中川 義仁

BACKGROUND AND AIMS: Early gastric cancers (EGCs) after Helicobacter pylori (H. pylori) eradication often appear as reddish depressed lesions (RDLs); the same features are also appeared in benign stomachs after eradication. We compared clinic-pathological and endoscopic features of benign and neoplastic RDLs after H. pylori eradication. METHODS: 228 neoplastic RDLs after H. pylori eradication were studied. All lesions were divided into neoplastic RDLs (differentiated carcinoma or adenoma, n=114) and benign RDLs (n=114) according to the histology. Clinical and pathological characteristics were compared in neoplastic and benign groups. Endoscopic diagnostic yields using the white light (WL) endoscopy, chromoendoscopy (CE) using indigo carmine dye and the magnifying endoscopy with narrow-band imaging (ME-NBI) were also evaluated in relation to the pathological diagnosis. RESULTS: Size of neoplastic RDLs was larger than that of benign RDLs (p<0.01). Sensitivity, specificity and accuracy for predicting pathological types of RDLs was 70.1%, 52.6% and 61.4% for the WL, 65.8%, 63.1% and 65.4% for the CE, while the ME-NBI scored better with the 88.6%, 88.6%, 99.1% and 93.9% of sensitivity, specificity and accuracy. The accuracy of the ME-NBI was 99.9% (113/114) in the benign RDLs and 89.4% (101/114) for the neoplastic RDLs. Undiagnosed neoplastic RDLs using the ME-NBI were associated with more differentiated tumors such as adenoma and well-differentiated adenocarcinoma (tub1) and the presence of an unclear demarcation line. CONCLUSIONS: ME-NBI is useful to diagnose RDLs after H. pylori eradiation, while some of neoplastic lesions are difficult to diagnose using the ME-NBI.

Introduction. Colorectal cancer (CRC) is a leading cause of cancer deaths, closely linked to the intestinal microbiota and bile acid metabolism. Secondary bile acids, like deoxycholic and lithocholic acid, are associated with increased CRC risk due to their disruption of vital cellular functions. In contrast, isoallolithocholic acid (isoalloLCA) shows potential health benefits, highlighting the complex role of bile acids in CRC. A specific primer set was previously developed to amplify homologs of the 5α-reductase gene (5ar), which are involved in the biosynthesis of isoalloLCA, thereby enabling the estimation of abundance of 5ar (5ar levels) in the intestine.Hypothesis/Gap Statement. We hypothesized that 5ar levels in the intestine are associated with CRC.Aim. This study aimed to investigate intestinal 5ar levels and compare them across different stages of the adenoma-carcinoma sequence, providing insights into novel strategies for monitoring CRC risk.Methodology. DNA was extracted from intestinal lavage fluids (ILF) collected during 144 colonoscopies. Next-generation sequencing (NGS) was employed to examine the sequence of 5ar homologues, using a specific primer set on DNA from seven selected ILFs - four from carcinoma patients and three from individuals with non-neoplastic mucosa. Additionally, we used quantitative PCR (qPCR) to measure 5ar levels in all 144 DNA samples.Results. We conducted 144 colonoscopies and categorized patients according to the adenoma-cancer sequence: 52 with non-neoplastic mucosa, 69 with adenomas and 23 with carcinoma. Analysis of 292,042 NGS-derived 5ar sequences revealed the seven most prevalent amplicon sequence variants, each 254 base pairs in length. These closely matched or were identical to 5ar sequences in Bacteroides uniformis, Phocaeicola vulgatus and Phocaeicola dorei. Furthermore, qPCR analysis demonstrated significantly lower 5ar levels in the carcinoma group compared to those in the non-neoplastic mucosa group (P = 0.0004). A similar, though not statistically significant, trend was observed in the adenoma group (P = 0.0763), suggesting that 5ar levels decrease as CRC progresses.Conclusion. These findings indicate that PCR-based monitoring of 5ar levels in intestinal samples over time could provide a non-invasive, rapid and cost-effective method for assessing an increased risk of CRC.

