Cancer risk and genotype-phenotype correlation in Japanese patients with Cowden syndrome.

BACKGROUND: Cowden syndrome (CS) is an autosomal-dominant hereditary disorder caused by a germline PTEN variant and characterized by multiple hamartomas and a high risk of cancers. However, no detailed data on CS in Asian patients nor genotype-phenotype correlation have been reported. METHODS: We performed the first Japanese nationwide questionnaire survey on CS and obtained questionnaire response data on 49 CS patients. RESULTS: Patients included 26 females (median age 48 years). The incidence of breast, thyroid, endometrium, and colorectal cancer was 32.7%, 12.2%, 19.2% (among females), and 6.1%, respectively. The incidence of any cancers was relatively high among all patients (46.9%, 23/49), and particularly female patients (73.1%, 19/26), compared with previous reports from Western countries. Gastrointestinal (GI) polyps were more frequently found throughout the GI tract compared with previous studies. PTEN variants were detected in 95.6% (22/23) of patients; 12 in the N-terminal region (11 in phosphatase domain) and 10 in the C-terminal (C2 domain) region. The incidence of cancer in the C2 domain group was significantly higher than in the N-terminal region (phosphatase) group. All female patients with C2 domain variant had breast cancer. CONCLUSION: Our data suggest that Japanese patients with CS, particularly female patients and patients with C2 domain variant may have a high risk of cancers.

Clinical outcomes of endoscopic resection for superficial non-ampullary duodenal tumors.

Background and study aims Because superficial non-ampullary duodenal epithelial tumors (SNADETs) are relatively rare, studies evaluating the outcomes of endoscopic resection (ER) for SNADETs are limited. Therefore, this study aimed to evaluate the clinical validity of ER for SNADETs. Patients and methods The study participants included 163 consecutive patients (108 men; mean age, 61.5 ±â€Š11.3 years) with 171 SNADETs, excluding patients with familial adenomatous polyposis resected by ER, at Hiroshima University Hospital between May 2005 and September 2016. Clinicopathological features and the outcomes of ER for 171 cases were retrospectively analyzed. Additionally, the prognosis of 135 patients with more than 12 months' follow-up was analyzed. Results Mean diameter of SNADETs was 10.7 ±â€Š7.2 mm. Most of the SNADET cases were classified as category 3 (71 %, 121/171), but some were category 5 (2 %, 3/171). En bloc resection rates were 93 % (146/157), 100 % (7/7), and 86 % (6/7) in endoscopic mucosal resection (EMR), polypectomy, and in endoscopic submucosal dissection (ESD) cases, respectively. Complete resection rates were 90 % (141/157), 100 % (7/7), and 71 % (5/7) in EMR, polypectomy, and ESD cases, respectively. Emergency surgery was performed in two patients with intraoperative perforation and in two with delayed perforation without artificial ulcer bed closure after ER. Since endoscopic closure of ulcer by clipping was performed, delayed perforation has not occurred. Local recurrence occurred in 1.2 %, but no metastasis to lymph nodes or other organs occurred after ER. No patient died of primary SNADETs. Conclusion Our data supported the clinical validity of ER for SNADETs. However, delayed perforation should be given much attention.

Accuracies of Endoscopic Diagnosis of Helicobacter pylori-Gastritis: Multicenter Prospective Study Using White Light Imaging and Linked Color Imaging.

