Incidence of lymph node metastasis from early gastric cancer: estimation with a large number of cases at two large centers

Clinical significance of the number of retrieved lymph nodes in early gastric cancer with submucosal invasion

The prognosis of early gastric cancer (EGC) with submucosal invasion is favorable; however, several cases of recurrence have been reported even after curative gastrectomy. This study aimed to investigate risk factors and evaluate the clinical significance of the number of retrieved lymph nodes (LNs) in EGC with submucosal invasion. We retrospectively analyzed the data of 443 patients with gastric cancer with submucosal invasion after curative gastrectomy for recurrent risk factors. Recurrence was observed in 22 of the 443 gastric cancer patients with submucosal invasion. In the univariate analysis, the risk factors for recurrence were the number of retrieved LNs ≤ 25 and node metastasis. In the multivariate analysis, retrieved LNs ≤ 25 (hazard ratio [HR] = 5.754, P-value = .001) and node metastasis (HR = 3.031, P-value = .029) were independent risk factors for recurrence after curative gastrectomy. Body mass index was related to retrieved LNs ≤ 25 in univariate and multivariate analyses (HR = .510, P = .002). The number of retrieved LNs and node metastases were independent risk factors for EGC with submucosal invasion. For EGC with submucosal invasion, retrieved LNs > 25 are necessary for appropriate diagnosis and treatment.

Loss of GNE Predicts Lymph Node Metastasis in Early Gastric Cancer

Endoscopic surgery is increasingly utilized for the treatment of early gastric cancer (EGC) worldwide, whereas lymph node metastasis (LNM) remains a critical risk factor for the relapse of EGC after endoscopic surgery. Therefore, identifying potential predictive factors and understanding the molecular mechanisms are urgently needed for improving the outcome of EGC patients with LNM. UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) is the key enzyme in the process of biosynthesis of CMP-Neu5Ac from UDP-N-acetylglucosamine (UDP-GlcNAc), which acts as a substrate for several reactions in glycan metabolism. In this study, we found that GNE was down-regulated in EGC patients with LNM. GNE expression as well as localization, tumor size, intravascular tumor thrombi and Lauren's classification were further identified as independent predictive factors for LNM. Combining GNE expression with traditional risk factors, including tumor size and differentiation degrees, could generate a better model for predicting LNM in EGC patients. Overall, our study implies that low GNE expression is a potential predictor of LNM in EGC.

Underestimation of endoscopic size in large gastric epithelial neoplasms

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is an effective method for resecting gastric adenomas and adenocarcinomas. A significant discrepancy was observed between endoscopic and pathological sizes in samples obtained from patients undergoing ESD. This study elucidates the factors affecting size discrepancy after formalin fixation.

METHODS

The records of 64 patients with 69 lesions were analyzed, including 50 adenomas and 19 adenocarcinomas. Data on location, gross shape, histology, and size after fixation in formalin were collected.

RESULTS

The mean size of the resected specimen appeared to decrease after formalin fixation (37.5 mm prefixation vs. 35.8 mm postfixation, p<0.05). The mean long axis diameter of the lesions was 20.3±7.9 mm prefixation and 13.4±7.9 mm postfixation. Size differences in lesions smaller than 20 mm were significantly greater than those in lesions larger than 20 mm (7.6±5.6 mm vs. 2.5±5.8 mm, p<0.01). In multivariate analysis, a tumor size of ≥20 mm was found to be an independent factor affecting size postformalin fixation (p<0.05).

CONCLUSION

The endoscopic size of lesions before ESD may be underestimated in tumors larger than 20 mm in size. Therefore, increased attention must be paid during ESD to avoid instances of incomplete resection.

Feasibility, efficacy, and cautionary note of endoscopic resection for gastric tube cancer after esophagectomy

BACKGROUND

Gastric tube cancer (GTC), whose usual histology is adenocarcinoma, occurs frequently as a result of improved survival after esophagectomy. Whether endoscopic resection (ER) for GTC is safe and suitable and guidelines for treatment and follow-up remains unclear.

METHODS

Patients with GTC who underwent ER at Kanagawa Cancer Center Hospital between 1997 and 2020 were studied retrospectively to evaluate clinical characteristics and short- and long-term outcomes.

RESULTS

Twenty-two consecutive patients with 43 lesions were treated in 42 sessions of ER. Lesions were discovered at a median of 9.0 (0-21.8) years after esophageal surgery. Nine (40.9%) patients had multiple lesions at the time of the initial ER session. However, six (54.5%) of the 11 co-existing lesions were overlooked. The location of the middle third was an estimated risk factor for overlooking (p = 0.028). In endoscopic submucosal dissection (ESD) cases, the en bloc dissection rate was as high as 97.1%, and the rates of bleeding, perforation, and aspiration pneumonitis were 17.6%, 0%, and 2.9%, respectively. The bleeding rate was relatively higher than that in usual gastric ESD. Twelve patients (54.5%) experienced synchronous and/or metachronous multiple GTCs during their life span. Thirteen (61.9%) patients died during the median follow-up period of 5.9 (0.7-15.5) years. One patient (7.7%) died of GTC recurrence, 15.4 years after the initial non-curative ER date; 3 (23.1%) patients died of esophageal cancer recurrence, and 3 (23.1%) died of other organ malignancies. The 5-year overall survival rate was 85.0%, and the 5-year disease-specific survival rate was 100%.

CONCLUSIONS

ER is feasible for GTCs. However, the rate of bleeding was high in ESD cases. Life-long endoscopic screening of metachronous lesions is desirable. Care should be taken not to overlook lesions in the middle third of the gastric tube. Early detection of esophageal cancer recurrence and other organ malignancies may improve prognosis.

Applicability of endoscopic submucosal dissection for patients with early gastric cancer beyond the expanded indication for endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) application for patients with tumors beyond the expanded indication for ESD is inconclusive. This study aimed to identify the preoperative clinical features that can be curatively treated with ESD in patients with early gastric cancer (EGC) beyond the indication of ESD.

METHODS

From 2006 to 2016, 673 patients who underwent gastrectomy for EGC beyond the expanded indication for ESD based on preoperative assessments were retrospectively reviewed. We identified tumors curatively resected by ESD based on the postoperative pathologic findings. We also analyzed the clinical and pre-treatment features to determine the risk factors associated with curative resection of ESD.

RESULTS

39% of the patients (263/673) who had undergone gastrectomy had tumors of endoscopic curability A or B (eCuraA/B) that could be treated by ESD alone. In multivariate analysis, tumor size ≤ 10 mm (OR 0.240; 95% CI = 0.12-0.46), no ulceration (OR 0.500; 95% CI = 0.29-0.87), differentiated histology (OR 0.599; 95% CI = 0.43-0.84), and location in the distal two-thirds of the stomach (OR 0.499; 95% CI = 0.28-0.88) in pre-treatment assessment were identified as independent predictors of eCuraA/B. Considering the risk factors, 63.6% (7/11)/61.3% (19/31) of patients with a differentiated/undifferentiated tumor size ≤ 10 mm located in distal two-third of the stomach without ulceration were deemed as eCuraA/B.

CONCLUSIONS

This study suggests that patients with EGC indicated for surgery can be treated by ESD by adding tumor locations in the indication for ESD. Thus, ESD can be applied for patients with a tumor size ≤ 10 mm located in the lower/middle stomach without ulceration.

Correlation between imaging features on computed tomography and combined positive score of PD-L1 expression in patients with gastric cancer

OBJECTIVE

To explore the correlation between computed tomography (CT) features and combined positive score (CPS) of programmed cell death ligand 1 (PD-L1) expression in patients with gastric cancer (GC).

METHODS

This study reviewed an institutional database of patients who underwent GC operation without neoadjuvant chemotherapy between December 2019 and September 2020. The CPS results of PD-L1 expression of postoperative histological examination were recorded by pathology. Baseline CT features were measured, and their correlation with CPS 5 or 10 score groups of PD-L1 expression was analyzed.

