therapeutic strategy of colorectal polyps and endoscopic surveillance intervals. However, many endoscopists frequently make incorrect size estimations without being aware of their errors. This cross-sectional study aimed to clarify the characteristics of endoscopists associated with inaccurate estimation. METHODS: We previously conducted a web trial involving 261 endoscopists in 51 institutions in Japan to assess their ability to estimate polyp size. Participants answered questions about polyp size using visual estimates in a test involving images of 30 polyps. Here, we investigated the relationships between inaccurate size estimation and the backgrounds of participants. The rates of overestimation and underestimation of polyp size were also compared to clarify any trends in the answers of participants with low accuracy (< 50%). RESULTS: Multivariable logistic regression analysis revealed that the number of colonoscopic procedures in the past year was the only factor associated with a low accuracy of polyp size estimation (odds ratio 0.750, 95% confidence interval 0.609-0.925; P = 0.007). Endoscopists with low accuracy had a greater tendency to overestimate polyp size (42.3% overestimation and 21.2% underestimation, P < 0.001) compared with other endoscopists (16.6% overestimation and 17.9% underestimation, P = 0.951). CONCLUSIONS: Endoscopists with limited experience of colonoscopy in the past year were more likely to make frequent errors in size estimation. Furthermore, endoscopists making inaccurate size estimations had a propensity to overestimate polyp size.

Clinical importance of cold polypectomy during the insertion phase in the left side of the colon and rectum: a multicenter randomized controlled trial (PRESECT study).

BACKGROUND AND AIMS: Colorectal polyps are often detected during the insertion phase of colonoscopy but are commonly removed during the withdrawal phase. We aimed to investigate the clinical advantages of instant removal of colorectal polyps during the insertion phase to determine the appropriate strategy for polyps detected on insertion. METHODS: This prospective, multicenter, randomized trial targeted patients with at least 1 left-sided polyp <10 mm in size detected unintentionally on endoscope insertion from April 2018 to March 2019. Patients were allocated to the following 2 groups: study group, consisting of patients who had polyp removal instantly on insertion, and control group, comprising patients who had the endoscope inserted to the cecum first and polyps removed subsequently on withdrawal. Carbon dioxide gas insufflation and cold polypectomy were applied to minimize the influences of polypectomy on endoscope insertion. Twenty advanced endoscopists from 7 community-based institutions participated in this trial. RESULTS: Of 1451 patients enrolled, 220 patients were eligible for full assessment. Mean total procedure time was significantly shorter in the study group (18.9 vs 22.3 minutes, P < .001). Mean pure cecal intubation time and number of polyps per patient were similar between the 2 groups. In the control group, among 107 polyps found during insertion, 48 (45.8%) required reinspection and 7 (6.5%) were completely missed, with an average reinspection time of approximately 3 minutes. CONCLUSIONS: Polypectomy during the insertion phase in the colon and rectum significantly shortens the total procedure time and eliminates all missed polyps without experiencing any disadvantages.

Linked-color imaging versus white-light colonoscopy in an organized colorectal cancer screening program.

BACKGROUND AND AIMS: Linked-color imaging (LCI), a new image-enhancing technology emphasizing contrast in mucosal color, has been demonstrated to substantially reduce polyp miss rate as compared with standard white-light imaging (WLI) in tandem colonoscopy studies. Whether LCI increases adenoma detection rate (ADR) remains unclear. METHODS: Consecutive subjects undergoing screening colonoscopy after fecal immunochemical test (FIT) positivity were 1:1 randomized to undergo colonoscopy with LCI or WLI, both in high-definition systems. Insertion and withdrawal phases of each colonoscopy were carried out using the same assigned light. Experienced endoscopists from 7 Italian centers participated in the study. Randomization was stratified by gender, age, and screening round. The primary outcome measure was represented by ADR. RESULTS: Of 704 eligible subjects, 649 were included (48.9% men, mean age ± standard deviation, 60.8 ± 7.3 years) and randomized to LCI (n = 326) or WLI (n = 323) colonoscopy. The ADR was higher in the LCI group (51.8%) than in the WLI group (43.7%) (relative risk, 1.19; 95% confidence interval, 1.01-1.40). The proportions of patients with advanced adenomas and sessile serrated lesions were, respectively, 21.2% and 8.6% in the LCI arm and 18.9% and 5.9% in the WLI arm (not significant for both comparisons). At multivariate analysis, LCI was independently associated with ADR, along with male gender, increasing age, and adequate (Boston Bowel Preparation Scale score ≥6) bowel preparation. At per-polyp analysis, the mean ± standard deviation number of adenomas per colonoscopy was comparable in the LCI and WLI arms, whereas the corresponding figures for proximal adenomas was significantly higher in the LCI group (.72 ± 1.2 vs .55 ± 1.07, P = .05) CONCLUSIONS: In FIT-positive patients undergoing screening colonoscopy, the routine use of LCI significantly increased the ADR. (Clinical trial registration number: NCT03690297.).

