The incidence of nonampullary duodenal cancer in Japan 2016-2020: analysis of a national cancer registry.

BACKGROUND AND AIM: Epidemiological research is scarce in Asian countries including Japan. We aimed to clarify the epidemiological trend of nonampullary duodenal cancer (NADC) in Japan using a national database. METHODS: All patients with NADC diagnosed between 2016 and 2020 were identified from the Japanese national cancer registry. The crude and age-adjusted incidences were determined and temporal trends including diagnostic mode, tumor stage, and treatments were analyzed. RESULTS: A total of 14 484 patients were included. The crude and age-adjusted incidences were 21.8-23.5 and 10.7-12.1 per 1 000 000 person-years. Male-to-female ratio was 1.7:1, and the incidence increased with age. The number of patients was highest among 70-79 year age group in both sexes. In total, 55% of patients were diagnosed during screening or surveillance for other diseases. In 54% of patients, the tumor stage was localized. The major treatment was surgery (32%), followed by endoscopic resection (27%). The trends for detection mode, tumor stage, and treatment were consistent during 2016-2020. CONCLUSIONS: This study clarified and confirmed the high incidence of duodenal cancer in Japan. Characteristically, many NADC cases are diagnosed asymptomatically and treated by endoscopic or surgical treatment.

Feasibility of Colorectal Endoscopic Submucosal Dissection in Elderly Patients: The Impact of Sarcopenia.

INTRODUCTION: Colorectal cancer is a public health concern associated with high incidence rates. Sarcopenia is a known risk factor for postoperative complications, although an association between increased complications after colorectal endoscopic submucosal dissection (ESD) and sarcopenia remains undocumented. Herein, we aimed to explore the feasibility of colorectal ESD in patients with sarcopenia. METHODS: This retrospective study included 499 patients (69 with and 430 without sarcopenia). We evaluated the short- and long-term outcomes of colorectal ESD. RESULTS: There were no significant differences between the two groups regarding en bloc, R0, or curative resection rates. However, poor bowel preparation was significantly more common in the sarcopenia group. Moreover, patients with sarcopenia exhibited a significant increase in complications (37.7% vs. 10.5%). Multivariate analysis revealed that sarcopenia (odds ratio [OR]: 3.78, 95% confidence interval [Cl]: 1.85-7.73, p < 0.001), anticoagulation therapy (OR: 3.59, 95% Cl: 1.86-6.92, p < 0.001), procedure time (OR: 1.28, 95% Cl: 1.11-1.47, p < 0.001), and resection size (OR: 1.25, 95% Cl: 1.03-1.52, p = 0.02) were significantly correlated with the Common Terminology Criteria for Adverse Events (CTCAE) ≥ grade 2. The correlation between sarcopenia and CTCAE ≥ grade 2 was maintained after matching, resulting in more extended hospital stays in patients with sarcopenia. However, we detected no association between sarcopenia and overall survival and ESD-related death. CONCLUSION: Sarcopenia is a risk factor for complications in colorectal ESD, suggesting that colorectal ESD could be performed for patients with sarcopenia, although much caution should be taken.

Association between perioperative management of antiplatelet agents and risk of post-endoscopic submucosal dissection bleeding in early gastric cancer: analysis of a nationwide multicenter study.

BACKGROUND AND AIMS: Data are lacking regarding post-endoscopic submucosal dissection (ESD) bleeding in patients with early gastric cancer (EGC) who take antiplatelet agents (APAs), particularly in those taking thienopyridine and cilostazol. We aimed to clarify the association between the status of APA medication and post-ESD bleeding risk. METHODS: This study is a secondary analysis using data from a recently conducted nationwide multicenter study in Japan. We retrospectively reviewed patients treated with APAs or on no antithrombotic therapy recruited from 33 institutions who underwent ESD for EGC between November 2013 and October 2016. The primary outcome of this study was the relationship between the rate of post-ESD bleeding and the status of each APA medication. RESULTS: A total of 9736 patients were included in the analysis. Among 665 aspirin users, the continuation group was significantly associated with post-ESD bleeding (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.77-4.37). Among 227 thienopyridine users, the aspirin or cilostazol replacement group was not significantly associated with post-ESD bleeding (OR, 1.85; 95% CI, .72-4.78). Among 158 cilostazol users, there was no significant association with post-ESD bleeding, irrespective of medication status. The rate of post-ESD bleeding was approximately 10% to 20% irrespective of the status of APA administration among dual-antiplatelet therapy users. No patients experienced thromboembolic events in this study. CONCLUSIONS: Replacement of thienopyridine with aspirin or cilostazol may be acceptable for minimizing both the risk of post-ESD bleeding and thromboembolism in patients with EGC. In patients on cilostazol monotherapy undergoing ESD, continuation of therapy may be acceptable.

