Clinical Outcomes of Follow-Up Observation After Endoscopic Submucosal Dissection for Esophageal Squamous Cell Carcinoma Invading the Muscularis Mucosa Without Lymphovascular Involvement.

BACKGROUND: The therapeutic approach after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) diagnosed as pathological T1a-muscularis mucosa (pT1a-MM) without lymphovascular involvement (LVI) remains uncertain. We aimed to determine whether observation after ESD is acceptable for patients without LVI showing pT1a-MM cancer. METHODS: We retrospectively registered 566 ESCC patients who were treated with ESD at ten institutions between January 2007 and December 2015. Of those, 447 cases showing pT1a-epithelium/lamina propria mucosa (EP/LPM) without LVI and vertical margin (VM) (EP/LPM group), and 41 cases showing pT1a-MM without LVI and VM (MM group) were analyzed in this investigation. The clinical outcomes were assessed between the groups. RESULTS: The 5 year cumulative incidence of metastatic recurrence was 0.5% and 3.3% in the EP/LPM and MM groups, respectively (P = 0.121). Two cases showing pT1a-EP/LPM and one showing pT1a-MM experienced lymph node recurrence. The 5 year cumulative incidence of local recurrence was 1.5% and 3.8% in the EP/LPM and MM groups, respectively (P = 0.455). The 5 year disease-specific survival (DSS) rate was 99.3% and 96.6% in the EP/LPM and MM groups, respectively (P = 0.118), whereas the 5 year overall survival rate was significantly higher in the EP/LPM group than in the MM group (92.6% versus 81.1%, respectively; P = 0.021). CONCLUSIONS: As regards metastatic recurrence and DSS, ESCC patients with pT1a-MM without LVI showed favorable outcomes that were equivalent to those with pT1a-EP/LPM, even when they were not treated with additional therapy after ESD.

Risk and prognostic factors of invasive gastric cancer detection during surveillance endoscopy: Multi-institutional cross-sectional study.

OBJECTIVES: Esophagogastroduodenoscopy (EGD) is important for the detection of curable gastric cancer (GC). However, there are no appropriate surveillance data during routine endoscopic inspections. This study aimed to clarify the risk factors of pT1b or deeper GC detection during surveillance endoscopy. METHODS: This was a retrospective, multicenter, cross-sectional study conducted in 15 Japanese hospitals. We retrospectively analyzed patients with GC who had previously undergone surveillance endoscopy at each institution from January 2014 to March 2020. Patients who had undergone gastrectomy, non-infection of Helicobacter pylori (Hp), and those with intervals <3 months or >10 years from a previous endoscopy were excluded. RESULTS: In total, 1085 patients with GCs detected during surveillance endoscopy were enrolled. The multivariate logistic analysis revealed that current Hp infection (odds ratio [OR] 2.18; 95% confidence interval [CI] 1.50-3.16) and a surveillance interval of >1.5 years (OR 1.96; 95% CI 1.35-2.84) were independent risk factors for pT1b or deeper GC. The 5-year disease-specific survival (5y-DSS) rate of GC was significantly lower in patients with surveillance interval of >1.5 years than in those with surveillance interval of ≤1.5 years (93.7% vs. 98.3%, P < 0.001). Similarly, the 5y-DSS rate of GC was significantly lower in patients with active Hp infection than in those without (93.7% vs. 99.4%, P < 0.001). CONCLUSION: In this study, a surveillance interval of >1.5 years and current Hp infection were independent risk factors for detecting pT1b or deeper GC. Additionally, these factors were poor prognostic factors of the detected GC during surveillance endoscopy.

Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients Aged 85 Years Old or Older Is Associated with a Good Prognosis Compared to Conservative Treatment without Any Invasive Procedure.

INTRODUCTION: Studies have reported the feasibility of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in elderly people with respect to both short- and long-term outcomes. As the elderly population in society increases, the requirement for managing super-elderly patients aged ≥85 years with EGC will also increase. This study aims to identify the long-term clinical outcomes of ESD for clinical T1N0 EGC in patients aged ≥85 years. METHODS: A total of 370 consecutive patients aged ≥85 years with clinical T1N0 EGC who were managed in 11 institutions were reviewed retrospectively. On the basis of treatment strategy, we compared the overall survival (OS) and disease-specific survival (DSS) after performing propensity score-matched analysis between patients undergoing ESD (ESD group) and those not undergoing treatment (conservative treatment group). The potential prognostic factors were also investigated in the propensity score-matched patients. RESULTS: After propensity score matching, we found that the 3-year OS and DSS rates were significantly higher in the ESD group than in the conservative treatment group (OS, 82.2% vs. 50.5%; p < 0.001; DSS, 100% vs. 80.1%; p = 0.008). Furthermore, ESD was identified as a significant factor for prolonged OS, whereas Charlson comorbidity index (CCI) ≥3 and prognostic nutritional index (PNI) <36.2 were associated with reduced OS. CONCLUSION: ESD was associated with improved OS in patients with clinical T1N0 EGC aged ≥85 years compared with the absence of treatment. Furthermore, CCI and PNI were helpful for patient selection.