RESULTS

Data for 153 patients with GC were collected. Among them, 124 were advanced GC patients, and 29 were early GC patients. None of the CT features significantly differed between CPS groups with a cutoff score of 5 and a score of 10 in patients with early GC. In advanced GC, the presence of lymph nodes with short diameters >10 mm was significantly different (P=0.024) between the CPS<5 and CPS≥5 groups. CT features such as tumor attenuation in the arterial phase, long and short diameter of the largest lymph node, the sum of long diameter of the two largest lymph nodes, the sum of short diameter of the two largest lymph nodes, and the presence of lymph nodes with short diameters >10 mm significantly differed between the CPS<10 and CPS≥10 groups in advanced GC. The sensitivity, specificity and area under receiver operating characteristic (ROC) curve of logistic regression model for predicting CPS≥10 was 71.7%, 50.0% and 0.671, respectively. Microsatellite instability (MSI) status was significantly different in CPS groups with cutoff score of 5 and 10 in advanced GC patients.

CONCLUSIONS

CT findings of advanced GC patients with CPS≥10 showed greater arterial phase enhancement and larger lymph nodes. CT has the potential to help screen patients suitable for immunotherapy.

Establishment of a nomogram for predicting lymph node metastasis in patients with early gastric cancer after endoscopic submucosal dissection

Background

Endoscopic submucosal dissection (ESD) has been accepted as the standard treatment for the appropriate indication of early gastric cancer (EGC). Determining the risk of lymph node metastasis (LNM) is critical for the following treatment selection after ESD. This study aimed to develop a predictive model to quantify the probability of LNM in EGC to help minimize the invasive procedures.

Methods

A total of 952 patients with EGC who underwent radical gastrectomy were retrospectively reviewed. LASSO regression was used to help screen the potential risk factors. Multivariate logistic regression was used to establish a predictive nomogram, which was subjected to discrimination and calibration evaluation, bootstrapping internal validation, and decision curve analysis.

Results

Results of multivariate analyses revealed that gender, fecal occult blood test, CEA, CA19-9, histologic differentiation grade, lymphovascular invasion, depth of infiltration, and Ki67 labeling index were independent prognostic factors for LNM. The nomogram had good discriminatory performance, with a concordance index of 0.816 (95% CI 0.781–0.853). The validation dataset yielded a corrected concordance index of 0.805 (95% CI 0.770–0.842). High agreements between ideal curves and calibration curves were observed.

Conclusions

The nomogram is clinically useful for predicting LNM after ESD in EGC, which is beneficial to identifying patients who are at low risk for LNM and would benefit from avoiding an unnecessary gastrectomy.

Clinical factors associated with noncurative endoscopic submucosal dissection for the expanded indication of intestinal-type early gastric cancer: Post hoc analysis of a multi-institutional, single-arm, confirmatory trial (JCOG0607)

OBJECTIVES

The multi-institutional, single-arm, confirmatory trial JCOG0607 showed excellent efficacy of endoscopic submucosal dissection (ESD) for the expanded indication of intramucosal intestinal-type early gastric cancer (EGC), which consists of two groups: lesions >2 cm if clinical finding of ulcer (cUL)-negative, or those ≤3 cm if cUL-positive because of the expected low risk of lymph node metastasis. However, the proportion of noncurative resections (NCR) requiring additional surgery was high (32.4%). This post hoc analysis aimed to explore the clinical factors associated with NCR.

METHODS

As the expanded indication includes two different groups, we explored the clinical factors associated with NCR separately in cUL-negative (>2 cm) and cUL-positive (≤3 cm) groups using the log-linear model.

RESULTS

Two hundred and sixty cUL-negative and 206 cUL-positive EGCs were analyzed. The proportions of NCR were 33.8% in the cUL-negative group and 29.6% in the cUL-positive group. A multivariable analysis demonstrated that moderately differentiated predominant histology diagnosed in pretreatment biopsy (risk ratio [RR] 1.93, 95% confidence interval [CI] 1.34-2.77, P < 0.001) and lesion in the upper stomach (RR 1.75, 95% CI 1.03-2.96, P = 0.038) in the cUL-negative EGCs, and tumor size >2 cm (RR 1.78, 95% CI 1.22-2.58, P = 0.003) and female sex (RR 1.62, 95% CI 1.07-2.44, P = 0.021) in the cUL-positive EGCs were independent factors associated with NCR.

CONCLUSIONS

Clinical risk factors associated with NCR were different between cUL-negative and cUL-positive EGCs. To avoid NCR, we need to take these factors into account when deciding expanded indications for ESD.

Risk factors of gastric cancer as a basis for the development of a prognostic questionnaire for the register of patients with precancerous gastroduodenal diseases

The article is a critical analysis of the world scientific literature devoted to the search for risk factors for stomach cancer for the timely prognosis of this disease and the implementation of cancer prevention measures. The paper presents data from numerous studies to determine the role of environmental factors, including unfavorable ecology, as well as gender, age, smoking, alcohol abuse. The authors’ opinions are presented on the essential role of the alimentary factor in the genesis of neoplasms in the stomach, including the predominance of animal fats in food, the abuse of overcooked, pickled foods rich in nitrosoamines, foods saturated with spices, the use of too hot food, the use of foods infected with mycotoxins in nutrition. The role of environmental factors in the prognosis of gastric cancer is noted: the state of secretory activity of the stomach, the dynamics of inflammatory and atrophic processes in the mucous membrane. A special role for the prognosis of stomach cancer is assigned by many authors to the pyloric helicobacter, as well as the quantitative indicator of glycated blood hemoglobin and its dynamics. The significance of genetic changes in the genesis of gastric cancer and their role as prognostic factors of the disease is ambiguous. The article draws attention to the multidirectional results of many authors in understanding a large number of factors they have studied that could be used as prognostic witnesses of stomach cancer. The expediency of searching for the most significant regional factors for the prognosis of gastric cancer is substantiated, on the basis of which it is very important to create registers of patients with precancerous diseases of the stomach for the organization and implementation of personalized and effective measures of cancer prevention.

Machine learning-based gray-level co-occurrence matrix signature for predicting lymph node metastasis in undifferentiated-type early gastric cancer

BACKGROUND

The most important consideration in determining treatment strategies for undifferentiated early gastric cancer (UEGC) is the risk of lymph node metastasis (LNM). Therefore, identifying a potential biomarker that predicts LNM is quite useful in determining treatment.

AIM

To develop a machine learning (ML)-based integral procedure to construct the LNM gray-level co-occurrence matrix (GLCM) prediction model.

METHODS

We retrospectively selected 526 cases of UEGC confirmed through pathological examination after radical gastrectomy without endoscopic treatment in four tertiary hospitals between January 2015 to December 2021. We extracted GLCM-based features from grayscale images and applied ML to the classification of candidate predictive variables. The robustness and clinical utility of each model were evaluated based on the following factors: Receiver operating characteristic curve (ROC), decision curve analysis, and clinical impact curve.

RESULTS

GLCM-based feature extraction significantly correlated with LNM. The top 7 GLCM-based factors included inertia value 0° (IV_0), inertia value 45° (IV_45), inverse gap 0° (IG_0), inverse gap 45° (IG_45), inverse gap full angle (IG_all), Haralick 30° (Haralick_30), Haralick full angle (Haralick_all), and Entropy. The areas under the ROC curve (AUCs) of the random forest classifier (RFC) model, support vector machine, eXtreme gradient boosting, artificial neural network, and decision tree ranged from 0.805 [95% confidence interval (CI): 0.258-1.352] to 0.925 (95%CI: 0.378-1.472) in the training set and from 0.794 (95%CI: 0.237-1.351) to 0.912 (95%CI: 0.355-1.469) in the testing set, respectively. The RFC (training set: AUC: 0.925, 95%CI: 0.378-1.472; testing set: AUC: 0.912, 95%CI: 0.355-1.469) model that incorporates Entropy, Haralick_all, Haralick_30, IG_all, IG_45, IG_0, and IV_45 had the highest predictive accuracy.

CONCLUSION

The evaluation results indicate that the method of selecting radiological and textural features becomes more effective in the LNM discrimination against UEGC patients. Additionally, the ML-based prediction model developed using the RFC can be used to derive treatment options and identify LNM, which can hence improve clinical outcomes.

Studies on endoscopic submucosal dissection in the past 15 years: A bibliometric analysis

Background and aims

Endoscopic submucosal dissection (ESD) is an advanced minimally invasive technique for en bloc resection of superficial gastrointestinal lesions, which is drawn an increasing attention from its emergence. This bibliometric analysis is to evaluate the origin, current hotspots, and research trends on ESD.

Methods

A total of 2,131 publications on ESD from 2006 to 2020 were obtained from the Web of Science Core Collection (WoSCC) database. Bibliometric visualization analyses of countries/regions, institutes, authors, journals, references and keywords were performed by CiteSpace V.5.8.R3.

