[Ascending colon cancer with submucosal tumor-like morphology arising near ileal valve lipohyperplasia:a case report].

An 89-year-old man was diagnosed with a submucosal tumor suspected to be a lipoma and was followed up for 6 years. The patient was admitted to the hospital because of increased tumor size and morphological changes despite negative bioptic findings. The lesion was diagnosed as an advanced adenocarcinoma of the ascending colon (cT3N0M0, cStage IIa). Laparoscopic-assisted right hemicolectomy with D3 lymph node dissection was performed. Pathological diagnosis of a surgically resected specimen revealed adenocarcinoma with lipohyperplasia (pT3N2aM0, pStage IIIb). Reports of colon cancer accompanied by colonic lipomas or lipohyperplasia are limited. This case showed an interesting submucosal tumor-like morphology because the cancer developed at the base of the lipohyperplasia and grew and spread below it.

Impact of an artificial intelligence-aided endoscopic diagnosis system on improving endoscopy quality for trainees in colonoscopy: Prospective, randomized, multicenter study.

OBJECTIVE: This study was performed to evaluate whether the use of CAD EYE (Fujifilm, Tokyo, Japan) for colonoscopy improves colonoscopy quality in gastroenterology trainees. METHODS: The patients in this multicenter randomized controlled trial were divided into Group A (observation using CAD EYE) and Group B (standard observation). Six trainees performed colonoscopies using a back-to-back method in pairs with gastroenterology experts. The primary end-point was the trainees' adenoma detection rate (ADR), and the secondary end-points were the trainees' adenoma miss rate (AMR) and Assessment of Competency in Endoscopy (ACE) tool scores. Each trainee's learning curve was evaluated using a cumulative sum (CUSUM) control chart. RESULTS: We analyzed data for 231 patients (Group A, n = 113; Group B, n = 118). The ADR was not significantly different between the two groups. Group A had a significantly lower AMR (25.6% vs. 38.6%, P = 0.033) and number of missed adenomas per patient (0.5 vs. 0.9, P = 0.004) than Group B. Group A also had significantly higher ACE tool scores for pathology identification (2.26 vs. 2.07, P = 0.030) and interpretation and identification of pathology location (2.18 vs. 2.00, P = 0.038). For the CUSUM learning curve, Group A showed a trend toward a lower number of cases of missed multiple adenomas by the six trainees. CONCLUSION: CAD EYE did not improve ADR but decreased the AMR and improved the ability to accurately locate and identify colorectal adenomas. CAD EYE can be assumed to be beneficial for improving colonoscopy quality in gastroenterology trainees. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN000044031).

A rare case of inflammatory myofibroblast tumor of the stomach successfully treated by inverted laparoscopic and endoscopic cooperative surgery.

BACKGROUND: An Inflammatory myofibroblastic tumor (IMT) is a rare intermediate malignancy characterized by myofibroblast proliferation and inflammatory cell infiltration. Various organs are the primary sites of origin. However, primary tumors originating in the stomach tend to be extremely rare, making the diagnosis difficult. Herein, we present a case of IMT originating in the stomach that was effectively managed using inverted laparoscopic endoscopic cooperative surgery (LECS). CASE PRESENTATION: A 47-year-old male who was admitted to the hospital because of a submucosal tumor that was discovered during upper gastrointestinal endoscopy. The diameter of the tumor was approximately 20 mm. A KIT-negative gastrointestinal stromal tumor was suspected based on the biopsy findings. Therefore, partial resection of the stomach was performed using inverted laparoscopic and endoscopic cooperative surgery. Histopathological examination revealed collagen fiber proliferation from the submucosal layer to the muscular layer, accompanied by infiltration of spindle-shaped cells, lymphocytes, and numerous inflammatory cells. Immunohistochemistry results were positive for SMA and negative for CD34, desmin, and c-kit. IgG4-positive cells were observed with an IgG4/IgG ratio > 50%, and specific nuclei were positive for ALK. Therefore, IMT was diagnosed. This condition may be difficult to diagnose both before and after surgery because of its rarity and submucosal tumor-like morphology. CONCLUSION: When a submucosal tumor originating in the stomach is observed, IMT should be considered. Partial resection of the stomach with LECS and immunohistochemical diagnosis may be useful.

