Association Between Vonoprazan and the Risk of Gastric Cancer After Helicobacter pylori Eradication

BACKGROUND & AIMS

Potassium-competitive acid blockers (PCABs) have been increasingly used to treat upper gastrointestinal disorders, replacing proton pump inhibitors (PPIs). Whereas PPIs are associated with an increased risk of gastric cancer (GC) after Helicobacter pylori (Hp) eradication, it is uncertain whether PCABs carry the same risk.

METHODS

Using a population-based claims database in Japan, we identified patients who were prescribed a clarithromycin-based first regimen of Hp eradication between 2015 and 2018. Patients who failed this regimen and those diagnosed with GC before or within 1 year after Hp eradication were excluded. We compared GC incidence between PCAB users and histamine type-2 receptor antagonist (H2RA) users, matching them on the basis of propensity scores calculated with considerations for age, sex, smoking, alcohol consumption, comorbidities, and co-administered medications. PCABs included only vonoprazan in this study.

RESULTS

Among 54,055 patients, 568 (1.05%) developed GC during the follow-up period (mean, 3.65 years). The cumulative incidence of GC was 1.64% at 3 years, 2.02% at 4 years, and 2.36% at 5 years in PCAB users and 0.71% at 3 years, 1.04% at 4 years, and 1.22% at 5 years in H2RA users. The use of PCABs was associated with a higher GC risk (matched hazard ratio, 1.92; 95% confidence interval, 1.13-3.25; P = .016). Longer PCAB use and high-dose PCAB use were significantly associated with higher incidence of GC. Sensitivity analyses showed the risk of GC incidence among PCAB users was comparable with that of PPI users.

CONCLUSIONS

The use of PCABs was associated with an increased risk of GC among Hp-eradicated patients, with duration/dose response effects.

Impaired Glycosylation of Gastric Mucins Drives Gastric Tumorigenesis and Serves as a Novel Therapeutic Target

BACKGROUND & AIMS

Gastric cancer is often accompanied by a loss of mucin 6 (MUC6), but its pathogenic role in gastric carcinogenesis remains unclear.

METHODS

Muc6 knockout (Muc6-/-) mice and Muc6-dsRED mice were newly generated. Tff1Cre, Golph3-/-, R26-Golgi-mCherry, Hes1flox/flox, Cosmcflox/flox, and A4gnt-/- mice were also used. Histology, DNA and RNA, proteins, and sugar chains were analyzed by whole-exon DNA sequence, RNA sequence, immunohistochemistry, lectin-binding assays, and liquid chromatography-mass spectrometry analysis. Gastric organoids and cell lines were used for in vitro assays and xenograft experiments.

RESULTS

Deletion of Muc6 in mice spontaneously causes pan-gastritis and invasive gastric cancers. Muc6-deficient tumor growth was dependent on mitogen-activated protein kinase activation, mediated by Golgi stress-induced up-regulation of Golgi phosphoprotein 3. Glycomic profiling revealed aberrant expression of mannose-rich N-linked glycans in gastric tumors, detected with banana lectin in association with lack of MUC6 expression. We identified a precursor of clusterin as a binding partner of mannose glycans. Mitogen-activated protein kinase activation, Golgi stress responses, and aberrant mannose expression are found in separate Cosmc- and A4gnt-deficient mouse models that lack normal O-glycosylation. Banana lectin-drug conjugates proved an effective treatment for mannose-rich murine and human gastric cancer.

CONCLUSIONS

We propose that Golgi stress responses and aberrant glycans are important drivers of and promising new therapeutic targets for gastric cancer.

Comparison of clinical utility of deep learning-based systems for small-bowel capsule endoscopy reading

BACKGROUND AND AIM

Convolutional neural network (CNN) systems that automatically detect abnormalities from small-bowel capsule endoscopy (SBCE) images are still experimental, and no studies have directly compared the clinical usefulness of different systems. We compared endoscopist readings using an existing and a novel CNN system in a real-world SBCE setting.

METHODS

Thirty-six complete SBCE videos, including 43 abnormal lesions (18 mucosal breaks, 8 angioectasia, and 17 protruding lesions), were retrospectively prepared. Three reading processes were compared: (A) endoscopist readings without CNN screening, (B) endoscopist readings after an existing CNN screening, and (C) endoscopist readings after a novel CNN screening.

RESULTS

The mean number of small-bowel images was 14 747 per patient. Among these images, existing and novel CNN systems automatically captured 24.3% and 9.4% of the images, respectively. In this process, both systems extracted all 43 abnormal lesions. Next, we focused on the clinical usefulness. The detection rates of abnormalities by trainee endoscopists were not significantly different across the three processes: A, 77%; B, 67%; and C, 79%. The mean reading time of the trainees was the shortest during process C (10.1 min per patient), followed by processes B (23.1 min per patient) and A (33.6 min per patient). The mean psychological stress score while reading videos (scale, 1-5) was the lowest in process C (1.8) but was not significantly different between processes B (2.8) and A (3.2).

CONCLUSIONS

Our novel CNN system significantly reduced endoscopist reading time and psychological stress while maintaining the detectability of abnormalities. CNN performance directly affects clinical utility and should be carefully assessed.

Improvement of dyspeptic symptoms after Helicobacter pylori eradication therapy in Japanese patients

Background and Aim

Helicobacter pylori eradication therapy effectively improves the abdominal symptoms and bowel habits of patients. Patients in whom dyspepsia is under control by 6 to 12 months after successful H. pylori eradication are defined as having H. pylori-associated dyspepsia, and patients with dyspepsia that is refractory to successful eradication are defined as having functional dyspepsia. Here, we aimed to investigate the association between H. pylori eradication and improvement of dyspepsia in the short and long term after eradication therapy.

Methods

Dyspeptic symptoms before treatment and at 2 and 12 months after eradication were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS) in 282 H. pylori-positive Japanese patients who underwent eradication therapy.

Results

Of the Japanese H. pylori-positive patients, 48.2% (136/282) had upper abdominal symptoms. Eradication improved dyspepsia in 34.5% (47/136) of the patients at 2 months post eradication, which continued to be under control up to 12 months. A significant decrease at 2 and 12 months after eradication, compared with before eradication, was observed in total GSRS (from 25.7 ± 10.4 [before eradication, n = 249] to 23.3 ± 7.2 [after 2 months, n = 249] and 24.8 ± 7.8 [after 12 months, n = 81]; P = 0.014 and 0.321, respectively), gastric pain score (from 4.1 ± 1.9 to 3.7 ± 1.3 and 3.7 ± 1.2; P = 0.025 and 0.047), and constipation score (from 5.9 ± 3.1 to 5.2 ± 2.3 and 5.9 ± 3.0; P < 0.021 and 0.862).

Conclusion

H. pylori-positive dyspepsia patients should be recommended to undergo H. pylori eradication to alleviate dyspepsia-associated symptoms.

Special Issue: The Role of Gut Microbiota in Gastrointestinal Cancers-From Pathogenesis to Therapeutic Perspectives

Associations between the gut microbiota and gastrointestinal carcinogenesis have been intensively studied [...].

Association of probiotic use with nivolumab effectiveness against various cancers: A multicenter retrospective cohort study

BACKGROUND

Previous studies have revealed an association between probiotic use and effectiveness of immune checkpoint inhibitors in renal and lung cancers. However, little is known regarding other cancers, including gastrointestinal cancer.

METHODS

To address this issue, we conducted a multicenter retrospective cohort study and the duration of nivolumab treatment for various cancers was compared between probiotic users and non-users.

RESULTS AND CONCLUSIONS

In total, 488 patients who received nivolumab therapy were included. In all cancers, no significant differences in treatment duration of nivolumab were observed between probiotic users and non-users (median 62.0 vs. 56.0, hazard ratio = 1.02, p = 0.825), whereas probiotic use, compared with non-use, in patients with gastric cancer was significantly associated with a longer duration of nivolumab treatment (55.0 vs. 31.0 days, hazard ratio = 0.69, p = 0.039). In conclusion, probiotics may improve the response to nivolumab and potentially prolong progression-free survival in patients with gastric cancer.