Transcriptome analysis reveals the essential role of NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) in gastric adenocarcinoma of fundic-gland type.

BACKGROUND: Gastric adenocarcinoma of fundic-gland type (GA-FG) is a gastric malignancy with little relation to Helicobacter pylori. Clinical characteristics of GA-FG have been established, but molecular mechanisms leading to tumorigenesis have not yet been elucidated. METHODS: We subjected three GA-FG tumors-normal mucosa pairs to microarray analysis. Network analysis was performed for the top 30 up-regulated gene transcripts, followed by immunohistochemical staining to confirm the gene expression analysis results. AGS and NUGC4 cells were transfected with the gene-encoding NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) to evaluate transcriptional changes in its target genes. RESULTS: Comprehensive gene expression analysis identified 1410 up-regulated and 1395 down-regulated gene probes with ≥ two-fold difference in expression. Among the top 30 up-regulated genes in GA-FG, we identified transcription factor NKX2-1/TTF-1, a master regulator of lung/thyroid differentiation, together with surfactant protein B (SFTPB), SFTPC, and secretoglobin family 3A member 2(SCGB3A2), which are regulated by NKX2-1/TTF-1. Immunohistochemical analysis of 16 GA-FG specimens demonstrated significantly higher NKX2-1/TTF-1 and SFTPB levels, as compared to that in adjacent normal mucosa (P < 0.05), while SCGB3A2 levels did not differ (P = 0.341). Transduction of NKX2-1/TTF-1 into AGS and NUGC4 cells induced transactivation of SFTPB and SFTPC, indicating that NKX2-1/TTF-1 can function as normally in gastric cells as it can in the lung cells. CONCLUSIONS: Our first transcriptome analysis of GA-FG indicates significant expression of NKX2-1/TTF1 in GA-FG. Immunohistochemistry and cell biology show ectopic expression and normal transactivation ability of NKX2-1/TTF-1, suggesting that it plays an essential role in GA-FG development.

Reduced DEFA5 Expression and STAT3 Activation Underlie the Submucosal Invasion of Early Gastric Cancers.

INTRODUCTION: Submucosal invasion is a core hallmark of early gastric cancer (EGC) with poor prognosis. However, the molecular mechanism of the progression from intramucosal gastric cancer (IMGC) to early submucosal-invasive gastric cancer (SMGC) is not fully understood. The objective of this study was to identify genes and pathways involved in the submucosal invasion in EGC using comprehensive gene expression analysis. METHODS: Gene expression profiling was performed for eight cases of IMGC and eight cases of early SMGC with submucosal invasion ≥500 µm. To validate the findings of gene expression analysis and to examine the gene expression pattern in tissues, immunohistochemical (IHC) staining was performed for 50 cases of IMGC and SMGC each. RESULTS: Gene expression analysis demonstrated that the expression levels of small intestine-specific genes were significantly decreased in SMGC. Among them, defensin alpha 5 (DEFA5) was the most downregulated gene in SMGC, which was further validated in SMGC tissues by IHC staining. Gene set enrichment analysis showed a strong association between SMGC, the JAK-STAT signaling pathway, and the upregulation of STAT3-activating cytokines. The expression of phosphorylated STAT3 was significant in the nucleus of tumor cells in SMGC tissues but not in areas expressing DEFA5. CONCLUSION: The results of this study strongly suggest that the downregulation of DEFA5 and the activation of STAT3 play a significant role in the submucosal invasion of EGC.