Machine learning-based model for prediction and feature analysis of recurrence in pancreatic neuroendocrine tumors G1/G2.

BACKGROUND: Pancreatic neuroendocrine neoplasms (PanNENs) are a heterogeneous group of tumors. Although the prognosis of resected PanNENs is generally considered to be good, a relatively high recurrence rate has been reported. Given the scarcity of large-scale reports about PanNEN recurrence due to their rarity, we aimed to identify the predictors for recurrence in patients with resected PanNENs to improve prognosis. METHODS: We established a multicenter database of 573 patients with PanNENs, who underwent resection between January 1987 and July 2020 at 22 Japanese centers, mainly in the Kyushu region. We evaluated the clinical characteristics of 371 patients with localized non-functioning pancreatic neuroendocrine tumors (G1/G2). We also constructed a machine learning-based prediction model to analyze the important features to determine recurrence. RESULTS: Fifty-two patients experienced recurrence (14.0%) during the follow-up period, with the median time of recurrence being 33.7 months. The random survival forest (RSF) model showed better predictive performance than the Cox proportional hazards regression model in terms of the Harrell's C-index (0.841 vs. 0.820). The Ki-67 index, residual tumor, WHO grade, tumor size, and lymph node metastasis were the top five predictors in the RSF model; tumor size above 20 mm was the watershed with increased recurrence probability, whereas the 5-year disease-free survival rate decreased linearly as the Ki-67 index increased. CONCLUSIONS: Our study revealed the characteristics of resected PanNENs in real-world clinical practice. Machine learning techniques can be powerful analytical tools that provide new insights into the relationship between the Ki-67 index or tumor size and recurrence.

Utility and safety of the self-expandable metallic colonic stent in Japanese patients who received systemic chemotherapy or palliative treatment for obstructive primary advanced colorectal cancer: A retrospective single-center medical chart evaluation.

Background and Aim: The present study aimed to compare the utility and safety of the colonic self-expandable metallic stent between patients with obstructive primary colorectal cancer who underwent chemotherapy or palliative treatment care and patients bridging for surgery. Methods: The cases of 71 patients with colonic obstructive stenosis and in-dwelling stents who were hospitalized between May 2012 and April 2020 at Karatsu Red Cross Hospital were retrospectively analyzed. The patients were classified into three groups: bridging for curative surgery (group I), receiving systemic chemotherapy (group II-A), and receiving only palliative treatment (group II-B). Technical and clinical success rates and complication rates after stenting were evaluated. Results: No significant differences were observed in the technical (procedure) success rates (group I: 100%; group II, 97.6% [II-A: 100%; II-B: 95.8%]). The total clinical success rate was 85.9% (61/71) and did not vary significantly among the groups (group I: 82.8%; group II 88.0% [II-A: 83.3%; II-B: 91.6%]). No significant differences were observed in the early complication rates between groups I and II and in the late complication rates between groups II-A and II-B. Nutrition status, general condition, tumor staging, and 1-year survival were poorer in group II than in group I. Conclusion: The findings show that colonic stenting for malignant obstruction was performed successfully and safely both in patients who received systemic chemotherapy or palliative therapy and in patients bridging for curative surgery, regardless of risk status for malnutrition, poor general condition, cancer stage progression, and short survival.

Efficacy of elobixibat as bowel preparation agent for colonoscopy: Prospective, randomized, multi-center study.