The Association between Diverticular Rebleeding and Early-Morning Blood Pressure and Surge: A Prospective Observational Trial

INTRODUCTION

Colonic diverticular bleeding is the major cause of lower gastrointestinal bleeding. Hypertension is a major risk factor for diverticular rebleeding. Direct evidence of an association between actual 24-h blood pressure (BP) and rebleeding is lacking. Therefore, we analyzed the association between 24-h BP and diverticular rebleeding.

METHODS

We performed a prospective observational cohort trial involving hospitalized patients with colonic diverticular bleeding. We performed 24-h BP measurements (ambulatory BP monitoring [ABPM]) in the patients. The primary outcome was diverticular rebleeding. We evaluated the 24-h BP difference and the morning and pre-awaking BP surge between rebleeding and non-rebleeding patients. Morning BP surge was defined as early-morning systolic BP minus the lowest night systolic BP >45 mm Hg (highest quartile of morning BP surge). The pre-awaking BP surge was defined as the difference between morning BP and pre-awaking BP.

RESULTS

Of 47 patients, 17 were excluded, leaving 30 who underwent ABPM. Of the 30 patients, 4 (13.33%) had rebleeding. The mean 24-h systolic and diastolic BP were 125.05 and 76.19 mm Hg in rebleeding patients and 129.98 and 81.77 mm Hg in non-rebleeding patients, respectively. Systolic BP at 5:00 (difference -23.53 mm Hg, p = 0.031) and 11:30 (difference -31.48 mm Hg, p = 0.006) was significantly lower in rebleeding patients than in non-rebleeding patients. Diastolic BP at 2:30 (difference -17.75 mm Hg, p = 0.023) and 5:00 (difference -16.12 mm Hg, p = 0.043) was significantly lower in rebleeding patients than in non-rebleeding patients. A morning surge was observed in one rebleeding patient and no non-rebleeding patients. The pre-awaking surge was significantly higher in rebleeding patients (28.44 mm Hg) than in non-rebleeding patients (9.30 mm Hg) (p = 0.015).

CONCLUSION

Lower BP in the early-morning and a higher pre-awaking surge were risk factors for diverticular rebleeding. A 24-h ABPM can identify these BP findings and reduce the risk of rebleeding by enabling interventions in patients with diverticular bleeding.

Gastric squamous metaplasia observed by image-enhanced endoscopy

A 61-year-old Helicobacter pylori-positive female with gastroesophageal reflux disease has undergone surveillance endoscopy every year for 13 years at Tokyo Medical University Hospital. At the first surveillance in 2009, conventional white light endoscopy showed a 10-mm whitish slightly depressed lesion at the lesser curvature of the gastric cardia. This lesion gradually increased in size to 15 mm over the 13-year observational period. Indigo carmine chromoendoscopy, narrow band imaging, and texture and color enhancement imaging in both mode 1 and mode 2 clearly emphasized the presence of a depressed whitish mucosa around the gastric mucosa compared with white light imaging. None of the three image-enhanced endoscopy techniques showed any abnormality in the vascular or structural pattern. Pathological findings showed squamous epithelium without atypia and revealed no evidence of malignancy in the stomach. We thus report a case of gastric squamous metaplasia without gastric neoplastic lesion in the gastric cardia whose lesions were endoscopically observed to change the size for more than 10 years and whose lesions were endoscopically evaluated with a texture and color enhancement imaging mode 1 and mode 2 and narrow band imaging.

Improved Object Detection Artificial Intelligence Using the Revised RetinaNet Model for the Automatic Detection of Ulcerations, Vascular Lesions, and Tumors in Wireless Capsule Endoscopy

The use of computer-aided detection models to diagnose lesions in images from wireless capsule endoscopy (WCE) is a topical endoscopic diagnostic solution. We revised our artificial intelligence (AI) model, RetinaNet, to better diagnose multiple types of lesions, including erosions and ulcers, vascular lesions, and tumors. RetinaNet was trained using the data of 1234 patients, consisting of images of 6476 erosions and ulcers, 1916 vascular lesions, 7127 tumors, and 14,014,149 normal tissues. The mean area under the receiver operating characteristic curve (AUC), sensitivity, and specificity for each lesion were evaluated using five-fold stratified cross-validation. Each cross-validation set consisted of between 6,647,148 and 7,267,813 images from 217 patients. The mean AUC values were 0.997 for erosions and ulcers, 0.998 for vascular lesions, and 0.998 for tumors. The mean sensitivities were 0.919, 0.878, and 0.876, respectively. The mean specificities were 0.936, 0.969, and 0.937, and the mean accuracies were 0.930, 0.962, and 0.924, respectively. We developed a new version of an AI-based diagnostic model for the multiclass identification of small bowel lesions in WCE images to help endoscopists appropriately diagnose small intestine diseases in daily clinical practice.

Risk and preventive factors of early-onset colorectal neoplasms: endoscopic and histological database analysis

BACKGROUND AND AIM

The incidence of early-onset colorectal neoplasms has been increasing in both Western and Eastern countries. However, the risks and preventive factors for these neoplasms in Eastern countries remain unclear.

METHODS

The data of 5580 patients who underwent colonoscopy between 2016 and 2021 were retrospectively evaluated. The primary outcome was advanced colorectal neoplasm (ACRN), defined as advanced adenomas (adenoma ≥10 mm, or with high-grade dysplasia or villous component) or adenocarcinoma. The clinical factors associated with ACRNs were determined for each age category (≤50 and >50 years), and the differences between the two categories were assessed. Odds ratios adjusted for age and sex were calculated.

RESULTS

Among 1001 patients (age ≤50 years), ACRN was found in 94 (9.4%). In this younger category, male sex (adjusted odds ratio [aOR]:2.34, 95% confidence interval [CI]:1.51-3.63) and a family history of colorectal cancer (aOR:2.14, 95% CI:1.17-3.89) were significantly associated with higher odds of developing ACRNs. ACRNs were detected in 726 (15.9%) of 4579 patients (age >50 years). In the older age category, smoking (aOR:1.32, 95% CI:1.08-1.63) was significantly associated with a higher risk of ACRNs. Exercise of >3.5 metabolic equivalent of task (METs) (aOR,0.80; 95% CI:0.67-0.96) was significantly associated with a lower risk of ACRNs.

CONCLUSION

The development of early-onset ACRNs was primarily associated with congenital factors, whereas that of late-onset ACRNs was associated with acquired ones. Colonoscopy is recommended for young male patients, particularly for those with a family history of colorectal cancer.

Efficacy of high-vision transnasal endoscopy using texture and colour enhancement imaging and narrow-band imaging to evaluate gastritis: a randomized controlled trial

BACKGROUND

A new image-enhanced endoscopy method called texture and colour enhancement imaging (TXI) enhances brightness, surface irregularities, and subtle colour changes in endoscopic images. However, it is unclear whether TXI and narrow-band imaging (NBI) with third-generation high-vision transnasal ultrathin endoscopy are advantageous over white-light imaging (WLI) for detecting atrophy, intestinal metaplasia, map-like redness and gastric cancer. We investigated to compare the endoscopic efficacy for evaluation of gastritis between TXI and NBI with high-vision transnasal endoscopy and clarified the endoscopic efficacy of TXI and NBI compared to WLI.

METHODS

We enrolled 60 patients who underwent high-vision transnasal endoscopy as part of a health check-up from March to November 2021 and randomized patients into two groups (the WLI-NBI group and the WLI-TXI group) using the minimization method based on Helicobacter pylori infection status, age and sex. Colour differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) colour space was compared between WLI and TXI or NBI.