Results

The quantity of publications on ESD increased significantly during the past 15 years. Japan occupied the leading position in terms of research power. Professor Yutaka Saito, together with the institute he belongs, the Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan, were the most productive author and institute, respectively. Colorectal ESD led the main thematic concentrations in ESD research. The most prolific journal was Gastrointestinal Endoscopy. European ESD Guideline was the most frequently co-cited reference. Guideline, meta-analysis, endoscopic resection, poly-glycolic acid sheet, Barrett's esophagus, fibrin glue, risk and colorectal neoplasm will be the active research hotspots in the future.

Conclusions

These findings provide the trends and frontiers in the field of ESD, as well as valuable information for clinicians and scientists to discover the future perspectives with potential collaborators.

Evaluating the optimal treatment strategy for early and advanced remnant gastric cancer

BACKGROUND

This study assessed lymph node metastasis characteristics to investigate the optimal treatment strategy for early and advanced remnant gastric cancer (RGC).

METHODS

Cases of completion gastrectomy for RGC were enrolled. The frequency of lymph node metastasis was investigated, and risk factors for metastasis were identified. The clinical significance of completion gastrectomy in early remnant gastric carcinoma cases was also examined. In advanced cases, 3-year survival was analysed to investigate the prognostic importance of lymph node dissection and splenectomy.

RESULTS

Seventy-nine patients were included. Lymphatic invasion and pathological tumour depth were identified as risk factors for lymph node metastasis. There was no metastasis in the pT1 cases. In advanced cases, the incidence of lymph node #10 and jejunal lymph node metastasis was 8.3-10.0% and 17.6%, respectively. Prognosis was found to be unrelated with splenectomy.

CONCLUSIONS

Lymphatic invasion and pathological T status were identified as risk factors for LN metastasis in RGC. Additional gastrectomy after ESD might not be mandatory for early RGC cases. For advanced RGC cases, splenectomy might not improve patient prognosis, however, lymph node dissection of jejunal and #10 lymph nodes should be considered due to its high incidence of metastasis.

Effectiveness of second-look endoscopy after gastric endoscopic submucosal dissection in patients taking antithrombotic agents: a multicenter propensity score matching analysis

BACKGROUND

The risk of bleeding after gastric endoscopic submucosal dissection (ESD) in antithrombotic agent users has increased, and its management remains a problem. Second-look endoscopy (SLE) following gastric ESD in antithrombotic agent users may be effective in preventing delayed bleeding, but this requires elucidation. Therefore, this study aimed to investigate the efficacy of SLE in reducing bleeding after gastric ESD in patients receiving antithrombotic agents.

METHODS

This retrospective cohort study was conducted at 19 referral hospitals in Japan. A total of 1,245 patients who were receiving antithrombotic agents underwent gastric ESD between January 2013 and July 2018. The incidence of delayed bleeding was compared between SLE and non-SLE groups using propensity score matching analysis.

RESULTS

Overall, 858 patients (SLE group, 657 patients; non-SLE group, 201 patients) were analyzed. After matching, 198 pairs were created. Delayed bleeding occurred in 10 patients (5.1%) in the SLE group and 16 patients (8.1%) in the non-SLE group [odds ratio (OR) 0.605, 95% confidence interval (CI) 0.23-1.46, p = 0.310]. In the subgroup analysis, SLE reduced the incidence of delayed bleeding in patients receiving heparin bridging therapy (6.3% and 40.0%, respectively; p = 0.004). In the SLE group, prophylactic coagulation did not significantly reduce delayed bleeding compared to the no treatment group (14.6% and 8.6%, respectively; p = 0.140).

CONCLUSIONS

SLE was ineffective in reducing bleeding after gastric ESD in antithrombotic agent users, overall. A prospective comparative study is warranted to definitively evaluate the effectiveness of SLE in reducing bleeding in high-risk patients.

The effect of antithrombotic drug use on delayed bleeding with esophageal endoscopic resection

BACKGROUND AND AIM

Whether antithrombotic drugs increase the risk of post-esophageal endoscopic resection bleeding is unknown. This study examined the effect of antithrombotic drugs, aspirin, thienopyridine, direct oral anticoagulants (DOAC), and warfarin, on post-esophageal endoscopic resection bleeding.

METHODS

We enrolled 957 patients (1202 esophageal tumors) treated with endoscopic resection and classified them based on antithrombotic drug use as no use, aspirin, thienopyridine, DOAC, and warfarin. Patients using antiplatelet drugs (i.e. aspirin and thienopyridine) were further sub-classified based on their continued or discontinued use before endoscopic resection. The bleeding rates were compared between these groups to assess the effects of antithrombotic drug use and interruption of antiplatelet therapy on post-esophageal endoscopic resection bleeding.

RESULTS

The post-endoscopic resection bleeding rate was 0.3% (95% CI, 0.1-1) in the group without antithrombotic drug use, 4.5% (95% CI, 0.1-23) in the aspirin-continued group, 2.9% (95% CI, 0.1-15) in the aspirin-discontinued group, 0% (95% CI, 0-78) in the replaced thienopyridine with aspirin group, 0% (95% CI, 0-26) in the thienopyridine-discontinued group, 13% (95% CI, 1.6-38) in the DOAC group, and 0% (95% CI, 0-45) in the warfarin group. The post-endoscopic resection bleeding rate in the DOAC group was significantly higher than that in the group without antithrombotic drugs (P = 0.003). The post-endoscopic resection bleeding rates did not differ between the other groups.

CONCLUSIONS

Our results suggest that discontinuing aspirin is not necessary for esophageal endoscopic resection while we must be careful regarding DOAC.

Effect of endoscopic resection of gastrointestinal stromal tumors in the stomach under double-channel gastroscopy: A retrospective observational study

We aimed to investigate the safety and efficacy of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors (GISTs) under single-channel gastroscopy and double-channel gastroscopy. We identified 154 patients with GISTs of the stomach who underwent endoscopic resection and were retrospectively analyzed at our hospital between May 2016 and March 2020, including 49 patients by single-channel gastroscopy and 105 patients by double-channel gastroscopy. We observed the clinical efficacy, complications, and safety of endoscopic resection of gastric GISTs, and the data were evaluated retrospectively. All patients underwent endoscopic resection successfully, without conversion to open surgery. In the single-channel gastroscopy group, 7 patients had lesions in the gastric cardia, 17 in the gastric fundus, 20 in the gastric corpus, and 5 in the gastric antrum. In the double-channel gastroscopy group, 13 patients had lesions in the gastric cardia, 34 in the gastric fundus, 46 in the gastric body, 10 in the gastric antrum, 1 in the pylorus, and 1 in the gastric angular incisure. The double-channel gastroscopy group had a shorter operation time than the single-channel gastroscopy group (59.9 ± 34.9 minutes vs 74.8 ± 26.7 minutes; P = .009 and P < .01, respectively), while they also had a lower perforation rate than the single-channel gastroscopy group (34.3% vs 51.0%; P = .048 and P < .05, respectively). No residual or recurrent lesions were discovered in any patients by gastroscopy reexamination. Both single-channel gastroscopy and double-channel gastroscopy can provide safe, effective, feasible endoscopic resection. However, double-channel gastroscopy has some distinct advantages in endoscopic resection.

Management of Superficial Esophageal Squamous Cell Carcinoma and Early Gastric Cancer following Non-Curative Endoscopic Resection

According to the European and Japanese guidelines, additional treatment is recommended for cases of superficial esophageal squamous cell carcinoma (ESCC) and early gastric cancer (EGC) that do not meet the curability criteria for endoscopic resection (ER), i.e., non-curative ER, owing to the risk of lymph node metastasis (LNM). However, the rates of LNM in such cases were relatively low (e.g., 8% for EGC). Several recent advances have been made in this field. First, pathological risk stratification for metastatic recurrence following non-curative ER without additional treatment was developed for both superficial ESCC and EGC. Second, the pattern of metastatic recurrence and prognosis after recurrence following non-curative ER without additional treatment was found to be considerably different between superficial ESCC and EGC. Third, a combination of ER and selective chemoradiotherapy was developed as a minimally invasive treatment method for clinical T1b-SM ESCC. These findings may help clinicians decide the treatment strategy for patients following non-curative ER; however, for optimal therapeutic decision-making in such patients, it is also important to predict the prognosis other than SESCC or EGC and impaired quality of life. Thus, a novel algorithm that considers these factors, as well as metastatic recurrence, should be developed.