Repeated steroid injection and polyglycolic acid shielding for prevention of refractory esophageal stricture.

BACKGROUND: Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this study was to assess the efficacy of steroid injection, polyglycolic acid (PGA) shielding, and of additional steroid injection thereafter for the prevention of refractory esophageal stricture. METHODS: This is a retrospective cohort study of 816 consecutive cases of esophageal ESD performed between 2002 and 2021 at the University of Tokyo Hospital. After 2013, all patients with a diagnosis of superficial esophageal carcinoma covering over 1/2 the esophageal circumference underwent preventive treatment immediately after ESD with either "PGA shielding", "steroid injection", or "steroid injection + PGA shielding". Additional steroid injection was performed for high-risk patients after 2019. RESULTS: The risk of refractory stricture was especially high in the cervical esophagus (OR 24.77, p = 0.002) and after total circumferential resection (OR 894.04, p < 0.001). "Steroid injection + PGA shielding" was the only method significantly effective in preventing stricture occurrence (OR 0.36; 95% CI 0.15-0.83, p = 0.012). This method also decreased the risk of refractory stricture (OR 0.38; 95% CI 0.10-1.28, p = 0.096), but additional steroid injection was the only significantly effective method for prevention of refractory stricture (OR 0.42; 95% CI 0.14-0.98, p = 0.029). CONCLUSION: Combining steroid injection and PGA shielding is effective for preventing post-ESD stricture and refractory stricture. Additional steroid injection is a viable option for patients at high-risk for refractory stricture.

The impact of sarcopenia on adverse events associated with gastric endoscopic submucosal dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) is one of the main methods of treatments for early gastric cancer. Sarcopenia is a known risk factor for postoperative adverse events; however, the effect of sarcopenia on gastric ESD is unclear. We investigated the impact of sarcopenia on short-term prognosis after gastric ESD. METHODS: This was a retrospective cohort study. We reviewed 832 patients who underwent gastric ESD between January 2015 and December 2019 and classified them into two groups: sarcopenia and non-sarcopenia groups. The curative resection rate, adverse events, and lengths of hospital stay were evaluated. We also evaluated risk factors associated with adverse events. RESULTS: 700 patients were analyzed (239 in the sarcopenia group and 461 in the non-sarcopenia group). The curative resection rates were similar in both groups. Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 2 (17% vs. 10%) were significantly more common, and the length of hospital stay was longer (8 vs. 7 days) in the sarcopenia group. Univariate analysis identified age ≥ 75 years, antithrombotic medication, history of gastric surgery, submucosal (SM) invasion, and sarcopenia as risk factors for CTCAE grade ≥ 2. Multivariate analysis showed that sarcopenia [odds ratio (OR) 1.79, 95% confidence interval (CI) 1.11-2.89, p = 0.016], history of gastric surgery (OR 9.32, 95% CI 1.97-44.05, p = 0.005), and SM invasion (OR 2.14, 95% CI 1.24-3.70, p = 0.006) were significant independent risk factors. CONCLUSIONS: Sarcopenia significantly affected short-term prognosis and is a novel risk factor for gastric ESD.

Rapidly declining trend of signet ring cell cancer of the stomach may parallel the infection rate of Helicobacter pylori.

BACKGROUND: Studies indicate that gastric cancer (GC) incidence has decreased, whereas signet ring cell carcinoma (SRC) incidence has increased. However, recent trends in GC incidence are unclear. We used our hospital cancer registry to evaluate the changes in the incidence of GC, SRC, and non-SRC (NSRC) over time in comparison to changes in the H. pylori infection rates over time. METHODS: We identified 2532 patients with GC enrolled in our registry between January 2007 and December 2018 and statistically analyzed SRC and NSRC incidence. The H. pylori infection rate in patients with SRC was determined by serum anti-H. pylori antibody testing, urea breath test, biopsy specimen culture, and immunohistochemical analysis (IHC) of gastric tissue. Additionally, genomic detection of H. pylori was performed in SRCs by extracting DNA from formalin-fixed paraffin-embedded gastric tissue and targeting 16S ribosomal RNA of H. pylori. RESULTS: Overall, 211 patients had SRC (8.3%). Compared with patients with NSRC, those with SRC were younger (P <  0.001) and more likely to be female (P <  0.001). Time series analysis using an autoregressive integrated moving average model revealed a significant decrease in SRC (P <  0.001) incidence; NSRC incidence showed no decline. There was no difference in H. pylori infection prevalence between the SRC and NSRC groups. IHC and genomic methods detected H. pylori in 30 of 37 (81.1%) SRCs. CONCLUSIONS: Reduction in H. pylori infection prevalence may be associated with the decrease in the incidence of SRC, which was higher than that of NSRC.