Prognostic risk factors associated with esophageal squamous cell carcinoma patients undergoing endoscopic submucosal dissection: a multi-center cohort study.

BACKGROUND: Long-term outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) have not been assessed in a large, multicenter cohort. We aimed to evaluate long-term outcomes of ESD for ESCC in a real-world setting. METHODS: We retrospectively recruited 659 patients who underwent ESD for ESCC at ten institutions from January 2007 to December 2015. Of these, 566 patients were analyzed and classified into three groups according to the pathologic invasion depth after ESD: epithelium/lamina propria mucosa (EP/LPM group: 454 patients), muscularis mucosa/submucosa invasion ≤ 200 µm below the inferior margin of the muscularis mucosa (MM/SM1 group: 81 patients), and submucosa invasion > 200 µm below the MM inferior margin (SM2 group: 31 patients). RESULTS: The 5-year overall survival rates in the EP/LPM, MM/SM1, and SM2 groups were 92.6%, 80.0%, and 62.7%, respectively, while the 5-year disease-specific survival rates were 99.7%, 96.9%, and 88.3%, respectively. Multivariate analyses revealed that the invasion depth, Charlson Comorbidity Index (CCI), and prognostic nutritional index (PNI) were independent prognostic factors. Hazard ratios in the MM/SM1 and SM2 groups were 2.25 (95% confidence interval [CI] 1.04-4.83; P = 0.038) and 3.18 (95% CI 1.08-9.34; P = 0.036), respectively, compared to those in the EP/LPM group, while those for patients with a CCI ≥ 3 and PNI ≤ 47.75 were 3.25 (95% CI 1.79-5.89; P < 0.001) and 2.42 (95% CI 1.26-4.65; P = 0.008), respectively. CONCLUSIONS: This study identified that invasion depth, presence of comorbid diseases and preoperative nutritional status are independent prognostic risk factors associated with ESCC patients undergoing ESD.

Clinical Outcomes of Vonoprazan-Treated Patients after Endoscopic Submucosal Dissection for Gastric Neoplasms: A Prospective Multicenter Observation Study.

BACKGROUND: Vonoprazan (VPZ) has the potential to prevent delayed bleeding and promote ulcer healing after endoscopic submucosal dissection (ESD) similar to proton pump inhibitors (PPIs). OBJECTIVE: We aimed to evaluate the outcomes of VPZ-treated patients after ESD and compared the efficacy and feasibility in preventing a delayed bleeding and in healing an artificial ulcer after ESD between the VPZ and PPI therapies. METHODS: This was a prospective, observation study in 11 Japanese medical institutions. We enrolled and evaluated 223 patients who underwent gastric ESD followed by VPZ treatment (VPZ group). We selected 385 patients who underwent gastric ESD followed by PPI treatment as historical controls (PPI group) to compare the outcomes between the VPZ and PPI groups using a propensity score matching analysis. RESULTS: Among the 223 patients treated with VPZ, 173 were men and 50 were women with a median age of 72 years and with a median tumor size of 12.0 mm. Rates of en bloc resection and complete resection were 99.1 and 94.2%, respectively. Lymphovascular invasion was found in 6 (6.3%) cases. Intraoperative perforation and delayed bleeding occurred in 3 (1.3%) and 10 patients (4.5%), respectively. Scarring of artificial post-ESD ulcer was found in 153 patients (68.6%) at 6 weeks after ESD. The 205 pairs of propensity score-matched patients were comparable between the VPZ and PPI groups. The rate of delayed bleeding in the VPZ and PPI groups was 3.9 and 4.4%, respectively (difference, 0.5 percentage points; 95% confidence interval, -3.7 to 2.8%; non-inferiority, p = 0.01). Therefore, VPZ therapy demonstrated non-inferiority against PPI therapy in reducing the rate of delayed bleeding. The scar-stage ulcer at 6 weeks in the VPZ group and 8 weeks in the PPI group was 68.3 and 74.6%, respectively (p = 0.19). CONCLUSIONS: VPZ therapy showed an efficacy and feasibility in preventing a delayed bleeding after ESD similar to the PPI therapy. VPZ for 6 weeks and PPI for 8 weeks were similarly effective for an artificial ulcer healing after ESD.