RESULTS

No significant differences were observed in colour differences surrounding atrophy, intestinal metaplasia and map-like redness between NBI and TXI (p = .553, .057 and .703, respectively). Endoscopic scores based on the Kyoto classification of gastritis for atrophy, intestinal metaplasia, and map-like redness were similar between WLI and TXI. In contrast, NBI identified intestinal metaplasia at a significantly greater rate than WLI (p = .018). Further, colour differences surrounding atrophy and intestinal metaplasia on TXI and NBI were significantly greater than those on WLI (atrophy: TXI vs WLI p = .003, NBI vs WLI p < .001; intestinal metaplasia: TXI vs WLI p = .016, NBI vs WLI p < .001). However, TXI and NBI were not advantageous over WLI for detecting map-like redness.

CONCLUSION

Third-generation high-vision transnasal ultrathin endoscopy using TXI and/or NBI is useful for detecting atrophic borders and intestinal metaplasia.Key MessagesHigh-vision transnasal endoscopy using TXI or NBI is useful for diagnosing and detecting atrophy and intestinal metaplasia.TXI and NBI increase colour differences surrounding atrophy and intestinal metaplasia, thereby increasing diagnostic efficiency to improve risk stratification for gastric cancer.The image quality and detection rate have improved markedly with the latest ultrathin high-vision transnasal endoscopes.

Chemoprevention for Colorectal Cancers: Are Chemopreventive Effects Different Between Left and Right Sided Colorectal Cancers?

BACKGROUND AND AIMS

Recent studies have suggested that right- and left-sided colorectal cancers (CRCs) are molecularly distinct. In this study, we examined the association between the risk of right- and left-sided CRC and drug use to estimate their chemopreventive effects METHODS: This multicenter retrospective cohort study was conducted using the data of hospitalized patients between 2014 and 2019 from nine hospital databases. The primary outcomes were right- and left-sided CRC. We evaluated the association of CRCs with drug use and clinical factors. Odds ratios adjusted for age, sex, Charlson Comorbidity Index scores, and smoking status were calculated. We also compared the transcriptional profiling in precancerous lesions, including sessile serrated lesions (SSLs) RESULTS: A total of 307,938 patients, including 2745 with right-sided CRC and 4819 with left-sided CRC, were analyzed. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, cyclooxygenase-2 inhibitors, and steroids was associated with a lower risk of both right- and left-sided CRCs. In contrast, statins, other lipid-lowering agents, and metformin were associated with a lower risk of left-sided CRC. Transcriptomic analysis showed that SSL, which predominantly develops in the right colon, was associated with a lower expression of lipid metabolism-related genes.

CONCLUSIONS

Targeting lipid metabolism may be useful for chemoprevention of left-sided CRCs, while development of right-sided CRCs may be independent of this pathway.

Investigation of the New Advantages of Colonoscope Insertion with an Endoscopic Position Detection Unit

BACKGROUND

The use of an endoscopic position detection unit (UPD) enables better and more objective understanding of the shape and position of the colonoscope. Here, we investigated the reproducibility of the insertion of a colonoscope with UPD.

MATERIALS AND METHODS

Study participants were 122 patients who received a colonoscopy with UPD twice for the purpose of large bowel screening and surveillance. The mean age of participants was 69.7 ± 10.4 years, and the male-to-female ratio was 9.2:1. The colonoscope insertion technique was primarily based on the shaft-holding, shortening insertion method. The cecal intubation time was recorded; the method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure.

RESULTS

The mean cecal intubation time was 990 ± 511 s. The cecal intubation time and the patterns for passing through the SDJ and hepatic flexure were significantly correlated between the first and second colonoscopies.

CONCLUSION

Use of a UPD revealed good reproducibility of colonoscope insertion. This is the first time we have proved that both time and pattern are inserted in much the same way for the first and second times. In patients' conducted UPD combination TCS after the second time, it was suggested that individual tailor-made insertions are possible based on the information from the first time.

Present status and the future of ultrathin endoscopy

Endoscopic population-based screening for gastric cancer began in April 2016, and the use of transnasal ultrathin esophagogastroduodenoscopy (UT-EGD) has rapidly become popular. With UT-EGD, discomfort associated with an examination is reduced, patient satisfaction is high, and adverse effects on cardiopulmonary function are fewer. Consequently, UT-EGD is a good option for gastric screening in an aging society. Because of the narrower diameter of the endoscope, however, image quality is inferior to that obtained using transoral conventional esophagogastroduodenoscopy (C-EGD). As a result, lesions observed by UT-EGD must be viewed at close proximity and chromoendoscopy should be used concurrently, which is burdensome for the endoscopist. Recent innovations by endoscope manufacturers have enabled dramatic improvements in transnasal UT-EGD and facilitated Hi-Vision imaging. Furthermore, image enhancement that allows for observation on a par with transoral C-EGD is now feasible. In the future, UT-EGD will be equipped with functions that permit magnified endoscopic image. It is anticipated that a multiroute transition between transnasal and transoral UT-EGD will become possible.

Efficacy of Early Video Capsule Endoscopy for Acute Overt Lower Gastrointestinal Bleeding with Colonic Diverticulosis: A Prospective Observational Study

BACKGROUND/AIMS

Although most patients with presumptive colonic diverticular bleeding (CDB) do not undergo a small bowel investigation in clinical practice, no prospective study supports this management. We evaluated the utility of early small bowel capsule endoscopy (CE) after negative colonoscopy results.

METHODS

This prospective study evaluated the diagnostic yield of early small bowel CE (≤3 days from visit) for consecutive patients with acute-onset hematochezia, when colonoscopy found colonic diverticulosis but did not identify the definite bleeding source (n = 51; presumptive CDB). As a matched control for comparing clinical outcomes, presumptive CDB patients without CE (n = 51) were retrospectively extracted.

RESULTS

On CE for the prospective cohort, the rates of total positive findings, P2 findings (high bleeding potential according to the P classification), and blood pooling in the colon were 57%, 12% (ulceration, 8%; angioectasia, 4%), and 24%, respectively. The rates of rebleeding within 30 and 365 days were 16% and 29% in the prospective cohort with CE, respectively, and were not significantly different from those in the retrospective cohort without CE (10% and 25%, respectively). In addition, thromboembolism and mortality within 30 and 365 days were not significantly different between those with and without CE.

CONCLUSION

Early CE detected a suspected small bowel bleeding source in 12% of acute-onset presumptive CDB patients but did not significantly improve major clinical outcomes. Therefore, routine CE is unnecessary for presumptive CDB patients after colonoscopy (UMIN000026676).

Effectiveness and safety of chemotherapy for patients with malignant gastrointestinal obstruction: A Japanese population-based cohort study

BACKGROUND

The impacts of chemotherapy on patients with malignant gastrointestinal obstructions remain unclear, and multicenter evidence is lacking.

AIM

To evaluate the effectiveness and safety of chemotherapy in patients with unresectable malignant gastrointestinal obstructions.

METHODS

We conducted a multicenter retrospective cohort study that compared the chemotherapy group who received any chemotherapeutics after interventions, including palliative surgery or self-expandable metal stent placement, for unresectable malignant gastrointestinal obstruction vs the best supportive care (BSC) group between 2014 and 2019 in nine hospitals. The primary outcome was overall survival, and the secondary outcomes were patency duration and adverse events, including gastrointestinal perforation and gastrointestinal bleeding.

RESULTS

In total, 470 patients in the chemotherapy group and 652 patients in the BSC group were analyzed. During the follow-up period of 54.1 mo, the median overall survival durations were 19.3 mo in the chemotherapy group and 5.4 mo in the BSC group (log-rank test, P < 0.01). The median patency durations were 9.7 mo [95% confidence interval (CI): 7.7-11.5 mo] in the chemotherapy group and 2.5 mo (95%CI: 2.0-2.9 mo) in the BSC group (log-rank test, P < 0.01). The perforation rate was 1.3% (6/470) in the chemotherapy group and 0.9% (6/652) in the BSC group (P = 0.567). The gastrointestinal bleeding rate was 1.5% (7/470) in the chemotherapy group and 0.5% (3/652) in the BSC group (P = 0.105).