INTRODUCTION: The diagnosis of Helicobacter pylori infection status with white light imaging (WLI) is difficult. We evaluated the accuracies of using WLI and linked color imaging (LCI) for diagnosing H. pylori-active gastritis in a multicenter prospective study setting. METHODS: Patients who underwent esophagogastroduodenoscopy were prospectively included. The image collection process was randomized and anonymous, and the image set included 4 images with WLI or 4 images with LCI in the corpus that 5 reviewers separately evaluated. Active gastritis was defined as positive when there was diffuse redness in WLI and crimson coloring in LCI. The H. pylori infection status was determined by the urea breath test and the serum antibody test. Cases in which both test results were negative but atrophy or intestinal metaplasia was histologically confirmed were defined as past infections. The primary endpoint was the diagnostic accuracies of WLI and LCI, and the secondary endpoint was inter-observer agreement. RESULTS: Data for 127 patients were analyzed. The endoscopic diagnostic accuracy for active gastritis was 79.5 (sensitivity of 84.4 and specificity of 74.6) with WLI and 86.6 (sensitivity of 84.4 and specificity of 88.9) with LCI (p = 0.029). LCI significantly improved the accuracy in patients with past infections over WLI (36.8 in WLI and 78.9 in LCI, p < 0.01). The κ values were 0.59 in WLI and 0.70 in LCI. CONCLUSIONS: LCI is useful for endoscopic diagnosis of H. pylori-active or inactive gastritis, and it is advantageous for patients with past infections of inactive gastritis.

Management of adverse events related to endoscopic resection of upper gastrointestinal neoplasms: Review of the literature and recommendations from experts.

Prevention therapy is recommended for lesions >1/2 of the esophageal circumference. Locoregional steroid injection is recommended for lesions >1/2-3/4 of the esophageal circumference and oral steroids are recommended for lesions >1/2 of the subtotal circumference. For lesions of the entire circumference, oral steroid combined with injection steroid is considered. Endoscopic balloon dilatation (EBD) is the first choice of treatment for stricture after esophageal endoscopic submucosal dissection (ESD). Radical incision and cutting or self-expandable metallic stent can be considered for refractory stricture after EBD. In case of intraoperative perforation during esophageal ESD, endoscopic clip closure should be initially attempted. Surgery is considered for treatment of delayed perforation. Current standard practice for prevention of delayed bleeding after gastric ESD includes prophylactic coagulation of vessels on post-ESD ulcers and giving proton pump inhibitors. Chronic kidney disease stage 4 or 5, multiple antithrombotic drug use, anticoagulant use, and heparin bridging therapy are high-risk factors for delayed bleeding after gastric ESD. Intraoperative perforation during gastric ESD is initially managed by endoscopic clip closure. If endoscopic clip closure is difficult, other methods such as over-the-scope clip (OTSC), polyglycolic acid (PGA) sheet shielding etc. are attempted. Delayed perforation usually requires surgical intervention, but endoscopic closure by OTSC or PGA sheet may be considered. Resection of three-quarters of the circumference is a risk factor for stenosis after gastric ESD. Giving prophylactic local steroid injection and/or oral steroid is reported, but effectiveness has not been fully verified as has been done for esophageal stricture. The main management method for gastric stenosis is EBD but it may cause perforation.

A Questionnaire Survey on the Sequence of Events Prior to Undergoing Colonoscopy: The Influence of the Behavioral Response after a Fecal Occult Blood Test on the Early Detection of Colorectal Cancer.

Objective The fecal occult blood (FOB) test is commonly used for colorectal cancer screening; however, it is uncertain if further diagnostic interventions, such as a colonoscopy, should be performed based on its results. Method To better understand patient behavior following the FOB test, 6,414 patients (3,807 men and 2,607 women) who underwent colonoscopy between August 2015 and March 2016 at any of the 26 medical institutions throughout Hiroshima Prefecture were invited to participate in the study. All patients provided their written consent, after which they completed a questionnaire, and their colonoscopy results were obtained. These datasets were analyzed in a blinded manner, and the unique codes linking the records were revealed at the end of the analysis. Results Of the total study population, 4,749 patients (74.0%) had previously undergone FOB testing. After classification of common behavioral responses that the patients displayed following their FOB test, the group who had undergone the test several times, who had not had positive test results in the past, and whose latest FOB test results were positive had a significantly higher diagnosis rate of both early- and advanced-stage cancer than the other groups. Furthermore, patients in whom several previous FOB test results had been negative whose previous colonoscopy was positive were associated with a higher diagnosis rate of early-stage cancer than other groups. Conclusion These results suggested that colonoscopy should be performed immediately for patients with positive FOB test results due to their association with colorectal cancer and the possible detection of cancer at an early stage.

Construction of a risk model for the development of metachronous squamous cell carcinoma after endoscopic resection of esopahageal squamous cell carcinoma.