膵腫瘍には様々な種類が存在し,予後と治療法は異なる.そのため,最善の治療計画を決定するには正確な診断が重要である.経腹的超音波検査は,膵腫瘍の画像診断のためのスクリーニング検査としてよく用いられる.本論説では,比較的稀な膵腫瘍の超音波所見の特徴に焦点を当てて解説する.(著者抄録)

Abstract Background and study aims Esophageal endoscopic submucosal dissection (ESD) has a higher complication rate than gastric ESD. Scissor-type devices, including the stag beetle (SB) knife, are reportedly safer and have shorter procedure times than tip devices. To clarify the characteristics of the SB knife, we compared the treatment outcomes of esophageal ESD with a tip-type knife to those with an SB knife combination. Patients and methods Between January 2016 and March 2023, clinical data from 197 lesions in 178 patients who underwent esophageal ESD were analyzed retrospectively. Every lesion was assigned to either the tip-type group or the SB group based on the devices with which the submucosa was initially dissected. We compared procedure time and complications and analyzed the risk of muscular exposure using multivariate analysis. Results Procedure time was not significantly different between the tip-type and SB groups (60.3±42.2 min vs. 58.8±29.1 min). The variation in procedure time was significant according to F test P=0.002). Incidence of muscular exposure was significantly lower in the SB group than in the tip-type group (24.5% vs. 11.1%, P=0.016). These differences were significant in resected specimens larger than 21 mm. Procedure time over 60 minutes (odds ratio [OR] 2.5, 95% confidence interval [CI]: 1.15–5.42, P=0.02) was a risk factor for muscular exposure, and submucosal dissection with an SB knife was a safety factor (OR 0.4, 95% CI: 0.18–0.89, P=0.02). Conclusions Performing esophageal ESD with an SB knife is a safe procedure with less variation in procedure time and less muscule exposure.

Helicobacter pylori induces DNA methylation in gastric mucosa, which links to gastric cancer (GC) risk. In contrast, CpG island methylator phenotype (CIMP) is defined as high levels of cancer-specific methylation and provides distinct molecular and clinicopathological features of GC. The association between those two types of methylation in GC remains unclear. We examined DNA methylation of well-validated H. pylori infection associated genes in GC and its adjacent mucosa and investigated its association with CIMP, various molecular subtypes and clinical features. We studied 50 candidate loci in 24 gastric samples to identify H. pylori infection associated genes. Identified loci were further examined in 624 gastric tissue from 217 primary GC, 217 adjacent mucosa, and 190 mucosae from cancer-free subjects. We identified five genes (IGF2, SLC16A2, SOX11, P2RX7, and MYOD1) as hypermethylated in H. pylori infected gastric mucosa. In non-neoplastic mucosa, methylation of H. pylori infection associated genes was higher in patients with GC than those without. In primary GC tissues, higher methylation of H. pylori infection associated genes correlated with CIMP-positive and its related features, such as MLH1 methylated cases. On the other hand, GC with lower methylation of these genes presented aggressive clinicopathological features including undifferentiated histopathology, advanced stage at diagnosis. H. pylori infection associated DNA methylation is correlated with CIMP, specific molecular and clinicopathological features in GC, supporting its utility as promising biomarker in this tumor type.

BACKGROUND/AIM: The combination of atezolizumab plus bevacizumab (Atz/Bev) has become widely used as a first-line therapy for advanced hepatocellular carcinoma (HCC). However, for post-Atz/Bev therapy, evidence on the outcomes of molecular targeted agents, such as lenvatinib, is limited. The present study aimed to assess the clinical effectiveness of lenvatinib on advanced HCC in patients who had previously undergone Atz/Bev treatment. PATIENTS AND METHODS: Twenty patients with HCC, who received lenvatinib after Atz/Bev treatment, were enrolled in the study. In particular, we examined the impact of adverse events (AEs), such as anorexia and general fatigue. During the treatment, lenvatinib dosages were adjusted or temporarily discontinued in response to AEs. Treatment outcomes were retrospectively evaluated. RESULTS: The objective response rate (ORR) and disease control rate (DCR) for lenvatinib treatment were 25.0% and 95.0%, respectively, according to the Response Evaluation Criteria in Solid Tumors. The median progression-free survival (PFS) was 6.0 months, and the median overall survival (OS) was 10.5 months. Eleven patients experienced anorexia or fatigue, leading to a reduction in the dose of lenvatinib but not to a significant difference in the time to drug discontinuation. Importantly, there were no significant differences between the 11 anorexia/fatigue-suffering patients and the nine other patients with regard to PFS and OS. CONCLUSION: Lenvatinib can be efficacious and safe for treating advanced HCC patients previously treated with Atz/Bev, and AEs such as anorexia and general fatigue can be effectively managed without losing lenvatinib's therapeutic benefits.