BACKGROUND AND AIM: Elobixibat is a novel ileal bile acid transporter inhibitor. This study aimed to compare the efficacy, tolerability, and safety of the combination of elobixibat and 1 L of polyethylene glycol formulation containing ascorbic acid (PEG-Asc) solution versus the combination of sodium picosulfate and 1-L PEG-Asc solution as bowel preparation for colonoscopy. METHODS: This multi-center, randomized, observer-blinded, non-inferiority study recruited 210 outpatients who were assigned to either the elobixibat plus 1-L PEG-Asc group (group A) or the sodium picosulfate plus 1-L PEG-Asc group (group B). The quality of the bowel cleansing level was assessed by the Boston Bowel Preparation Scale (BBPS) and compared the bowel cleansing level between the groups. Data regarding bowel preparation time, patients' tolerability, and adverse events were also analyzed. RESULTS: Data for 196 patients (99 in group A and 97 in group B) were analyzed finally. BBPS was comparable between group A and B (8.3 ± 0.9 vs. 8.3 ± 0.7; P = 0.88). Consequently, the adequate bowel preparation rate in groups A and B was 95.0% and 99.0%, respectively (-4.0%, 95% CI -9.3 to 1.5). Bowel preparation time in group A was similar to that in group B (348.2 ± 79.8 min vs. 330.8 ± 82.5 min; P = 0.13), whereas, sleep disturbance was significantly less frequent in group A than in group B (10.2% vs. 22.7%; P = 0.02). CONCLUSIONS: The combination of elobixibat and 1-L PEG-Asc can be considered an alternative bowel preparation for colonoscopy considering the equivalent bowel cleansing effect and less frequent sleep disturbance. The Japan Registry of Clinical Trials (jRCTs41180026).

Safety and Efficacy of the Noncessation Method of Antithrombotic Agents after Emergency Endoscopic Hemostasis in Patients with Nonvariceal Upper Gastrointestinal Bleeding: A Multicenter Pilot Study.

Background and Aims: The present study aimed to clarify the safety and efficacy of the noncessation method of antithrombotic agents after emergency endoscopic hemostasis in patients with nonvariceal upper gastrointestinal bleeding (UGIB). Methods: In this multicenter, prospective, pilot study, we performed emergency endoscopic hemostasis for nonvariceal UGIB in patients taking antithrombotic agents and resumed the medications without a cessation period (group A). The clinical characteristics, types of antithrombotic agents, UGIB etiology, treatment outcome, and adverse events were evaluated. We used propensity score matching to compare treatment outcomes and adverse events with our previous cohort (group B) in whom antithrombotic agents were transiently discontinued after emergency endoscopic hemostasis. Results: Forty-three consecutive patients were prospectively enrolled. The main antithrombotic agents were low-dose aspirin and direct oral anticoagulants; 11 patients (25.6%) were taking multiple antithrombotics. Peptic ulcers were the main cause of bleeding (95.4%). Endoscopic hemostasis was successful in all patients and the incidence of rebleeding within a month was 7.0%. Propensity score matching created 40 matched pairs. Endoscopic hemostasis was performed by soft coagulation significantly more frequently in group A than in group B (97.5% versus 60.0%, P < 0.001). Neither the rebleeding rate within a month nor thromboembolic event rate was different between the two groups. However, the mean duration of hospitalization was significantly shorter in group A than in group B (8.6 ± 5.2 d versus 14.4 ± 7.1 d, P < 0.001). Conclusions: Antithrombotic agents possibly can be continued after successful emergency endoscopic hemostasis for nonvariceal UGIB.

Risk Factors for Post-Endoscopic Retrograde Pancreatography Pancreatitis: A Retrospective Chart Review in a Regional Hospital in Japan.

BACKGROUND: Endoscopic retrograde pancreatography (ERCP) is sometimes complicated by post-ERCP pancreatitis (PEP), which is a severe adverse effect. OBJECTIVE: The present study was performed to (i) evaluate the risk factors for PEP and (ii) compare the risk of PEP after ERCP performed in the off hours versus regular hours. METHODS: This retrospective study included 374 patients who underwent ERCP from January 2013 to December 2017. Among these patients, 38 (10.2%) developed PEP. The potential risk factors for PEP were evaluated by multivariate regression analysis, and the risk of PEP was compared between ERCP performed during regular hours and off hours. RESULTS: The independent risk factors for PEP were a relatively younger age (<75 years; p = 0.024), female sex (p = 0.002), a history of pancreatitis (p = 0.044), and performance of pancreatography (p = 0.010). Use of a diclofenac suppository and performance of pancreatic stenting were not preventive for PEP after ERCP. The complication rate of PEP did not differ between ERCP performed during the off hours versus regular hours. CONCLUSIONS: A relatively younger age (<75 years), female sex, a history of pancreatitis, and performance of pancreatography were potential risk factors for PEP, whereas the risk of PEP was not different between ERCP performed during the off hours versus regular hours.