BACKGROUND: Previously, we identified that rs1229984 in ADH1B, rs671 in ALDH2, and smoking status were independently associated with the risk of developing metachronous squamous cell carcinoma (SCC) after endoscopic resection (ER) for esophageal SCC (ESCC). However, this analysis included cases with short-term follow-up. In the present study, we investigated the environmental and genetic factors associated with developing metachronous SCC using long-term follow-up observation after ER for ESCC. METHODS: One hundred and thirty ESCC patients who underwent treatment with ER were followed up using endoscopy for ≥ 30 months. We investigated the incidence of, and genetic/environmental factors associated with, metachronous SCC development after ER for ESCC. We also analyzed the potential risk factors for multiple metachronous SCC development using Cox's proportional hazards model. Moreover, we constructed a risk model for the development of metachronous SCC after ER for ESCC. RESULTS: Male, rs1229984, rs671, alcohol consumption (> 20 g/day), smoking, and multiple Lugol-voiding lesions (LVLs) significantly affected the incidence of multiple metachronous SCCs. Multiple Cox proportional analysis revealed that rs1229984, rs671, alcohol consumption, smoking, and multiple LVLs were independently associated with the risk of developing metachronous SCC. Patients who had ≤ 2 risk factors did not develop metachronous SCC, and the risk of developing metachronous SCC in patients with ≥ 3 risk factors was significantly higher than in patients with ≤ 2 risk factors. CONCLUSION: The risk model using these 5 genetic and environmental factors is useful as an indication for multiple metachronous development in ESCC patients.

Use of anticoagulants increases risk of bleeding after colorectal endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Japanese guidelines for gastroenterological endoscopy have recommended temporary withdrawal of anticoagulants (warfarin, direct oral anticoagulants [DOAC], or heparin) to prevent hemorrhagic complications during endoscopic submucosal dissection (ESD) for colorectal neoplasias (CRNs). However, serious thrombosis might occur during temporary withdrawal of anticoagulants. The current study aimed to evaluate outcomes with anticoagulants in patients undergoing ESD for CRNs. PATIENTS AND METHODS: This study was a single-institution retrospective cohort study based on clinical records. We assessed 650 consecutive patients with 698 CRNs who underwent ESD at Hiroshima University Hospital between December 2010 and June 2016. The patients were divided into three groups: the warfarin group (19 patients with 19 CRNs), DOAC group (7 patients with 9 CRNs), and no-antithrombotics group (624 patients with 670 CRNs). We replaced warfarin with heparin 3 to 5 days before endoscopy. Although DOAC was suspended on the morning of endoscopy, we did not replace heparin. RESULTS: Bleeding after the procedure occurred in 26.3 % (5/19), 22.0 % (2/9), and 2.7 % (18/670) of patients in the warfarin, DOAC, and no-antithrombotics groups, respectively. In the warfarin group, four patients who bled after the procedure took not only warfarin but also other antiplatelets. En bloc resection rates were 94.7 % (18/19), 100 % (9/9), and 96.6 % (647/670) in the warfarin, DOAC, and no-antithrombotics groups, respectively. No patients experienced ischemic events in the perioperative period. CONCLUSIONS: Among patients undergoing ESD for CRNs, risk of bleeding was higher among patients who took anticoagulants than among those who did not. In particular, careful attention to patients who took antiplatelets in addition to warfarin before ESD for CRNs is warranted.

Magnifying Endoscopy with Narrow Band Imaging in Estimating the Invasion Depth of Superficial Esophageal Squamous Cell Carcinomas.