(1) Background: This study aimed to investigate clinical outcomes for cabozantinib in clinical practice in patients with advanced hepatocellular carcinoma (HCC) previously treated with atezolizumab plus bevacizumab (Atz/Bev), with a focus on whether patients met criteria of Child-Pugh Class A and Eastern Cooperative Oncology Group performance status (ECOG-PS) score 0/1 at baseline. (2) Methods: Eleven patients (57.9%) met the criteria of both Child-Pugh class A and ECOG-PS score 0/1 (CP-A+PS-0/1 group) and eight patients (42.1%) did not (Non-CP-A+PS-0/1 group); efficacy and safety were retrospectively evaluated. (3) Results: Disease control rate was significantly higher in the CP-A+PS-0/1 group (81.1%) than in the non-CP-A+PS-0/1 group (12.5%). Median progression-free survival, overall survival and duration of cabozantinib treatment were significantly longer in the CP-A+PS-0/1 group (3.9 months, 13.4 months, and 8.3 months, respectively) than in the Non-CP-A+PS-0/1 group (1.2 months, 1.7 months, and 0.8 months, respectively). Median daily dose of cabozantinib was significantly higher in the CP-A+PS-0/1 group (22.9 mg/day) than in the non-CP-A+PS-0/1 group (16.9 mg/day). (4) Conclusions: Cabozantinib in patients previously treated with Atz/Bev has potential therapeutic efficacy and safety if patients have good liver function (Child-Pugh A) and are in good general condition (ECOG-PS 0/1).

The combination of atezolizumab plus bevacizumab (Atz/Bev) is now widely used in clinical practice as a first-line treatment for patients with advanced hepatocellular carcinoma (HCC). However, the established regimen for post-treatment after Atz/Bev is unknown. We investigated the efficacy and safety of cabozantinib in patients previously treated with Atz/Bev in real clinical practice, with a focus on whether patients met criteria of Child-Pugh Class A and Eastern Cooperative Oncology Group performance status (ECOG-PS) score 0/1 at baseline. Our results suggest that cabozantinib in patients with advanced HCC previously treated with Atz/Bev can be expected to yield similar outcomes to those seen in the CELESTIAL trial conducted using cabozantinib for post-sorafenib treatment if patients have good liver function and are in good general condition.(1) Background: This study aimed to investigate clinical outcomes for cabozantinib in clinical practice in patients with advanced hepatocellular carcinoma (HCC) previously treated with atezolizumab plus bevacizumab (Atz/Bev), with a focus on whether patients met criteria of Child-Pugh Class A and Eastern Cooperative Oncology Group performance status (ECOG-PS) score 0/1 at baseline. (2) Methods: Eleven patients (57.9%) met the criteria of both Child-Pugh class A and ECOG-PS score 0/1 (CP-A+PS-0/1 group) and eight patients (42.1%) did not (Non-CP-A+PS-0/1 group); efficacy and safety were retrospectively evaluated. (3) Results: Disease control rate was significantly higher in the CP-A+PS-0/1 group (81.1%) than in the non-CP-A+PS-0/1 group (12.5%). Median progression-free survival, overall survival and duration of cabozantinib treatment were significantly longer in the CP-A+PS-0/1 group (3.9 months, 13.4 months, and 8.3 months, respectively) than in the Non-CP-A+PS-0/1 group (1.2 months, 1.7 months, and 0.8 months, respectively). Median daily dose of cabozantinib was significantly higher in the CP-A+PS-0/1 group (22.9 mg/day) than in the non-CP-A+PS-0/1 group (16.9 mg/day). (4) Conclusions: Cabozantinib in patients previously treated with Atz/Bev has potential therapeutic efficacy and safety if patients have good liver function (Child-Pugh A) and are in good general condition (ECOG-PS 0/1).

