Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer

A case of gastric pseudoaneurysm following endoscopic submucosal dissection of early gastric cancer

A woman in her 80s underwent endoscopic submucosal dissection (ESD) for a 20-mm-sized early gastric cancer lesion in the posterior wall of the upper gastric body. The lesion was resected en bloc with no adverse events. However, bleeding was observed in a post-ESD mucosal defect the day after ESD, so endoscopic hemostasis was performed. Moreover, hematemesis occurred 4 days after ESD, when the bleeding site showed a sign of pulsatile aneurysm. Therefore, endoscopic hemostasis was considered difficult, and angiographic treatment was chosen. Since angiography revealed a pseudoaneurysm in a portion of a branch of the left gastric artery, embolization with microcoils was performed. Thereafter, no bleeding occurred. To the best of our knowledge, there is no case report about the formation of a pseudoaneurysm in a post-gastric ESD mucosal defect. Thus, this case is being reported to document valuable information.

Switching from endoscopic submucosal dissection to salvage piecemeal knife-assisted snare resection to remove a lesion: A preoperative risk score from the beginning

BACKGROUND AND AIMS

endoscopic submucosal dissection (ESD) in the Western setting remains a challenge. Therefore, other simplified techniques such as knife-assisted snare resection (KAR) have been reported to overcome this issue.

METHODS

patients who underwent an ESD for the treatment of gastrointestinal neoplasms were included in a retrospective cross-sectional observational study. Factors associated with the end of ESD as a salvage p-KAR were identified and a logistic regression model was developed.

RESULTS

a total of 136 lesions in 133 patients were analyzed. Operator experience of under 50 cases and the combination of lesion size > 30 mm and colorectal location were independent predictive factors for switching to a salvage p-KAR according to the multivariate logistic regression analysis. We developed a risk scoring system based on these four variables (experience, size, location and the combination of size and location) with a receiver operating characteristic curve of 0.81 (95% CI: 0.74-0.89). The diagnostic accuracy of the score for a cut-off point ≥ 5 had a sensitivity of 0.79 (95% CI: 0.66-0.93) and a specificity of 0.71 (95% CI: 0.61-0.80).

CONCLUSION

a simple predictive score system that includes four preoperative factors accurately predicts ESD to finish as a p-KAR. A careful selection of cases considering these variables could be useful to achieve better outcomes in the Western setting.

Helicobacter pylori Infection following Endoscopic Resection of Early Gastric Cancer

The role of Helicobacter pylori (H. pylori) infection in patients following endoscopic resection of early gastric cancer (EGC) remains unclear. This article presents a review of literature published in the past 15 years. H. pylori-mediated persistent methylation levels are associated with the development of metachronous gastric cancer. The methylation of certain specific genes can be used to identify patients with a high risk of metachronous gastric cancer even after H. pylori eradication. H. pylori eradication after endoscopic resection should be performed as early as possible for eradication success and prevention of metachronous precancerous lesions. Although whether the eradication of H. pylori could prevent the development of metachronous cancer after endoscopic resection is controversial, several meta-analyses concluded that H. pylori eradication could reduce the incidence of metachronous gastric cancer significantly. In addition, H. pylori eradication in gastric cancer survivors after endoscopic resection could reduce healthcare cost and save lives in a cost-effective way. Taken together, H. pylori eradication after endoscopic resection of EGC is recommended as prevention for metachronous precancerous lesions and metachronous gastric cancer.

Gastric endoscopic submucosal dissection: a systematic review and meta-analysis on risk factors for poor short-term outcomes

OBJECTIVE

Endoscopic submucosal dissection (ESD) is now established as the first option to manage early gastric neoplasms, but its efficacy may vary according to diverse factors. We aimed to systematically identify risk factors for poor short-term outcomes of gastric ESD with the purpose to improve patients' selection and management.

METHODS

Three online databases (MEDLINE, ISI Web of Knowledge and Scopus) were searched (last search on June 2018) for poor outcomes of gastric ESD (deep submucosal invasion, piecemeal/incomplete resection, noncurative resection and local recurrence).