An Investigation of Nine Patients with Gastrointestinal Immune-Related Adverse Events Caused by Immune Checkpoint Inhibitors.

INTRODUCTION/AIMS: Immune checkpoint inhibitors (ICIs) sometimes cause immune-related adverse events (irAEs), of which there is little information in the literatures. The objective of this study was to characterize the clinical features of gastrointestinal irAEs (GI irAEs). MATERIALS AND METHODS: From a total of 250 patients who were administered anti-PD-1 antibodies (nivolumab and pembrolizumab), we retrospectively identified 9 patients with grade 2 or higher GI irAE based on medical records. Patient characteristics, clinical features, imaging and pathological findings, and treatment course were evaluated. RESULTS: Grade 2 or higher GI irAEs were observed in 9 (3.6%) patients. Of the 9 patients who experienced GI irAE, 8 were male, and mean age was 63.2 years. Five patients received nivolumab and 4 received pembrolizumab. The GI irAEs observed were diarrhea in 7 patients and bloody stool in 2 patients. Grade 2 GI irAEs were identified in 3 patients and grade 3 GI irAEs in 6 patients. The average time from ICI administration to the onset of GI irAEs was 22.2 weeks (range 7-56 weeks) for nivolumab and 19.7 weeks (range 11-28 weeks) for pembrolizumab. Endoscopic findings showed ulcerative colitis-like findings in 3 of 7 patients, and pathological examination revealed crypt epithelial cell apoptosis in 6 of 7 patients. Eight of the 9 patients received steroids, and 2 patients received infliximab additionally. All GI irAEs were manageable. CONCLUSIONS: Because of the lack of specific clinical, imaging, and pathological findings, information of ICI use was indispensable for diagnosis. Although GI irAEs are controllable by steroid and infliximab, further studies regarding management strategy will be needed.

Correlation of Barrett's esophagus with colorectal polyps in Japanese patients: A retrospective chart review.

BACKGROUND AND AIM: Barrett's esophagus and colorectal polyps have several overlapping risk factors. Whereas several reports in Western countries have indicated a close relationship between Barrett's esophagus and colorectal polyps, the relationship between these two diseases remains unclear in Japan. This study was performed to determine whether the prevalence of Barrett's esophagus is related to that of colorectal polyps in Japanese patients. METHODS: The present retrospective chart review included 1582 Japanese patients who underwent both total colonoscopy and esophagogastroduodenoscopy from January 2010 to December 2016. The data on colorectal polyps and Barrett's esophagus were obtained from the endoscopic findings. The medical record of each patient was checked for age, sex, body mass index, smoking, alcohol drinking, use of acid suppression agents, and comorbidities including a history of diabetes, ischemic heart disease, gastroesophageal reflux disease, hiatal hernia, and Helicobacter pylori infection. RESULTS: Colorectal polyps were detected in 789 of the 1582 patients (49.9%). Barrett's esophagus was detected in 233 patients (14.7%), and most cases of Barrett's esophagus (n = 229) were classified as short-segment Barrett's esophagus. Colorectal polyps were more frequent in patients with than without Barrett's esophagus (odds ratio, 1.79; 95% confidence interval, 1.31-2.46; P < 0.001). In addition to Barrett's esophagus, the data indicated that old age, male sex, obesity, smoking, alcohol drinking, diabetes mellitus, and ischemic heart disease were independent risk factors for colorectal polyps. CONCLUSIONS: The present study revealed the correlation between the prevalence of Barrett's esophagus and colorectal polyps in Japanese patients.

Lower Rebleeding Rate after Endoscopic Band Ligation than Endoscopic Clipping of the Same Colonic Diverticular Hemorrhagic Lesion: A Historical Multicenter Trial in Saga, Japan.