Topical issues of prevention of stomach cancer: A review

Prevention of gastric cancer, both primary and secondary, is an extremely important component of the management of gastroenterological patients. The correct collection of anamnesis with an assessment of the hereditary (family) cancer risk, the action of risk factors (eating disorders, habitual/chronic intoxication, obesity, Helicobacter pylori infection, etc.), as well as the use of gastroprotectors (in particular, the drug Regastim Gastro), especially in persons with potentially precancerous the condition is chronic atrophic gastritis. According to the data of a double-blind placebo-controlled randomized study Regastim Gastro (active ingredient alpha-glutamyl tryptophan) in the treatment of chronic atrophic gastritis, it was found that this drug has a powerful anti-inflammatory effect and regenerative activity. Taking the drug Regastim Gastro, compared with placebo, statistically significantly contributed to a decrease in the number of inflammatory infiltration cells per 1 mm2 of the gastric mucosa. Regastim Gastro decreases in eosinophilic (3 times) and neutrophilic (4 times) infiltration of the gastric mucosa and also reduced the number of macrophages, lymphocytes and plasmocytes. In addition to anti-inflammatory properties, the drug also had a pronounced regenerative effect. Taking of Regastim Gastro statistically significant (p=0.028) increases in the number of glands per 1 mm2 of the gastric mucosa by 26.1% compared with the initial screening indicators. In the group of patients taking placebo, on the contrary, there was a further progression of the pathological process, accompanied by a decrease in the number of glands per 1 mm2 of the gastric mucosa after the end of treatment in comparison with the initial indicators. After the course of therapy, the number of glands per 1 mm2 of the gastric mucosa in patients taking the drug Regastim Gastro was statistically significantly higher in comparison with the results in the placebo group (p=0.013). After the course of Regastim Gastro, there was an improvement in acid production: a shift in the acidic side of the average pH value (1.6 times) and an increase in the value of the acidity index, both when compared with the initial values (5.4 times) and in comparison with the placebo group (2.9 times). The intake of Regastim Gastro to patients with gastritis, both H. pylori (+) and H. pylori (-) before the development of atrophy of the gastric mucosa can reduce the inflammatory factor, prevent the occurrence of atrophy and may have maximum anti-carcinogenic action.

Indications for Adjuvant Chemotherapy in Stage II Gastric Cancer After D2 Gastrectomy-A Chinese Multicenter Study

BACKGROUND

The benefit of adjuvant chemotherapy (AC) for patients with stage II gastric cancer remains controversial. This study aimed to explore the indications for adjuvant chemotherapy in patients with stage II gastric cancer by constructing an individual prediction model.

PATIENTS AND METHODS

In this Chinese multicenter study, a total of 1012 patients with stage II gastric cancer after D2 radical gastrectomy were retrospectively analyzed. All patients were randomly assigned to a training cohort (n = 674) or a validation cohort (n = 338). A nomogram was constructed according to the training cohort. Concordance index (C-index), the area under the receiver operating characteristic (ROC) curves (AUC), calibration curves, and decision curve analysis (DCA) were applied to evaluate the performance of the nomogram. ROC curves and stratified survival were used to determine the patients' cutoff score for a benefit from adjuvant chemotherapy. An additional 338 patients were used as a validation cohort to validate the feasibility of using this nomogram to guide individualized therapy for patients with stage II gastric cancer.

RESULTS

Univariate and multivariate analyses illustrated that age, sex, tumor location, size, carcinoembryonic antigen (CEA), hemoglobin (HB), and T stage were independent prognostic factors for overall survival (OS), and they were used to establish a nomogram. The cutoff value was determined by ROC curve analysis, and patients were divided into a high-risk group (< 239 points) and a low-risk group (≥ 239 points). There was no significant difference in the OS of low-risk patients in either the training cohort or the validation cohort. However, the OS of high-risk patients in the AC group was better than that of patients in the surgery-only group.

CONCLUSIONS

This prediction model can be applied to guide treatment of patients with stage II gastric cancer. High-risk patients (< 239 points) are likely to benefit from AC after D2 radical gastrectomy.

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.

Potential Applicability of Local Resection With Prophylactic Left Gastric Artery Basin Dissection for Early-Stage Gastric Cancer in the Upper Third of the Stomach

PURPOSE

Total or proximal gastrectomy of the upper-third early gastric cancer (u-EGC) often causes severe post-gastrectomy syndrome, suggesting that these procedures are extremely invasive for patients without pathologically positive lymph node (LN) metastasis. This study aimed to evaluate the clinical applicability of a stomach function-preserving surgery, local resection (LR), with prophylactic left gastric artery (LGA)-basin dissection (LGA-BD).

MATERIALS AND METHODS

The data of patients with u-EGC (pathologically diagnosed as T1) were retrospectively analyzed. Total gastrectomy was performed in 30 patients, proximal gastrectomy in 45, and subtotal gastrectomy in 6; the LN status was evaluated assuming that the patients had already underwent LR + LGA-BD. This procedure was considered feasible in patients without LN metastases or in patients with cancer in the LGA basin. The reproducibility of the results was also evaluated using an external validation dataset.

RESULTS

Of the 82 eligible patients, 79 (96.3%) were cured after undergoing LR + LGA-BD, 74 (90.2%) were pathologically negative for LN metastases, and 5 (6.1%) had LN metastases, but these findings were only observed in the LGA basin. Similarly, of the 406 eligible tumors in the validation dataset, 396 (97.5%) were potentially curative. Tumors in the lesser curvature, post-endoscopic resection status, and small tumors (<20 mm) were considered to be stronger indicators of LR + LGA-BD as all subpopulation cases met our feasibility criteria.

CONCLUSIONS

More than 95% of the patients with u-EGC might be eligible for LR + LGA-BD. This function-preserving procedure may contribute to the development of u-EGC without pathological LN metastases, especially for tumors located at the lesser curvature.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Endoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

ESGE recommends that the evaluation of superficial gastrointestinal (GI) lesions should be made by an experienced endoscopist, using high definition white-light and chromoendoscopy (virtual or dye-based).ESGE does not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection.ESGE recommends endoscopic submucosal dissection (ESD) as the treatment of choice for most superficial esophageal squamous cell and superficial gastric lesions.For Barrett's esophagus (BE)-associated lesions, ESGE suggests the use of ESD for lesions suspicious of submucosal invasion (Paris type 0-Is, 0-IIc), for malignant lesions > 20 mm, and for lesions in scarred/fibrotic areas.ESGE does not recommend routine use of ESD for duodenal or small-bowel lesions.ESGE suggests that ESD should be considered for en bloc resection of colorectal (but particularly rectal) lesions with suspicion of limited submucosal invasion (demarcated depressed area with irregular surface pattern or a large protruding or bulky component, particularly if the lesions are larger than 20 mm) or for lesions that otherwise cannot be completely removed by snare-based techniques.ESGE recommends that an en bloc R0 resection of a superficial GI lesion with histology no more advanced than intramucosal cancer (no more than m2 in esophageal squamous cell carcinoma), well to moderately differentiated, with no lymphovascular invasion or ulceration, should be considered a very low risk (curative) resection, and no further staging procedure or treatment is generally recommended.ESGE recommends that the following should be considered to be a low risk (curative) resection and no further treatment is generally recommended: an en bloc R0 resection of a superficial GI lesion with superficial submucosal invasion (sm1), that is well to moderately differentiated, with no lymphovascular invasion, of size ≤ 20 mm for an esophageal squamous cell carcinoma or ≤ 30 mm for a stomach lesion or of any size for a BE-related or colorectal lesion, and with no lymphovascular invasion, and no budding grade 2 or 3 for colorectal lesions.ESGE recommends that, after an endoscopically complete resection, if there is a positive horizontal margin or if resection is piecemeal, but there is no submucosal invasion and no other high risk criteria are met, this should be considered a local-risk resection and endoscopic surveillance or re-treatment is recommended rather than surgery or other additional treatment.ESGE recommends that when there is a diagnosis of lymphovascular invasion, or deeper infiltration than sm1, or positive vertical margins, or undifferentiated tumor, or, for colorectal lesions, budding grade 2 or 3, this should be considered a high risk (noncurative) resection, and complete staging and strong consideration for additional treatments should be considered on an individual basis in a multidisciplinary discussion.ESGE recommends scheduled endoscopic surveillance with high definition white-light and chromoendoscopy (virtual or dye-based) with biopsies of only the suspicious areas after a curative ESD.