BACKGROUND/AIM: The aim of this study was to compare the accuracy of magnifying endoscopy with narrow band imaging for the diagnosis of depth of invasion by Japan Esophageal Society (JES) classification and inter- and intraobserver agreement of JES intrapapillary capillary loop (IPCL) classification. METHODS: It was a retrospective observational study that has analyzed 136 patients with esophageal malignant neoplasia with magnifying endoscopy narrow band imaging to compare JES's IPCL classification to the histopathologic findings and to evaluate the inter- and intraobserver agreement. RESULTS: Histopathologic examinations revealed 34 (25.7%) intraepithelial neoplasias, 70 (51.5%) squamous cell carcinomas (SCCs) in the epithelium or with invasion into the lamina propria mucosa, 21 (15.4%) SCCs with invasion into the muscularis mucosa or mild invasion into the submucosa, and 11 (8.1%) SCCs with moderate or deep invasion into the submucosa. IPCL types B1, B2, and B3 also showed high accuracies of 80.8, 83.1, and 94.1%, respectively. The kappa values for inter- and intraobserver agreements of the IPCL classifications were moderate to almost perfect. CONCLUSIONS: In the present study, the JES's IPCL classification has good accuracy to predict the depth of SCC invasion and moderate to almost perfect intra- and interobserver agreements.

Clinical Significance of Reddish Depressed Lesions Observed in the Gastric Mucosa after Helicobacter pylori Eradication.

BACKGROUND AND AIM: Reddish depressed lesions (RDLs) frequently observed in patients following Helicobacter pylori eradication are indistinguishable from gastric cancer. We examined the clinical and histological feature of RDLs and its relevant endoscopic diagnosis including magnifying narrow-band imaging (M-NBI). METHODS: We enrolled 301 consecutive patients with H. pylori eradication who underwent endoscopy using white light imaging (WLI). We examined the prevalence and host factors contributing to the presence of RDLs. Next, we used M-NBI in 90 patients (104 RDLs), and compared the diagnostic efficacy between M-NBI and WLI groups using propensity-score matching analysis. RESULTS: In 301 patients after eradication, 117 (39%) showed RDLs. Male, open-type atrophy, and gastric cancer history were risk factors for RDLs. A gastric biopsy was needed in 83 (71%) during WLI observation and only 2 were diagnosed with adenocarcinoma. In M-NBI group, a biopsy was performed in 21 (20%), and 9 were diagnosed with adenocarcinoma. A biopsy was required in fewer patients, and the positive predictive value of a biopsy was statistically higher in M-NBI than in the WLI group (p < 0.01). CONCLUSIONS: RDLs are frequently observed in high-risk patients for gastric cancer after eradication. M-NBI demonstrated significantly superior diagnostic efficacy with respect to RDL.

Taking Warfarin with Heparin Replacement and Direct Oral Anticoagulant Is a Risk Factor for Bleeding after Endoscopic Submucosal Dissection for Early Gastric Cancer.

BACKGROUND: Although bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) remains problematic, especially in patients taking anticoagulants, there are differing views on the ideal and optimal management for these patients. This study investigated the risk of bleeding after ESD in patients taking anticoagulants. METHODS: We enrolled 61 consecutive patients taking anticoagulants (anticoagulant group) and 968 patients taking no antithrombotic agents (non-antithrombotic group) treated with ESD for EGC between December 2010 and October 2016. We analyzed the risk factors for bleeding after ESD in relation to the various clinical factors. RESULTS: Incidences of bleeding after ESD were significantly higher (14%; 11/76) in the anticoagulant group compared to the non-antithrombotic group (3%; 40/1,167). Moreover, bleeding after ESD was significantly more common in patients in the warfarin monotherapy group (14%; 5/37) and in the direct oral anticoagulant (DOAC) monotherapy group (22%; 4/18), compared to the non-antithrombotic group. Multivariate analysis revealed that dialysis, the use of anticoagulants, and an operation time ≥75 min were independent risk factors for bleeding after ESD. CONCLUSIONS: Our data suggest that patients who take warfarin and receive heparin bridging, and those who take DOAC medication, are prone to bleeding after ESD for EGC.

Evaluation of the visibility of early gastric cancer using linked color imaging and blue laser imaging.