[Refractory eosinophilic gastroenteritis with gastritis, duodenal ulcer, and colitis: a case report].

Eosinophilic gastroenteritis is a rare disease that causes various abdominal symptoms that result from the infiltration of eosinophils in the digestive tract. However, this condition has been poorly explored, and the treatment criteria and prognosis after treatment are still unclear. A 20-year-old man with a refractory duodenal ulcer had been undergoing treatment since 14 years of age at another hospital. He was admitted to our hospital with abdominal pain and anemia (hemoglobin:6.3g/dL). His blood test showed elevated serum immunoglobulin E levels, considering that he was allergic to many foods. Furthermore, endoscopic biopsy detected the occurrence of eosinophilic gastroenteritis with gastritis, duodenal ulcer, and colitis. We treated him by avoiding allergenic foods and prescribing antihistamine and vonoprazan;however, duodenal ulcer and gastrointestinal tract inflammation did not show improvement. Thus, he was diagnosed with wide-ranging and refractory eosinophilic gastroenteritis and treated with 40mg/day of steroids. After 2 months, he recovered from gastritis and duodenal ulcer, and his eosinophil level decreased, as assessed using endoscopic biopsy. Eosinophilic gastroenteritis is poorly investigated, and its treatment standards have not yet been determined. Nonetheless, steroid treatment is often applied in severe cases.

EpsinR, a target for pyrenocine B, role in endogenous MHC-II-restricted antigen presentation.

While the presentation mechanism of antigenic peptides derived from exogenous proteins by MHC class II molecules is well understood, relatively little is known about the presentation mechanism of endogenous MHC class II-restricted antigens. We therefore screened a chemical library of 200 compounds derived from natural products to identify inhibitors of the presentation of endogenous MHC class II-restricted antigens. We found that pyrenocine B, a compound derived from the fungus Pyrenochaeta terrestris, inhibits presentation of endogenous MHC class II-restricted minor histocompatibility antigen IL-4 inducible gene 1 (IL4I1) by primary dendritic cells (DCs). Phage display screening and surface plasmon resonance (SPR) analysis were used to investigate the mechanism of suppressive action by pyrenocine B. EpsinR, a target molecule for pyrenocine B, mediates endosomal trafficking through binding of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). Lentiviral-mediated short hairpin (sh) RNA downregulation of EpsinR expression in DCs resulted in a decrease in the responsiveness of CD4+ T cells. Our data thus suggest that EpsinR plays a role in antigen presentation, which provides insight into the mechanism of presentation pathway of endogenous MHC class II-restricted antigen.

Overexpression of stearoyl-coenzyme A desaturase 1 in macrophages promotes reverse cholesterol transport.