A case of clinical stage I gastric cancer with a schwannoma on the left supraclavicular fossa suspected as Virchow's node metastasis

Background

Gastric cancer is relatively prone to metastasis, although distant metastasis is rare during the early stage of disease. Here we report a rare case of schwannoma-associated Virchow metastasis of a patient with early-stage gastric cancer.

Case presentation

A 73-year-old man, diagnosed with early-stage gastric cancer, underwent preoperative scrutiny, and was only suspected to have Virchow metastasis. Owing to atypical metastatic findings, a lymph node biopsy was performed to confirm the diagnosis and to determine the treatment strategy. The pathology results of the biopsy showed a diagnosis of schwannoma, the patient was judged to be surgically resectable, and a laparoscopic gastrectomy was performed to achieve a radical resection. The patient is currently under outpatient observation with no apparent recurrence.

Conclusion

Systemic chemotherapy is generally administered according to the physician’s clinical judgment, although the results of a lymph node biopsy contribute to a more curative treatment. When nonspecific metastases are found, it is important to make a reliable diagnosis and to select a treatment that achieves a cure.

Therapeutic approach to non-curative resection after endoscopic treatment in early gastric cancer

Background: Endoscopic resection is indicated for early or superficial gastrointestinal neoplasms with a negligible risk of lymph node metastasis. This procedure could preserve the organ while allowing en bloc resection of tumors, irrespective of the size and location of the lesion. Histological evaluation of the resected specimen determines whether curative resection, which implies a favorable long-term outcome, was achieved. If the resected specimen reveals non-curative, additional treatment is necessary as it is strongly associated with recurrence.Current Concepts: Surgical resection is recommended after non-curative resection of gastrointestinal neoplasms. However, rather than surgical resection, additional endoscopic treatment can be recommended if non-curative resection is solely because of the positive involvement at the horizontal resection margin without any other findings compatible with the non-curative resection criteria.Discussion and Conclusion: Adopting precise indications of endoscopic resection is important to reduce the risk of non-curative resection. If curative resection is not achieved after endoscopic resection, additional treatment should be considered to prevent local recurrence as well as lymph node metastasis.

Endoscopic treatment for early gastric cancer

Background: In Korea, the number of screening endoscopies to detect early stage gastric neoplasms has increased exponentially following the active implementation of the National Cancer Screening Program.Current Concepts: Endoscopic treatment, including endoscopic mucosal resection and endoscopic submucosal dissection, is recognized as a minimally invasive treatment method with low morbidity and mortality for gastric dysplasia or early gastric cancer. Owing to improvement in the detection of early gastric cancer and advances in techniques, cases of endoscopic resection have increased and indications have been expanded. Endoscopic resection can preserve gastric function with excellent maintenance of the patient’s quality of life, and previous studies have shown better long-term follow-up outcomes compared to those with surgery. However, the fundamental limitation of endoscopic procedures is that gastric lymph-node dissection is not possible using endoscopic resection.Discussion and Conclusion: Although the usefulness of endoscopic resection is proven for tumors with a very low risk of lymph-node metastasis, follow-up examination using endoscopy and computed tomography should be performed for at least 5 years after curative resection of early gastric cancer.

Advanced Endoscopic Resection Techniques: Endoscopic Submucosal Dissection and Endoscopic Full-Thickness Resection

Endoscopic resection is first-line therapy in the management of superficial neoplasms throughout the gastrointestinal tract, as well as an increasingly viable therapeutic alternative in the resection of selected small deep lesions throughout the upper and lower gastrointestinal tract. The mainstay of therapy has traditionally been endoscopic snare polypectomy and endoscopic mucosal resection. However, recent innovative advancements in therapeutic endoscopy have provided for the ability to resect large superficial lesions and selected subepithelial lesions in en bloc and margin-negative fashion. In this review, we discuss the current state of the art in advanced endoscopic resection techniques including endoscopic submucosal dissection and endoscopic full-thickness resection.

The future of endoscopic resection for early gastric cancer

Endoscopic resection for early gastric cancer is recommended when the risk of lymph node metastasis is negligible and should be performed through submucosal dissection due to well-established short- and long-term results. To overcome technical difficulties and decrease adverse events some techniques have been studied. This review outlines current strategies for improving patient selection and highlights innovative techniques that help minimize adverse events. Moreover, we discuss how to improve management after curative and noncurative resections.

Reevaluation of the expanded indications in undifferentiated early gastric cancer for endoscopic submucosal dissection

BACKGROUND

Although the criteria for the indication of endoscopic submucosal dissection (ESD) for undifferentiated early gastric cancer (UD-EGC) have been recently proposed, accumulating reports on the non-negligible rate of lymph node metastasis (LNM) after indicated ESD raise questions on the reliability of the current criteria.

AIM

To investigate the prevalence and risk factors of LNM in UD-EGC cases meeting the expanded indication for ESD.

METHODS

We retrospectively reviewed 4780 UD-EGC cases that underwent surgical resection between January 2008 and February 2019 at Asan Medical Center, a tertiary university hospital in Korea. To identify the risk factors of LNM of UD-EGC meeting the expanded criteria for ESD, we performed a case-control study by matching the cases with LNM to those without at a ratio of 1:4. We reviewed the clinical, endoscopic, and histologic features of the cases to identify features with a significant difference according to the presence of LNM. Univariate and multivariate logistic regression analyses were performed to estimate the odds ratios (ORs).

RESULTS

Of the 4780 UD-EGC cases, 1240 (25.9%) were identified to meet the expanded indication for ESD. Of the 1240 cases, 14 (1.1%) cases had LNM. Among the various clinical, endoscopic, and histopathological features that were evaluated, mixed histology (tumors consisting of 10%-90% of signet ring cells) had a marginally significant association (P = 0.059) with the risk of LNM. Moreover, diffuse blurring of the muscularis mucosae (MM) underneath the tumorous epithelium, a previously unrecognized histologic feature, had a significant association with the absence of LNM (P = 0.028). Multivariate logistic regression analysis showed that the blurring of MM was the only explanatory variable significantly associated with a reduced risk of LNM (OR: 0.12, 95%CI: 0.02-0.95; P = 0.045).

CONCLUSION

The risk of LNM is higher than expected when using the current expanded indication for UD-EGC. Histological evaluation could provide useful clues for reducing the risk of LNM.

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

The clinicopathological features of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) are incompletely understood, and the capacity of endoscopic submucosal dissection (ESD) to treat mixed-type cancer remains controversial. This systematic review analyzed the rate of lymph node metastasis (LNM) in mixed-type EGC. We gathered articles published up to February 21, 2021, that analyzed the relationship between LNM and mixed-type EGC from Embase, PubMed, and Web of Science. The primary outcome was the LNM rate associated with different histological types of EGC, and the secondary outcomes were the odds ratios (ORs) for LNM risk factors among EGC patients. From the 24 studies included in this meta-analysis, the overall rate of LNM in predominantly differentiated mixed-type (MD) EGC was 12%, whereas the LNM rate in predominantly undifferentiated mixed-type (MU) EGC was 22%. We further divided these studies into 2 groups according to the depth of invasion. In mixed-type mucosal EGC, the pooled LNM rate was 15%; in submucosal EGC, the rate was 33% for MU, which was higher than the rates for pure types (pure differentiated type, 13%; pure undifferentiated type, 21%; p<0.05). The LNM rate of MD was 20%, it was higher than those of the pure differentiated type and nearly the same as pure undifferentiated type. Other pooled statistics showed that submucosal invasion, pure undifferentiated EGC, and mixed-type EGC were independent risk factors for LNM. This meta-analysis showed that MD submucosal EGC has a high rate of LNM and is highly correlated with LNM; thus, the management of MD EGC as purely differentiated EGC according to the indications for ESD is inappropriate, and the mixed type should be added as a parameter in these indications.

Diagnosis of histological type of early gastric cancer by magnifying narrow‐band imaging: A multicenter prospective study

Objectives

Distinguishing undifferentiated‐type from differentiated‐type early gastric cancers (EGC) is crucial for determining the indication of endoscopic resection. We aimed to investigate the diagnostic performance of white‐light endoscopy (WLE) and magnifying narrow‐band imaging (M‐NBI) for the histological type of EGC.