Continuous Anticoagulation and Cold Snare Polypectomy Versus Heparin Bridging and Hot Snare Polypectomy in Patients on Anticoagulants With Subcentimeter Polyps: A Randomized Controlled Trial.

Background: Management of anticoagulants for patients undergoing polypectomy is still controversial. Cold snare polypectomy (CSP) is reported to cause less bleeding than hot snare polypectomy (HSP). Objective: To compare outcomes between continuous administration of anticoagulants (CA) with CSP (CA+CSP) and periprocedural heparin bridging (HB) with HSP (HB+HSP) for subcentimeter colorectal polyps. Design: Multicenter, parallel, noninferiority randomized controlled trial. (University Hospital Medical Information Network Clinical Trials Registry: UMIN000019355). Setting: 30 Japanese institutions. Patients: Patients receiving anticoagulant therapy (warfarin or direct oral anticoagulants) who had at least 1 nonpedunculated subcentimeter colorectal polyp. Intervention: Patients were randomly assigned to undergo HB+HSP or CA+CSP and followed up 28 days after polypectomy. Measurements: The primary end point was incidence of polypectomy-related major bleeding (based on the incidence of poorly controlled intraprocedural bleeding or postpolypectomy bleeding requiring endoscopic hemostasis). The prespecified inferiority margin was -5% (CA+CSP vs. HB+HSP). Results: A total of 184 patients were enrolled: 90 in the HB+HSP group, 92 in the CA+CSP group, and 2 who declined to participate after enrollment. The incidence of polypectomy-related major bleeding in the HB+HSP and CA+CSP groups was 12.0% (95% CI, 5.0% to 19.1%) and 4.7% (CI, 0.2% to 9.2%), respectively. The intergroup difference for the primary end point was +7.3% (CI, -1.0% to 15.7%), with a 0.4% lower limit of 2-sided 90% CI, demonstrating the noninferiority of CA+CSP. The mean procedure time for each polyp and the hospitalization period were longer in the HB+HSP than in the CA+CSP group. Limitation: An open-label trial assessing 2 factors (anticoagulation approach and polypectomy procedure type) simultaneously. Conclusion: Patients having CA+CSP for subcentimeter colorectal polyps who were receiving oral anticoagulants did not have an increased incidence of polypectomy-related major bleeding, and procedure time and hospitalization were shorter than in those having HB+HSP. Primary Funding Source: Japanese Gastroenterological Association.

Short educational video to improve the accuracy of colorectal polyp size estimation: Multicenter prospective study.

BACKGROUND AND AIM: Accurate polyp size estimation is necessary for appropriate management of colorectal polyps. Polyp size is often determined by subjective visual estimation in clinical situations; however, it is inaccurate, especially for beginner endoscopists. We aimed to clarify the usefulness of our short training video, available on the Internet, for accurate polyp size estimation. METHODS: We conducted a multicenter prospective controlled study in Japan. After completing a pretest composed of near and far images of 30 polyps, participants received the educational video lecture (<10 min long). The educational content included the knowledge of strategies based on polyp size and criteria for size estimation including the endoscopic equipment size and videos of polyps in vivo. After one month, the participants undertook a posttest. The primary outcome was a change in the accuracy of polyp size visual estimation between the pretest and posttest in beginners. RESULTS: Participants including 111 beginners, 52 intermediates, and 97 experts from 51 institutions completed both tests. Accuracy of polyp size estimation in the beginners showed a significant increase after the video lecture [54.1% (51.3-57.0%) to 59.0% (56.5-61.5%), P = 0.003]. Multivariable logistic regression analysis showed that the category of beginners and a low score on pretest (P = 0.020 and <0.001, respectively) were the factors that contributed to an increase of ≥10% in the accuracy. CONCLUSION: Our educational video led to an improvement in polyp size estimation in beginners. Furthermore, this video may be useful for non-beginners with insufficient polyp size estimation accuracy.