Stearoyl-coenzyme A desaturase 1 (SCD1) is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. However, the impact of SCD1 on atherosclerosis remains unclear. The aim of this study was to determine whether SCD1 affects macrophage reverse cholesterol transport (RCT) in mice. Compared to the control, adenoviral-mediated SCD1 overexpression in RAW264.7 macrophages increased cholesterol efflux to HDL, but not to apoA-I, without clear changes in ABCA1, ABCG1 and SR-BI expressions. While knockdown of ABCG1 and SR-BI did not affect the SCD1-induced cholesterol efflux to HDL, SCD1-overexpressing macrophages promoted the formation of both normal- and large-sized HDL in media, accompanying increased apolipoprotein A-I levels in HDL fractions. Transformation to larger particles of HDL was independently confirmed by nuclear magnetic resonance-based lipoprotein analysis. Interestingly, media transfer assays revealed that HDL generated by SCD1 had enhanced cholesterol efflux potential, indicating that SCD1 transformed HDL to a more anti-atherogenic phenotype. To study macrophage RCT in vivo, (3)H-cholesterol-labeled RAW264.7 cells overexpressing SCD1 or the control were intraperitoneally injected into mice. Supporting the in vitro data, injection of SCD1-macrophages resulted in significant increases in (3)H-tracer in plasma, liver, and feces compared to the control. Moreover, there was a shift towards larger particles in the (3)H-tracer distribution of HDL fractions obtained from the mice. In conclusion, macrophage-specific SCD1 overexpression promotes overall RCT through increased cholesterol efflux to HDL, suggesting that macrophage SCD1 achieves an anti-atherogenic effect by enhancing RCT.

Coils versus gelatin particles with or without intraarterial antibiotics for partial splenic embolization: a comparative evaluation.

PURPOSE: To compare the efficacy, complications, and inflammatory levels in partial splenic embolization (PSE) with coils or gelatin sponge (GS) particles with or without intraarterial antibiotic agents. MATERIALS AND METHODS: Forty-four patients with hypersplenism treated by PSE were assessed. GS particles were used in 31 patients, and coils were used in 13 patients. In 17 of the 31 patients who received GS, GS suspended in antibiotic solution was injected via the splenic artery. In the other 14 patients, antibiotic agents were not used. In all 13 coil group patients, an antibiotic solution was intraarterially injected before embolization. Platelet counts were compared between the GS and coil groups. Complications and serum C-reactive protein (CRP) levels were compared among the three groups. RESULTS: There were no significant differences in platelet counts and platelet increased ratios at 6 months (10.0 × 10(4)/µL and 193% in the GS group vs 9.0 × 10(4)/µL and 221% in the coil group), and no significant differences in frequencies of complications. However, one splenic abscess occurred in a patient treated with GS without antibiotics, resulting in death. The mean serum CRP level in the GS with antibiotic group at 2 weeks was significantly lower than in the other two groups. CONCLUSIONS: The efficacy of PSE is similar with the use of coils versus GS particles. Prophylactic intraarterial antibiotic treatment could be useful in preventing inflammatory reactions after PSE.

Clinical meaning of sarcopenia in patients undergoing endoscopic treatment.

With increasing global life expectancy, the significance of geriatric assessment parameters has increased. Sarcopenia is a crucial assessment parameter and is defined as the age-related loss of muscle mass and strength. Sarcopenia is widely acknowledged as a risk factor for postoperative complications in diverse advanced malignancies and has a detrimental effect on the long-term prognosis. While most studies have primarily concentrated on the correlation between sarcopenia and advanced cancer, more recent investigations have focused on the relationship between sarcopenia and early-stage cancer. Endoscopic submucosal dissection (ESD), which is less invasive than surgical intervention, is extensively employed in the management of early-stage cancer, although it is associated with complications such as bleeding and perforation. In recent years, several reports have revealed the adverse consequences of sarcopenia in patients with early-stage cancer undergoing ESD. This literature review briefly summarizes the recent studies on the association between sarcopenia and ESD.

Verification of the increase in concomitant dysplasia and cancer with the size of sessile serrated lesions.