RESULTS

One hundred five studies were included referring to 52.126 ESDs. Undifferentiated histology and upper location (vs lower) were associated with submucosal invasion [odds ratio (OR) = 2.42 [95% confidence interval (CI), 1.62-3.61] and OR = 3.20 (1.04-9.86), respectively] and deep submucosal invasion [OR = 2.98 (2.02-4.39) and OR = 2.35 (1.45-3.81), respectively]. Lesion size greater than 30 mm and ulceration were associated with piecemeal resection [OR = 2.78 (1.17-6.60) and OR = 2.76 (1.23, 6.20), respectively]. Lesion size greater than 30 mm, ulceration, upper location and fibrosis were risk factors for incomplete resection [OR = 3.83 (2.68-5.49), OR = 4.06 (1.62-10.16), OR = 3.71 (2.49-5.54) and OR = 4.46 (1.66-11.96), respectively]. A noncurative resection was more often observed for lesions located in the upper third of the stomach [OR = 1.49 (1.24-1.79)], depressed morphology [OR = 1.49 (1.04-2.12)] and those outside standard criteria [OR = 3.56 (2.31-5.48)]. Older age was significantly linked with local recurrence rates [OR = 3.08 (1.13-5.02)].

CONCLUSION

Several risk factors influence poor efficacy short-term outcomes of gastric ESD that may be used to inform both patients and health providers about the expected efficacy.

Endoscopic or Surgical Resection for Gastro-Esophageal Cancer

BACKGROUND

Early gastro-esophageal cancer is staged as m1 to m3 depending on the infiltration of the anatomical layers of the mucosa or, analogously, as sm1 to sm3 depending on the depth of infiltration into the submucosa. The risk of lymph node metastases is low in mucosal carcinoma but increases with the depth of infiltration into the submucosa.

METHODS

This review is based on pertinent publications retrieved by a selective search in MEDLINE, PubMed, the Cochrane Library, and the International Standard Randomised Controlled Trial Number (ISRCTN) registry.

RESULTS

New technologies such as narrow-band imaging have improved the endo- scopic diagnosis and staging of early gastro-esophageal cancer. The development of endoscopic submucosal dissection has led to a higher R0 resection rate, a lower risk of recurrence, and an increase in the number of endoscopic resections that are performed with curative intent. In squamous-cell carcinoma of the esophagus, surgical oncological esophagectomy is indicated if the cancer infiltrates into the third mucosal layer (T1a, m3) or deeper. In esophageal adenocarcinoma, the prevalence of lymph node metastases is low if the cancer is restricted to the mucosa and in- creases only when the submucosa is infiltrated. In the current German S3 guideline, endoscopic resection is recommended for intramucosal adenocarcinoma as long as there are no further histopathological risk factors. Lymph node metastasis in gastric carcinoma begins in the deep mucosal infiltration stage (m3). If certain special con- ditions ("extended criteria") are met, carcinoma expanding into the first submucosal layer (sm1) can be removed endoscopically. All further stages must be treated with total or subtotal gastrectomy with systematic D2 lymphadenectomy.

CONCLUSION

Borderline cases between endoscopic and surgical resection of early carcinoma of the esophagus or stomach must be managed with an interdisciplinary treatment algorithm. If there is a risk of lymph node metastasis, surgical oncological resection is indicated. Such resections of gastroesophageal cancer in the locally advanced stage should always be part of a multimodal treatment approach.

Feasibility of endoscopic treatment and predictors of lymph node metastasis in early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) has been routinely performed in applicable early gastric cancer (EGC) patients as an alternative to conventional surgical operations that involve lymph node dissection. The indications for ESD have been recently expanded to include larger, ulcerated, and undifferentiated mucosal lesions, and differentiated lesions with slight submucosal invasion. The risk of lymph node metastasis (LNM) is the most important consideration when deciding on a treatment strategy for EGC. Despite the advantages over surgical procedures, lymph nodes cannot be removed by ESD. In addition, whether patients who meet the expanded indications for ESD can be managed safely remains controversial.

AIM

To determine whether the ESD indications are applicable to Chinese patients and to investigate the predictors of LNM in EGC.