CONCLUSION

Chemotherapy after interventions for unresectable malignant gastrointestinal obstruction was associated with increased overall survival and patency duration.

Artificial intelligence versus expert endoscopists for diagnosis of gastric cancer in patients who have undergone upper gastrointestinal endoscopy

AIMS

To compare endoscopy gastric cancer images diagnosis rate between artificial intelligence (AI) and expert endoscopists.

PATIENTS AND METHODS

We used the retrospective data of 500 patients, including 100 with gastric cancer, matched 1:1 to diagnosis by AI or expert endoscopists. We retrospectively evaluated the noninferiority (prespecified margin 5 %) of the per-patient rate of gastric cancer diagnosis by AI and compared the per-image rate of gastric cancer diagnosis.

RESULTS

Gastric cancer was diagnosed in 49 of 49 patients (100 %) in the AI group and 48 of 51 patients (94.12 %) in the expert endoscopist group (difference 5.88, 95 % confidence interval: -0.58 to 12.3). The per-image rate of gastric cancer diagnosis was higher in the AI group (99.87 %, 747 /748 images) than in the expert endoscopist group (88.17 %, 693 /786 images) (difference 11.7 %).

CONCLUSIONS

Noninferiority of the rate of gastric cancer diagnosis by AI was demonstrated but superiority was not demonstrated.

Chemoprevention of Oesophageal Squamous-Cell Carcinoma and Adenocarcinoma: A Multicentre Retrospective Cohort Study

BACKGROUND

Oesophageal cancer comprises 2 different histological variants: oesophageal squamous-cell carcinoma (ESCC) and adenocarcinoma (EAC). While there are multiple therapeutic options for both types, patients with advanced or metastatic oesophageal cancer still suffer from poor prognosis.

AIMS

The study aimed to examine the association between the risk of oesophageal cancer and medications and to estimate the chemopreventive effects of commonly used drugs.

METHODS

A multicentre retrospective cohort study was conducted using data from 9 hospital databases of hospitalized patients between 2014 and 2019. The primary outcomes were ESCC and EAC. The association of oesophageal cancer with drug use and clinical factors was evaluated. Odds ratios (ORs) were adjusted for age, sex, Charlson comorbidity index scores, and smoking with/without gastro-oesophageal reflux disease.

RESULTS

The use of proton pump inhibitors (PPIs) (adjusted OR [aOR] 0.48, p < 0.0001), aspirin (aOR 0.32, p < 0.0001), cyclooxygenase-2 inhibitor (COX2I) (aOR 0.70, p = 0.0005), steroid (aOR 0.19, p < 0.0001), statin (aOR 0.43, p < 0.0001), and metformin (aOR 0.42, p < 0.0001) was associated with a lower risk of ESCC than that in non-use. The use of aspirin (aOR 0.33, p = 0.0006) and steroids (aOR 0.54, p = 0.022) was associated with a lower risk of EAC than that in non-use.

CONCLUSION

COX2Is, statins, metformin, and PPIs could help in prevention of ESCC, and aspirin and steroids may be chemopreventive for both types of oesophageal cancer.

Machine learning-based personalized prediction of gastric cancer incidence using the endoscopic and histologic findings at the initial endoscopy

BACKGROUND AND AIMS

Accurate risk stratification for gastric cancer is required for optimal endoscopic surveillance in patients with chronic gastritis. We aimed to develop a machine learning (ML) model that incorporates endoscopic and histologic findings for an individualized prediction of gastric cancer incidence.

METHODS

We retrospectively evaluated 1099 patients with chronic gastritis who underwent EGD and biopsy sampling of the gastric mucosa. Patients were randomly divided into training and test sets (4:1). We constructed a conventional Cox proportional hazard model and 3 ML models. Baseline characteristics, endoscopic atrophy, and Operative Link on Gastritis-Intestinal Metaplasia Assessment (OLGIM)/Operative Link on Gastritis Assessment (OLGA) stage at initial EGD were comprehensively assessed. Model performance was evaluated using Harrel's c-index.

RESULTS

During a mean follow-up of 5.63 years, 94 patients (8.55%) developed gastric cancer. The gradient-boosting decision tree (GBDT) model achieved the best performance (c-index from the test set, .84) and showed high discriminative ability in stratifying the test set into 3 risk categories (P < .001). Age, OLGIM/OLGA stage, endoscopic atrophy, and history of malignant tumors other than gastric cancer were important predictors of gastric cancer incidence in the GBDT model. Furthermore, the proposed GBDT model enabled the generation of a personalized cumulative incidence prediction curve for each patient.

CONCLUSIONS

We developed a novel ML model that incorporates endoscopic and histologic findings at initial EGD for personalized risk prediction of gastric cancer. This model may lead to the development of effective and personalized follow-up strategies after initial EGD.

Efficacy of a Third-Generation High-Vision Ultrathin Endoscope for Evaluating Gastric Atrophy and Intestinal Metaplasia in Helicobacter pylori-Eradicated Patients

Background: Image-enhanced endoscopy methods such as narrow-band imaging (NBI) are advantageous over white-light imaging (WLI) for detecting gastric atrophy, intestinal metaplasia, and cancer. Although new third-generation high-vision ultrathin endoscopes improve image quality and resolution over second-generation endoscopes, it is unclear whether the former also enhances color differences surrounding atrophy and intestinal metaplasia for endoscopic detection. We compared the efficacy of a new third-generation ultrathin endoscope and an older second-generation endoscope. Methods: We enrolled 50 Helicobacter pylori-eradicated patients who underwent transnasal endoscopy with a second-generation and third-generation endoscope (GIF-290N and GIF-1200N, respectively) in our retrospective study. Color differences based on the International Commission on Illumination 1976 (L*, a*, b*) color space were compared between second-generation and third-generation high-vision endoscopes. Results: Color differences surrounding atrophy produced by NBI on the GIF-1200N endoscope were significantly greater than those on GIF-290N (19.2 ± 8.5 vs. 14.4 ± 6.2, p = 0.001). In contrast, color differences surrounding intestinal metaplasia using both WLI and NBI were similar on GIF-1200N and GIF-290N endoscopes. NBI was advantageous over WLI for detecting intestinal metaplasia on both endoscopes. Conclusions: NBI using a third-generation ultrathin endoscope produced significantly greater color differences surrounding atrophy and intestinal metaplasia in H. pylori-eradicated patients compared with WLI.

Clinicopathological Features of Gastric Cancer with Autoimmune Gastritis

Most gastric cancers develop in patients with chronic gastritis. Chronic gastritis can be classified into two major subtypes: Helicobacter pylori (H. pylori)-induced gastritis and autoimmune gastritis (AIG). Whereas H. pylori-related gastric cancers are more common and have been extensively investigated, the clinicopathological features of gastric cancer with autoimmune gastritis are unclear. Patients diagnosed with gastric cancer and hospitalized in the University Tokyo Hospital from 1998 to 2017 were enrolled. Diagnosis of autoimmune gastritis was based on positivity for serum anti-parietal cell antibody (APCA). We evaluated mucin expression and immune cell infiltration by immunohistochemical staining for MUC5AC, MUC6, PD-L1, CD3, CD11, Foxp3, and PD1. We also examined the presence of bacterial taxa that are reportedly enriched in AIG. Survival analyses of recurrence and 5-year mortality were also performed. In total, 261 patients (76 APCA-positive and 185 APCA-negative) were analyzed. Immunohistochemical staining in the matched cohort showed that AIG-related gastric cancer had higher MUC5AC expression (p = 0.0007) and MUC6 expression (p = 0.0007). Greater infiltration of CD3-positive (p = 0.001), Foxp3-positive (p < 0.001), and PD1-positive cells (p = 0.001); lesser infiltration of CD11b-positive (p = 0.005) cells; and a higher prevalence of Bacillus cereus (p = 0.006) were found in AIG-related gastric cancer patients. The cumulative incidences of gastric cancer recurrence were 2.99% at 2 years, 15.68% at 6 years, and 18.81% at 10 years in APCA-positive patients; they were 12.79% at 2 years, 21.35% at 6 years, and 31.85% at 10 years in APCA-negative patients. The cumulative incidences of mortality were 0% at 3 years and 0% at 5 years in APCA-positive patients; they were 1.52% at 3 years and 2.56% at 5 years in APCA-negative patients. We identified molecular differences between AIG and non-AIG gastric cancer. Differences in T-cell populations and the gastric microbiota may contribute to the pathogenesis of gastric cancers and potentially affect the response to immunotherapy.