Helicobacter pylori eradication therapy outcome according to clarithromycin susceptibility testing in Japan.

BACKGROUND: Helicobacter pylori (Hp) infection increases the risk of gastric cancer. Therefore, eradication is a global goal, which requires continuous monitoring of therapeutic regimens and effectiveness. Clarithromycin resistance is an important contributor to eradication failure, and metronidazole is recommended as second-line treatment in such cases. Here, we retrospectively evaluated the clarithromycin and metronidazole resistance rates and treatment effectiveness in patients with Hp using tailored therapies according to clarithromycin susceptibility testing. METHODS: Data on drug susceptibility were obtained for 5249 Japanese Hp patients between July 2005 and August 2018. Clarithromycin/metronidazole resistance rates were analyzed according to year, gender, and age with Fisher's exact test. The relationship between clarithromycin resistance and Hp therapy outcomes was assessed for 1300 patients. Treatment regimens included a clarithromycin- or metronidazole-containing 7-day triple therapy with one of several proton pump inhibitors and vonoprazan. RESULTS: Clarithromycin resistance increased annually and was higher in women and younger patients (<30 years). Rates of metronidazole resistance were stable but decreased with age. Hp treatment regimens using PPIs had eradication rates of 88% and 45% among clarithromycin-sensitive and clarithromycin-resistant cases, respectively, while regimens including vonoprazan had eradication rates of around 90% regardless of clarithromycin susceptibility. In particular, triple therapy with vonoprazan, amoxicillin, and metronidazole achieved 98% eradication. CONCLUSION: Clarithromycin-containing triple therapy even using vonoprazan did not achieve satisfactory eradication rates even in the clarithromycin-sensitive group. To avoid antibiotic misuse in population with low metronidazole resistance, 7-day vonoprazan, amoxicillin, and metronidazole triple therapy might be a strong candidate as a first-line eradication therapy.

Carbon monoxide promotes gastric wound healing in mice via the protein kinase C pathway.

Previous studies have shown that carbon monoxide (CO) is involved in a variety of physiological and pathophysiological processes including anti-inflammatory, anti-apoptotic and anti-oxidant responses. However, it remains unclear whether CO promotes gastric ulcer healing. In the present study, we evaluated the efficacy of CO-saturated saline in the treatment of gastric ulcers and its underlying mechanism. Acute gastric ulcers were induced in C57BL/6 male mice using acetic acid. A CO-saturated solution was prepared by bubbling 50% CO gas into saline. To investigate the effect of CO on gastric mucosal healing, CO solution was orally administrated twice a day beginning on day 3 after the induction of gastric ulcer. Mice were sacrificed on day 7 after ulcer induction. The stomach was removed, and the ulcerated lesions were measured. In vitro wound healing assays were used to determine the mechanism of action of CO in the restoration of murine gastric epithelial cells. The oral administration of CO solution accelerated the gastric ulcer healing by promoting re-epithelialization. Furthermore, the wound healing assay performed using the murine gastric epithelial cells revealed that the CO-saturated medium enhanced cell migration through the activation of protein kinase C (PKC). Based on these data, CO may represent a novel therapeutic approach for the treatment of gastric mucosal injuries.

Role of metallothionein in murine experimental colitis.

Metallothioneins (MTs) are a family of cysteine-rich low molecular-weight proteins that can act as reactive oxygen species scavengers. Although it is known that the induction of MT expression suppresses various inflammatory disorders, the role of MTs in intestinal inflammation remains unclear. In this study, we investigated the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the MT-I/II genes. Acute colitis was induced by 2% DSS in male MT-I/II double knockout (MT-null) and C57BL/6 (wild-type) mice. The disease activity index (DAI) was determined on a daily basis for each animal, and consisted of a calculated score based on changes in body weight, stool consistency and intestinal bleeding. Histology, colon length, myeloperoxidase (MPO) activity and colonic mRNA expression and the concentration of inflammatory cytokines were evaluated by real-time-PCR and enzyme-linked immunosorbent assay (ELISA). The localization of MTs and macrophages was determined by immunohistological and immunofluorescence staining. To investigate the role of MTs in macrophages, peritoneal macrophages were isolated and their responses to lipopolysaccharide were measured. Following DSS administration, the DAI score increased in a time-dependent manner and was significantly enhanced in the MT-I/II knockout mice. Colonic MPO activity levels and inflammatory cytokines [tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-17] production increased following DSS administration, and these increases were significantly enhanced in the MT-I/II knockout mice compared with the wild-type mice. MT-positive cells were detected in the lamina propria and submucosal layer by immunohistochemical and immunofluorescence staining, and were mainly co-localized in F4/80-positive macrophages. The production of inflammatory cytokines (TNF-α, IFN-γ and IL-17) from isolated peritoneal macrophages increased following lipopolysaccharide stimulation, and these increases were significantly enhanced in the macrophages obtained from the MT-I/II knockout mice. These data indicate that MTs play an important role in the prevention of colonic mucosal inflammation in a mouse model of DSS-induced colitis, thus suggesting that endogenous MTs play a protective role against intestinal inflammation.