METHODS

We retrospectively analyzed 12552 patients who underwent surgery for gastric cancer between June 2007 and December 2018 at the Affiliated Hospital of Qingdao University. A total of 1262 (10.1%) EGC patients were eligible for inclusion in this study. Data on the patients’ clinical, endoscopic, and histopathological characteristics were collected. The absolute and expanded indications for ESD were validated by regrouping the enrolled patients and determining the positive LNM results in each subgroup. Predictors of LNM in patients were evaluated by univariate and multivariate analyses.

RESULTS

LNM was observed in 182 (14.4%) patients. No LNM was detected in the patients who met the absolute indications (0/90). LNM occurred in 4/311 (1.3%) patients who met the expanded indications. According to univariate analysis, LNM was significantly associated with positive tumor marker status, medium (20-30 mm) and large (>30 mm) lesion sizes, excavated macroscopic-type tumors, ulcer presence, submucosal invasion (SM1 and SM2), poor differentiation, lymphovascular invasion (LVI), perineural invasion, and diffuse and mixed Lauren’s types. Multivariate analysis demonstrated SM1 invasion (odds ration [OR] = 2.285, P = 0.03), SM2 invasion (OR = 3.230, P < 0.001), LVI (OR = 15.702, P < 0.001), mucinous adenocarcinoma (OR = 2.823, P = 0.015), and large lesion size (OR = 1.900, P = 0.006) to be independent risk factors.

CONCLUSION

The absolute indications for ESD are reasonable, and the feasibility of expanding the indications for ESD requires further investigation. The predictors of LNM include invasion depth, LVI, mucinous adenocarcinoma, and lesion size.

Clinicopathologic Characteristics of Patients with Gastric Superficial Neoplasia and Risk Factors for Multiple Lesions after Endoscopic Submucosal Dissection in a Western Country

Background

Endoscopic submucosal dissection (ESD) is a treatment for early gastric neoplasms that preserves the stomach. However, the risk of multiple lesions persists.

Objectives

To assess clinicopathologic characteristics of patients with early gastric neoplasms in a Western country and evaluate risk factors for multiple gastric lesions, synchronous, or metachronous.

Methods

A retrospective cohort of 230 consecutive patients who underwent ESD for primary neoplasms from 2012 to 2017 (median follow-up: 33 months) was assessed to determine the clinicopathologic characteristics and risk factors for multiple lesions.

Results

The mean age was 68 years, and 53.9% were male. Current/former smoking status was present in 40.4%, and 29.5% had family history of gastric cancer. A third of the patients had only focal gastric atrophy/metaplasia (operative link on gastritis assessment/operative link on gastric intestinal metaplasia assessment [OLGA/OLGIM] I/II; endoscopic grading of gastric intestinal metaplasia [EGGIM] 1-4). Synchronous and me-tachronous lesions occurred in 14.3 and 8.6% of patients, respectively. There was a trend for higher risk of multiple lesions in smokers and patients with extensive metaplasia (EGGIM >4), but only older age was an independent risk factor (OR 3.30; 95% CI 1.05-10.34). Age >60 years (OR 10.10, 95% CI 1.40-88.04), current/former smoking status (OR 3.64, 95% CI 1.07-12.40), and OLGIM III/IV (OR 3.07, 95% CI 1.01-9.36) were independent risk factors for synchronous lesions. No risk factors for metachronous lesions were found.

Conclusions

Surveillance limited to patients with advanced stages of gastritis may miss some primary superficial neoplasms. Although older age increases the risk of multiple lesions, no risk factors were found for metachronous lesions. Therefore, endoscopic surveillance after ESD should be done equally in all patients.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Clinicopathologic parameters associated with the FDG-avidity in staging of early gastric cancer using 18F-FDG PET