Background and study aims This study aimed to evaluate the relationship between sessile serrated lesion (SSL) size and the comorbidity rate of SSL with dysplasia (SSLD) and cancer in SSL (SSL-cancer). Patients and methods This retrospective, single-center analysis identified SSL cases that underwent endoscopic resection between January 2015 and December 2022. The prevalence of SSL, SSLD, and SSL-cancer and their annual trends were assessed. The tumor diameter was stratified as 0 to 5 mm, 6 to 9 mm, 10 to 19 mm, and ≥ 20 mm in size. Furthermore, the frequency of SSL-D/SSL-cancer was determined in each group. Results The prevalence of SSL was 2.9% (1328/45799). This prevalence was 1.8% (112/6192) in 2015 and 4.2% (230/5500) in 2022, indicating an increasing trend over time. A total of 1825 lesions were assessed: 1751 (96.0%), 55 (3.0%), 14 (0.8%), and 5 (0.3%) of lesions were SSL, SSL with low-grade dysplasia, SSL with high-grade dysplasia and SSL-cancer, respectively. Stratifying the SSLs by size: 0 to 5 mm, 5 to 9 mm, 10 to 19 mm, and ≥ 20 mm, SSLD and SSL-cancer rates were 2.3% (10/429), 2.4% (16/674), 5.3% (31/584), and 11.8% (16/136), respectively. SSLD and SSL-cancer were observed in 2.4% (26/1103) of small SSLs < 10 mm. Conclusions In cases of SSL, the rate of SSLD and SSL-cancer increased as the lesion diameter increased. A certain rate of SSLD and SSL-cancer was observed even in small SSLs less than 5mm.

The impact of sarcopenia on short- and long-term outcomes of endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Sarcopenia prevalence has increased in proportion to the aging population in Japan. We aimed to investigate the association between sarcopenia and clinical outcomes and the prognostic factors of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). METHODS: This retrospective study involved patients aged ≥ 65 years who had undergone gastric ESD for EGC at our institution between January 2009 and December 2019. Patients were divided into two groups, namely, a sarcopenia group (109 patients) and a non-sarcopenia group (658 patients), based on the skeletal muscle index and intramuscular adipose tissue content (IMAC). Clinicopathological features, ESD-related adverse events, and outcomes were then compared. RESULTS: In the sarcopenia group, the mean age was higher, whereas performance and nutritional statuses were lower. There were no between-group differences in terms of treatment outcomes. Multivariate analyses (odds ratio [95% confidence interval (CI)]) indicated that a geriatric nutritional risk index score (GNRI) < 92 (2.12 [1.09-4.11], p = 0.03), anticoagulant therapy (1.76 [1.13-2.76], p = 0.01), tumor size ≥ 30 mm (2.09 [1.23-3.55], p = 0.01), and sarcopenia (1.90 [1.05-3.45], p = 0.03) were significantly associated with ESD-related adverse events. High Charlson comorbidity index, low prognostic nutritional index, low GNRI, and high IMAC were significantly associated with poor overall survival (OS). OS was significantly shorter in the sarcopenia group even after matching. CONCLUSIONS: Patients with sarcopenia had significantly more adverse events and shorter OS; therefore, evaluation of a patient's general condition, including sarcopenia, before ESD is important.

Long-term prognosis after endoscopic resection of T1a-MM/T1b-SM1 esophageal squamous cell carcinoma.

The objective of this study was to evaluate the long-term prognosis of T1a-MM/T1b-SM 1 esophageal squamous cell carcinoma (ESCC) after endoscopic resection (ER) and to validate the follow-up policy for pT1a-MM lymphovascular invasion (LVI)-negative ESCC. In this retrospective single-center analysis, patients who underwent ER for superficial ESCC between April 2002 and June 2021 were identified. The overall survival (OS), metastatic recurrence, and recurrence-free survival (RFS) rates were estimated using the Kaplan-Meier method. Cox proportional hazards models for OS, metastatic recurrence, and RFS were used. A total of 104 ESCC patients were eligible for the analysis. Of 104 patients, 81 had pT1a-MM, and 23 had pT1b-SM1. The 5-year OS, RFS, and metastatic recurrence rates of the 56 cases of pT1a-MM LVI-negative ESCC without additional treatment were 0.848 (95% confidence interval [CI]: 0.687-0.931), 0.817 (95% CI: 0.647-0.911), and 0.061 (95% CI: 0.014-0.240), respectively. Cox regression analysis for OS, RFS, and metastatic recurrence showed that only lymphatic invasion was strongly associated with metastatic recurrence (adjusted hazard ratio, 10.3; 95% CI: 2.01-53.3; P = .005). The proportion of deaths from other diseases was considerably higher (17/104, 16.3%) than that from ESCC (2/104, 1.9%). This may be related to the high complication rate of malignant tumors in other organs (43.3%, 45/104). The prognosis of ER for pT1a-MM and LVI-negative ESCC is good, and the follow-up policy is valid. Malignant tumors in other organs may be a major prognostic factor for superficial ESCC after ER.

