Endoscopic resection of early gastric cancer: the Japanese perspective

Endoscopic diagnosis and treatment of superficial non-ampullary duodenal epithelial tumors: A review

The surface of the small bowel mucosa is covered more than any other section of the digestive canal; however, the overall prevalence of small bowel tumors of the whole gastrointestinal tract is evidently low. Owing to the improvement in endoscopic techniques, the prevalence of small bowel tumors has increased across multiple countries, which is mainly due to an increase in duodenal tumors. Superficial non-ampullary duodenal epithelial tumors (SNADETs) are defined as tumors originating from the non-ampullary region in the duodenum that share similarities and discrepancies with their gastric and colorectal counterparts in the pathogenesis and clinicopathologic characteristics. To date, white light endoscopy (WLE) remains the cornerstone of endoscopic diagnosis for SNADETs. Besides, narrow-band imaging (NBI) techniques and magnifying endoscopy (ME) have been widely used in the clinic and endorsed by multiple guidelines and consensuses for SNADETs' evaluation. Confocal laser endomicroscopy (CLE), endocytoscopy (ECS), and artificial intelligence (AI) are also up-and-coming methods, showing an exceptional value in the diagnosis of SNADETs. Similar to the endoscopic treatment for colorectal polyps, the choices for SNADETs mainly include cold snare polypectomy (CSP), endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and laparoscopic endoscopic cooperative surgery (LECS). However, owing to the narrow lumen, rich vascularity, weak muscle layer, abundant Brunner's gland, and the hardship of endoscope control, the duodenum ranks as one of the most dangerous operating areas in the digestive tract. Therefore, endoscopists must anticipate the difficulties in endoscopic maneuverability, remain aware of the increased risk of complications, and then select the appropriate treatment according to the advantages and disadvantages of each method.

The First Systematic Gastroscopy Training Program for Surgeons in Korea

BACKGROUND

Endoscopic evaluation of the stomach is essential for preoperative planning and post-surgical surveillance for various diseases of the stomach, including malignancy. The gastroscopy education program for surgeons is currently in its infancy and is not systematically organized in Korea. This study aimed to introduce the first systematic gastroscopy education program for surgeons in Korea.

METHODS

The gastroscopy education program entitled "Gastroscopy School for Surgeons (GSS)" comprised of theoretical education, dry lab hands-on training, and clinical practice. All participants were beginners without any gastroscopy experience. Clinical practice started after the completion of the theoretical and dry lab training. The gastroscopy practices utilized simple luminal observation, biopsy, localization using clips or dye injection, and limited therapeutic gastroscopy. The educational performances and surveys from 33 participants were analyzed.

RESULTS

The participants consisted of surgical residents, general surgeons, gastrointestinal-specialized surgeons, and physicians. Participants performed a total of 2,272 gastroscopies, 2,008 of which were post-gastrectomy cases. Currently, of the 33 participants, 7 (21.2%) of the participants performed gastroscopy regularly, and 7 (21.2%) occasionally. According to the self-reported survey, one participant assessed their current gastroscopic technique to be at the expert level, and 25 (75.8%) at a proficient level. All participants considered gastroscopy education for surgeons to be necessary, and 28 (84.8%) stated that systematic education is not currently provided in Korea.

CONCLUSION

We introduced the first systematic gastroscopy education program for surgeons in Korea, namely the GSS, which is practical and meets clinical needs. More training centers are needed to expand gastroscopy training among Korean surgeons.

Identification and Validation of a Malignant Cell Subset Marker-Based Polygenic Risk Score in Stomach Adenocarcinoma Through Integrated Analysis of Bulk and Single-Cell RNA Sequencing Data

Objectives: The aim of the present study was to construct a polygenic risk score (PRS) for poor survival among patients with stomach adenocarcinoma (STAD) based on expression of malignant cell markers.

Methods: Integrated analyses of bulk and single-cell RNA sequencing (scRNA-seq) of STAD and normal stomach tissues were conducted to identify malignant and non-malignant markers. Analyses of the scRNA-seq profile from early STAD were used to explore intratumoral heterogeneity (ITH) of the malignant cell subpopulations. Dimension reduction, cell clustering, pseudotime, and gene set enrichment analyses were performed. The marker genes of each malignant tissue and cell clusters were screened to create a PRS using Cox regression analyses. Combined with the PRS and routine clinicopathological characteristics, a nomogram tool was generated to predict prognosis of patients with STAD. The prognostic power of the PRS was validated in two independent external datasets.

Results: The malignant and non-malignant cells were identified according to 50 malignant and non-malignant cell markers. The malignant cells were divided into nine clusters with different marker genes and biological characteristics. Pseudotime analysis showed the potential differentiation trajectory of these nine malignant cell clusters and identified genes that affect cell differentiation. Ten malignant cell markers were selected to generate a PRS: RGS1, AADAC, NPC2, COL10A1, PRKCSH, RAMP1, PRR15L, TUBA1A, CXCR6, and UPP1. The PRS was associated with both overall and progression-free survival (PFS) and proved to be a prognostic factor independent of routine clinicopathological characteristics. PRS could successfully divide patients with STAD in three datasets into high- or low-risk groups. In addition, we combined PRS and the tumor clinicopathological characteristics into a nomogram tool to help predict the survival of patients with STAD.

Conclusion: We revealed limited but significant intratumoral heterogeneity in STAD and proposed a malignant cell subset marker-based PRS through integrated analysis of bulk sequencing and scRNA-seq data.

Deep neural network approaches for detecting gastric polyps in endoscopic images

Gastrointestinal endoscopy is the primary method used for the diagnosis and treatment of gastric polyps. The early detection and removal of polyps is vitally important in preventing cancer development. Many studies indicate that a high workload can contribute to misdiagnosing gastric polyps, even for experienced physicians. In this study, we aimed to establish a deep learning-based computer-aided diagnosis system for automatic gastric polyp detection. A private gastric polyp dataset was generated for this purpose consisting of 2195 endoscopic images and 3031 polyp labels. Retrospective gastrointestinal endoscopy data from the Karadeniz Technical University, Farabi Hospital, were used in the study. YOLOv4, CenterNet, EfficientNet, Cross Stage ResNext50-SPP, YOLOv3, YOLOv3-SPP, Single Shot Detection, and Faster Regional CNN deep learning models were implemented and assessed to determine the most efficient model for precancerous gastric polyp detection. The dataset was split 70% and 30% for training and testing all the implemented models. YOLOv4 was determined to be the most accurate model, with an 87.95% mean average precision. We also evaluated all the deep learning models using a public gastric polyp dataset as the test data. The results show that YOLOv4 has significant potential applicability in detecting gastric polyps and can be used effectively in gastrointestinal CAD systems. Gastric Polyp Detection Process using Deep Learning with Private Dataset.

Balloon-assisted endoscopic submucosal dissection for treating small intestinal lipomas: Report of two cases

BACKGROUND

Most small intestinal lipomas are treated surgically, and some require repeated surgeries for multiple lipomas. However, application of endoscopic submucosal dissection (ESD) technology in the deep small intestine is rarely reported owing to the special anatomical structure of the small intestine, medical equipment limitations, and the lack of relevant experience among endoscopists.

CASE SUMMARY

Two patients with small intestinal lipomas treated at the Air Force Medical Center from November 2015 to September 2019 were selected to undergo balloon-assisted ESD to treat the lipomas and explore the technical feasibility and safety of ESD for treating small intestinal lipomas. The two patients successfully underwent balloon-assisted ESD to treat four small intestinal lipomas, with a complete resection rate of 100% (4/4), without intraoperative or postoperative bleeding, perforation, or other complications. After 3-6 mo of postoperative follow-up, the clinical symptoms caused by the lipomas were significantly relieved or disappeared after treatment.

CONCLUSION

Balloon-assisted ESD is a safe and reliable new method for treating deep intestinal lipomas and shows good clinical feasibility.