Methods

In this multicenter prospective study, patients with histologically proven cT1 EGC, macroscopically depressed or flat type, size ≥5 mm, and without erosion/ulcer, were recruited. The diagnostic criterion of WLE for undifferentiated‐type EGC was pale color. The M‐NBI algorithm was created based on microsurface and microvascular patterns, and lesions with absent microsurface pattern and opened‐loop microvascular patterns were diagnosed as undifferentiated‐type. The center of the lesion was defined as the evaluation point and was initially evaluated by WLE, then by M‐NBI, and a biopsy specimen was taken as a reference standard. The primary and key secondary endpoints were overall diagnostic accuracy and specificity, respectively.

Results

In total, 167 lesions (122 differentiated‐type and 45 undifferentiated‐type EGCs) in 167 patients were analyzed. The overall accuracy, sensitivity, specificity, and positive likelihood ratio of WLE for undifferentiated‐type cancer were 80%, 69%, 84%, and 4.4, respectively, and those of M‐NBI were 82%, 53%, 93%, and 7.2, respectively. There was no significant difference in overall accuracy (p = 0.755), but specificity was significantly higher in M‐NBI (p = 0.041).

Conclusions

The use of M‐NBI did not improve the accuracy of WLE for the diagnosis of depressed/flat undifferentiated‐type EGCs but improved the specificity. It may reduce surgical overtreatment by preventing misdiagnosis of differentiated‐type EGC as undifferentiated‐type.

Implementation of artificial intelligence in upper gastrointestinal endoscopy

The application of artificial intelligence (AI) using deep learning has significantly expanded in the field of esophagogastric endoscopy. Recent studies have shown promising results in detecting and differentiating early gastric cancer using AI tools built using white light, magnified, or image-enhanced endoscopic images. Some studies have reported the use of AI tools to predict the depth of early gastric cancer based on endoscopic images. Similarly, studies based on using AI for detecting early esophageal cancer have also been reported, with an accuracy comparable to that of endoscopy specialists. Moreover, an AI system, developed to diagnose pharyngeal cancer, has shown promising performance with high sensitivity. These reports suggest that, if introduced for regular use in clinical settings, AI systems can significantly reduce the burden on physicians. This review summarizes the current status of AI applications in the upper gastrointestinal tract and presents directions for clinical practice implementation and future research.

Endoscopic submucosal dissection versus surgery in elderly patients with early gastric cancer of relative indication for endoscopic resection

OBJECTIVES

Surgery is recommended for early gastric cancer (EGC) beyond the endoscopic resection (ER)-indication for the risk of lymph node metastasis; however, ER may be chosen as a "relative ER-indication" considering age and comorbidities. This study aimed to compare outcomes of endoscopic submucosal dissection (ESD) only and surgery (primary surgery and additional surgery after non-curative ESD) among elderly patients with relative ER-indication EGC and to further assess prognostic factors.

METHODS

Outcomes of ESD and surgery (417 cases; 114 ESD, 303 surgery) in elderly patients (≥75 years) with relative ER-indication EGC were retrospectively analyzed. Prognostic factors were also examined.

RESULTS

During the observation period (median; ESD, 34 months; surgery, 61 months), 29% of ESD and 35% of surgery patients died, including 4% and 5% from gastric cancer (GC), respectively. ESD showed lower overall survival (OS) than surgery (P = 0.027) but comparable disease-free survival (P = 0.916). OS-associated factors were age and prognostic nutritional index (PNI) in males (age ≥79, hazard ratio [HR] 2.21, P = 0.001; PNI <45, HR 2.06, P = 0.031) and age in females (age ≥82, HR 4.06, P = 0.004). Treatment was not a prognostic factor in either subgroup. Pathological category ≥pT1b2 (submucosal invasion ≥500 µm) and lymphovascular invasion (LVI) were significantly associated with GC death (mortality: ≥pT1b2, 7.7%, P = 0.002; LVI, 10.1%, P < 0.001).

CONCLUSIONS

In elderly patients with relative ER-indication EGC, ESD may have comparable long-term efficacy to surgery, and treatment selection had a minor contribution to OS. For patients with poor preoperative prognostic factors, diagnostic ESD may be performed first, followed by additional surgery based on pathological results.

Increasing utilization of endoscopic local excision for early-stage gastric cancers in the United States

BACKGROUND

The Japanese Gastric Cancer Association provided updated criteria for endoscopic local excision of early-stage gastric cancer in 2018. The purpose of this study was to evaluate utilization patterns for endoscopic local excision in the United States for resectable gastric adenocarcinoma.

METHODS

Patients with resectable gastric adenocarcinoma were identified from the National Cancer Database between 2010 and 2017. Patients were classified into strict appropriate criteria, expanded criteria, and inappropriate based on the Japanese Gastric Cancer Association guidelines. Factors associated with endoscopic local excision were identified using univariate and logistic multivariate regression.

RESULTS

Within the National Cancer Database, 46,334 patients were stratified into strict appropriate criteria (n = 1,405), expanded criteria (n = 727), and inappropriate (n = 43,675). Annual cases of local excision increased by 76.9% over the study period, from 273 in 2010 to 483 in 2017. Among patients who underwent local excision, 10.1% were classified as strict appropriate criteria, 1.6% were classified as expanded criteria, and 84.5% were classified as inappropriate. Among inappropriate patients, factors associated with endoscopic local excision were: more recent year of diagnosis, increasing age, female sex, tumor located in the cardia, smaller size, low-grade, absence of lymphovascular invasion, and treatment at an academic facility.

CONCLUSION

The use of endoscopic local excision for gastric cancer has nearly doubled since 2010. However, most patients do not satisfy consensus criteria for endoscopic therapy.

Epithelial-derived factors induce muscularis mucosa of human induced pluripotent stem cell-derived gastric organoids

Human gastric development has not been well studied. The generation of human pluripotent stem cell-derived gastric organoids (hGOs) comprising gastric marker-expressing epithelium without an apparent smooth muscle (SM) structure has been reported. We modified previously reported protocols to generate hGOs with muscularis mucosa (MM) from hiPSCs. Time course analyses revealed that epithelium development occurred prior to MM formation. Sonic hedgehog (SHH) and TGF-β1 were secreted by the epithelium. HH and TGF-β signal inhibition prevented subepithelial MM formation. A mechanical property of the substrate promoted SM differentiation around hGOs in the presence of TGF-β. TGF-β signaling was shown to influence the HH signaling and mechanical properties. In addition, clinical specimen findings suggested the involvement of TGF-β signaling in MM formation in recovering gastric ulcers. HH and TGF-β signaling from the epithelium to the stroma and the mechanical properties of the subepithelial environment may influence the emergence of MM in human stomach tissue.

•

We successfully induce hGOs with MM by culturing for 8 weeks

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The emergence of MM occurs after epithelial maturation

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HH, TGF-β, and the mechanical environment are suggested to be involved in MM formation

Bleeding Risk Factors after Endoscopic Submucosal Dissection in Early Gastric Cancer and the Necessity of "Second-Look" Endoscopic Examination on the following Day

Background and Aim: Hemorrhage is often encountered after endoscopic submucosal dissection (ESD). In addition to active bleeding after resection, exposed blood vessels and blood clots without active bleeding on the post-dissection ulcer floor have been recognized within our department. We consider exposed and/or observable vessel findings and clots on the ulcer floor after re-section as important risk factors for hemorrhage. Here, we compared and examined the active bleeding frequency and “post-resection ulcer at risk of bleeding” on the day following ESD, in relation to their risk factors. Method: We retrospectively examined 447 patients who underwent second-look endoscopy in our department between August 2008 and March 2018. Logistic regression analyses were performed to determine the hazard ratio and 95% confidence interval. We compared the association of each factor mentioned above with active bleeding on the day after ESD and the presence of ulcers at risk of bleeding after resection. Results: Our retrospective analysis revealed that the risk factors were larger ulcer sizes and the administration of antithrombotic drugs. Additionally, the risk was low for upper body lesions but high for antral lesions. Conclusion: Our results may help determine whether second-look endoscopy should be performed to minimize active bleeding after ESD, reduce postoperative complications, and improve medical safety.

Endoscopic Submucosal Dissection for Early Gastric Cancer in Elderly vs. Non-Elderly Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed to review the applicability and complications rate associated with endoscopic submucosal dissection (ESD) for early gastric cancer in elderly patients.

