Search

Background/Aims: To date, only thinner-diameter metal stents have been evaluated for unresectable malignant distal biliary obstruction (UR-MDBO). This study investigated the outcomes and optimal cohorts for a 6-mm-diameter fully covered self-expandable metal stent (FCSEMS) compared with those for a 10-mm-diameter FCSEMS. Methods: This single-center retrospective cohort study included patients who underwent initial transpapillary metal stenting for UR-MDBO. Propensity score matching (1:1) analysis was performed. Results: Of 133/68 patients who underwent 6-mm/10-mm-diameter FCSEMS deployment, 59 in each group were selected. The median time to recurrent biliary obstruction was not significantly different between the groups (p=0.46). In contrast, use of the 6-mm-diameter FCSEMS resulted in a significantly reduced incidence of stent-related adverse events (AEs) (p=0.016), especially cholecystitis (p=0.032), and patients aged <70 years were particularly affected by this significant reduction. Among the patients in the end-stage cohort who were unable to continue chemotherapy after FCSEMS deployment, the free rate of stent-related events, including recurrent biliary obstruction and stent-related AEs, was significantly higher in the 6-mm group (p=0.027). Conclusions: For UR-MDBO, a 6-mm-diameter FCSEMS can be an optimal and safe option in the younger cohort with a relatively high risk of AEs and in the end-stage cohort requiring safer drainage without interference from stent-related events during times of poor prognosis. [ABSTRACT FROM AUTHOR]

Introduction: This study investigated the detection rate of colorectal neuroendocrine neoplasms (NENs) using large-scale colonoscopy data., Methods: This cross-sectional analysis used large-scale data from a Japanese multicenter observational study of colonoscopies performed from 2010 to 2020., Results: Among 82,005 colonoscopy cases, colorectal NENs were identified in 71 (67 of which were neuroendocrine tumors), with a detection rate of 0.087% (95% confidence interval: 0.069-0.109). Most were small rectal lesions, with only 4 >10 mm in size and 3 located in the colon., Discussion: The detection rate of colorectal NENs during colonoscopy is substantially higher than expected., (Copyright © 2024 by The American College of Gastroenterology.)

Background:  The effectiveness of prophylactic clip closure in reducing the risk of delayed bleeding after colorectal endoscopic submucosal dissection (ESD) is uncertain among patients on anticoagulants. We therefore aimed to assess this effectiveness using data from a large multicenter study., Methods:  We used the ABCD-J study database to analyze delayed bleeding among 34 455 colorectal ESD cases from 47 Japanese institutions. Delayed bleeding rates among the no/partial and complete closure groups were compared in patients on direct oral anticoagulants (DOACs) or warfarin. Propensity score matching was used for baseline characteristics to reduce the effects of selection bias., Results:  Overall, data from 1478 patients on anticoagulants who underwent colorectal ESD were examined. After propensity score matching, the complete and no/partial closure groups were compared in 212 patients on DOACs and 82 on warfarin. The complete closure group showed a significantly lower delayed bleeding rate in patients receiving DOACs (10.8 % vs. 5.2 %, absolute risk reduction [ARR] 5.7 %, P  = 0.048) and warfarin (17.1 % vs. 6.1 %, ARR 11.0 %, P  = 0.049). Additionally, complete closure significantly reduced the risk of delayed bleeding among patients taking DOACs for right-sided lesions (ARR 6.7 %, P  = 0.04), whereas no risk reduction was observed for left-sided ( P  > 0.99) or rectal ( P  = 0.50) lesions. A similar trend was observed among patients on warfarin., Conclusions:  Prophylactic complete clip closure after colorectal ESD significantly reduced the delayed bleeding rate in patients receiving DOACs or warfarin. It should be performed after ESD, particularly for right-sided lesions., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