This study investigated the clinicopathologic factors associated with 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) uptake of early gastric cancer (EGC) and used them to design a clinical scoring method to predict FDG-avidity of EGC.Two hundred twenty-nine retrospectively enrolled patients underwent preoperative F-FDG positron emission tomography/computed tomography (PET/CT). Histologic information was obtained by gastrectomy (n = 195) or endoscopic mucosal dissection (n = 34). The association between clinicopathologic factors and F-FDG uptake by the primary tumor was determined. The results were used to develop a clinical scoring method.F-FDG uptake was detected in 49 (17.5%) patients. According to univariate analysis, location, gross type, World Health Organization classification, Lauren classification, size, depth of invasion, and lymphatic invasion were significant variables affecting F-FDG uptake (all P < .05). According to multivariate analysis, location (lower 3rd, P = .035), gross type (0-I, 0-IIa, P < .001), size (≥2.5 cm, P = .026), and depth of invasion (submucosa, P = .007) were significantly associated with FDG-avidity. A clinical scoring system, ranged from 0 to 4, was developed by giving one score to 4 independent variables. A cut-off value of 2.5 showed good prediction of FDG-avidity in EGCs, with a sensitivity and specificity of 65.0% and 85.2%, respectively.F-FDG uptake by EGC depends on location, gross type, size, and depth of invasion of the primary tumor. A clinical scoring system based on clinicopathologic variables can predict the FDG-avidity of primary tumors in patients with EGC.

Low Frequency of Lymph Node Metastases in Patients in the United States With Early-stage Gastric Cancers That Fulfill Japanese Endoscopic Resection Criteria

BACKGROUND & AIMS

In the West, early gastric cancer is increasingly managed with endoscopic resection (ER). This is, however, based on the assumption that the low prevalence and risk of lymph node metastases observed in Asian patients is applicable to patients in the United States. We sought to evaluate the frequency of and factors associated with metastasis of early gastric cancers to lymph nodes, and whether the Japanese ER criteria are applicable to patients in the US.

METHODS

We performed a retrospective study of 176 patients (mean age 68.5 years; 59.1% male; 58.5% white) who underwent surgical resection with lymph node dissection of T1 and Tis gastric adenocarcinomas, staged by pathologists, at 7 tertiary care centers in the US from January 1, 1999, through December 31, 2016. The frequency of lymph node metastases and associated risk factors were determined.

RESULTS

The mean size of gastric adenocarcinomas was 23.0 ± 16.6 mm-most were located in the lower-third of the stomach (67.0%), invading the submucosa (55.1%), and moderately differentiated (31.3%). Lymphovascular invasion was observed in 18.2% of lesions. Overall, 20.5% of patients had lymph node metastases. Submucosal invasion (odds ratio, 3.9; 95% CI, 1.4-10.7) and lymphovascular invasion (odds ratio, 4.6; 95% CI, 1.8-12.0) were independently associated with increased risk of metastasis to lymph nodes. The frequency of lymph node metastases among patients fulfilling standard and expanded Japanese criteria for ER were 0 and 7.5%, respectively.

CONCLUSIONS

The frequency of lymph node metastases among patients with early gastric cancer in a US population is higher than that of published Asian series. However, early gastric cancer lesions that meet the Japanese standard criteria for ER are associated with negligible risk of metastasis to lymph nodes, so ER can be recommended for definitive therapy. Expanded criteria cancers appear to have a higher risk of metastasis to lymph nodes, so ER may be considered for select cases.

Is Additional Surgery Always Sufficient for Preventing Recurrence After Endoscopic Submucosal Dissection with Curability C-2 for Early Gastric Cancer?

BACKGROUND

When a lesion does not meet the curative criteria of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), referred to as non-curative resection or curability C-2 in the guidelines, an additional surgery is the standard therapy because of the risk of lymph node metastasis (LNM).

OBJECTIVE

This study aimed to identify high-risk patients for recurrence after additional surgery for curability C-2 ESD of EGC.

METHODS

This multicenter retrospective cohort study enrolled 1064 patients who underwent additional surgery after curability C-2 ESD for EGC. We evaluated the recurrence rate and the risk factors for recurrence after additional surgery in these patients.

RESULTS

The 5-year recurrence rate after additional surgery was 1.3%. Multivariate Cox analysis revealed that the independent risk factors for recurrence after additional surgery were LNM (hazard ratio [HR] 32.47; p < 0.001) and vascular invasion (HR 4.75; p = 0.014). Moreover, patients with both LNM and vascular invasion had a high rate of recurrence after additional surgery (24.6% in 5 years), with a high HR (119.32) compared with those with neither LNM nor vascular invasion. Among patients with no vascular invasion, a high rate of recurrence was observed in those with N2/N3 disease according to the American Joint Committee on Cancer TNM staging system (27.3% in 5 years), in contrast with no recurrence in those with N1 disease.