Standards of diagnostic colonoscopy for early-stage neoplasia: Recommendations by an Asian private group.

BACKGROUND AND AIM: In recent years, the incidence of colorectal cancer has been increasing, and it is now becoming the major cause of cancer death in Asian countries. The aim of the present study was to develop Asian expert-based consensus to standardize the preparation, detection and characterization for the diagnosis of early-stage colorectal neoplasia. METHODS: A professional group was formed by 36 experts of the Asian Novel Bio-Imaging and Intervention Group (ANBI2 G) members. Representatives from 12 Asia-Pacific countries participated in the meeting. The group organized three consensus meetings focusing on diagnostic endoscopy for gastrointestinal neoplasia. The Delphi method was used to develop the consensus statements. RESULTS: Through the three consensus meetings with debating, reviewing the literature and regional data, a consensus was reached at third meeting in 2016. The consensus was reached on a total of 10 statements. Summary of statements is as follows: (i) Adequate bowel preparation for high-quality colonoscopy; (ii) Antispasmodic agents for lesion detection; (iii) Image-enhanced endoscopy (IEE) for polyp detection; (iv) Adenoma detection rate for quality indicators; (v) Good documentation of colonoscopy findings; (vi) Complication rates; (vii) Cecal intubation rate; (viii) Cap-assisted colonoscopy (CAC) for polyp detection; (ix) Macroscopic classification using indigocarmine spray for characterization of colorectal lesions; and (x) IEE and/or magnifying endoscopy for prediction of histology. CONCLUSION: This consensus provides guidance for carrying out endoscopic diagnosis and characterization for early-stage colorectal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early-stage colorectal neoplasia.

A comparison of the resection rate for cold and hot snare polypectomy for 4-9 mm colorectal polyps: a multicentre randomised controlled trial (CRESCENT study).

OBJECTIVE: To investigate the success rate of cold snare polypectomy (CSP) for complete resection of 4-9 mm colorectal adenomatous polyps compared with that of hot snare polypectomy (HSP). DESIGN: A prospective, multicentre, randomised controlled, parallel, non-inferiority trial conducted in 12 Japanese endoscopy units. Endoscopically diagnosed sessile adenomatous polyps, 4-9 mm in size, were randomly assigned to the CSP or HSP group. After complete removal of the polyp using the allocated technique, biopsy specimens from the resection margin after polypectomy were obtained. The primary endpoint was the complete resection rate, defined as no evidence of adenomatous tissue in the biopsied specimens, among all pathologically confirmed adenomatous polyps. RESULTS: A total of 796 eligible polyps were detected in 538 of 912 patients screened for eligibility between September 2015 and August 2016. The complete resection rate for CSP was 98.2% compared with 97.4% for HSP. The non-inferiority of CSP for complete resection compared with HSP was confirmed by the +0.8% (90% CI -1.0 to 2.7) complete resection rate (non-inferiority p<0.0001). Postoperative bleeding requiring endoscopic haemostasis occurred only in the HSP group (0.5%, 2 of 402 polyps). CONCLUSIONS: The complete resection rate for CSP is not inferior to that for HSP. CSP can be one of the standard techniques for 4-9 mm colorectal polyps. (Study registration: UMIN000018328).

Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia.