Clinico-pathologic determinants of non-e-curative outcome following en-bloc endoscopic submucosal dissection in patients with early gastric neoplasia

Background

Endoscopic submucosal dissection (ESD) is gaining enormous popularity in the treatment of early gastric cancers (EGCs) in many institutions across the world. However, appropriate selection of candidates for endoscopic resection is crucial to sufficiently mitigate non-e-curative (NEC) resection. This study aims at identifying the various clinico-pathologic factors that independently predict the NEC outcome and depth of submucosal invasion following ESD procedure in patients with EGC.

Methods

Multiple logistic regression analysis was applied to investigate factors that independently predict both non-curability phenomenon and the level of submucosal invasion in patients with early gastric neoplasia. Statistical Packages for the Social Sciences version 23 was used for analysis.

Results

A total of 153 patients (162 EGC lesions) underwent en-bloc ESD after which the rate of complete resection and non-e-curative outcome were 95% and 22.2%, correspondingly. Multivariate analysis depicted that tumor location in the upper two third of stomach (odds ratio [OR], 5.46; 95% confidence interval [95% CI], 1.65–18.12; p = 0.006), tumor size > 2 cm (OR, 7.63; 95% CI, 2.29–25.42; p = 0.001), histologically undifferentiated tumor (OR, 15.54; 95% CI, 1.65–146.22; p = 0.001), and tumors with 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc (OR, 9.77; 95% CI, 1.23–77.65; p = 0.031) were all independent predictors of NEC resection for early gastric tumors. Additionally, location in the upper two third of the stomach (OR, 8.88; 95% CI, 2.90–27.17; p < 0.001), ulcerated lesions (OR, 3.70; 95% CI, 1.15–11.90; p = 0.028), lesions with > 2 cm (OR, 2.94; 95% CI, 1.08–8.02; p = 0.036) and those with poor differentiation (OR, 6.51; 95% CI, 2.23–18.98; p = 0.001) were found to have significant association with submucosal invasion.

Conclusions

Tumors located in the upper two third of the stomach having a larger size (> 2 cm), poor histo-differentiation and a gross type of 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc were significantly associated with a risk of NEC after ESD procedure. Thus, early gastric tumors displaying these features need to be handled carefully during endoscopic resection. Our findings may shed light on the pre-procedural detection of clinicopathologic factors that determine non-e-curability in patients with EGC.

Regional Lymph Node Dissection as an Additional Treatment Option to Endoscopic Resection for Expanded Indications in Gastric Cancer: a Prospective Cohort Study

Purpose

Expanded indications for endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) remain controversial due to the potential risk of undertreatment after adequate lymph node dissection (LND). Regional LND (RLND) is a novel technique used for limited lymphadenectomy to avoid gastrectomy. This study established the safety and effectiveness of RNLD as an additional treatment option after ESD for expanded indications.

Materials and Methods

A total of 69 patients who met the expanded indications for ESD were prospectively enrolled from 2014 to 2017. The tumors were localized using intraoperative esophagogastroduodenoscopy (EGD) before RLND. All patients underwent RLND first, followed by conventional radical gastrectomy with LND. The locations of the preoperative and intraoperative EGD were compared. Pathologic findings of the primary lesion and the RLND status were analyzed.

Results

The concordance rates of tumor location between the preoperative and intraoperative EGD were 79.7%, 76.8%, and 63.8% according to the longitudinal, circumferential, and regional locations, respectively. Of the 4 patients (5.7%) with metastatic LNs, 3 were pathologically classified as beyond the expanded indication for ESD and 1 had a single LN metastasis in the regional lymph node.

Conclusions

RLND is a safe additional option for the treatment of EGC in patients meeting expanded indications after ESD.

Factors Associated with Worse Outcome in Early Stage Gastric Cancer Using the Surveillance, Epidemiology, and End Results (SEER) Database

Background The benefit of adjuvant treatment in gastric adenocarcinoma patients with involvement of the muscularis propria but not beyond is unclear. We aim to establish a model that identifies the factors that adversely affect the prognosis in these patients. Methods We used the Surveillance, Epidemiology, and End Results (SEER) database to identify subjects with stage T2aN0M0 gastric adenocarcinoma who had tumor resection between 2004 and 2015. Data pertaining to the following variables were collected: age, gender, ethnicity, tumor size, grade, site, number of lymph nodes (LNs) being examined, and extent of surgery. Results A total of 1307 patients met our inclusion criteria. The five-year overall survival (OS) was 65%. The following factors were significantly associated with a shorter OS in univariate analysis. Age > 60 years, non-Hispanic whites and non-Hispanic blacks, patients with less than 15 lymph nodes examined at the time of surgery, tumors at the fundus and cardia of the stomach, and those who underwent endoscopic resection or had partial esophagectomy. On multivariate Cox regression, the following factors were predictors for worse OS: age > 60 years with a hazards ratio (HR) = 2.03 (95% CI: 1.49-2.76), patients with less than 15 lymph nodes examined with HR = 1.72 (95% CI: 1.34-2.20), non-Hispanic whites and non-Hispanic blacks with HR = 1.62 (95% CI: 1.26-2.08), and tumors within the cardia and fundus of the stomach with HR = 1.51 (95% CI: 1.21-1.89). Conclusion Patients with stage T2aN0M0 gastric cancer who had their tumor located at the cardia or fundus of the stomach or those with inadequate lymph nodes resection had inferior survival and could potentially benefit from adjuvant chemotherapy.

Upper Endoscopy up to 3 Years Prior to a Diagnosis of Gastric Cancer Is Associated With Lower Stage of Disease in a USA Multiethnic Urban Population, a Retrospective Study

OBJECTIVES

In the USA, certain races and ethnicities have a disproportionately higher gastric cancer burden. Selective screening might allow for earlier detection and curative resection. Among a USA-based multiracial and ethnic cohort diagnosed with non-cardia gastric cancer (NCGC), we aimed to identify factors associated with curable stage disease at diagnosis.

METHODS

We retrospectively identified endoscopically diagnosed and histologically confirmed cases of NCGC at Mount Sinai Hospital in New York City. Demographic, clinical, endoscopic and histologic factors, as well as grade/stage of NCGC at diagnosis were documented. The primary outcome was the frequency of curable-stage NCGC (stage 0-1a) at diagnosis in patients with versus without an endoscopy negative for malignancy prior to their index exam diagnosing NCGC. Additional factors associated with curable-stage disease at diagnosis were determined.

RESULTS

A total of 103 racially and ethnically diverse patients were included. Nearly 38% of NCGC were stage 0-Ia, 34% stage Ib-III, and 20.3% stage IV at diagnosis. A significantly higher frequency of NCGC was diagnosed in curable stages among patients who had undergone an endoscopy that was negative for malignancy prior to their index endoscopy that diagnosed NCGC, compared to patients without a negative endoscopy prior to their index exam (69.6% vs. 28.6%, p=0.003). A prior negative endoscopy was associated with 94.0% higher likelihood of diagnosing curable-stage NCGC (p=0.003). No other factors analyzed were associated with curable-stage NCGC at diagnosis.

CONCLUSIONS

Endoscopic screening and surveillance in select high-risk populations might increase diagnoses of curable-stage NCGC. These findings warrant confirmation in larger, prospective studies.

Circulating microRNA-22-3p Predicts the Malignant Progression of Precancerous Gastric Lesions from Intestinal Metaplasia to Early Adenocarcinoma

BACKGROUND

Gastric cancer has a poor outcome and identifying useful biomarkers from peripheral blood or tissue could allow its early detection, or potentially precancerous changes, thus improving the curative rates. MicroRNAs (miRNAs) have been shown to offer great potential in cancer diagnosis and prediction.

AIM

Here, we investigated the role of plasma miRNAs in the natural course of gastric cancer, from intestinal metaplasia to early cancer. The findings were used to understand whether patients at a high risk of malignancy could be given appropriate interventions in the early disease process, such as using endoscopic submucosal dissection to treat gastric dysplasia or early gastric cancer.

METHODS

Participants were divided into healthy control, intestinal metaplasia (IM), and dysplasia/early cancer (pT1a/b) groups. Microarray was used to select potential markers in tissue.

RESULTS

Quantitative real-time polymerase chain reaction data showed circulating miRNA-22-3p had significantly different expression in patients with precancerous lesions or gastric adenocarcinoma. The areas under the curve of incomplete IM versus healthy control, low-grade/high-grade dysplasia, early gastric cancer, and GED were 0.8080, 0.8040, 0.8494, and 0.8095, respectively (all P values < 0.05).