Vonoprazan versus proton pump inhibitors for postendoscopic submucosal dissection bleeding in the stomach: a multicenter population-based comparative study

BACKGROUND AND AIMS

The effectiveness of vonoprazan relative to that of proton pump inhibitors (PPIs) after gastric endoscopic submucosal dissection (ESD) is unclear. Although previous studies used post-ESD ulcer healing as the outcome measure, post-ESD bleeding rate is the most objective and appropriate outcome measure because it has less ascertainment bias. We aimed to compare the post-ESD bleeding rates between vonoprazan and PPIs.

METHODS

This nationwide population-based retrospective cohort study was conducted between 2014 and 2018 and involved 9 hospitals. After 2 days of intravenous PPI administration, either vonoprazan or PPI was administrated from postoperative day 2 to 30.

RESULTS

Overall, data of 1715 patients (627 patient pairs) were analyzed through propensity score matching. The vonoprazan group had significantly lower post-ESD bleeding rates than the PPI group (overall, 11.9% vs 17.2%, P = .008; bleeding between days 2 and 30, 7.8% vs 11.8%, P = .015). The readmission rate because of post-ESD bleeding was lower in the vonoprazan group (2.4% vs 4.1%, P = .081). Blood transfusion (2.1% vs 3.0%, P = .15) and additional surgery because of delayed perforation (.5% vs 1.0%, P = .32) were not significantly different between the 2 groups. No deaths within 30 days occurred in both groups. On Cox regression analysis, vonoprazan use, lesion location (antrum), aspirin use, direct oral anticoagulant use, and Charlson Comorbidity Index (≥2) were associated with an increased risk of post-ESD bleeding within 30 days.

CONCLUSIONS

Vonoprazan has a lower post-ESD bleeding rate than PPIs. Further prospective studies are required to confirm these results.

Association between dyspeptic symptoms and endoscopic findings based on the Kyoto classification of gastritis in Japanese male

The Kyoto gastritis classification is used to categorize the endoscopic characteristics of Helicobacter pylori infection-associated gastritis. We aimed to clarify the association among endoscopic findings and abdominal dyspeptic symptoms in Japanese male. We administered a questionnaire to 418 subjects who underwent endoscopy as part of a health check-up from August 2003 to April 2004 to investigate the association among endoscopic findings of the Kyoto classification and the presence of dyspeptic symptoms. Logistic regression analyses were performed to evaluate risk based on dyspeptic symptoms. Among 418 health check-up subjects, 21.3% (89/418) reported dyspeptic symptoms in the questionnaire. The incidence of fundic gland polyp among patients with dyspeptic symptoms was 12.4% (11/89), which was significantly higher than that among non-symptomatic subjects (4.3%, 14/329, p = 0.004). Logistic regression analyses showed that fundic gland polyp was a risk factor for dyspeptic symptoms [odds ratio (OR): 3.413, 95% confidence interval (CI): 1.430–8.142], while short-segment Barrett’s esophagus and male sex were protective factors (OR: 0.569, 95% CI: 0.349–0.928 and OR: 0.333, 95% CI: 0.117–0.948, respectively). In conclusion, Endoscopic findings of fundic gland polyp may be associated with dyspeptic symptoms, which in turn may be a useful marker of gastric condition.

Linked color imaging effectively detects the endoscopic atrophic border in transnasal endoscopy

In oral endoscopy, linked color imaging (LCI) detects atrophic border and gastric mucosal diseases better than white light imaging (WLI), but its usefulness in transnasal endoscopy has not been fully investigated. Here, we retrospectively compared WLI and LCI using the L*a*b* color space in images from 57 patients aged ≥20 years who had undergone transnasal endoscopy as part of a health check-up from May 2016 to January 2017. We measured color differences at the atrophic/non-atrophic and fundic/pyloric mucosal borders. Gastritis severity scored using the Kyoto classification of gastritis was similar between the two techniques. However, in patients with current and with past Helicobacter pylori infection, color difference at the atrophic border was greater with LCI (21.58 ± 6.97 and 27.34 ± 10.32, respectively) than with WLI [14.42 ± 5.95 (p = 0.004) and 17.9 ± 8.48 (p<0.001)]; in those never infected with Helicobacter pylori, color difference at the fundic/pyloric mucosal border was greater with LCI than with WLI (p<0.001). Because of its enhancement of atrophic border detection, we recommend linked color imaging as the method of choice for transnasal endoscopy in health check-ups, particularly for identifying people at high risk of gastric cancer.

Long Survival after Gastrointestinal Bleeding in a New-Onset Heyde's Syndrome Patient Treated with Multiple Endoscopic Hemostatic Procedures and Repeated Transfusions after Aortic Valve Replacement

Heyde's syndrome, which is caused by aortic stenosis and subsequent acquired von Willebrand factor deficiency, is a gastrointestinal bleeding disease. Gastrointestinal bleeding develops in patients with Heyde's syndrome, which may have a different prognosis from general gastrointestinal bleeding; thus, it is important to understand the clinical course. We report a 76-year-old Japanese female who underwent aortic mechanical valve replacement 1 year ago and presented with recurrent gastrointestinal bleeding in angiodysplasia of the sigmoid colon. Endoscopic interventions achieved hemostasis. However, 6 rebleeding events occurred due to a sigmoid colon ulcer and gastric and jejunal angiodysplasia 7 years after first hemostasis. The patient underwent multiple endoscopic hemostatic procedures (upper, lower, and balloon-assisted endoscopy) and repeated transfusions (total of 394 units of red blood cells). The intensive treatment contributed to the survival time of 10 years. In addition, we performed a literature review of the prognosis of patients with Heyde's syndrome.

Erratum: Feasibility and safety of colonoscopy performed by nonexperts for acute lower gastrointestinal bleeding: post hoc analysis

[This corrects the article DOI: 10.1055/a-1464-0809.].

Impact of clinical characteristics of colonic diverticular bleeding in extremely elderly patients treated with direct oral anti-coagulant drugs: a retrospective multi-center study

Since there were no available data about colonic diverticular bleeding in extremely elderly patients (>80 years old) treated with direct oral anticoagulants (DOACs), we tried to determine clinical characteristics in those with colonic diverticular bleeding taking DOACs and to compare clinical outcomes of those in DOAC-treated to those in warfarin-treated . We enrolled DOAC-treated (n = 20) and warfarin-treated (n = 23) extremely elderly patients with diverticular bleeding diagnosed by colonoscopy. We performed a retrospective review of patients’ medical charts and endoscopic findings. We classified colonic diverticular bleeding based on endoscopic features due to modified previous study following three groups, type A (active bleeding), type B (non-active bleeding) and type C (bleeding suspected). Clinical outcomes such as number of recurrent bleeding, thrombotic events and mortality were estimated. There were no differences in endoscopical features and clinical characteristics between patients treated with DOAC and warfarin therapy. However, the number of recurrent bleeding, frequency of required blood transfusions and units of blood transfusion in warfarin-treated patients were significantly higher (p<0.05) compared to those in DOAC-treated groups. In addition, mortality and thrombotic events did not differ between DOAC- and warfarin-treated patients. Clinical outcomes suggest that DOACs can be recommended for extremely elderly patients with colonic diverticular disease.