BACKGROUND: Blue laser imaging (BLI) and linked color imaging (LCI) are the color enhancement features of the LASEREO endoscopic system, which provide a narrow band light observation function and expansion and reduction of the color information, respectively. METHODS: We examined 82 patients with early gastric cancer (EGC) diagnosed between April 2014 and August 2015. Five expert and 5 non-expert endoscopists retrospectively compared images obtained on non-magnifying BLI bright mode (BLI-BRT) and LCI with those obtained via conventional white light imaging (WLI). Interobserver agreement was also assessed. RESULTS: In experts' evaluation of the images, an improvement in visibility was observed in 73% (60/82) and 20% (16/82) of cases under LCI and BLI-BRT, respectively. In non-experts' evaluation of the images, an improvement in visibility was observed in 76.8% (63/82) and 24.3% (20/82) of cases under LCI and BLI-BRT, respectively. There were no significant differences between experts and non-experts in the evaluation of the images. The improvement in visibility was significantly higher with LCI than with BLI-BRT in experts and non-experts (p < 0.01). With regard to tumor color on WLI, the improvement in the visibility of reddish and whitish tumors was significantly higher than that of isochromatic tumors when LCI was used. The improvement in visibility with LCI was observed in 71% (12/17) and 74% (48/65) of patients with and without Helicobacter pylori (Hp) eradication, respectively; no significant difference in improvement was observed between these groups. The interobserver agreement was good to satisfactory at ≥ 0.62. CONCLUSIONS: In conclusion, our study showed that LCI improved the visibility of EGC, regardless of the level of endoscopists' experience or Hp eradication in patients, particularly for EGCs with a reddish or whitish color. The improvement in visibility was significantly higher with LCI than that with BLI.

Magnifying Blue Laser Imaging versus Magnifying Narrow-Band Imaging for the Diagnosis of Early Gastric Cancer: A Prospective, Multicenter, Comparative Study.

BACKGROUND/AIMS: The diagnostic efficacy of magnifying blue laser imaging (M-BLI) and M-BLI in bright mode (M-BLI-bright) in the identification of early gastric cancer (EGC) was evaluated for comparison to that of magnifying narrow-band imaging (M-NBI). METHODS: This prospective, multicenter study evaluated 114 gastric lesions examined using M-BLI, M-BLI-bright, and M-NBI between May 2012 and November 2012; 104 EGCs were evaluated by each modality. The vessel plus surface classification system was used to evaluate the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP). RESULTS: M-BLI, M-BLI-bright, and M-NBI revealed a DL for 96.1, 98.1, and 98.1% and irregular MVP for 95.1, 95.1, and 96.2% of lesions, respectively, with no significant difference. Irregular MSP was observed by M-BLI, M-BLI-bright, and M-NBI in 97.1, 90.4, and 78.8% of lesions, respectively, with significant differences (p < 0.001). The proportion of moderately differentiated adenocarcinoma with irregular MSP on M-BLI and absent MSP on M-NBI was significantly higher than that with irregular MSP on M-BLI and M-NBI (35.0 and 9.9%, respectively; p = 0.002). CONCLUSION: M-BLI and M-BLI-bright provided excellent visualization of microstructures and microvessels similar to M-NBI. Irregular MSP in a moderately differentiated adenocarcinoma might be frequently visualized using M-BLI and M-BLI-bright compared with using M-NBI.

Clinical Usefulness of the VS Classification System Using Magnifying Endoscopy with Blue Laser Imaging for Early Gastric Cancer.

BACKGROUND: Blue laser imaging (BLI) enables the acquisition of more information from tumors' surfaces compared with white light imaging. Few reports confirm the validity of magnifying endoscopy (ME) with BLI (ME-BLI) for early gastric cancer (EGC). We aimed to assess the detailed endoscopic findings from EGCs using ME-BLI. METHODS: We enrolled 386 consecutive patients with 417 EGCs that were diagnosed using ME-BLI and resected by endoscopic submucosal dissection. Using the VS classification system, three highly experienced endoscopists (HEEs) and three less experienced endoscopists (LEEs) evaluated the demarcation line (DL), microsurface pattern (MSP), and microvascular pattern (MVP) within the endoscopic images of EGCs obtained using ME-BLI, assigning high-confidence (HC) or low-confidence (LC) levels. We investigated the clinicopathological features associated with each confidence level. RESULTS: The HEEs' evaluations determined the presence of DL in 99%, irregular MSP in 96%, and irregular MVP in 96%, and the LEEs' evaluations determined the presence of DL in 98%, irregular MSP in 95%, and irregular MVP in 95% of the EGCs. When DL was present, HC levels in the Helicobacter pylori- (H. pylori-) eradicated group and noneradicated group were evident in 65% and 89%, a difference that was significant (p < 0.001). CONCLUSIONS: In the diagnosis of EGC with ME-BLI, the VS classification system with ME-NBI can be applied, but identifying the DL after H. pylori was difficult.