Rebamipide ameliorates indomethacin-induced small intestinal injury in rats via the inhibition of matrix metalloproteinases activity.

BACKGROUND AND AIM: The pathogenesis of non-steroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal lesions remains unclear, although it is considered to be quite different from that of upper gastrointestinal tract ulcers due to the absence of acid and the presence of bacteria and bile in the small intestine. The aim of this study was to characterize specific gene expression profiles of intestinal mucosa in indomethacin-induced small intestinal injury, and to investigate the effects of rebamipide on the expression of these genes. METHODS: Intestinal injury was induced in male Wistar rats by subcutaneous administration of indomethacin. Total RNA of the intestinal mucosa was extracted 24 h after indomethacin administration, gene expression was investigated using microarray analysis, and the identified genes were confirmed by real-time polymerase chain reaction (PCR). In addition, we investigated whether the treatment with rebamipide altered the expression of these identified genes. RESULTS: The administration of indomethacin induced small intestine injuries, and these lesions were significantly inhibited by the treatment with rebamipide. Microarray analysis showed that the genes for several matrix metalloproteinases (MMPs) and several chemokine-related genes were significantly upregulated, and metallothionein 1a (MT1a) was downregulated in the intestinal mucosa after administration of indomethacin. The expressions of these genes were reversed by the treatment with rebamipide. CONCLUSION: These data suggest that MMPs, chemokines, and MT1a may play an important role in the intestinal mucosal injury induced by indomethacin. In particular, the inhibition of MMP genes and chemokine-related genes by rebamipide may be important for the therapeutic effect against NSAIDs-induced small intestinal injury.

Daikenchuto, a Kampo medicine, regulates intestinal fibrosis associated with decreasing expression of heat shock protein 47 and collagen content in a rat colitis model.

Heat shock protein (HSP) 47 may play an important role in the pathogenesis of intestinal fibrosis. Daikenchuto (DKT), a traditional Japanese herbal (Kampo) medicine, has been reported to ameliorate intestinal inflammation. The aims of this study were to determine time-course profiles of several parameters of fibrosis in a rat model, to confirm the HSP47-expressing cells in the colon, and finally to evaluate DKT's effects on intestinal fibrosis. Colitis was induced in male Wistar rats weighing 200 g using an enema of trinitrobenzene sulfonic acid (TNBS). HSP47 localization was determined by immunohistochemistry. Colonic inflammation and fibrosis were assessed by macroscopic, histological, morphometric, and immunohistochemical analyses. Colonic mRNA expression of transforming growth factor ß1 (TGF-ß1), HSP47, and collagen type I were assessed by real time-polymerase chain reaction (PCR). DKT was administered orally once a day from 8 to 14 d after TNBS administration. The colon was removed on the 15th day. HSP47 immunoreactivity was coexpressed with α-smooth muscle actin-positive cells located in the subepithelial space. Intracolonic administration of TNBS resulted in grossly visible ulcers. Colonic inflammation persisted for 6 weeks, and fibrosis persisted for 4 weeks after cessation of TNBS treatment. The expression levels of mRNA and proteins for TGF-ß1, HSP47, and collagen I were elevated in colonic mucosa treated with TNBS. These fibrosis markers indicated that DKT treatment significantly inhibited TNBS-induced fibrosis. These findings suggest that DKT reduces intestinal fibrosis associated with decreasing expression of HSP47 and collagen content in the intestine.

Suppression of indomethacin-induced apoptosis in the small intestine due to Bach1 deficiency.