CONCLUSIONS

Circulating miRNA-22-3p could be a potential biomarker for gastric precancerous dysplasia and early cancer detection.

Pilot Research for the Correlation between the Expression Pattern of E-cadherin-β-Catenin Complex and Lymph Node Metastasis in Early Gastric Cancer

Aims and background

Early gastric cancer without lymph node metastasis can be treated with minimally invasive endoscopic surgery. Hence, a better modality for predicting lymph node metastasis should be beneficial to early gastric cancer patients who may only require minimally invasive treatment. In vitro, phosphorylation of β-catenin induces the loss of membranous β-catenin and E-cadherin, subsequently increasing the potential for metastasis. We investigated the behavior of these molecules comparing lymph node metastasis-positive and lymph node metastasis-negative groups, using the specimens from the patients with early gastric cancer. This was a pilot research evaluating the usefulness of combined analysis of these molecules in predicting lymph node metastasis in early gastric cancer.

Methods

The clinicopathological features and immunohistochemical expression patterns of E-cadherin and β-catenin in the primary lesion were studied retrospectively in 28 patients (lymph node metastasis-positive versus lymph node metastasis-negative: 14 vs 14) selected from 272 patients. These patients underwent radical surgery for the early gastric cancer treatment from April 2000 to March 2004 at our hospital. All patients gave written informed consent to use their tissues for the clinical study. Statistical analyses were performed by the chi-square test and Mann-Whitney test.

Results

More loss of membranous E-cadherin was observed in the lymph node metastasis-positive group than in the lymph node metastasis-negative group. Although the finding was slightly more marked in the intestinal than in the diffuse type early gastric cancer, there was no statistical significance. Loss of membranous β-catenin showed a similar trend and no statistical significance. When we evaluated the expression patterns of both molecules, dual loss of membranous E-cadherin and β-catenin significantly correlated with lymph node metastasis [dual loss in lymph node metastasis-positive versus lymph node metastasis-negative patients: 12 (86%) vs 6 (43%), P = 0.046]. Additionally, corresponding proportions in intestinal type early gastric cancer were 5 of 6 (83%) vs 0 of 6 (0%), P = 0.015.

Conclusions

Based on our results, the combined analysis of E-cadherin and β-catenin localizations may be helpful to accurately predict lymph node metastasis in intestinal type early gastric cancer.

Circulating microRNA-196a is an early gastric cancer biomarker

MicroRNA-196a (miRNA-196a) is associated with the development of gastric cancer and metastasis. Intestinal metaplasia and low- or high-grade dysplasia are considered to be precursors of intestinal type gastric cancer. Accordingly, we investigated the expression of plasma miRNA-196a as an early detection biomarker in precancerous gastric lesions and early cancer (pT1a/b), which is otherwise treated with endoscopic submucosal dissection. Our data showed that levels of circulating (plasma) miRNA-196a were higher in patients with precancerous lesions/early gastric adenocarcinoma than in healthy controls. The area under the receiver operating characteristic curve (AUC) for healthy controls vs. intestinal metaplasia was 0.9736; healthy controls vs. low-grade/high-grade dysplasia 0.9495; and healthy controls vs. early gastric cancer 0.9318. These results indicate that circulating miRNA-196a is a novel biomarker for detection of early gastric cancer and its precursor.

Postoperative bleeding in patients on antithrombotic therapy after gastric endoscopic submucosal dissection

AIM

To investigated the relationship between postoperative bleeding following gastric endoscopic submucosal dissection (ESD) and individual antithrombotic agents.

METHODS

A total of 2488 gastric neoplasms in 2148 consecutive patients treated between May 2001 and June 2016 were studied. The antithrombotic agents were categorized into antiplatelet agents, anticoagulants, and other antithrombotic agents, and we included combination therapies [e.g., dual antiplatelet therapy (DAPT)]. The risk factors associated with post-ESD bleeding, namely, antithrombotic agents overall, individual antithrombotic agents, withdrawal or continuation of antithrombotic agents, and bleeding onset period (during the first six days or thereafter), were analyzed using univariate and multivariate analyses.

RESULTS

The en bloc resection and complete curative resection rates were 99.2% and 91.9%, respectively. Postoperative bleeding occurred in 5.1% cases. Bleeding occurred in 10.3% of the patients administered antithrombotic agents. Being male (P = 0.007), specimen size (P < 0.001), and antithrombotic agent used (P < 0.001) were independent risk factors for postoperative bleeding. Heparin bridging therapy (HBT) (P = 0.002) and DAPT/multidrug combinations (P < 0.001) were independent risk factors associated with postoperative bleeding. The bleeding rate of the antithrombotic agent continuation group was significantly higher than that of the withdrawal group (P < 0.01). Bleeding within postoperative day (POD) 6 was significantly higher in warfarin (P = 0.015), and bleeding after POD 7 was significantly higher in DAPT/multidrug combinations (P = 0.007). No thromboembolic events were reported.

CONCLUSION

We must closely monitor patients administered HBT and DAPT/multidrug combinations after gastric ESD, particularly those administered multidrug combinations after discharge.

Sentinel Node Mapping Using a Fluorescent Dye and Visible Light During Laparoscopic Gastrectomy for Early Gastric Cancer: Result of a Prospective Study From a Single Institute

OBJECTIVE

The aim of this study was to investigate the feasibility of sentinel node mapping using a fluorescent dye and visible light in patients with gastric cancer.

BACKGROUND

Recently, fluorescent imaging technology offers improved visibility with the possibility of better sensitivity or accuracy in sentinel node mapping.

METHODS

Twenty patients with early gastric cancer, for whom laparoscopic distal gastrectomy with standard lymphadenectomy had been planned, were enrolled in this study. Before lymphadenectomy, the patients received a gastrofiberoscopic peritumoral injection of fluorescein solution. The sentinel basin was investigated via laparoscopic fluorescent imaging under blue light (wavelength of 440-490 nm) emitted from an LED curing light. The detection rate and lymph node status were analyzed in the enrolled patients. In addition, short-term clinical outcomes were also investigated.

RESULTS

No hypersensitivity to the dye was identified in any enrolled patients. Sentinel nodes were detected in 19 of 20 enrolled patients (95.0%), and metastatic lymph nodes were found in 2 patients. The latter lymph nodes belonged to the sentinel basin of each patient. Meanwhile, 1 patient (5.0%) experienced a postoperative complication that was unrelated to sentinel node mapping. No mortality was recorded among enrolled cases.

CONCLUSIONS

Sentinel node mapping with visible light fluorescence was a feasible method for visualizing sentinel nodes in patients with early gastric cancer. In addition, this method is advantageous in terms of visualizing the concrete relationship between the sentinel nodes and surrounding structures.

Tumor budding in intestinal-type gastric adenocarcinoma is associated with nodal metastasis and recurrence

Gastric adenocarcinoma (GAC) is a common cause of cancer-related death worldwide. GAC can be classified as intestinal or diffuse. Intestinal-type cancers are common and reported to have a better prognosis compared to diffuse cancers. Studies have shown the presence and amount of tumor budding in intestinal carcinomas of the colon and esophagus to predict nodal metastasis and recurrence. Our aim is to determine if tumor budding in intestinal-type GAC correlates with prognostic features. One hundred four patients treated with primary surgical excision between 1999 and 2013 were identified. Histologic type (intestinal, diffuse, or mixed), tumor grade, T-stage, and lymph node status were evaluated. Tumor bud scores were assigned to all intestinal-type cancers using methods previously described for colorectal adenocarcinoma. Scores of <1 were designated as low and ≥1 as high. Tumor characteristics were as follows: 52 intestinal (50%), 36 diffuse (35%), and 16 mixed (15%). Of the 52 cases with intestinal histology, 4 were well (8%), 28 were moderately (54%), and 20 were poorly differentiated (38%). Thirty-three (63%) of the intestinal tumors had high tumor bud scores. Cases with high scores were associated with higher T-stage, N-stage, and grade (P<.001, P<.001, and P=.002). These also had a higher likelihood of recurrence (P=.007). In our cohort, high tumor bud scores in intestinal-type GAC have higher T-stage, N-stage, grade, and likelihood of recurrence. Assessment of tumor budding may guide clinical management in a subset of patients.