BACKGROUND AND AIM: Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps. METHODS: Histopathological data of patients, who underwent colonoscopy at our center between January 2011 and December 2016, were reviewed. Data of patients with ≥ 1 SSA/P were retrieved, and clinicopathological characteristics were retrospectively analyzed. RESULTS: A total of 281 patients with 326 SSA/Ps, including 258 patients who had 300 SSA/Ps without CD (SSA/Ps-CD[-]) and 23 patients who had 26 SSA/Ps with CD (SSA/Ps-CD[+]), were evaluated in this study. Although SSA/Ps-CD(+) were often found in older female patients and in the proximal colon, there were no significant differences between SSA/Ps-CD(-) and SSA/Ps-CD(+). Endoscopic morphological findings, such as large or small nodules on the surface and partial protrusion of the lesions, were significantly more common in SSA/Ps-CD(+) than in SSA/Ps-CD(-). Although the diagnostic ability of nodule/protrusion in lesions to predict CD within SSA/Ps was very high with an accuracy of 93.9% and a negative predictive value of 95.4%, sensitivity was low at 46.2%. SSA/Ps-CD(+) were significantly larger than SSA/Ps-CD(-), and the rate of CD within SSA/Ps significantly increased with lesion size (≤ 5 mm, 0%; 6-9 mm, 6.0%; ≥ 10 mm, 13.6%). CONCLUSION: The study proposes removing all SSA/Ps ≥ 6 mm in order to remove high-risk SSA/Ps-CD(+), with high sensitivity.

Additional chromoendoscopy for colorectal lesions initially diagnosed with low confidence by magnifying narrow-band imaging: Can it improve diagnostic accuracy?

BACKGROUND AND AIM: Magnifying chromoendoscopy has been one of the most reliable diagnostic methods for distinguishing neoplastic from non-neoplastic lesions. The aim of this prospective study was to clarify the clinical usefulness of magnifying chromoendoscopy for colorectal polyps initially diagnosed with low confidence (LC) by magnifying narrow-band imaging (NBI). METHODS: Consecutive adult patients who underwent total colonoscopic examination with magnifying NBI between July and December 2016 at Sano Hospital were prospectively recruited. Endoscopists were asked to carry out additional magnifying chromoendoscopy for cases that had been initially diagnosed as Japan NBI Expert Team (JNET) Type 1 or 2A with LC by magnifying NBI. We investigated the diagnostic performance of magnifying NBI for polyps diagnosed as JNET Type 1 or 2A with LC (first phase) and that of subsequent magnifying chromoendoscopy (second phase) in differentiating neoplasia from non-neoplasia. RESULTS: In 50 patients, we analyzed 53 polyps classified as JNET Type 1 or 2A with LC prediction. Accuracy and negative predictive value of magnifying NBI (first phase) were 58.5% (95% CI, 44.1-71.9%) and 66.0% (95% CI, 36.6-77.9%), and those of magnifying chromoendoscopy (second phase) were 66.0% (95% CI, 51.7-78.5%) and 61.1% (95% CI, 43.5-76.9%), respectively. CONCLUSION: Regardless of the findings of additional chromoendoscopy, all polyps should be resected and submitted for histopathological examination when the confidence level in differentiating adenomatous from hyperplastic polyps by magnifying NBI is low.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions.

BACKGROUND AND AIM: The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions. METHODS: Twenty-five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis. RESULTS: Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non-polypoid) had a minor influence on the key diagnostic performance for types 2B and 3. CONCLUSION: Based on the present data, we reached a consensus for developing the JNET classification.

Colorectal cancer screening of the general population in East Asia.

In recent years, the incidence of colorectal cancer (CRC) has been increasing, and CRC has been becoming the major cause of cancer deaths in Asian countries. Therefore, an organized screening program to reduce CRC incidence and mortality is currently implemented in each country. In the present review, we summarize the current status and future perspectives of CRC screening of the general population in East Asian and South-East Asian countries. The fecal occult blood test is widely used for CRC screening in these countries, and its effectiveness in reducing CRC incidence and mortality has been demonstrated; however, the low participation rate in CRC screening programs is a problem to be solved in every country. Improvement in the public awareness of CRC and promotion of CRC screening by physicians will help to raise the participation rate and reduce the number of deaths caused by CRC. Regarding screening colonoscopy, several studies have recently demonstrated its effectiveness in reducing CRC incidence and mortality. However, at present, CRC screening colonoscopy is not adopted as a primary population-based screening tool because of staffing constraints in relation to large population sizes, increased medical costs, and potential adverse events (e.g., perforation and drug-induced anaphylaxis). Further study is required to consider colonoscopy as CRC screening that is established in Western countries.

Narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Many clinical studies on narrow-band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low-grade intramucosal neoplasia, high-grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.