Clinical usefulness of magnifying endoscopy for non-ampullary duodenal tumors.

Study aims This study aimed to investigate the clinical usefulness of magnifying endoscopy (ME) for non-ampullary duodenal tumors. Patients and methods We enrolled 103 consecutive patients with non-ampullary duodenal tumors that were observed by ME with narrow-band imaging (ME-NBI) and had pit pattern analysis before endoscopic resection at Hiroshima University Hospital before December 2014. ME-NBI images were classified as Type B or Type C according to the Hiroshima classification, and pit patterns were classified as regular or irregular. We studied the clinicopathological features and diagnoses with ME-NBI and pit pattern analyses according to the Vienna classification (category 3: 73 patients; category 4: 30 patients). Results Category 4 lesions were significantly larger than category 3 lesions. According to ME-NBI images, category 4 Type C lesions (83 %) were significantly more common than category 4 Type B lesions (17 %). According to pit pattern analyses, category 4 irregular lesions 4 (77 %) were significantly more common than category 4 regular lesions (23 %). The accuracies of using Type C ME-NBI images and irregular pit patterns to diagnose category 4 lesions were 87 % and 84 %, the sensitivities were 83 % and 77 %, and the specificities were 89 % and 88 %, respectively. There was no significant difference between ME-NBI and pit pattern analyses for diagnosing the histologic grade of non-ampullary duodenal tumors. Conclusion Our study showed that ME-NBI and pit pattern analysis had equivalent abilities to determine the histologic grade of non-ampullary duodenal tumors. ME-NBI may be more useful because it is a simple, less time-consuming procedure.

Useful condition of chromoendoscopy with indigo carmine and acetic acid for identifying a demarcation line prior to endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Identifying a precise demarcation line (DL) is indispensable for pathological complete en bloc endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We evaluated the useful condition of chromoendoscopy with indigo carmine and acetic acid for marking dots around lesions before ESD for EGC. METHODS: We examined 98 consecutive patients with 109 intramucosal EGCs (mean diameter, 17.8 ± 12.4 mm; main histologic type, 96 intestinal and 13 diffuse) resected by en bloc ESD after chromoendoscopy with indigo carmine and acetic acid between December 2012 and February 2014. The DL was identified by this technique just before ESD (mean chromoendoscopy observation time, 71.6 s); subsequently, marking dots were placed around the EGC. EGCs were classified into two groups: useful for identifying the DL or useless. Clinicopathological characteristics and clinical outcomes were evaluated in each group. RESULTS: Forty-two of the 109 cases (38.5 %) were determined useful for chromoendoscopy with indigo carmine and acetic acid. Multivariate analysis with logistic regression showed that macroscopic type (protruded or flat elevated-type) and atrophic border (the oral side of tumor) were independently associated with the usefulness of chromoendoscopy using indigo carmine and acetic acid for identifying the DL of EGCs (P < 0.05). The histologically positive horizontal margin after ESD was 0 % (0/42) in useful cases, and 7.5 % (5/67) in useless cases. CONCLUSIONS: Before ESD, chromoendoscopy with indigo carmine and acetic acid can be used for creating precise markings in protruded or flat elevated-type EGC or at the atrophic border on the oral side of EGCs.

Long-term prognosis after endoscopic submucosal dissection for early gastric cancer in super-elderly patients.