Predictive factors for lymph node metastasis in early gastric cancer with lymphatic invasion after endoscopic resection

BACKGROUND

Lymph node (LN) metastasis is found in only about 5-10% of the patients who undergo additional surgery after non-curative endoscopic resection. Lymphatic invasion after endoscopic submucosal dissection (ESD) is regarded as non-curative resection due to risk of reginal LN metastasis. This study was aimed to identify clinicopathologic predictive factors for LN metastasis in early gastric cancer (EGC) with lymphatic invasion after endoscopic resection.

METHODS

Among a total of 2036 patients who underwent endoscopic resection for EGC at Samsung Medical Center from April 2000 to May 2011, 146 patients were diagnosed with lymphatic invasion. And 123 patients who had gastrectomy with LN dissection due to presence of lymphatic invasion as one of the non-curative factors were included in this study. Demographics, endoscopic tumor findings, histological findings, surgical findings with pathologic reports, and follow-up data were collected from the patient's medical records. Pathological re-evaluation of resected specimens was performed.

RESULTS

Among a total of 123 patients, LN metastases were found in seven patients (5.7%). The univariate analysis revealed that the LN metastasis was significantly more frequent in patients with certain morphology of lymphatic invasion that shows adhesion to endothelium of lymphatic tumor emboli (p = 0.016), higher number of lymphatic tumor emboli in whole section (p < 0.001) and papillary adenocarcinoma component (p = 0.024). In multivariate analysis, the number of lymphatic tumor emboli [OR 93.5, 95% CI (2.62-3330.81)] and the presence of papillary adenocarcinoma component [OR 552.5, 95% CI (1.20-254871.81)] were identified as independent predictors of LN metastasis in patients with lymphatic invasion after endoscopic resection.

CONCLUSIONS

The number of lymphatic tumor emboli and the presence of papillary adenocarcinoma component were significant predictors for LN metastasis in patients with lymphatic invasion after endoscopic resection.

Role of endoscopic ultrasonography in TNM staging of gastric cancer

Gastric cancer is a common malignancy that has a poor prognosis and high mortality. Cancer staging is the optimal method for evaluating prognosis. Endoscopic ultrasonography (EUS) has been considered the first-choice imaging modality for regional staging of gastric cancer because different structural layers of the gastric wall show remarkable differences in their echogenic appearance. However, the results of recent studies about the accuracy of EUS for staging of gastric cancer are contradictory. The aim of this article is to review the role of EUS in preoperative TNM staging of gastric cancer.

Mixed Carcinoma as an Independent Prognostic Factor in Submucosal Invasive Gastric Carcinoma

Mixed carcinoma shows a mixture of glandular and signet ring/poorly cohesive cellular histological components and the prognostic significance of each component is not fully understood. This study aimed to investigate the significance of the poorly cohesive cellular histological component as a risk factor for lymph node metastasis and to examine the diagnostic reliability of endoscopic biopsy. Clinicopathologic characteristics of 202 patients who underwent submucosal invasive gastric carcinoma resection with lymph node dissection in 2005-2012 were reviewed. Mixed carcinoma accounted for 27.2% (56/202) of cases. The overall prevalence of lymph node metastasis was 17.3% (35/202). Lymphatic invasion (P < 0.001), family history of carcinoma (P = 0.025), tumor size (P = 0.004), Lauren classification (P = 0.042), and presence of any poorly cohesive cellular histological component (P = 0.021) positively correlated with the lymph node metastasis rate on univariate analysis. Multivariate analyses revealed lymphatic invasion, family history of any carcinoma, and the presence of any poorly cohesive cellular histological component to be significant and independent factors related to lymph node metastasis. Review of preoperative biopsy slides showed that preoperative biopsy demonstrated a sensitivity of 63.6% and a specificity of 100% in detecting the presence of the poorly cohesive cellular histological component, compared with gastrectomy specimens. The presence of any poorly cohesive cellular histological component was an independent risk factor associated with lymph node metastasis in submucosal invasive gastric carcinoma. Endoscopic biopsy had limited value in predicting the presence and proportion of the poorly cohesive cellular histologic component due to the heterogeneity of mixed carcinoma.

Risk of lymph node metastasis in mixed-type early gastric cancer determined by the extent of the poorly differentiated component

AIM: To predict the rate of lymph node (LN) metastasis in diffuse- and mixed-type early gastric cancers (EGC) for guidelines of the treatment.

METHODS: We reviewed 550 cases of EGC with diffuse- and mixed-type histology. We investigated the clinicopathological factors and histopathological components that influence the probability of LN metastasis, including sex, age, site, gross type, presence of ulceration, tumour size, depth of invasion, perineural invasion, lymphovascular invasion, and LN metastasis status. We reviewed all slides and estimated the proportions of each tumour component; pure diffuse type, mixed-predominantly diffuse type (diffuse > intestinal type), mixed-predominantly intestinal type (intestinal > diffuse type), and mixed diffuse = intestinal type. We calculated the extents of the respective components.

RESULTS: LN metastasis was observed in 12.9% (71/550) of early gastric cancers cases [15/288 mucosal EGCs (5.2%) and 56/262 submucosal EGCs (21.4%)]. Of 550 cases, 302 were diffuse-type and 248 were mixed-type EGCs. Of 248 mixed-type EGCs, 163 were mixed-predominantly diffuse type, 82 were mixed-predominantly intestinal type, and 3 were mixed diffuse = intestinal type. Mixed-type cases with predominantly diffuse type histology showed a higher frequency of LN metastasis (20.2%) than cases of pure diffuse type (9.3%) and predominantly intestinal type (12.2%) histology. We measured the dimensions of each component (intestinal and diffuse type) to determine the association of the extent of each component with LN metastasis in mixed-type gastric carcinoma. The total tumour size and the extent of poorly differentiated components was associated with LN metastasis, while that of signet ring cell components was not.

CONCLUSION: We recommend careful identification and quantitative evaluation of mixed-type early gastric cancer components after endoscopic resection to determine the intensity of the treatment.

Upgrading the definition of early gastric cancer: better staging means more appropriate treatment

Since Murakami defined early gastric cancer (EGC) as a "carcinoma limited to the gastric mucosa and/or submucosa regardless of the lymph node status", several authors have focused on the most influential histopathological parameters for predicting the development of lymph node metastases by considering the lymph node status as an important prognostic factor. A few authors have also considered the depth of invasion as one of the keys to explaining the existence of subgroups of patients affected by EGC with poor prognoses. In any case, EGC is still considered an initial phase of tumor progression with good prognosis. The introduction of modern endoscopic devices has allowed a precise diagnosis of early lesions, which can lead to improved definitions of tumors that can be radically treated with endoscopic mucosal resection or endoscopic submucosal dissection (ESD). Given the widespread use of these techniques, the Japanese Gastric Cancer Association (JGCA) identified in 2011 the standard criteria that should exclude the presence of lymph node metastases. At that time, EGCs with nodal involvement should have been asserted as no longer fitting the definition of an early tumor. Some authors have also demonstrated that the morphological growth pattern of a tumor, according to Kodama's classification, is one of the most important prognostic factors, thereby suggesting the need to report it in histopathological drafts. Notwithstanding the acquired knowledge regarding the clinical behavior of EGC, Murakami's definition is still being used. This definition needs to be upgraded according to the modern staging of the disease so that the appropriate treatment would be selected.

Magnifying narrow-band imaging endoscopy is superior in diagnosis of early gastric cancer

AIM: To evaluate the diagnostic effectiveness of white light endoscopy, magnifying endoscopy (ME), and magnifying narrow-band imaging endoscopy (ME-NBI) in detecting early gastric cancer (EGC).