Objective This historical control study was performed to evaluate i) the rebleeding rate of bleeding colon diverticula treated with endoscopic band ligation (EBL) versus endoscopic clipping (EC) and ii) risk factors for rebleeding of diverticula initially treated by endoscopic hemostasis. Methods From January 2010 to December 2012, 68 patients were treated with EC, and from January 2013 to August 2016, 67 patients were treated with EBL. All patients in each group were followed up for one year to check for rebleeding. Results The rebleeding rate was lower in the EBL group (7 of 67, 10%) than in the EC group (21 of 68, 31%; p<0.01). This difference was mainly due to the lower rebleeding rate from the same hemorrhagic diverticulum initially treated by hemostasis (EBL: 4 of 67, 6%; EC: 15 of 68, 22%; p<0.01). The time span until rebleeding in the EBL group was ≤1 week. A multivariate analysis indicated that bleeding from the diverticula on the right side of the colon was a high-risk factor for rebleeding from the diverticula (odds ratio, 4.48; 95% confidence interval, 1.22-16.46; p=0.02). Conclusion The low rebleeding rate in the EBL group was attributed to the low degree of rebleeding from the same diverticulum, indicating that EBL was superior to EC in preventing rebleeding of an initially treated diverticulum.

The Palliative Effect of Endoscopic Uncovered Self-expandable Metallic Stent Placement Versus Gastrojejunostomy on Malignant Gastric Outlet Obstruction: A Pilot Study with a Retrospective Chart Review in Saga, Japan.

Objective Endoscopic self-expandable metallic stent (SEMS) placement and gastrojejunostomy (GJY) are palliative treatments for malignant gastric outlet obstruction (GOO). The aim of the present study was to compare the palliative effects of these treatments and identify predictors of a poor oral intake after treatment. Methods and Patients In total, 65 patients with GOO at multiple centers in Saga, Japan, were evaluated. Thirty-eight patients underwent SEMS placement, and 27 underwent GJY from January 2010 to December 2016. The characteristics and outcomes of the two groups were compared to detect predictors of treatment failure. Results No significant differences in the technical success, clinical success, post-treatment total protein, hospital discharge, duration from eating disability to death, or post-treatment overall survival were present between the SEMS and GJY groups. More patients in the GJY group than in the SEMS group received chemotherapy (51.4% vs. 26.3%, respectively; p=0.042). The period from treatment to the first meal was longer in the GJY group than in the SEMS group (4.5 vs. 3.0 days, respectively; p=0.013). The present study did not identify any risk factors for failure of SEMS placement. Although the stent length tended to be associated with a poor prognosis, the correlation was not statistically significant (odds ratio: 0.60, 95% confidence interval: 0.36-1.01, p=0.053). Conclusion Patients with GOO started meals more promptly after SEMS than after GJY, but the clinical outcomes were not markedly different between the SEMS and GJY groups. These findings suggest that endoscopic uncovered SEMS placement might be a feasible palliative treatment for GOO.

Outcomes of Patients Undergoing Endoscopic Hemostasis for the Upper Gastrointestinal Bleeding Were Not Influenced by the Timing of Hospital Emergency Visits: A Situation Prevailing in Japan.

BACKGROUND: The aim of the present study was to determine differences in the prognosis of patients in Japan who underwent emergency endoscopic hemostasis (i) during regular hours versus off hours and (ii) as outpatients versus hospitalized patients. METHODS: The present retrospective study included 443 patients who underwent emergency endoscopic hemostasis for non-variceal upper gastrointestinal bleeding from January 2008 to December 2014. These patients were classified into 2 groups: hospitalized patients and outpatients. The outpatients were further subclassified into those who visited the hospital during regular hours and those who visited during off hours. RESULTS: The outcomes of outpatients who underwent emergency hemostasis during off hours did not differ from patients treated during regular hours. Multivariate analysis revealed that outcomes of hospitalized patients, including mortality, need for blood transfusion and length of hospitalization, were worse than those of outpatients; it also revealed that patient age, malnutrition rate and prevalence of diabetes and neoplasms were higher among hospitalized patients than those in outpatients. CONCLUSIONS: The clinical outcomes of patients who underwent emergency endoscopic hemostasis for upper gastrointestinal bleeding during off hours did not differ from those of patients treated during regular hours. Outcomes were worse among hospitalized patients, mainly because of their bad general condition.