METHODS

Databases of PubMed, Embase, CENTRAL, and ScienceDirect were searched till 15^th April 2021. All types of studies comparing ESD in the elderly vs non-elderly were included. Subgroup analysis was conducted for the following groups: ≥80 years vs <80 years, ≥75 years vs < 75 years, and ≥65 years vs <65 years.

RESULTS

17 studies were included. Meta-analysis indicated no statistically significant difference in the en-bloc resection rates (OR: 0.92 95% CI: 0.68, 1.26 I² = 8% p=0.62) and histological complete resection rates (OR: 0.93 95% CI: 0.75, 1.15 I² = 26% p=0.50) between elderly and non-elderly patients. The results were non-significant even on subgroup analysis. Overall, we found a non-significant but a tendency of increased perforation rates in the elderly as compared to non-elderly patients (OR: 1.22 95% CI: 0.99, 1.52 I² = 0% p=0.06). However, there was a significantly increased risk of perforation in elderly patients aged ≥80 years as compared to patients <80 years (OR: 1.50 95% CI: 1.00, 2.24 I² = 3% p=0.05). Bleeding rates were not different in the two groups (OR: 1.07 95% CI: 0.87, 1.32 I² = 19% p=0.52). Pooled analysis indicated a statistically significantly increased risk of pneumonia in elderly patients (OR: 2.52 95% CI: 1.72, 3.70 I² = 7% p<0.00001). Length of hospital stay was reported only by five studies. Meta-analysis indicated no significant difference between the two study groups (MD: 0.67 95% CI: -0.14, 1.48 I² = 83% p=0.10).

CONCLUSION

En-bloc and histological complete resection rates do not differ between elderly and non-elderly patients undergoing ESD for early gastric cancer. Elderly patients have a small tendency of increased risk of perforation with significantly increased rates in the super-elderly (≥80 years of age). The risk of pneumonia is significantly higher in elderly patients but the rates of bleeding do not differ. The certainty of evidence is "very low" and there is a need for high-quality studies taking into account confounding factors to enhance the quality of evidence.

Application of convolutional neural networks for evaluating the depth of invasion of early gastric cancer based on endoscopic images

BACKGROUND AND AIM

Recently, artificial intelligence (AI) has been used in endoscopic examination and is expected to help in endoscopic diagnosis. We evaluated the feasibility of AI using convolutional neural network (CNN) systems for evaluating the depth of invasion of early gastric cancer (EGC), based on endoscopic images.

METHODS

This study used a deep CNN model, ResNet152. From patients who underwent treatment for EGC at our hospital between January 2012 and December 2016, we selected 100 consecutive patients with mucosal (M) cancers and 100 consecutive patients with cancers invading the submucosa (SM cancers). A total of 3508 non-magnifying endoscopic images of EGCs, including white-light imaging, linked color imaging, blue laser imaging-bright, and indigo-carmine dye contrast imaging, were included in this study. A total of 2288 images from 132 patients served as the development dataset, and 1220 images from 68 patients served as the testing dataset. Invasion depth was evaluated for each image and lesion. The majority vote was applied to lesion-based evaluation.

RESULTS

The sensitivity, specificity, and accuracy for diagnosing M cancer were 84.9% (95% confidence interval [CI] 82.3%-87.5%), 70.7% (95% CI 66.8%-74.6%), and 78.9% (95% CI 76.6%-81.2%), respectively, for image-based evaluation, and 85.3% (95% CI 73.4%-97.2%), 82.4% (95% CI 69.5%-95.2%), and 83.8% (95% CI 75.1%-92.6%), respectively, for lesion-based evaluation.

CONCLUSIONS

The application of AI using CNN to evaluate the depth of invasion of EGCs based on endoscopic images is feasible, and it is worth investing more effort to put this new technology into practical use.

Scoring Model Based on Nodal Metastasis Prediction Suggesting an Alternative Treatment to Total Gastrectomy in Proximal Early Gastric Cancer

Purpose

Total gastrectomy (TG) with lymph node (LN) dissection is recommended for early gastric cancer (EGC) but is not indicated for endoscopic resection (ER). We aimed to identify patients who could avoid TG by establishing a scoring system for predicting lymph node metastasis (LNM) in proximal EGCs.

Materials and Methods

Between January 2003 and December 2017, a total of 1,025 proximal EGC patients who underwent TG with LN dissection were enrolled. Patients who met the absolute ER criteria based on pathological examination were excluded. The pathological risk factors for LNM were determined using univariate and multivariate logistic regression analyses. A scoring system for predicting LNM was developed and applied to the validation group.

Results

Of the 1,025 cases, 100 (9.8%) showed positive LNM. Multivariate analysis confirmed the following independent risk factors for LNM: tumor size >2 cm, submucosal invasion, lymphovascular invasion (LVI), and perineural invasion (PNI). A scoring system was created using the four aforementioned variables, and the areas under the receiver operating characteristic curves in both the training (0.85) and validation (0.84) groups indicated excellent discrimination. The probability of LNM in mucosal cancers without LVI or PNI, regardless of size, was <2.9%.

Conclusions

Our scoring system involving four variables can predict the probability of LNM in proximal EGC and might be helpful in determining additional treatment plans after ER, functioning as a good indicator of the adequacy of treatments other than TG in high surgical risk patients.

Extragastric Metastasis of Early Gastric Cancer After Endoscopic Submucosal Dissection With Lymphovascular Invasion and Negative Resected Margins

Purpose

Lymphovascular invasion is a criterion for non-curative resection in patients who have undergone endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to determine the rate of extragastric metastasis (EGM) and identify the predictors of EGM in patients with negative resection margins (R0 resection) and lymphovascular invasion in post-ESD pathology.

Materials and Methods

A total of 2,983 patients underwent ESD for EGC. Among them, 110 had a pathology of R0 resection and positive lymphovascular invasion. Patients underwent additional gastrectomy (n=63) or further follow-up without gastrectomy (n=47).

Results

The 110 patients were assigned to one of the 3 groups according to ESD indications based on post-ESD pathology. The first group satisfied the absolute indication for ESD (n=18), the second group satisfied the expanded indications for ESD (n=34), and the last group satisfied the beyond indication (n=58). The number of occurrences of EGM in each group was 1 (5.6%), 3 (8.8%), and 3 (5.2%), respectively. The logistic regression analysis adjusted for age, sex, tumor size, and indication for ESD, showed that larger tumor size was associated with EGM (odds ratio, 1.76; 95% confidence interval, 1.00–3.10; P=0.048). In contrast, ESD indication criteria did not affect EGM (P=0.349).

Conclusions

Tumor size was the only predictive indicator for EGM in patients who underwent R0 resection and lymphovascular invasion on post-ESD pathology. Even patients with pathology corresponding to the absolute indication criteria of ESD had lymphovascular invasion, which means that they require additional gastrectomy due to the risk of EGM.

Advances in the Aetiology & Endoscopic Detection and Management of Early Gastric Cancer

Simple Summary

Gastric adenocarcinoma has remained a highly lethal disease. Awareness and recognition of preneoplastic conditions (including gastric atrophy and intestinal metaplasia) using high-resolution white-light endoscopy as well as chromoendoscopy is therefore essential. Helicobacter pylori, a class I carcinogen, remains the main contributor to the development of sporadic distal gastric neoplasia. Management of early gastric neoplasia with endoscopic resections should be in line with standard indications. A multidisciplinary approach to any case of an early gastric neoplasia is imperative. Hereditary forms of gastric cancer require a tailored approach and individua-lized surveillance.

Abstract

The mortality rates of gastric carcinoma remain high, despite the progress in research and development in disease mechanisms and treatment. Therefore, recognition of gastric precancerous lesions and early neoplasia is crucial. Two subtypes of sporadic gastric cancer have been recognized: cardia subtype and non-cardia (distal) subtype, the latter being more frequent and largely associated with infection of Helicobacter pylori, a class I carcinogen. Helicobacter pylori initiates the widely accepted Correa cascade, describing a stepwise progression through precursor lesions from chronic inflammation to gastric atrophy, gastric intestinal metaplasia and neoplasia. Our knowledge on He-licobacter pylori is still limited, and multiple questions in the context of its contribution to the pathogenesis of gastric neoplasia are yet to be answered. Awareness and recognition of gastric atrophy and intestinal metaplasia on high-definition white-light endoscopy, image-enhanced endoscopy and magnification endoscopy, in combination with histology from the biopsies taken accurately according to the protocol, are crucial to guiding the management. Standard indications for endoscopic resections (endoscopic mucosal resection and endoscopic submucosal dissection) of gastric dysplasia and intestinal type of gastric carcinoma have been recommended by multiple societies. Endoscopic evaluation and surveillance should be offered to individuals with an inherited predisposition to gastric carcinoma.