METHODS: From March 2010 to June 2012, a total of 3616 patients received screening for gastric cancer by magnifying endoscopy. There were 3675 focal gastric lesions detected using conventional high definition white light endoscopy (HD-WLE) in four different referential hospitals that were recruited for further investigation using ME and ME-NBI. The images obtained from HD-WLE, ME, and ME-NBI were reviewed by four experienced endoscopists to evaluate their diagnostic effectiveness for EGC. The diagnosis of cancerous and non-cancerous lesions was conducted by evaluating the microvascular and microsurface patterns using the VS classification system. The final endoscopic diagnosis of each lesion was determined by consultation when a disagreement occurred. We used histopathological results as the gold standard for the diagnosis of EGC.

RESULTS: Among the 3675 lesions found, 1508 were validated by pathological findings as chronic gastritis, 1279 as chronic gastritis with intestinal metaplasia, 631 as low-grade neoplasia, and 257 as EGC. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of HD-WLE for the diagnosis of EGC were 71.2%, 99.1%, 85.5%, 97.9% and 97.1%, respectively. The results of ME for diagnosing EGC were 81.3%, 98.8%, 83.3%, 98.6% and 97.6%, respectively. The results of ME-NBI for the diagnosis of EGC were 87.2%, 98.6%, 82.1%, 99.0% and 97.8%, respectively. The diagnostic sensitivity and accuracy of paired ME and ME-NBI were significantly better than those of HD-WLE (P < 0.05).

CONCLUSION: HD-WLE has a relatively high accuracy for diagnosing EGC and is an effective screening tool. Further investigations of ME and ME-NBI are required to achieve superior accuracy.

Safety and efficacy of carbon dioxide insufflation during gastric endoscopic submucosal dissection

AIM: To compare the safety and efficacy of carbon dioxide (CO₂) and air insufflation during gastric endoscopic submucosal dissection (ESD).

METHODS: This study involved 116 patients who underwent gastric ESD between January and December 2009. After eliminating 29 patients who fit the exclusion criteria, 87 patients, without known pulmonary dysfunction, were randomized into the CO₂ insufflation (n = 36) or air insufflation (n = 51) groups. Standard ESD was performed with a CO₂ regulation unit (constant rate of 1.4 L/min) used for patients undergoing CO₂ insufflation. Patients received diazepam for conscious sedation and pentazocine for analgesia. Transcutaneous CO₂ tension (PtcCO₂) was recorded 15 min before, during, and after ESD with insufflation. PtcCO₂, the correlation between PtcCO₂ and procedure time, and ESD-related complications were compared between the two groups. Arterial blood gases were analyzed after ESD in the first 30 patients (12 with CO₂ and 18 with air insufflation) to assess the correlation between arterial blood CO₂ partial pressure (PaCO₂) and PtcCO₂.

RESULTS: There were no differences in respiratory functions, median sedative doses, or median procedure times between the groups. Similarly, there was no significant difference in post-ESD blood gas parameters, including PaCO₂, between the CO₂ and air groups (44.6 mmHg vs 45 mmHg). Both groups demonstrated median pH values of 7.36, and none of the patients exhibited acidemia. No significant differences were observed between the CO₂ and air groups with respect to baseline PtcCO₂ (39 mmHg vs 40 mmHg), peak PtcCO₂ during ESD (52 mmHg vs 51 mmHg), or median PtcCO₂ after ESD (50 mmHg vs 50 mmHg). There was a strong correlation between PaCO₂ and PtcCO₂ (r = 0.66; P < 0.001). The incidence of Mallory-Weiss tears was significantly lower with CO₂ insufflation than with air insufflation (0% vs 15.6%, P = 0.013). CO₂ insufflation did not cause any adverse events, such as CO₂ narcosis or gas embolisms.

CONCLUSION: CO₂ insufflation during gastric ESD results in similar blood gas levels as air insufflation, and also reduces the incidence of Mallory-Weiss tears.

Risk factors and correlations of immediate, early delayed, and late delayed bleeding associated with endoscopic resection for gastric neoplasms

BACKGROUND

Bleeding is a major complication following endoscopic resection (ER) of gastric mucosal lesions. We aimed to determine the risk factors for post-ER bleeding and their correlations according to the time elapsed since the procedure.

METHODS

We retrospectively enrolled 670 lesions in 610 patients who underwent ER between March 2009 and December 2010. We classified these lesions into three types in accordance with the bleeding time, i.e., immediate bleeding (IB), early delayed bleeding (EDB), and late delayed bleeding (LDB). We analyzed the risk factors for each bleeding type according to baseline patient characteristics, procedure-related factors, and correlations between the occurrence of each bleeding type.

RESULTS

There were 408 post-ER bleeding events in our study cohort: 302 IB events, 88 EDB events, and 18 LDB events. In multivariate analysis, a histologic finding of carcinoma and the resection time were significant predictors of IB (p < 0.001). Of the 302 IB events, 13.9% showed EDB. Additionally, LDB occurred in 2.4% of lesions with EDB and 4.6% of lesions without EDB. Similar to the IB group, of 368 lesions without IB, 12.5% showed EDB. In addition, LDB occurred in 2.2% of lesions with EDB and 1.2% of lesions without EDB. IB was associated with a higher risk of EDB (p < 0.001) and LDB (p < 0.001), whereas EDB was not related to an increased risk of LDB (p = 0.997).

CONCLUSION

IB significantly increases the risk of EDB and LDB, but EDB does not increase the risk of LDB. Histologically confirmed carcinoma or a prolonged time for resection increases the risk of post-ER IB. We recommend careful follow-up approaches following ER of a gastric mucosal lesion in high-risk patients to prevent a potentially critical occurrence of delayed bleeding.

Redefining early gastric cancer

BACKGROUND

The problem is that current definitions of early gastric cancer allow the inclusion of regional lymph node metastases. The increasing use of endoscopic submucosal dissection to treat early gastric cancer is a concern because regional lymph nodes are not addressed. The aim of the study was thus to critically evaluate current evidence with regard to tumour-specific factors associated with lymph node metastases in "early gastric cancer" to develop a more precise definition and improve clinical management.

METHODS

A systematic and comprehensive search of major reference databases (MEDLINE, EMBASE, PubMed and the Cochrane Library) was undertaken using a combination of text words "early gastric cancer", "lymph node metastasis", "factors", "endoscopy", "surgery", "lymphadenectomy" "mucosa", "submucosa", "lymphovascular invasion", "differentiated", "undifferentiated" and "ulcer". All available publications that described tumour-related factors associated with lymph node metastases in early gastric cancer were included.

RESULTS

The initial search yielded 1494 studies, of which 42 studies were included in the final analysis. Over time, the definition of early gastric cancer has broadened and the indications for endoscopic treatment have widened. The mean frequency of lymph node metastases increased on the basis of depth of infiltration (mucosa 6% vs. submucosa 28%), presence of lymphovascular invasion (absence 9% vs. presence 53%), tumour differentiation (differentiated 13% vs. undifferentiated 34%) and macroscopic type (elevated 13% vs. flat 26%) and tumour diameter (≤2 cm 8% vs. >2 cm 25%).

CONCLUSION

There is a need to re-examine the diagnosis and staging of early gastric cancer to ensure that patients with one or more identifiable risk factor for lymph node metastases are not denied appropriate chemotherapy and surgical resection.

Endoscopic resection as a first therapy for gastric epithelial atypia: is it reasonable?

BACKGROUND AND AIMS

Gastric atypical cell (GAC), an indefinite pathologic finding, often requires repeated biopsy or other diagnostic treatments, such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or operation (OP). The aim of this study was to analyze the initial endoscopic and histologic findings of GAC and to discuss the necessity of EMR/ESD at establishing a correct diagnosis.

METHODS

This retrospective study enrolled 96 patients proven as GAC on index forceps biopsy. ESD (17/96, 17.7%), EMR (5/96, 5.2%), OP (20/96, 20.8%), and other treatment or follow-up (54/96, 56.3%) were performed. We analyzed the initial endoscopic and histologic characteristics of GAC lesions, predictive of neoplasm.