CONCLUSIONS

Patients with both LNM (N1-N3) and vascular invasion, as well as those with N2/N3 disease but no vascular invasion, would be candidates for adjuvant chemotherapy after additional surgery for curability C-2 ESD of EGC.

Oncologic Safety of Endoscopic Resection Based on Lymph Node Metastasis in Ulcerative Early Gastric Cancer

Background: There is little evidence regarding appropriate therapeutic modalities for ulcerative-type early gastric cancer (EGC) because the risks and implications of lymph node metastasis are unclear. The indication for endoscopic submucosal dissection (ESD) was investigated for ulcerative-type EGC. Methods: We retrospectively analyzed 192 patients with differentiated ulcerative-type EGC who underwent radical gastrectomy with D2 lymph node dissection. Lymph node metastasis (LNM) risk factors were evaluated using multivariate logistic regression. Results: The LNM rate was 15.1% overall, 0% for mucosa-confined lesions, and 28.2% for submucosa-infiltrating lesions. On multivariate analysis, only lymphovascular invasion (P < .001) was significantly associated with LNM. Among patients with minute submucosal invasion and no lymphovascular invasion, LNM was only observed for tumor sizes ≥2.1 cm. Conclusions: Because LNM risks are negligible, curative ESD could be considered in patients with ulcerative EGC that is confined to the mucosa and histologically differentiated, irrespective of tumor size. In addition, ESD can be attempted for ulcerative EGC with minute submucosal invasion and tumor size <2.1 cm.

Effect of double-layer structure in intramucosal gastric signet-ring cell carcinoma on lymph node metastasis: a retrospective, single-center study

BACKGROUND

Among all types of gastric cancer (GC), signet-ring cell carcinoma (sig-GC) accounts for 4-17% of cases. The prognosis of early sig-GC is relatively good, with the 5-year survival rate at 99.7%. However, the correlation between histological features and lymph node metastasis (LNM) among pT1a (M) sig-GC remains unclear. Sig-GC often exhibits a double-layer structure (DLS) in the intramucosal layer, demonstrating functional differentiation into the normal gastric gland. Assumedly, the loss of the differentiation makes the DLS deranged, accounting for the occurrence of submucosal invasion and LNM. This study aimed to assess the proportion of DLS, to elucidate the correlation between histological features (including DLS) and LNM status, and to determine the LNM-negative condition in pT1a (M) sig-GC.

METHODS

We reviewed the pathological data of 310 patients with 310 intramucosal sig-GCs who received gastrectomy with lymph node dissection. Immunohistochemistry was performed on all specimens to evaluate the presence of DLS. Furthermore, we review the clinicopathological features, including tumor size, lymphovascular invasion (LVI), ulceration (UL), and DLS results, and then statistically analyze the correlation between these features and LNM status.

RESULTS

Overall, 129 pT1a (M) sig-GCs (42%) were DLS present. The univariate analysis revealed that "Tumor size > 20 mm", "UL present", and "DLS absent" were significant risk factors of LNM. The multivariate logistic regression analysis revealed only "DLS absent" as statistically significant.

CONCLUSIONS

"DLS absent" is a risk factor of LNM detected by the multivariate analysis. In pT1a (M), LVI absent, UL absent, tumor size > 20 mm, sig-GC, no LNM occurred in "DLS present" cases.

Comparable rates of lymph node metastasis and survival between diffuse type and intestinal type early gastric cancer patients: a large population-based study

BACKGROUND AND AIMS

Limited evidence and contradictory results exist regarding the impact of Lauren type, namely diffuse and intestinal types, of lymph node metastasis (LNM) and prognosis for early gastric cancer (EGC). We aimed to compare LNM and prognosis between diffuse and intestinal type EGCs using comprehensive statistical analysis.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all patients with surgically resected, histologically diagnosed, intestinal or diffuse type EGC. Multivariate logistic regression, multivariate Cox regression, multivariate competing risk model, and propensity score matching were used to analyze association the Lauren type and LNM or prognosis.