Comparison of inflammatory bowel disease relapse after top-down or step-up therapy: a population-based cohort study

PURPOSE

The therapeutic effect of top-down therapy for inflammatory bowel disease (IBD) has not been fully evaluated in real-world clinical settings. We compared the effectiveness of top-down and step-up therapies for IBD.

METHODS

We retrospectively evaluated patients who were admitted with IBD (Crohn's disease [CD] or ulcerative colitis [UC]) between 2012 and 2019 using the nationwide Japan Diagnosis Procedure Combination database. Patients who received immunomodulators or biologic agents at the start of observation were assigned to the top-down group and those who did not were enrolled in the step-up group. Relapse was the primary outcome, a composite outcome defined as surgery, new steroid or immunomodulator use, hospitalization, a new biologic agent, or switching biologic agents.

RESULTS

We analyzed 6715 patients (CD, N = 3643; UC, N = 3072). Relapse occurred in 1982 CD cases (54.4%). The cumulative CD relapse incidence was 32.9% at 1 year and 61.3% at 5 years in the top-down group and 30.7% at 1 year and 58.6% at 5 years in the step-up group. Relapse occurred in 2032 UC cases (47.8%). The cumulative relapse incidence was 33.5% at 1 year and 50.0% at 5 years in the top-down group and 35.2% at 1 year and 51.6% at 5 years in the step-up group. No clinical factors associated with relapse were identified in patients with CD or UC.

CONCLUSION

Compared with step-up therapy, top-down therapy was not associated with a decreased relapse risk in a real-world population of patients with CD or UC.

Automatic detection of colorectal neoplasia in wireless colon capsule endoscopic images using a deep convolutional neural network

BACKGROUND

Although colorectal neoplasms are the most common abnormalities found in colon capsule endoscopy (CCE), no computer-aided detection method is yet available. We developed an artificial intelligence (AI) system that uses deep learning to automatically detect such lesions in CCE images.

METHODS

We trained a deep convolutional neural network system based on a Single Shot MultiBox Detector using 15 933 CCE images of colorectal neoplasms, such as polyps and cancers. We assessed performance by calculating areas under the receiver operating characteristic curves, along with sensitivities, specificities, and accuracies, using an independent test set of 4784 images, including 1850 images of colorectal neoplasms and 2934 normal colon images.

RESULTS

The area under the curve for detection of colorectal neoplasia by the AI model was 0.902. The sensitivity, specificity, and accuracy were 79.0 %, 87.0 %, and 83.9 %, respectively, at a probability cutoff of 0.348.

CONCLUSIONS

We developed and validated a new AI-based system that automatically detects colorectal neoplasms in CCE images.

Cumulative evidence for reducing recurrence of colonic diverticular bleeding using endoscopic clipping versus band ligation: Systematic review and meta-analysis

BACKGROUND AND AIM

Either clipping or band ligation will become the most common endoscopic treatment for colonic diverticular bleeding (CDB). Rebleeding is a significant clinical outcome of CDB, but there is no cumulative evidence comparing reduction of short-term and long-term rebleeding between them. Thus, we conducted a systematic review and meta-analysis to determine which endoscopic treatment is more effective to reduce recurrence of CDB.

METHODS

A comprehensive search of the databases PubMed/MEDLINE and Embase was performed through December 2019. Main outcomes were early and late rebleeding rates, defined as bleeding within 30 days and 1 year of endoscopic therapy for CDB. Initial hemostasis, need for transcatheter arterial embolization, or surgery were also assessed. Overall pooled estimates were calculated.

RESULTS

Sixteen studies fulfilled the eligibility criteria, and a total of 790 participants were included. The pooled prevalence of early rebleeding was significantly lower for band ligation than clipping (0.08 vs 0.19; heterogeneity test, P = 0.012). The pooled prevalence of late rebleeding was significantly lower for band ligation than clipping (0.09 vs 0.29; heterogeneity test, P = 0.024). No significant difference of initial hemostasis rate was noted between the two groups. Pooled prevalence of need for transcatheter arterial embolization or surgery was significantly lower for band ligation than clipping (0.01 vs 0.02; heterogeneity test, P = 0.031). There were two cases with colonic diverticulitis due to band ligation but none in clipping.

CONCLUSION

Band ligation therapy was more effective compared with clipping to reduce recurrence of colonic diverticular hemorrhage over short-term and long-term durations.

Nonsteroidal anti-inflammatory drugs prevent gastric cancer associated with the use of proton pump inhibitors after Helicobacter pylori eradication

Background and Aim

Proton pump inhibitors (PPIs) are a potential cause of gastric carcinogenesis after Helicobacter pylori eradication. Thus, appropriate management including chemoprevention is required. The aim of this study was to evaluate the association between nonsteroidal anti‐inflammatory drugs (NSAIDs) and the incidence of post‐eradication gastric cancer in PPI users.

Methods

A multicenter retrospective cohort study was conducted. Patients who used a PPI (≥30 days) after H. pylori eradication between 2014 and 2019 were analyzed in nine hospital databases. Gastric cancer incidence was a primary outcome, and their association with NSAIDs use and clinical factors was evaluated. Hazard ratios were adjusted by age, sex, smoking, and Charlson Comorbidity Index.

Results

During the mean follow‐up period of 2.38 years, 1.13% (31/2431) of all patients developed gastric cancer. The cumulative incidence of gastric cancer in PPI users was 0.25% at 1 year, 0.51% at 3 years, and 1.09% at 5 years in the NSAID users and 0.89% at 1 year, 2.32% at 3 years, and 3.61% at 5 years in nonusers. NSAIDs were associated with a lower gastric cancer risk (adjusted hazard ratio = 0.28, P = 0.005). No gastric cancer was observed in the cyclooxygenase‐2 inhibitor users (n = 256). NSAID use with high dose and long duration was significantly associated with a lower incidence of gastric cancer.

Conclusion

NSAIDs were associated with a 60% decrease in the gastric cancer incidence in H. pylori‐eradicated PPI users, with dose and duration response effects. NSAIDs may be effective for chemoprevention against PPI‐related gastric cancer.

Feasibility and safety of colonoscopy performed by nonexperts for acute lower gastrointestinal bleeding: post hoc analysis

Background and study aims  It remains unclear whether the experience of endoscopists affects clinical outcomes for acute lower gastrointestinal bleeding (ALGIB). We aimed to determine the feasibility and safety of colonoscopies performed by nonexperts using secondary data from a randomized controlled trial for ALGIB. Patients and methods  We analyzed clinical outcomes in 159 patients with ALGIB who underwent colonoscopies performed by two groups of endoscopists: experts and nonexperts. We compared endoscopy outcomes, including identification of stigmata of recent hemorrhage (SRH), successful endoscopic treatment, adverse events (AEs), and clinical outcomes between the two groups, including 30-day rebleeding, transfusion, length of stay, thrombotic events, and 30-day mortality. Results  Expert endoscopists alone performed colonoscopies in 96 patients, and nonexperts performed colonoscopies in 63 patients. The use of antiplatelets and warfarin was significantly higher in the expert group. The SRH identification rate (24.0 and 17.5 %), successful endoscopic treatment rate (95.0 and 100 %), rate of AEs during colonoscopy (0 and 0 %), transfusion rate (6.3 and 4.8 %), length of stay (8.0 and 6.4 days), rate of thrombotic events (0 and 1.8 %), and mortality (0 and 0 %) were not different between the expert and nonexpert groups. Rebleeding within 30 days occurred more often in the expert group than in the nonexpert group (14.3 vs. 5.4 % P  = 0.0914). Conclusions  The performance of colonoscopies for ALGIB by nonexperts did not result in worse clinical outcomes, suggesting that its use could be feasible for nonexperts for diagnosis and treatment of ALGIB.