BTB and CNC homologue 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1). This study hypothesized that Bach1 plays an important role in the indomethacin-induced apoptosis in the case of small-intestinal mucosal injury. Eight-week-old male C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice were included in this study. Mucosal injuries induced by subcutaneously administering indomethacin were evaluated macroscopically, histologically and biochemically. Indomethacin-induced injuries were improved in Bach1-deficient mice. Immunohistochemistry showed an increase in the number of HO-1-positive cells, which were mainly F4/80 positive macrophages, in Bach1-deficient mice. Indomethacin administration increased the expression of HO-1 mRNA and protein in the small intestine in Bach1-deficient mice. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining showed that the extent of apoptosis was suppressed in Bach1-deficent mice. In conclusion, deficiency of the Bach1 gene inhibited apoptosis and thus suppressed mucosal injury, indicating that Bach1 is a novel therapeutic target for indomethacin-induced intestinal injury.

Reduced small-intestinal injury induced by indomethacin in interleukin-17A-deficient mice.

BACKGROUND AND AIMS: The pathogenesis of enteropathy induced by non-steroidal anti-inflammatory drugs (NSAIDs) is still unclear, and there are no established treatments. Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has been associated with the development of chronic inflammatory diseases, including autoimmune diseases. To define the role of IL-17A in small intestinal injury and inflammation, we studied the effects of indomethacin administration in mice with targeted deletions of the IL-17A gene. METHODS: Male C57BL/6 (wild-type) and homozygous IL-17A(-/-) C57BL/6 mice were subjected to this study. Indomethacin (10 mg/kg) was subcutaneously administered to induce small-intestinal damage. Indomethacin-induced lesions in the small intestine were evaluated by measuring the injured area and by histopathology. Also assessed were myeloperoxidase (MPO) activity, as an index of neutrophil accumulation, and intestinal mRNA expression for inflammatory cytokines. RESULTS: The area of macroscopic ulcerative lesions, the MPO activity and the mRNA expression of inflammatory-associated chemokines, such as keratinocyte chemoattractant (KC), monocyte chemotactic protein-1 (MCP-1), and granulocyte-colony stimulating factor (G-CSF), were significantly increased in indomethacin-treated groups compared with the sham groups. The development of intestinal lesions by indomethacin was inhibited in IL-17A(-/-) mice compared with wild-type mice, together with significant suppression of the increased levels of MPO activities and KC, MCP-1, and G-CSF levels. CONCLUSION: These findings demonstrate that IL-17A contributes to the development of indomethacin-induced small intestinal injury through upregulation of G-CSF, KC, and MCP-1. IL-17A might be a promising new therapeutic target to treat NSAID-induced enteritis.

Role of tumor necrosis factor-α in the pathogenesis of indomethacin-induced small intestinal injury in mice.

The pathogenesis of small intestinal damage caused by non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin is still unclear. For this reason, there is currently no therapeutic strategy for ameliorating such damage. On the other hand, molecular treatment strategies targeting tumor necrosis factor (TNF)-α exert beneficial effects on intestinal lesions in patients with inflammatory bowel disease (IBD). To clarify the participation of TNF-α in NSAID-induced small intestinal damage, we investigated the effects of indomethacin administration in mice with targeted deletion of the TNF-α gene. Indomethacin (10 mg/kg) was administered subcutaneously to male C57BL/6 (wild-type: WT) mice and TNF-α-deficient (TNF-α-/-) mice to induce small intestinal damage. The ulcer score, the tissue-associated myeloperoxidase (MPO) activity as an index of neutrophil infiltration, and the expression of keratinocyte chemoattractant (KC) mRNA in the small intestinal mucosa were measured. In addition, we performed a TUNEL assay to evaluate indomethacin-induced apoptosis of intestinal epithelial cells and measured the expression of caspase-3 protein and Bcl-2 mRNA. The ulcer score, MPO activity, and expression of KC mRNA were significantly increased after indomethacin administration. These increases were significantly inhibited in TNF-α-/- mice compared with WT mice. Apoptotic cells were observed by the TUNEL assay in the area of the ulcerative lesion, and they were significantly fewer in TNF-α-/- mice compared with WT mice. The expression of cleaved caspase-3 protein was induced by indomethacin administration, and significantly inhibited in TNF-α-/- mice compared with that of WT mice. The expression level of Bcl-2 mRNA in indomethacin-treated TNF-α-/- mice was significantly higher than that in WT mice. TNF-α plays an important role in the pathogenesis of indomethacin-induced small intestinal damage. These results suggest that TNF-α could become a new therapeutic target for NSAID-induced small intestinal damage.