The diagnosis of bile duct tumors can be difficult at times. A transpapillary bile duct biopsy findings with endoscopic retrograde cholangiopancreatography sometimes contradict diagnostic imaging findings. In bile duct tumors, inflammatory polyps in the extrahepatic bile duct are relatively rare with extrahepatic cholangitis. The disease's clinical relevance, including its natural history and prognosis, is not always clear. We show here a rare case of an inflammatory polyp in the common bile duct. A 69-year-old woman with abdominal pain was diagnosed with cholangitis. The findings of contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography suggested that she had extrahepatic cholangiocarcinoma. The examination and therapy of cholangitis were performed by endoscopic retrograde cholangiopancreatography. The cholangiography revealed a suspected tumor in the hilar bile duct with some common bile duct stones. Then, after endoscopic sphincterotomy to remove tiny common bile duct stones, further detailed examinations were performed at the same time using an oral cholangioscope revealed a papillary raised lesion with a somewhat white surface in the bile duct; a biopsy was conducted on the same spot, and epithelial cells with mild atypia appeared in the shape of a papilla. Since the malignant tumor or the intraductal papillary neoplasm of the bile duct could not be ruled out, extrahepatic bile duct resection was conducted with the patient's informed consent. Bile duct inflammatory polyp was the histopathological diagnosis.

次世代シークエンサーをはじめとする難培養性の細菌を解析する研究技術の発展により,腸内細菌叢と疾患の関連性を示す研究が爆発的進歩を遂げている。消化器癌においても例外ではなくそれぞれの癌に特徴的な細菌との関連性が数多く報告されている。本稿では,腸内細菌を研究するうえでの基礎的な研究方法を紹介するとともに消化器癌における腸内細菌叢の影響に関し包括的に述べる。(著者抄録)

Objective In general, surface ulceration in gastric gastrointestinal stromal tumor (GIST) is considered a malignant feature; however, the mechanism underlying its formation has not been evaluated in detail. In this study, we analyzed the factors involved in ulceration using resected specimens of gastric GIST. Methods A total of 48 samples were retrospectively analyzed. We examined the association of surface ulceration of gastric GIST with the MIB-1 labeling index, mitotic number, tumor size, endoscopic ultrasound (EUS) findings and growth pattern on computed tomography (CT). Results The proportion of men was significantly higher in the ulceration group than in the non-ulceration group (p=0.04146), whereas age was not significantly different between the groups. Tumor was significantly larger in the ulceration group than in the non-ulceration group (p=0.0048). There was no correlation between tumor size and ulcer number. The MIB-1 index was not related to ulceration, nor were EUS findings. The number of mitotic cells tended to be higher in the ulceration group than in the non-ulceration group (p=0.05988). Intraluminal growth pattern was strongly associated with ulceration (p=0.00019). After a multivariate analysis, the growth pattern was the only factor associated with ulceration of gastric GIST. Conclusion Although formation of surface ulceration in gastric GIST was partially associated with the degree of malignancy, the growth pattern was the most important factor associated with ulceration in gastric GIST.

Pancreatic ductal adenocarcinoma (PDAC) can be treated with surgery, chemotherapy, and radiotherapy. Despite medical progress in each field in recent years, it is still insufficient for managing PDAC, and at present, the only curative treatment is surgery. A typical pancreatic cancer is relatively easy to diagnose with imaging. However, it is often not recommended for surgical treatment at the time of diagnosis due to metastatic spread beyond the pancreas. Even if it is operable, it often recurs during postoperative follow-up. In the case of PDAC with a diameter of 10 mm or less, the 5-year survival rate is as good as 80% or more, and the best index for curative treatment is tumor size. The early detection of pancreatic cancer with a diameter of less than 10 mm or carcinoma in situ is critical. Here, we provide an overview of the current status of diagnostic imaging features and genetic tests for the accurate diagnosis of early-stage PDAC.