Use of Antibiotics and Probiotics Reduces the Risk of Metachronous Gastric Cancer after Endoscopic Resection

Metachronous gastric cancer often occurs after endoscopic resection. Appropriate management, including chemoprevention, is required after the procedure. This study was performed to evaluate the association between medication use and the incidence of metachronous gastric cancer after endoscopic resection. This multicenter retrospective cohort study was conducted with data from nine hospital databases on patients who underwent endoscopic resection for gastric cancer between 2014 and 2019. The primary outcome was the incidence of metachronous gastric cancer. We evaluated the associations of metachronous gastric cancer occurrence with medication use and clinical factors. Hazard ratios were adjusted by age and Charlson comorbidity index scores, with and without consideration of sex, smoking status, and receipt of Helicobacter pylori eradication therapy during the study period. During a mean follow-up period of 2.55 years, 10.39% (140/1347) of all patients developed metachronous gastric cancer. The use of antibiotics other than those used for H. pylori eradication was associated with a lower incidence of metachronous gastric cancer than was non-use (adjusted hazard ratio (aHR) 0.56, 95% confidence interval (CI) 0.38-0.85, p = 0.006). Probiotic drug use was also associated with a lower incidence of metachronous gastric cancer compared with non-use (aHR 0.29, 95% CI 0.091-0.91, p = 0.034). In conclusion, the use of antibiotics and probiotic drugs was associated with a decreased risk of metachronous gastric cancer. These findings suggest that the gut microbiome is associated with metachronous gastric cancer development.

Association between the chronic use of gastric acid suppressants and high-risk colorectal polyps

Background and Aim

Although gastric acid suppressants such as proton pump inhibitors (PPIs) and histamine‐2 receptor antagonists (H2RAs) are considered safe, the consequences of hypochlorhydria and hypergastrinemia caused by chronic use are unclear. This study aimed to investigate the association between the chronic use of gastric acid suppressants and high‐risk colorectal polyps, focusing on polyp size.

Methods

A population‐based, nested case–control study was conducted using data from the Japanese Diagnosis Procedure Combination database between 2014 and 2019. Cumulative PPI or H2RA use prior to polypectomy was evaluated during the study period. Endoscopic polypectomy was categorized as polypectomy <2 cm, polypectomy ≥2 cm, and endoscopic submucosal dissection. Baseline characteristics were compared between the high‐risk (≥2 cm polyps or polyps treated by endoscopic submucosal dissection) and low‐risk (<2 cm polyps) endoscopic polypectomy groups. We calculated adjusted odds ratios (ORs) using multivariable logistic regression analysis.

Results

Of 27 694 patients who underwent endoscopic polypectomy, 2518 were treated with PPIs or H2RAs for >1 year prior to polypectomy. After adjusting for age, gender, and other confounders, a higher prevalence of high‐risk colorectal polyps was noted with PPI (OR: 2.67; 95% confidence interval: 2.37–3.01) and H2RA (OR: 1.86; 95% confidence interval: 1.52–2.26) use. Longer PPI or H2RA use was associated with increased risks of high‐risk colorectal polyps (P for trend <0.001). The highest OR (3.17) was observed among patients who received PPIs for ≥3 years.

Conclusion

Chronic use of PPIs and H2RAs may be associated with high‐risk colorectal polyps. Requirements for long‐term gastric acid suppressant use should be reevaluated.

International Observational Survey of the Effectiveness of Personal Protective Equipment during Endoscopic Procedures Performed in Patients with COVID-19

INTRODUCTION AND AIMS

This international survey was performed to evaluate the cumulative incidence of nosocomial novel coronavirus disease 2019 (COVID-19) among healthcare professionals during endoscopic procedures.

METHODS

We performed an international web-based self-reported questionnaire survey. Participants completed the questionnaires every week for 12 weeks. The questionnaire elicited responses regarding the development of COVID-19 and details of the personal protective equipment (PPE) used.

RESULTS

All 483 participants were included in the analysis. Participants had a mean age of 42.3 years and comprised 68.3% males. The geographic distribution of the study population was Asia (89.2%), Europe (2.9%), North and South America (4.8%), Oceania (0.6%), and Africa (1.5%). The most common endoscopy-related role of the participants was endoscopist (78.7%), and 74.5% had >10 years of experience. Fourteen participants had performed 83 endoscopic procedures in patients positive for COVID-19. During the mean follow-up period of 4.95 weeks, there were no cases of COVID-19 when treating COVID-19 positive patients. The most common PPE used by participants treating patients with COVID-19 was a surgical mask plus N95 mask plus face shield, goggles, cap, long-sleeved isolation gown, and single pair of gloves. The most common PPE used by participants treating patients without COVID-19 was a surgical mask, no face shield but goggles, cap, long-sleeved isolation gown, and single pair of gloves during all endoscopic procedures.

CONCLUSIONS

The risk of COVID-19 transmission during any endoscopic procedure was low in clinical practice.

Natural history of upper and lower gastrointestinal bleeding in hemodialysis patients: A dual-center long-term cohort study

BACKGROUND AND AIM

Knowledge on the risk of gastrointestinal (GI) bleeding in hemodialysis patients is limited. We evaluated the risk of GI bleeding in hemodialysis patients compared with non-hemodialysis patients.

METHODS

We performed a retrospective cohort study from 1996 to 2017 at the Graduate School of Medicine, University of Tokyo, and Horinouchi Hospital. We analyzed patients on hemodialysis for chronic renal failure and controls not on hemodialysis. The primary endpoint was GI bleeding. A survival analysis was performed to estimate the cumulative incidence and hazard ratio of GI bleeding.

RESULTS

A total of 14 451 patients were analyzed (417 hemodialysis and 14 034 non-hemodialysis patients). In total, 524 GI bleeding events occurred. Upper and lower GI bleeding occurred in 432 and 92 patients in the hemodialysis and non-hemodialysis groups, respectively. The most frequent source of upper and lower GI bleeding was gastric ulcer and colonic diverticular bleeding, respectively. The cumulative incidence of GI bleeding was 4.44% at 1 year, 7.15% at 3 years, and 10.40% at 5 years in hemodialysis patients; the respective rates were 2.35%, 2.98%, and 3.79% in non-hemodialysis patients during a mean follow-up period of 3.5 years. Hemodialysis was significantly associated with an increased risk of GI bleeding after adjustment (hazard ratio 1.67, P = 0.01, 95% confidence interval 1.13-2.50).

CONCLUSIONS

Hemodialysis patients had a GI bleeding rate of 10% over 5 years, and hemodialysis was a risk factor for GI bleeding.

Exploration of the characteristics of chronotypes in upper gastrointestinal tract diseases: a multicenter study in Japan

Characteristics of the chronotypes of patients with gastrointestinal disease are unknown. We evaluated chronotypes of patients with upper gastrointestinal diseases with the Munich ChronoType Questionnaire (MCTQ). A total of 2027 subjects from 29 institutions in Japan who had undergone esophagogastroduodenoscopy were asked to answer the MCTQ. The subjects' chronotypes were divided into three groups (early, intermediate, and late chronotype) using the sleep-corrected mid-point of sleep on free days (MSF_SC) values. According to their endoscopic diagnosis and abdominal symptoms, the subjects were divided into the reflux esophagitis (RE) group, gastroduodenal ulcer (GDU) group, upper gastrointestinal carcinoma (CA) group, functional dyspepsia (FD) group, non-FD group, and control group. In total, 1128 subjects were eligible for the analysis. The MSF_SC (average ± standard deviation, clock hours, h) of each disease group was as follows: control group: 02.51 ± 1.22, non-FD group: 02.69 ± 1.14, FD group: 02.91 ± 1.19, RE group: 02.58 ± 1.05, GDU group: 02.47 ± 1.31, and CA group: 02.11 ± 1.08 h. Compared to the control group, the rate of late chronotype of the FD group significantly increased to 33.3%, whereas that of early chronotype of the CA group significantly increased to 38.3% (P = .0177 and 0.0036, respectively). In both the FD and CA groups, chronotype was the independent factor related to the diseases. The adjusted odds ratio of late chronotype to early chronotype was 3.01 [95% CI, 1.23-7.35] in the FD group and 0.44 [95% CI, 0.23-0.85] in the CA group. In conclusion, late chronotype was common in patients with FD, and early chronotype was common in patients with upper gastrointestinal carcinoma.