BACKGROUND: No previous study has confirmed the safety of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in the super-elderly patient population. The current study aimed to evaluate the validity of ESD for EGC in super-elderly patients aged ≥85 years with comorbidities. METHODS: Our study group included 85 super-elderly patients (102 EGCs) who were diagnosed at Hiroshima University Hospital between April 2002 and October 2014. We evaluated the en bloc resection rates, R0 resection rates, complication rates, and prognosis in relation to the degree of comorbidities (group A-H, patients with high-risk comorbidities; group A-L, patients with low-risk comorbidities; group B, patients without comorbidities; and group C, patients followed without ESD). RESULTS: The en bloc resection rates were 100, 96, and 100 % in groups A-H, A-L, and B, respectively. R0 resection rates were 94, 96, and 94 % in groups A-H, A-L, and B, respectively. There were no severe complications related to ESD. During the follow-up period, there was a significantly higher frequency of death in group A than in group B (p < 0.01), and there were no significant differences between groups A-H and A-L. However, there were no cases of death related to gastric cancer. CONCLUSIONS: ESD was performed safely, and death related to gastric cancer was prevented in super-elderly patients with comorbidities, regardless of the degree of the disease. However, patients with comorbidities are at a high risk of poor prognosis.

Computer-aided diagnosis of colorectal polyp histology by using a real-time image recognition system and narrow-band imaging magnifying colonoscopy.

BACKGROUND AND AIMS: It is necessary to establish cost-effective examinations and treatments for diminutive colorectal tumors that consider the treatment risk and surveillance interval after treatment. The Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) committee of the American Society for Gastrointestinal Endoscopy published a statement recommending the establishment of endoscopic techniques that practice the resect and discard strategy. The aims of this study were to evaluate whether our newly developed real-time image recognition system can predict histologic diagnoses of colorectal lesions depicted on narrow-band imaging and to satisfy some problems with the PIVI recommendations. METHODS: We enrolled 41 patients who had undergone endoscopic resection of 118 colorectal lesions (45 nonneoplastic lesions and 73 neoplastic lesions). We compared the results of real-time image recognition system analysis with that of narrow-band imaging diagnosis and evaluated the correlation between image analysis and the pathological results. RESULTS: Concordance between the endoscopic diagnosis and diagnosis by a real-time image recognition system with a support vector machine output value was 97.5% (115/118). Accuracy between the histologic findings of diminutive colorectal lesions (polyps) and diagnosis by a real-time image recognition system with a support vector machine output value was 93.2% (sensitivity, 93.0%; specificity, 93.3%; positive predictive value (PPV), 93.0%; and negative predictive value, 93.3%). CONCLUSIONS: Although further investigation is necessary to establish our computer-aided diagnosis system, this real-time image recognition system may satisfy the PIVI recommendations and be useful for predicting the histology of colorectal tumors.

Risk factors for esophageal stenosis after entire circumferential endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma.

BACKGROUND: Endoscopic submucosal dissection (ESD) is used to perform en block resection for esophageal squamous cell carcinoma, but it is strongly associated with postoperative stenosis, especially during entire circumferential resection. This study aimed to clarify the risk factors for refractory postoperative stenosis after entire circumferential esophageal ESD. METHODS: Nineteen patients who underwent entire circumferential esophageal ESD from February 2006 to December 2013 at Hiroshima University Hospital were divided into two groups: refractory postoperative stenosis [≥6 endoscopic balloon dilation (EBD) procedures, 12 lesions in 12 patients] and non-refractory postoperative stenosis (≤5 EBD procedures, 7 lesions in 7 patients). We retrospectively examined the patient factors (age, sex, alcohol consumption, smoking index, and chemoradiation therapy history), tumor factors (location, macroscopic type, fibrosis, and depth), and treatment factors (mean procedure time, entire circumferential resection diameter, muscle layer damage, and steroid administration method) between the two groups. RESULTS: Muscle layer damage (p = 0.019) and ≥5 cm of longitudinal mucosal defect length after entire circumferential esophageal ESD (p = 0.010) were significant factors associated with the refractory group. Regarding the patient and tumor factors, there were no significant differences between the two groups. CONCLUSION: Our data suggest that refractory post-ESD stenosis occurs after entire circumferential esophageal ESD with muscle layer damage and ≥5 cm of longitudinal mucosal defect length.