BACKGROUND/AIM: Lymphoid follicles hyperplasia (LH) is sometimes observed in the normal colon as small, round, yellowish-white nodules. LH is associated with food hypersensitivity and bowel symptoms and histologically characterized as intense infiltration of lymphocytes or plasmacytes. It is suggested that LH represents inflammatory immune response in the colonic mucosa. We investigated the presence of LH in the normal colonic mucosa and its association with incidence of colorectal lesions including colorectal cancer, adenoma and hyperplastic polyp. PATIENTS/METHODS: 605 participants undergoing colonoscopy for various indications were enrolled. Presence of LH in the proximal colon (appendix, cecum and the ascending colon) was observed using the blue laser imaging (BLI) endoscopy, a new generation image enhanced endoscopy (IEE) system. LH was defined as well demarcated white nodules. Elevated LH with erythema was distinguished as LH severe. Association between presence of LH and occurrence of colorectal lesions was investigated. RESULTS: Prevalence of all colorectal lesions and adenoma were significantly lower in LH severe group compared to the LH negative group (P = 0.0008, 0.0009, respectively). Mean number of all colorectal lesions and adenoma were also lower in LH severe group compared to the LH negative group (P = 0.005, 0.003 respectively). The logistic regression with adjustment for gender and age demonstrated that presence of LH severe held significantly lower risk of all colorectal lesions (OR = 0.48, 95%CI = 0.27-0.86) and adenoma (OR = 0.47, 95%CI = 0.26-0.86). CONCLUSION: LH in the colonic mucosa visualized by IEE is useful endoscopic finding to predict risk of colorectal adenoma.

BACKGROUND AND AIM: In colorectal endoscopic submucosal dissection (ESD), post-ESD electrocoagulation syndrome (PECS) has been recognized as one of the major complications. There are no reports on the relationships between ESD findings and PECS. This study aims to evaluate the risk factors for PECS, including ESD findings such as muscularis propria exposure. METHODS: We performed a retrospective cohort study of patients who underwent colorectal ESD between January 2017 and December 2021 in Japan. The grade of injury to the muscle layer caused by ESD was categorized as follows: Grade 0, no exposure of muscularis propria; Grade 1, muscularis propria exposure; Grade 2, torn muscularis propria; and Grade 3, colon perforation. The risk factors for PECS, including injury to the muscle layer, were analyzed by univariate and multivariate analyses. RESULTS: Out of 314 patients who underwent colorectal ESD, PECS occurred in 28 patients (8.9%). The multivariate analysis showed that female sex (odds ratio [OR] 3.233; 95% confidence interval [95% CI]: 1.264-8.265, P = 0.014), large specimen size (≥ 40 mm) (OR 6.138; 95% CI: 1.317-28.596, P = 0.021), long procedure time (≥ 90 min) (OR 2.664; 95% CI: 1.053-6.742, P = 0.039), and Grade 1 or 2 injury to the muscle layer (OR 3.850; 95% CI: 1.090-13.61, P = 0.036) were independent risk factors for PECS. CONCLUSIONS: Injury to the muscle layer, such as exposure or tear, was identified as a novel independent risk factor for PECS. We should perform colorectal ESD carefully to avoid injuring the muscle layers.

In inflammatory bowel disease, including Crohn's disease and ulcerative colitis, an excessive immune response due primarily to T-cell lymphocytes causes inflammation in the gastrointestinal tract. Lesions in Crohn's disease can occur anywhere in the gastrointestinal tract, i.e., from the oral cavity to the anus. Endoscopically, aphthoid lesions/ulcers believed to be initial lesions progress to discrete ulcers, which coalesce to form a longitudinal array and progress to longitudinal ulcers with a cobblestone appearance, which is a typical endoscopic finding. Before long, complications such as strictures, fistulas, and abscesses form. Lesions in ulcerative colitis generally extend continuously from the rectum and diffusely from a portion of the colon to the entire colon. Endoscopically, lack of vascular pattern, fine granular mucosa, erythema, aphthae, and small yellowish spots are seen in mild cases; coarse mucosa, erosions, small ulcers, bleeding (contact bleeding), and adhesion of mucous, bloody, and purulent discharge in moderate cases; and widespread ulcers and marked spontaneous bleeding in severe cases.