Endoscopic Treatment of Superficial Gastric Cancer: Present Status and Future.

Although the mortality rates of gastric cancer (GC) are gradually declining, gastric cancer is still the fourth leading cause of cancer-related death worldwide. This may be due to the high rate of patients who are diagnosed with GC at advanced stages. However, in countries such as Japan with endoscopic screening systems, more than half of GCs are discovered at an early stage, enabling endoscopic resection (ER). Especially after the introduction of endoscopic submucosal dissection (ESD) in Japan around 2000, a high en bloc resection rate allowing pathological assessment of margin and depth has become possible. While ER is a diagnostic method of treatment and may not always be curative, it is widely accepted as standard treatment because it is less invasive than surgery and can provide an accurate diagnosis for deciding whether additional surgery is necessary. The curability of ER is currently assessed by the completeness of primary tumor removal and the possibility of lymph node metastasis. This review introduces methods, indications, and curability criteria for ER of EGC. Despite recent advances, several problems remain unsolved. This review will also outline the latest evidence concerning future issues.

Magnifying endoscopy with narrow-band imaging is useful in differentiating gastric cancer from matched adenoma in white light imaging.

This study assessed the effect of magnifying endoscopy with narrow-band imaging (M-NBI) on the endoscopic differential diagnosis between intramucosal gastric carcinomas and adenomas with matched characteristics. Associations between magnified endoscopic findings and pathological high-grade cellular and architectural atypia were also investigated. In total, the records of 50 adenomas and 50 intramucosal well-differentiated adenocarcinomas matched by tumor size (≥ 20 mm or < 20 mm), shape (depression or non-depression), and color (red or non-red) were extracted. Fourteen endoscopists diagnosed adenoma or cancer in the 100 cases with conventional white light imaging (C-WLI), then did the same with C-WLI + M-NBI.The cancer diagnostic sensitivity, specificity, and accuracy were assessed. The sensitivity of C-WLI + M-NBI for cancer diagnosis was 79.9% compared to 71.6% with C-WLI (p < 0.001). There were no significant differences in specificity (40.1% vs. 36.3%, p = 0.296) and accuracy (55.9% vs. 58.1%, p = 0.163). High-grade cytological or architectural atypia was diagnosed more often with irregular microvascular pattern (IMVP) or microsurface pattern (IMSP), respectively, than the low-grade forms. In conclusion, IMVP and IMSP correlate with high-grade cytological and architectural atypia. M-NBI is useful in differentiating intramucosal carcinoma from adenoma and can reduce underdiagnosis of cancer.

The feasibility of a novel injectable hydrogel for protecting artificial gastrointestinal ulcers after endoscopic resection: an animal pilot study.

Recently, covering materials for protecting post-endoscopic ulcers are being developed using hydrogels. Existing hydrogels are not ideal coating materials because it is difficult to control their physical properties. Therefore, we conducted an animal pilot study to investigate the protective effect of a novel ulcer coating material, whose physical properties can be easily controlled and designed. We applied the novel injectable hydrogel to artificial ulcers induced on the gastric mucosa of rats. Rats were assigned to the hydrogel or the control group. To measure the protective effect of hydrogel on ulcers, the perforation rate, ulcer diameter, and ulcer area were evaluated 48 h after gel application. As secondary endpoints, we assessed the residual rate of the hydrogel at the bottom of the ulcer, performed histological analysis, and analyzed adverse events associated with hydrogel. The perforation rate was significantly lower (16% vs. 75%) and the mean diameter of ulcers was significantly smaller (5.4 ± 1.8 mm vs. 7.8 ± 2.8 mm) in the hydrogel group. Histopathological findings revealed the inflammatory cell count was significantly higher in the control group. Our novel hydrogel showed a protective effect on artificial gastric ulcers in a rat model.