RESULTS

After diagnostic modalities, the final pathologic diagnoses were cancer (36/96, 37.6%), dysplasia (9/96, 9.4%), and non-neoplasm (51/96, 53.0%). In univariate analysis, age [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07], lesion size of 10 mm or greater (OR 3.94, 95% CI 1.61-9.61), lesion with depressed type (OR 2.50, 95% CI 1.09-5.72), and presence of H. pylori (OR 2.83, 95% CI 1.11-7.25) were risk factors for neoplasm. In multivariate analysis, lesion size of 10 mm or greater (OR 3.63, 95% CI 1.23-10.66), lesion with depressed type (OR 2.86, 95% CI 1.11-7.38) were independent risk factors for cancer.

CONCLUSION

Considering the neoplastic risk of GAC, which could be missed on biopsy, more comprehensive tissue sampling via EMR/ESD might be necessary to establish a definite diagnosis.

Safety of carbon dioxide insufflation during gastric endoscopic submucosal dissection in patients with pulmonary dysfunction under conscious sedation

BACKGROUND

Carbon dioxide (CO2) insufflation is effective for gastric endoscopic submucosal dissection (ESD). However, its safety is unknown in patients with pulmonary dysfunction. This study aimed to investigate the safety of CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation.

METHODS

We analyzed 322 consecutive patients undergoing ESD using CO2 insufflation (1.4 L/min) for gastric lesions. Pulmonary dysfunction was defined as a forced expiratory volume in 1.0 s/forced vital capacity (FEV1.0%) <70% or vital capacity <80%. Transcutaneous partial pressure of CO2 (PtcCO2) was recorded before, during, and after ESD.

RESULTS

In total, 127 patients (39%) had pulmonary dysfunction. There were no significant differences in baseline PtcCO2 before ESD, peak PtcCO2 during ESD, and median PtcCO2 after ESD between the pulmonary dysfunction group and normal group. There was a significant correlation between PtcCO2 elevation from baseline and ESD procedure time (r = 0.22, P < 0.05) only in the pulmonary dysfunction group. In patients with FEV1.0% <60%, the correlation was much stronger (r = 0.39, P < 0.05). Neither the complication incidences nor the hospital stay differed between the two groups. CO2 narcosis or gas embolism was not reported in either group.

CONCLUSIONS

CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation is safe with regard to complication risk and hospital stay. However, in patients with severe obstructive lung disease, especially in those with FEV1.0% <60%, longer procedure time may induce CO2 retention, thus requiring CO2 monitoring.

Her2+ and b-HCG Producing Undifferentiated Gastric Adenocarcinoma

A 25-year-old Hispanic female with a history of anemia, schizoaffective disorder, and psychosis was admitted for anemia associated with fatigue, weakness, shortness of breath, night sweats, weight loss, and abdominal and lower back pain for the past two months. On routine management, she was found to have a positive serum b-HCG of 80.4 (0–5 mIU/mL) but the patient denied any sexual activity in her life. During her admission, U/S of the pelvis was noncontributory. CT angiogram of the chest was significant for prominent mediastinal and hilar lymph nodes, diffusely thickened stomach suggesting gastric malignancy with multiple hypoenhancing lesions in the liver and diffuse lytic lesions in the spine and sacrum suspicious for metastatic disease. The MRI of the abdomen confirmed the CT angiogram findings. After these findings, EGD was performed which showed lesions in the antrum, body of the stomach, fundus, and cardia on the lesser curvature of the stomach body correlating with carcinoma. The biopsy was positive for Her2, b-HCG producing poorly differentiated gastric adenocarcinoma. Patient underwent one successful round of chemotherapy with Taxotene, Cisplatin, and 5-FU for Stage IV gastric adenocarcinoma.

[Endolifter, a new tool for safe and rapid submucosal endoscopic dissection]

BACKGROUND

The effectiveness of endoscopic submucosal dissection (ESD) is similar to that of surgery in the treatment of early lesions. The technique requires a high level of technical skill. Training on biologic models and the mastering of accessories facilitate ESD.

AIMS

The aim was to evaluate the usefulness of the Endolifter in facilitating tissue exposure during ESD in an in vivo porcine model performed at the experimental surgery laboratory of the School of Medicine at the Universidad de São Paulo in Brazil.

MATERIAL AND METHOD

A study with an experimental design employing an in vivo porcine model was conducted on 5 Yorkshire pigs weighing 20-25kg. ESDs were performed using the Endolifter. Mucosal layer dissection was carried out with a dual knife and IT knife and all the endoscopic procedures were performed by a single expert endoscopist.

RESULTS

A total of 25 ESDs were performed, with a technical success rate of 100%. The mean dissection time was 12.34min (range: 10.40-14.50 min) and the mean lesion size was 2.7cm (range: 2.3-3.2cm). There were no episodes of bleeding or perforations during the procedures.

CONCLUSIONS

The Endolifter enables rapid and effective ESDs to be carried out. It is an applicable and easy-to-use device that can be manipulated by a single operator.

Gastric cancer staging: EUS and CT

INTRODUCTION

Gastric cancer is the fourth most common cancer and the second leading cause of death from cancer. Only complete resection of all gross disease with negative microscopic margins (R0 resection) provides a long-term survival benefit, and the overall 5-year relative survival rate is approximately 20%. To improve survival and quality of life, new therapeutic approaches have been introduced.

MATERIAL AND METHODS

A total of 277 patients (171 men, 106 women) were included in this analysis. The results from the preoperative EUS and MDCT were compared to the postoperative pathological findings. A radial scanning ultrasonic endoscope was used. In patients with early gastric cancer, especially in cases confined to mucosa, endoscopic resection is performed to avoid unnecessary surgical procedures. To achieve R0 resection for locally-advanced gastric cancer, neoadjuvant treatments have been investigated.

RESULTS AND DISCUSSION

Laparoscopic surgery has been shown to improve quality of life for both early and locally advanced gastric cancer. Endoscopic ultrasonography (EUS), which is considered to be the most precise method for locoregional staging, was commonly used for differentiating mucosal lesions from submucosal lesions. By contrast, computed tomography (CT) was used to detect the presence of distant metastasis. The difference in accuracy between the < or = 20-mm group and other groups was statistically significant for both EUS and MDCT (P = 0.026 and P = 0.044, respectively).

CONCLUSION

However, recent technological advances with the helical and multi-detector scanners have provided better CT performance.

Endoscopic treatment for early gastric cancer

Gastric cancer remains one of the most common causes of cancer death. However the proportion of early gastric cancer (EGC) at diagnosis is increasing. Endoscopic treatment for EGC is actively performed worldwide in cases meeting specific criteria. Endoscopic mucosal resection can treat EGC with comparable results to surgery for selected cases. Endoscopic submucosal dissection (ESD) increases the en bloc and complete resection rates and reduces the local recurrence rate. ESD has been performed with expanded indication and is expected to be more widely used in the treatment of EGC through the technological advances in the near future. This review will describe the techniques, indications and outcomes of endoscopic treatment for EGC.

ESD around the world: Europe

In Europe, endoscopic mucosal resection (EMR) is widely accepted as an appropriate diagnostic approach to obtain specimens for accurate histopathologic evaluation, which may change grading and local staging of early neoplasia determined by prior biopsies and imaging. In contrast to EMR, endoscopic submucosal dissection (ESD) allows resection of even large lesions in a single piece. Evidence on the clinical value of ESD is still limited and mainly based on data from Japan, and may not be directly applicable to Europe, where the outcome of ESD may be less favorable because of the limited Western expertise in this challenging technique.

Comparison of endoscopic ultrasonography and multislice spiral computed tomography for the preoperative staging of gastric cancer - results of a single institution study of 610 Chinese patients

BACKGROUND

This study compared the performance of endoscopic ultrasonography (EUS) and multislice spiral computed tomography (MSCT) in the preoperative staging of gastric cancer.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 610 patients participated in this study, all of whom had undergone surgical resection, had confirmed gastric cancer and were evaluated with EUS and MSCT. Tumor staging was evaluated using the Tumor-Node-Metastasis (TNM) staging and Japanese classification. The results from the imaging modalities were compared with the postoperative histopathological outcomes. The overall accuracies of EUS and MSCT for the T staging category were 76.7% and 78.2% (P=0.537), respectively. Stratified analysis revealed that the accuracy of EUS for T1 and T2 staging was significantly higher than that of MSCT (P<0.001 for both) and that the accuracy of MSCT in T3 and T4 staging was significantly higher than that of EUS (P<0.001 and 0.037, respectively). The overall accuracy of MSCT was 67.2% when using the 13th edition Japanese classification, and this percentage was significantly higher than the accuracy of EUS (49.3%) and MSCT (44.6%) when using the 6th edition UICC classification (P<0.001 for both values).