Background: The relationship between pancreatic ductal adenocarcinoma (PDAC) and the intestinal environment is not fully understood. The purpose of this study was to elucidate the characteristics of the intestinal environment in PDAC. Methods: We performed a case-control study of 5 Japanese patients with unresectable PDAC located in the body or tail (PDAC-bt). The number of patients analyzed was limited for this preliminary study. We included 68 healthy subjects, herein control, of pre-printed study in the preliminary study. 16S rRNA amplicon sequencing and metabolomic analysis were performed using fecal samples from the subjects. Results: There was no difference in the Shannon index and Principal Coordinate Analysis between PDAC-bt and the control. However, a significant increase in oral-associated bacteria (Actinomyces, Streptococcus, Veillonella, Lactobacillus) was observed. A significant decrease of Anaerostipes was demonstrated in the feces of PDAC-bt compared with the control. The intestinal propionic acid and deoxycholic acid were significantly lower in PDAC-bt compared with the control. Conclusions: We showed that the intestinal environment of PDAC-bt is characterized by an increase in oral-associated bacteria and an imbalance of metabolites but without changes in alpha and beta diversity of the gut microbiota profiles.Clinical Trial Registration: www.umin.ac.jp, UMIN 000041974, 000023675, 000023970.

Gastric endoscopic submucosal dissection (ESD) is increasingly performed in patients receiving antithrombotic therapy. Second-look endoscopy (SLE) has been performed empirically in several clinical settings. We investigated whether SLE omission was associated with an increased risk of postESD bleeding in all patients, including those administered antithrombotic agents. Between July 2016 and June 2018, 229 patients were treated with a clinical pathway for gastric ESD that involved SLE on the day after ESD (SLE group). Between September 2018 and May 2020, 215 patients were treated using a clinical pathway that did not include SLE (nonSLE group). We retrospectively compared the incidence of postESD bleeding among the propensity score-matched cohorts and determined the risk factors for postESD bleeding using multivariate analysis. The propensity score-matched cohorts showed no significant differences in the incidence of postESD bleeding between the SLE (3.2%) and nonSLE (5.1%) groups. Multivariate analysis revealed that the presence of lesions in the lower gastric body (adjusted odds ratio [OR] 2.17, 95% confidence interval [CI] 1.06-4.35, P.03) was a significant risk factor for postESD bleeding during admission, whereas resected specimen size ≥ 40 mm (adjusted OR 3.21, 95% CI 1.19-8.19, P.02) and antiplatelet therapy (adjusted OR 4.16, 95% CI 1.47-11.80, P.007) were significant risk factors after discharge. Complete omission of SLE after gastric ESD does not increase postESD bleeding in clinical practice.

Small intestinal tumors (adenoma and adenocarcinoma, SIT) are rare, and their microRNA (miRNA) expression profiles have not been established. Previously, we reported a relationship between miRNA expression profiles and the development, growth, morphology, and anticancer drug resistance of colorectal tumors. Here, we demonstrate that the miRNA expression profile of SIT is significantly different from those of tumors of the colon. We compared the onco-related miRNA expression profiles of SIT and colorectal tumors and found them to be different from each other. The expressions of miR-143 and miR-145 were frequently downregulated in SIT and colorectal tumors but not in sessile serrated adenoma/polyp tumors. The profiles of SIT and colorectal carcinomas of miR-7, miR-21, and miR-34a were considerably different. Upregulation of miR-31 expression was not found in any SIT cases. Our data suggested that miR-143 and miR-145 might act as anti-oncomirs common to adenocarcinoma of the small intestine, similar to those of colorectal adenoma and other cancers. However, the expression profiles of the other miRNAs of SIT were significantly different from those of colorectal tumors. These findings contribute useful insights into the tumor development and diagnosis of SIT.