It is uncertain whether underwater endoscopic mucosal resection (UEMR) enables resection of the submucosal tissue with sufficient margins for T1 colorectal cancer (CRC) because UEMR forgoes submucosal injection. Therefore, we developed a novel "underwater injection EMR" (UIEMR) method that combines submucosal injection with UEMR to obtain an adequate vertical margin.We retrospectively analyzed procedure-related outcomes of 135 consecutive lesions from patients who underwent UIEMR for ≥10-mm nonpedunculated colorectal polyps (median size 15 mm). The outcomes included the en bloc, R0, RX, and R1 resection rates, and adverse events. Additionally, the vertical margin distance of seven T1 CRCs was evaluated.En bloc resection was achieved in 127 lesions (94.1%). R0 and RX resections were observed in 92 (68.1%) and 42 lesions (31.1%), respectively, while R1 resection was seen in only one lesion (0.7%). There were two cases with adverse events (1.5%), both delayed bleeding. In T1 CRCs, all seven cases had free vertical margins, and the median vertical margin distance was 1140 µm (range 731-1570 µm).UIEMR safely demonstrated high success rates for en bloc resection, and potentially ensures a sufficient vertical margin. This technique might be an option, particularly for relatively small lesions concerning for T1 CRC, and deserves further study., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Protein kinase C (PKC) is a family of serine/threonine kinases, and PKC ligands have the potential to be therapeutic seeds for cancer, Alzheimer's disease, and human immunodeficiency virus infection. However, in addition to desired therapeutic effects, most PKC ligands also exhibit undesirable pro-inflammatory effects. The discovery of new scaffolds for PKC ligands is important for developing less inflammatory PKC ligands, such as bryostatins. We previously reported that machine learning combined with our knowledge of the pharmacophore yielded 15 PKC ligand candidates, but we did not evaluate their PKC binding affinities fully. In this paper, PKC binding affinities of four candidates were examined to assess their potential as PKC ligands and to validate machine learning-assisted screening. Although compound 3' did not bind to PKC C1 domains, 1a, 2', and 4a exhibited moderate PKC binding affinities, suggesting that machine learning-assisted screening is advantageous in identifying new PKC ligand scaffolds., (© The Author(s) 2025. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

The tumor microenvironment has recently been well-studied in various gastrointestinal cancers, including colorectal cancer (CRC). The gut microbiota, a collection of microorganisms in the human gastrointestinal tract, is one of the microenvironments associated with colon carcinogenesis. It has been challenging to elucidate the mechanisms by which gut microbiota contributes to carcinogenesis and cancer progression due to complex interactions with the host, including its metabolites and immune and inflammatory responses. Various studies described the influence of diet on reported changes in the composition and microbiota of gut bacteria and its association with CRC. In recent years, metagenomic techniques such as shotgun sequencing and genome-wide association studies focused on understanding the role of the microbiota and the metabolome on early CRCs and colon carcinogenesis to determine if there are modifiable or intervenable targets for CRC. In this review, we will attempt to provide an overview of gut microbiota related to CRC, with particular attention to the findings of recent studies., Competing Interests: Conflicts of Interest This work was supported in part by The National Cancer Center Research and Development Fund 2023-Ａ-06 and AMED 24ck0106799h0002 for Yutaka Saito., (Copyright © 2025 The Japan Society of Coloproctology.)

Objectives: We aimed to determine the compliance, safety, and acceptance of colon capsule endoscopy (CCE) and small bowel capsule endoscopy (SBCE) in an out-of-clinic setting remotely supported by medical staff., Methods: We enrolled 30 examinees (24 with CCE and six with SBCE) who had not undergone CE at six gastroenterological centers. All examinees were provided with instructions on equipment and bowel preparations., Results: CCE was performed at home (n = 16) or at the workplace (n = 8). Compliance with data-recorder alerts was 100% for bowel preparation and 79% for equipment operation. Total capsule colonoscopy was achieved in 83.3%. The overall adequate endoscopic cleansing rate was 83.3%, and abnormalities, including colorectal polyps, were detected in 37.5%. CCE malfunction, such as the inability to automatically detect the small bowel mucosa occurred in one (4.2%). One experienced mild abdominal pain that required no treatment. Inquiries were present from half of the examinees. The proportions of examinees who desired and refused CCE at the next examination were 67% and 4%, respectively. SBCE was performed at home (n = 4) or at the workplace (n = 2). Compliance with the procedures was 100%. Whole small bowel images were recorded for all examinees. The overall adequate endoscopic clearness rate was 100%. One abnormality was detected. Inquiries were present from half of the examinees. There were no adverse events or malfunctions. The proportion of examinees who reported "quite easy" and "fairly easy" was 66%., Conclusion: CCE and SBCE with all procedures in the out-of-clinic setting supported by remote consultations were feasible. A multicenter prospective study of the safety and acceptance of capsule endoscopy examinations at home (HomeCam-J study) (jRCTs042220163)., (© 2025 Japan Gastroenterological Endoscopy Society.)