CONCLUSIONS/SIGNIFICANCE

Our results demonstrated that the overall accuracies of EUS and MSCT for preoperative staging were not significantly different. We suggest that a combination of EUS and MSCT is required for preoperative evaluation of TNM staging.

Endoscopic submucosal dissection of early gastric neoplastic lesions: a western series

OBJECTIVE

Endoscopic submucosal dissection (ESD) has been found to be effective and safe for endoscopic removal of early gastric neoplasia in large Asian series. However, few data are available on the use of ESD in western countries. We assessed the efficacy of ESD performed in patients with early gastric neoplastic lesions.

METHODS

We analyzed prospectively collected data of consecutive patients who underwent the ESD procedure for gastric neoplasia at a single Italian center. Procedure-related outcomes, including complete histological resection rate (i.e. R0 resection), immediate and late complication rate, procedure-related mortality, and follow-up were evaluated.

RESULTS

Forty-two patients underwent gastric ESD. The en-bloc removal of lesions was successful in all cases, whereas R0 was achieved in 39 (92.8%) patients. A bleeding episode was observed in three (7.1%) patients, which was successfully managed by endoclip positioning. No perforations and procedure-related deaths were observed. The median follow-up period was 19 months (range: 9-53). A small residue of adenomatous lesion and a recurrent dysplastic lesion were removed by endoscopic mucosal resection in two (5%) patients.

CONCLUSION

Our data are comparable with those of larger Asian series. Use of ESD for removal of gastric neoplastic lesions should be implemented in western countries.

Early gastric cancer: diagnosis, staging, and clinical impact. Evaluation of 530 patients. New elements for an updated definition and classification

BACKGROUND

The prevention and early diagnosis of gastric cancer permit clinicians to discover the tumor in the initial phase, during which time it can be completely eradicated, endoscopically or surgically. Since Murakami gave the definition of early gastric cancer (EGC) in 1971, many authors have identified various subtypes of EGC with different morphological characteristics and clinical behaviour.

METHODS

We evaluated retrospectively 530 patients: the median follow-up time was 10.4 months (range 0.3-29.2). All tumors were classified according to the macroscopic and microscopic criteria proposed by the Japanese Society of Gastroenterology and Endoscopy and Lauren, respectively. The infiltrative growth pattern was evaluated according to Kodama's classification. Only tumor-related death was considered as an endpoint of interest for the survival analysis.

RESULTS

The overall survival rates of our patients were 94 % (95 % CI, 92-96) and 90 % (95 % CI, 87-93) at 5 and 10 years, respectively. Only 44 patients (8.3 %) died of the disease. Kodama's type (p < 0.0001), lymph node status, both for number and pathological stage according to the 7th Edition of TNM (p < 0.0001), and depth of infiltration (p = 0.0006) were significant prognostic factors in univariate analysis. The multivariate analysis identified Kodama's PENA type (HR, 3.91; 95 % CI, 2.08-7.33; p < 0.0001) and lymph node status for more than three positive nodes versus negative nodes (HR, 12.78; 95 % CI, 5.37-30.43; p < 0.0001) as the only independent prognostic factors in our series.

CONCLUSION

Lymph node status, especially when more than three lymph nodes are involved, is the most important prognostic factor in EGC. However, it is also important to evaluate the infiltrative growth pattern of the cancers in their early phase according to Kodama's classification, considering PEN A type lesions to be more aggressive than the other EGC types. Then, we propose new elements for an updated definition and classification of EGC, with an important clinical impact on the treatment of patients.

Red-flag technologies in gastric neoplasia

Given its morbidity and mortality, the early detection and diagnosis of gastric cancer is an area of intense research focus. This article reviews the emerging use of enhanced endoscopic imaging technologies in the detection and management of gastric cancer. The combined use of white-light endoscopy with enhanced imaging technologies, such as magnification narrow-band imaging, chromoendoscopy, and autofluorescence endoscopy, demonstrates promise in the improved ability to detect and delineate gastric neoplasia. However, widespread clinical use is still limited, mainly because of the restricted availability of the technologies.

Missed diagnosis of early gastric cancer or high-grade intraepithelial neoplasia

AIM: To investigate the causes of missed diagnosis of early gastric cancer (EGC) or high-grade intraepithelial neoplasia (HGIN) in Chongqing, China.

METHODS: The present study summarizes 103 cases of EGC/HGIN detected by esophagogastroduodenoscopy (EGD) and pathological analysis from January 2010 to December 2011. Dimethyl silicone oil was administrated orally 15 min before the EGD procedures. The stomach was cleaned by repeated washing with saline when the gastroscope entered the stomach cavity. Suspected EGC lesions were subject to conventional biopsy sampling and pathological examinations. The correlation between lesion locations, endoscopic morphology of cancerous sites, training level of the examiners, pathological biopsies, and missed diagnosis was analyzed.

RESULTS: Twenty-three cases were missed among the 103 cases (22.23%) of EGC/HGIN. The rate of missed EGC in the gastroesophageal junction (8/19, 42.1%) was significantly higher than at other sites (15/84, 17.86%) (χ² = 5.253, P = 0.022). In contrast, the rate of missed EGC in the lower stomach body (2/14, 14.29%) was lower than at other sites (21/89, 23.6%), but there were no significant differences (χ² = 0.289, P = 0.591). The rate of missed EGC in the gastric antrum (5/33, 15.15%) was lower than at other sites (18/70, 25.71%), but there were no significant differences (χ² = 1.443, P = 0.230). Endoscopists from less prestigious hospitals were more prone to not diagnosing EGC than those from more prestigious hospitals (χ² = 4.261, P = 0.039). When the number of biopsies was < 4, the rate of missed diagnosis was higher (20/23, 89.96%) than for when there were > 4 biopsies (3/23, 13.04%) (P < 0.001). In addition, there was no significant difference in the rate of missed diagnosis in patients with 1-3 biopsy specimens (χ² = 0.141, P = 0.932).

CONCLUSION: Endoscopists should have a clear understanding of the anatomical characteristics of the esophagus/stomach, and endoscopic identification of early lesions increases with the number of biopsies.

Accurate preoperative staging of gastric cancer with combined endoscopic ultrasonography and PET-CT

Accurate staging of gastric cancer is helpful to determine the most appropriate therapy, but no staging modality has been accepted as the standard. Objective is to evaluate the usefulness of endoscopic ultrasonograph (EUS) combined with position emission tomography and computed tomograph (PET-CT) in gastric cancer staging. A total of 124 patients confirmed with gastric cancer were subjected to staging with EUS and PET-CT scanning. The detection rate of primary tumor was 99.2% by combination use of two modalities and 97.6% by EUS alone (p = 0.6219), but the detection rate was 90.3% (112 of 124) by PET-CT alone (compared with the combination, p = 0.0027; compared with EUS alone, p = 0.0299). The locoregional lymph node invasion was identified in 84/124 (67.7%) by combined PET-CT and EUS, which was obviously higher than that with EUS (52.4%) or PET-CT (43.5%) alone (p = 0.0194 and p = 0.0002, respectively). There was no statistical difference in identification of celiac axis lymph node metastasis among three methods, but the combined examination or PET-CT alone was more effective than EUS alone in the detection of distant metastases (all p < 0.01). Furthermore, the combined EUS and PET-CT was more optimal than using EUS or PET-CT alone in the accurate T and N staging and the effect on change of treatment. The present study indicates that the combination of EUS and PET-CT is an ideal modality in the preoperative staging of gastric cancer and it provides beneficial guidance for the treatment of gastric cancer.

Early gastric cancer and dysplasia

Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.