Improving the Diagnosis and Treatment of Early Gastric Cancer in the West

Gastric cancer is the third leading cause of cancer-related death. In Western countries, its lower prevalence and the absence of mass screening programmes contribute to late diagnosis and a slower implementation of minimally invasive treatments. A secondary prevention strategy through endoscopic surveillance of patients at high risk of intestinal-type gastric adenocarcinoma or by screening gastric cancer within colorectal screening programmes is cost-effective in intermediate-risk countries, though the identification of these patients remains challenging. Virtual chromoendoscopy with narrow-band imaging improves the accuracy of endoscopic diagnosis, significantly increasing the sensitivity for intestinal metaplasia while preserving specificity. Endoscopic grading of gastric intestinal metaplasia is feasible, correlates well with histological staging systems and also with gastric neoplasia risk and can be used to stratify risk. Endoscopic submucosal dissection (ESD) in the West achieves efficacy and safety outcomes similar to those reported for Eastern countries, and the long-term disease-specific survival is higher than 95%. A prospective comparative study with gastrectomy confirms its higher safety and its benefits concerning health-related quality of life. However, ESD is associated with a 5% risk of postprocedural bleeding and a 20% risk of non-curative resection. The knowledge of risk factors for adverse events and non-curative resection can improve patient selection. The risk of metachronous lesions after ESD is high (3–5% per year), and endoscopic surveillance is needed. The management of patients with non-curative resection can be optimized using risk scoring systems for lymph node metastasis.

Collective dynamics of gastric cancer cells in fluid

Gastric cancer (GC) is the most common digestive system malignant cancer, and gastric cancer cells (GCC) can migrate in normal solid tissue and lymphatic fluid. Previously, much research has focused on the migration process when the cells are in the solid condition, such as migration through tissue, adhesion, and invasion processes, while little is known about the migration process of GCC in lymphatic fluid. In the current study, we investigate the migration of GCC in a fluid condition in an in vitro environment. We find that the cells diffuse mainly because of their cell viability. Therefore, despite the fact that lymph fluid is almost quiescent, GCCs can migrate around easily. The dynamics of cells also demonstrate a collective glassy dynamic similar to ordinary inactive glassy materials. As density of the cells increases, the movement of the cells becomes slower, and the collective dynamic becomes heterogeneous, which is similar to the dynamically heterogeneous behavior in glassy materials. The results will help us gain a better knowledge of the characteristics of GCC dynamics in the liquid phase which is crucial for the understanding of the mechanism for lymphatic metastasis. This can also potentially help early diagnosis of lymph node metastasis in GC and provide new insights for future clinical treatment.

AGA Clinical Practice Update on Surveillance After Pathologically Curative Endoscopic Submucosal Dissection of Early Gastrointestinal Neoplasia in the United States: Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update was to review the available evidence and provide expert advice regarding surveillance using endoscopy and other relevant modalities after removal of dysplastic lesions and early gastrointestinal cancers with endoscopic submucosal dissection deemed to be pathologically curative. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors, who are advanced endoscopists with high-level expertise in performing endoscopic submucosal dissection to treat dysplasia and early cancers in the luminal gastrointestinal tract.

High-grade Papillary Early Gastric Carcinoma With High Risk for Lymph Node Metastasis and Poor Prognosis: A Clinicopathologic Study of 96 Cases Among 1136 Consecutive Radical Gastrectomies

Papillary early gastric carcinoma (EGC) is believed to have a low risk of lymph node metastasis (LNM) and thus can be resected endoscopically. We observed anecdotally that some papillary EGC tumors showed conspicuous high-grade dysplastic features, but the significance of these observations is unknown. In this bicenter study we investigated papillary EGCs that were divided into high-grade (n=96) and low-grade (n=118) groups among 1136 consecutive EGC radical resection cases. Concurrent 464 well-moderately differentiated tubular EGCs were served as the control group. Compared with low-grade papillary and well-moderately differentiated tubular EGCs, high-grade papillary EGC displayed significantly larger sizes (mean 2.51 cm), higher frequencies of the elevated macroscopic type (51%), lymphovascular invasion (LVI) (38.5%), and LNM (31.2%). Low-grade papillary EGCs exhibited a higher prevalence of the elevated macroscopic type, but not LVI nor LNM, compared with tubular EGC. Independent risk factors for LNM included high-grade histology, female sex, distal location, submucosal invasion, and LVI. The 5-year overall survival rate was significantly lower in high-grade (79.6%) papillary than in low-grade (88.9%) papillary or tubular (92.8%) EGCs, while no significant difference in prognosis was observed in the latter 2 groups. Age of 66 years or older and LNM were independent risk factors for overall survival. In conclusions, high-grade papillary EGC was associated with high frequencies of LVI, LNM, and poor prognosis, and thus unsuitable for endoscopic therapy, while low-grade papillary EGC showed clinicopathologic features and prognosis similar to well-moderately differentiated tubular EGC and may be treated endoscopically in appropriate clinical settings.

The risk of lymph node metastasis in gastric cancer conforming to indications of endoscopic resection and pylorus-preserving gastrectomy: a single-center retrospective study

Background

Lymph node metastasis (LNM) status is an important prognostic factor that strongly influences the treatment decision of early gastric cancer (EGC). This study aimed to evaluate the pattern and clinical significance of LNM in EGC.

Methods

A total of 354 patients with carcinoma in situ (n = 42), EGC (n = 312) who underwent radical gastrectomy were enrolled. Their clinicopathological features, pathological reports, and prognostic data were collected and analyzed.

Results

The incidence of LNM in all patients was 18.36% (65/354). The rates of D1 and D2 station metastases were 12.10% (43/354) and 6.21% (22/354), respectively. The rates of LNM in absolute indication of endoscopic resection and expanded indication were 3.27% (2/61) and 28.55% (4/14), respectively. Skip LNM was observed in 3.67% (13/354) of patients. For those with middle-third tumor, the metastasis rate of the No. 5 lymph node was 3.05% (5/164). The independent risk factors for LNM were tumors measuring > 30 mm, poorly differentiated tumors, and lymphovascular invasion (all P < 0.05; area under the curve, 0.783). The 5-year disease-free survival rates of patients with and without LNM were 96.26 and 79.17%, respectively (P = 0.011). Tumors measuring > 20 mm and LNM were independent predictive factors for poor survival outcome in all patients.

Conclusions

Patients with EGC conforming to expanded indications have a relatively high risk of LNM and may not be suitable for endoscopic submucosal dissection. Pylorus-preserving gastrectomy for patients with middle-third EGC remains controversial due to the high metastasis rate of the No. 5 lymph node.

Macroscopically complete excision is a beneficial strategy for selected patients with peritoneal sarcomatosis

The occurrence of peritoneal sarcomatosis (PS) in patients with retroperitoneal sarcoma (RPS) indicates a poor prognosis. However, the appropriate treatment modality remains unclear. This study aimed to identify its prognostic factors and further explore the role of macroscopically complete excision (CE) in the management of PS. A retrospective database was established to evaluate patients with RPS who underwent resection between January 2011 and January 2019. Univariate and multivariate survival analyses were performed to analyze the prognostic factors and identify the population that will optimally benefit from CE. This study included a total of 49 patients with PS from 211 patients with RPS, and 34 (69.4%) patients of whom with PS underwent CE successfully. The median follow-up time was 36.0 months. There were 8 patients excluded because of loss to follow-up (n = 4) or death from complications within 90 days postoperatively (n = 4). The CE group had a marginally better prognosis compared to the macroscopically incomplete excision (IE) group (median disease-specific survival: 20 months vs. 8 months). Multivariate survival analysis demonstrated that completeness of operation (CE vs. IE) was the only independent prognostic factor in PS patients (P = 0.042). There was no significant difference in the overall complications between the CE and IE groups (P = 0.205). In conclusion, completeness of macroscopical excision is an independent prognostic predictor of PS. If technically possible, CE is a feasible strategy to improve the prognosis of selected patients with PS.