Background and Aim: The risk of colorectal cancer among fecal immunochemistry test-positive individuals who had undergone previous colonoscopies remains unclear. Therefore, this study aimed to determine the differences in the risk of colorectal cancer among fecal immunochemistry test-positive individuals according to the timing of their previous colonoscopies., Methods: This multicenter, retrospective, observational study was conducted in Japan as a subgroup analysis of the J-SCOUT study (UMIN000040690), which integrated and analyzed a database comprising all colonoscopies performed at participating Japanese institutions between 2010 and 2020. This study used colonoscopy data of fecal immunochemistry test-positive individuals aged ≥ 20 years from three facilities that entered the timing of previous colonoscopies into the endoscopy database. Histologically confirmed advanced neoplasia was the study's primary outcome. Multivariate logistic regression analysis was used to calculate the odds ratios for each variable., Results: In total, 11,143 fecal immunochemistry test-positive patients underwent colonoscopy during the study period. Of these, 10,160 patients were included in the analysis after excluding those who met the exclusion criteria. The overall advanced neoplasia detection rate was 9.38% (953/10,160; 95% confidence interval: 8.82-9.96%). Compared with the first colonoscopy, the odds ratios for advanced neoplasia in individuals who underwent colonoscopies 1, 2, 3, 4, 5, > 5, and ≥ 10 years previously were 0.27, 0.15, 0.06, 0.10, 0.29, 0.31, and 0.31, respectively., Conclusions: The detection rates of advanced neoplasia were low among the fecal immunochemistry test-positive individuals who had undergone colonoscopy, particularly in the past 5 years., (© 2024 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Objective: Whether metal stents (MS) or plastic stents (PS) yield better outcomes for malignant biliary obstruction in endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is controversial. We aimed to compare outcomes of initial EUS-HGS performed with MS or PS., Methods: In this single-center retrospective study, we included patients (MS/PS groups: n = 151/72) with unresectable malignant biliary obstruction and performed multivariable analysis. The landmark date was defined as day 100 and used to evaluate the time to recurrent biliary obstruction (TRBO)., Results: The clinical success rate was similar in both groups. The mean total bilirubin percentage decrease at week 2 was significantly higher in the MS group than in the PS group (-45.1% vs. -23.7%, P = 0.016). Median TRBO was significantly different between the MS and PS groups (183 and 92 days, respectively; P = 0.017). TRBO within 100 days was comparable in both groups but was significantly shorter only after 100 days in the PS group (adjusted hazard ratio 12.8, P < 0.001). Adverse events were significantly more common in the MS group (23.8% vs. 9.7%, P = 0.012), although they occurred relatively frequently even with PS in the cholangitis subgroup (P interaction  = 0.034). After endoscopic re-intervention, TRBO tended to be longer with revision PS (hazard ratio 0.40, P = 0.47)., Conclusions: Although MS provided early improvement of jaundice and long stent patency, PS provided a better safety profile and comparable stent patency until 100 days. PS might also be an adequate and optimal palliation method in EUS-HGS., (© 2024 The Author(s). Digestive Endoscopy published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)

Background and Aim: Colorectal endoscopic submucosal dissection is a technically demanding procedure with a steep learning curve. In Japan, the National Cancer Center Hospital allows overseas doctors to participate in hands-on training. We aimed to assess the colorectal endoscopic submucosal dissection performance and learning curve of an endoscopist who participated in hands-on training., Methods: In this retrospective analysis using a prospectively collected database, 100 consecutive superficial colorectal tumors from 100 patients treated with endoscopic submucosal dissection by a colorectal surgeon between January 2020 and May 2024 were included. The cases were grouped into three learning periods: phase I (the initial 30 cases under local expert supervision before training in Japan), phase II (the middle 30 cases), and phase III (the last 40 cases). The primary outcome was resection speed., Results: The median resection speed was 5, 11.7, and 13.2 cm 2 /h in phases I, II, and III, respectively. In matched data, the resection speeds in phases II and III were higher than that in phase I (P = 0.02 and P < 0.001, respectively). En bloc and R0 resection rates were 99% and 95%, respectively. The en bloc resection, R0 resection, and complication rates were not different between phases. Cumulative sum analysis of the resection speed revealed that proficiency was achieved after 36 cases., Conclusions: An endoscopist who underwent a tutored approach and hands-on training in Japan achieved the proficiency benchmarks for colorectal endoscopic submucosal dissection after 36 cases. However, the endoscopist's extensive experience before training may contribute to excellent outcomes., (© 2024 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)