Helicobacter pylori in gastric malignancies

Helicobacter pylori infection remains common worldwide and is significantly associated with gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT)lymphoma. This article reviews recent developments in the field of H. pylori with an emphasis on mechanisms of carcinogenesis, and the bacterial, environmental and host factors that may alter risk of developing gastric cancer or gastric MALT lymphoma. The topic of eradication of H. pylori to prevent the development of malignancy and the possibility of a vaccine against H. pylori are also explored.

Endoscopic submucosal dissection of early gastric neoplasia with a water jet-assisted knife: a Western, single-center experience

BACKGROUND

Endoscopic submucosal dissection (ESD) of early gastric neoplasia has not yet been established in Western countries because of a lack of data and the difficult, time-consuming, and hazardous nature of the method. Some of the technical limitations may be overcome by use of a water jet-assisted knife, which allows a combination of a high-pressure water jet and electrosurgical interventions.

OBJECTIVE

To evaluate the efficacy and safety of water jet-assisted ESD (WESD) with a water jet-assisted knife in selected patients with early gastric neoplasia.

DESIGN

Single-center, prospective study.

PATIENTS

This study involved 29 consecutive patients (13 female; median age 61 years; age range 35-93 years) with early gastric neoplasia that met the expanded criteria of the Japanese Gastric Cancer Association. Histology of biopsies had shown gastric adenocarcinoma in 21 cases, adenoma in 8 case, and suspicion of a GI stromal tumor in 1 case. The median maximal diameter of the lesions was 20 mm (range 10-40 mm).

INTERVENTION

All procedures were done with patients under sedation with propofol. The water jet-assisted knife was used for setting coagulation markers around the neoplastic lesions, then for circumferential incision and dissection in combination with repeated submucosal injection of saline solution with a water jet system. Bleeding was treated with diathermia by use of the water jet-assisted knife or hemostatic forceps in case of failure or larger vessels. Clips were used for closure of perforations.

MAIN OUTCOME MEASUREMENTS

Complete resection of neoplasia, procedure time, complication and recurrence rates.

RESULTS

According to endoscopic criteria, complete resection of the targeted area could be achieved in all cases, with an en bloc resection rate of 90%. The median procedure duration was 74 minutes (range 15-402 minutes). Exchange of the device was needed in only 10 cases because of severe bleeding from larger vessels, which could be managed by use of hemostatic forceps. The 30-day morbidity rate was 4 of 30 (13.8%) because of postprocedure pain in 3 cases and delayed bleeding in 1 case. A 93-year-old patient died the night after WESD without evidence of a procedure-related complication. Histology of the resected specimens showed adenocarcinoma in 20 cases, adenoma in 7, no neoplasia in 2, and a plasmacytoma in 1. Complete resection (R0) was histologically confirmed in 18 of 28 patients (64.3%) with resected neoplastic specimens. A horizontal or vertical neoplasia-free margin could not be confirmed in 9 cases and 1 case, respectively. Complete local remission of neoplasia was achieved in 25 of 28 patients (89.3%) who were followed over a median period of 22 months (range 6-44 months). In 1 patient, a metachronous gastric adenocarcinoma was identified 54 weeks after initial WESD.

LIMITATIONS

Noncontrolled study with a limited number of patients.

CONCLUSION

The use of a water jet-assisted knife simplifies ESD because exchange of devices is rarely needed. WESD promises to be effective and safe. The study demonstrates that the high rates of en bloc resection of early gastric neoplasia reported in Asia can be reproduced in Western referral centers. However, histology may not always confirm complete resection of horizontal tumor margins. In spite of the unfavorable histology results, the high rate of complete local remission of neoplasia promises that surgical treatment of early gastric neoplasia can be avoided in the majority of cases.

Endoscopic mucosal resection, endoscopic submucosal dissection, and beyond: full-layer resection for gastric cancer with nonexposure technique (CLEAN-NET)

Mucosal cancer in the gastrointestinal tract generally has low risk of lymph node metastasis. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are techniques of local excision of neoplasia confined to the mucosal layer. Specimens from EMR/ESD contribute to several diagnoses, and histologic results affect treatment decisions. A combined laparoscopic and endoscopic approach to neoplasia with a nonexposure technique allows full-thickness resection of the stomach wall without exposing the gastric lumen to the peritoneal cavity, preventing cancer cell dissemination to the peritoneal cavity. This article reviews EMR/ESD and describes a new full-thickness resection method using the nonexposure technique (CLEAN-NET).

Endoscopic treatment of large colorectal tumors: comparison of endoscopic mucosal resection, endoscopic mucosal resection-precutting, and endoscopic submucosal dissection

BACKGROUND

Endoscopic mucosal resection (EMR) is a useful therapeutic technique for colorectal tumors. However, for tumors larger than 20 mm, the chance of piecemeal resection is high. Recently introduced endoscopic submucosal dissection (ESD) enables en bloc resection regardless of the tumor size. This study aimed to compare the effectiveness and outcomes of EMR, EMR-precutting (EMR-P), and ESD in the treatment of colorectal tumors 20 mm in size or larger.

METHODS

This study reviewed 523 nonpedunculated colorectal tumors (499 patients) 20 mm or larger that received endoscopic treatment (EMR in 140 cases, EMR-P in 69 cases, and ESD in 314 cases) from January 2004 to November 2009.

RESULTS

The mean sizes of the tumors were 21.7 ± 3.5 mm (EMR), 23.5 ± 5.6 mm (EMR-P), and 28.9 ± 12.7 mm (ESD). The ratios of adenocarcinomas were 15.7% (EMR), 29% (EMR-P), and 37.9% (ESD). The en bloc resection rates were 42.9% (EMR), 65.2% (EMR-P), and 92.7% (ESD), and the complete resection rates were 32.9% (EMR), 59.4% (EMR-P), and 87.6% (ESD). Perforation occurred in 2.9% of the EMR-P cases and 8% of the ESD cases. The recurrence rates were 25.9% (EMR; median follow-up period, 26 months), 3.2% (EMR-P; median follow-up period, 16 months), and 0.8% (ESD; median follow-up period, 17 months).

CONCLUSION

For the treatment of large, nonpedunculated colorectal tumors, ESD is more effective than either EMR or EMR-P. Although ESD is technically demanding, it has clinical significance by overcoming the limitations of both EMR and EMR-P.

The feasibility and safety of the endoscopic submucosal dissection of superficial gastric neoplastic lesions in patients with compensated liver cirrhosis: a retrospective study

Background/Aims

When undergoing endoscopic submucosal dissection (ESD), patients with liver cirrhosis (LC) may suffer from a high risk of bleeding, bacteremia and tissue vulnerability. There have been few reports evaluating the efficacy and safety of ESD in patients with LC.

Methods

From January 2004 to March 2010, 23 patients with LC (cirrhosis group) underwent ESD for superficial gastric neoplastic lesions. The number of patients with a liver function in the Child-Pugh classes A and B were 20 and 3, respectively. The clinical outcomes and complications were compared with 69 patients without LC (control group) that were matched for age and sex.

Results

The en bloc resection, R0 resection and en bloc plus R0 resection rates of the cirrhosis group were 82.6%, 91.3%, and 82.6%, respectively, and did not show significant differences from the rates of the control group. No local recurrence was found in either group during the follow-up period. The procedure length of time (41.0 vs 39.0 minutes), rate of bleeding (4.3% vs 7.2%) and rate of perforation (0.0% vs 1.4%) in the cirrhosis group were also comparable to the results from the control group.

Conclusions

ESD was safely performed in patients with LC, and satisfactory outcomes were achieved with high en bloc and R0 resection rates for superficial gastric neoplastic lesions.

Advances in treatment of early gastric cancer by endoscopic submucosal dissection

As a result of the emergence and application of magnifying chromoendoscopy, narrow band imaging, confocal laser endoscopy and the enhancement of the awareness of malignant tumors, more and more people have been diagnosed with gastric cancer at early stages. The postoperative five-year survival rate for early gastric cancer (EGC) can reach as high as 90%. Since the emergence of endoscopic submucosal dissection (ESD), its advantage in the treatment of EGC has become more and more evident due to definite therapeutic effect, less physical trauma, high safety, excellent patient compliance, and low therapeutic cost. This paper focuses on the clinical application of ESD in the management of EGC.