Distinct Features of Autoimmune Gastritis in Patients with Open-Type Chronic Gastritis in Japan

In Asia, the incidences of Helicobacter pylori infection and gastric cancer are high, but their association with autoimmune gastritis (AIG) is unclear. This was a retrospective cohort study of patients endoscopically diagnosed with chronic gastritis between 2005 and 2017. AIG was diagnosed according to anti-parietal cell antibody positivity. Laboratory, histological findings, and gastric cancer incidence were compared between AIG and non-AIG patients. The AIG group had more females and a higher rate of thyroid disease. Serum levels of gastrin were significantly higher in AIG patients (mean 1412 and 353 pg/mL, p < 0.001). The endoscopic findings included a significantly higher percentage of corpus-dominant atrophy in AIG (31.67%) than in non-AIG (7.04%) patients (p < 0.001). Clusters of ECL cells were observed in 28% of AIG patients and 7% of non-AIG patients (p = 0.032). The cumulative incidence of gastric cancer at 5 and 10 years was 0% and 0.03% in the AIG group and 0.03% and 0.05% in the non-AIG group, and no significant difference in gastric cancer incidence was observed. Despite significant differences in gastrin levels between AIG and non-AIG patients, there was no evidence of an impact of AIG on the incidence of gastric cancer.

Efficacy and safety of a new rifabutin-based triple therapy with vonoprazan for refractory Helicobacter pylori infection: A prospective single-arm study

BACKGROUND

A small proportion of Helicobacter pylori-infected individuals in Japan suffer failure of eradication therapy with third-line regimens containing the potent acid suppressor, vonoprazan, and a quinolone.

OBJECTIVES

This prospective study evaluated the efficacy and safety of rifabutin-based triple therapy with vonoprazan for refractory H pylori infection.

METHODS

Patients who failed H pylori eradication by clarithromycin-based first-line, metronidazole-based second-line, and sitafloxacin-based third-line therapies were recruited. After obtaining informed consent, patients received eradication therapy with vonoprazan (20 mg), amoxicillin (750 mg), and rifabutin (150 mg) twice daily for 10 days. Eradication was confirmed by a negative H pylori stool antigen or urea breath test at least 8 weeks after the end of therapy.

RESULTS

Nineteen patients were included in the study. All of the patients completed the course of medication. Eradication of H pylori was confirmed in all of the patients (19/19; 100%, 95% confidence interval; 83-100%). The most common adverse event was soft stool/diarrhea (4/19, 21%). No severe adverse event was observed.

CONCLUSIONS

Ten-day rifabutin with amoxicillin and vonoprazan triple therapy appears to be effective and safe for refractory H pylori infections. However, considering the recent publications showing high eradication rates with vonoprazan amoxicillin dual therapy, confirmation will require future studies comparing our new therapy with vonoprazan-amoxicillin dual with similar doses and duration and with vonoprazan-rifabutin dual therapy.

Automatic detection of different types of small-bowel lesions on capsule endoscopy images using a newly developed deep convolutional neural network

BACKGROUND : Previous computer-aided detection systems for diagnosing lesions in images from wireless capsule endoscopy (WCE) have been limited to a single type of small-bowel lesion. We developed a new artificial intelligence (AI) system able to diagnose multiple types of lesions, including erosions and ulcers, vascular lesions, and tumors. METHODS : We trained the deep neural network system RetinaNet on a data set of 167 patients, which consisted of images of 398 erosions and ulcers, 538 vascular lesions, 4590 tumors, and 34 437 normal tissues. We calculated the mean area under the receiver operating characteristic curve (AUC) for each lesion type using five-fold stratified cross-validation. RESULTS : The mean age of the patients was 63.6 years; 92 were men. The mean AUCs of the AI system were 0.996 (95 %CI 0.992 - 0.999) for erosions and ulcers, 0.950 (95 %CI 0.923 - 0.978) for vascular lesions, and 0.950 (95 %CI 0.913 - 0.988) for tumors. CONCLUSION : We developed and validated a new computer-aided diagnosis system for multiclass diagnosis of small-bowel lesions in WCE images.

Automatic detection of blood content in capsule endoscopy images based on a deep convolutional neural network

BACKGROUND AND AIM

Detecting blood content in the gastrointestinal tract is one of the crucial applications of capsule endoscopy (CE). The suspected blood indicator (SBI) is a conventional tool used to automatically tag images depicting possible bleeding in the reading system. We aim to develop a deep learning-based system to detect blood content in images and compare its performance with that of the SBI.

METHODS

We trained a deep convolutional neural network (CNN) system, using 27 847 CE images (6503 images depicting blood content from 29 patients and 21 344 images of normal mucosa from 12 patients). We assessed its performance by calculating the area under the receiver operating characteristic curve (ROC-AUC) and its sensitivity, specificity, and accuracy, using an independent test set of 10 208 small-bowel images (208 images depicting blood content and 10 000 images of normal mucosa). The performance of the CNN was compared with that of the SBI, in individual image analysis, using the same test set.

RESULTS

The AUC for the detection of blood content was 0.9998. The sensitivity, specificity, and accuracy of the CNN were 96.63%, 99.96%, and 99.89%, respectively, at a cut-off value of 0.5 for the probability score, which were significantly higher than those of the SBI (76.92%, 99.82%, and 99.35%, respectively). The trained CNN required 250 s to evaluate 10 208 test images.

CONCLUSIONS

We developed and tested the CNN-based detection system for blood content in CE images. This system has the potential to outperform the SBI system, and the patient-level analyses on larger studies are required.

Clinical usefulness of a deep learning-based system as the first screening on small-bowel capsule endoscopy reading

BACKGROUND AND AIM

To examine whether our convolutional neural network (CNN) system based on deep learning can reduce the reading time of endoscopists without oversight of abnormalities in the capsule-endoscopy reading process.

METHODS

Twenty videos of the entire small-bowel capsule endoscopy procedure were prepared, each of which included 0-5 lesions of small-bowel mucosal breaks (erosions or ulcerations). At another institute, two reading processes were compared: (A) endoscopist-alone readings and (B) endoscopist readings after the first screening by the proposed CNN. In process B, endoscopists read only images detected by CNN. Two experts and four trainees independently read 20 videos each (10 for process A and 10 for process B). Outcomes were reading time and detection rate of mucosal breaks by endoscopists. Gold standard was findings at the original institute by two experts.

RESULTS

Mean reading time of small-bowel sections by endoscopists was significantly shorter during process B (expert, 3.1 min; trainee, 5.2 min) compared to process A (expert, 12.2 min; trainee, 20.7 min) (P < 0.001). For 37 mucosal breaks, detection rate by endoscopists did not significantly decrease in process B (expert, 87%; trainee, 55%) compared to process A (expert, 84%; trainee, 47%). Experts detected all eight large lesions (>5 mm), but trainees could not, even when supported by the CNN.

CONCLUSIONS

Our CNN-based system for capsule endoscopy videos reduced the reading time of endoscopists without decreasing the detection rate of mucosal breaks. However, the reading level of endoscopists should be considered when using the system.