A case of granulomatous inflammation of the sigmoid colon caused by a fish bone that resembled cancer.

This case involved a 76-year-old man. Total colonoscopy was performed as a second examination for colorectal cancer because of positive fecal occult blood results, revealing a neoplasm with ulceration in the sigmoid colon. We suspected type-3 colorectal cancer and performed a biopsy, but the biopsy diagnosis showed only an ulcer with active inflammation. Colonoscopic re-examination in a highly advanced medical institution revealed granulomatous inflammation of the sigmoid colon caused by a fish bone, and the fish bone was removed endoscopically. Granulomatous inflammation of the colon caused by a fish bone is very rare, but sometimes needs to be differentiated from cancer. Endoscopic therapy can also be an option, depending on abdominal findings and the penetration status of the fish bone into the large intestinal wall.

Risk factors for resistance to proton pump inhibitor maintenance therapy for reflux esophagitis in Japanese women over 60 years.

AIM: The aim of this study was to evaluate risk factors for proton pump inhibitor (PPI) resistance in older Japanese female patients with reflux esophagitis evaluated by physicians. METHODS: The study included 462 Japanese female patients aged over 60 years with reflux esophagitis who received PPI maintenance therapy for more than 6 months. RESULTS: The characteristics of all 462 patients were: age: 76.4 ± 7.6 years, height: 147.2 ± 6.1 cm, weight: 49.9 ± 8.4 kg and body mass index: 24.0 ± 3.5. The reflux esophagitis grades were A in 69.5%, B in 15.8%, C in 9.1% and D in 5.6%. Helicobacter pylori was positive in 60.6%. Regarding PPI maintenance therapy for clinical symptoms evaluated by the attending physicians, 66.7% were 'good control', 26.8% were 'reasonable control' and 6.5% were 'bad control: resistant'. PPI maintenance therapy was less effective in patients with more severe reflux esophagitis of grades C and D (OR: 0.027; 95% CI: 0.010-0.077) and negative H. pylori infection status (OR: 4.470; 95% CI: 1.631-12.247). Lumbar kyphosis and hiatus hernia were risk factors for severity grading of reflux esophagitis. CONCLUSIONS: PPI maintenance therapy evaluated by attending physicians indicated that reflux esophagitis severity and negative H. pylori status were risk factors for treatment resistance.

Perforation and postoperative bleeding of endoscopic submucosal dissection in gastric tumors: analysis of 1190 lesions in low- and high-volume centers in Saga, Japan.

BACKGROUND: This retrospective study aimed to determine risk factors associated with serious complications of endoscopic submucosal dissection of gastric tumors in multicenters compared between high- and low-volume centers. METHODS: Between 2001 and 2010, gastric endoscopic submucosal dissection was performed in 1190 lesions of 1082 patients in five hospitals in Saga, three high-volume and two low-volume centers. Risk factors for serious complications were evaluated. Patients' background characteristics were evaluated, including anticoagulants use and underlying diseases. RESULTS: Postoperative bleeding was detected in 75 patients (6.9%), and perforation was detected in 40 patients (3.7%). Most postoperative bleeding and perforation cases were recovered with endoscopic procedures, although one case of each complication was treated by emergency surgery. Multivariate analysis indicated that risk factors for perforation were tumor location, massive submucusal invasion, endoscopists' experience of 100-149 cases and hypertension, and that risk factors for postoperative bleeding were tumor location, resected tumor size, and scar lesion. The serious complications were not different between high- and low-volume centers. CONCLUSIONS: The present study indicated that risk factors for perforation during endoscopic submucosal dissection were tumor, endoscopist and patient related, although risk factors for postoperative bleeding were tumor related. There was no difference in complications between high- and low-volume centers.