RESULTS

We identified 5593 EGCs from the SEER database, including 4376 intestinal types and 1217 diffuse types. No positive association was found between LNM and Lauren type (odds ratio, .93; 95% confidence interval [CI], .70-1.24; P = .62) after adjustment for other risk factors. Moreover, diffuse-type EGCs showed a similar prognosis to intestinal type EGCs in both multivariate Cox regression (HR [hazard ratio], .95; 95% CI, .77-1.18; P = .66) and the multivariate competing risk model (subdistribution HR [SHR], .99; 95% CI, .80-1.22; P = .926). Propensity score matching was used, and 733 diffuse types were matched with 733 intestinal types. We did not find any association between the Lauren type and LNM (odds ratio, .98; 95% CI, .71-1.37; P = .934) or prognosis in the univariate Cox regression (HR, .98; 95% CI, .76-1.26; P = .893) and univariate competing risk model (SHR, .98; 95% CI, .76-1.26; P = .893).

CONCLUSIONS

Diffuse-type EGC may have a comparable risk of LNM and prognosis to intestinal-type EGC. Nevertheless, these results should be carefully interpreted with caution when choosing endoscopic resection instead of surgery, because the treatment choice for EGC depends on the risk of lymphovascular invasion rather than LNM rate or prognosis.

Long-term outcomes and prognostic factors with non-curative endoscopic submucosal dissection for gastric cancer in elderly patients aged ≥ 75 years

BACKGROUND

Little is known about the long-term outcomes and prognostic factors with non-curative endoscopic submucosal dissection (ESD) in elderly patients with early gastric cancer.

METHODS

Clinicopathological findings and long-term outcomes were evaluated in 87 patients with early gastric cancer (EGC) aged ≥ 75 years who were treated with non-curative ESD. Prognostic factors for overall survival (OS) were analyzed with the Kaplan-Meier method and a Cox proportional hazards model.

RESULTS

During the follow-up period, among 27 patients who died of any cause, only one patient died of gastric cancer. OS probabilities after 3 and 5 years were 89.7% and 79.3%, respectively. Univariate analyses revealed that Eastern Cooperative Oncology Group performance status 2-3, Charlson comorbidity index (CCI) ≥ 3, neutrophil/lymphocyte ratio ≥ 3.3, prognostic nutritional index < 44.8, distal tumor location and macroscopically depressed or flat configuration were associated with poor OS. Cox multivariate analysis revealed high CCI (≥ 3) to be an independent prognostic factor associated with OS (hazard ratio: 2.63, 95% confidence interval [CI] 1.06-6.49, P = 0.037).

CONCLUSIONS

CCI may be a useful parameter for decision-making regarding additional surgery for elderly patients with gastric cancer treated by non-curative ESD.

Characterization of irreversible electroporation on the stomach: A feasibility study in rats

Irreversible electroporation (IRE) is a newly developed non-thermal ablative therapy. During the IRE procedure, the permeability of the cell membrane is irreversibly changed by application of high-energy pulses across the tissue. This induces the breakdown of cell homeostasis, and thereby cell death. Here, we present an in vivo study to demonstrate IRE ablation of gastric tissue and characterize the changes that occur with time therein. No significant complications were observed in the test rats during the experiment. The electroporated tissues exhibited apoptosis at 10, 24 and 48 h after IRE ablation. The apoptosis peaked at 10 h after IRE and then declined, suggesting that the ablated tissue rapidly recovered owing to intense metabolic activity. In addition, the electroporated tissues exhibited morphological changes such as pyknosis and karyorrhexis, while histological analysis showed that the blood vessels were preserved. Interestingly, electroporation greatly affected the mucosa and muscularis propria, but not the submucosa and serosa. This study suggests that IRE could potentially be used as a minimally invasive treatment for early gastric cancer that does not exhibit lymph node metastasis or dysplasia.

A pilot study to assess the safety and usefulness of combined transurethral endoscopic mucosal resection and en-bloc resection for non-muscle invasive bladder cancer

Background

Transurethral resection (TUR) is the standard operation used for non-muscle invasive bladder cancer (NMIBC). Although most solid tumors are principally removed via single block resection without incising the mass, disruption of the lesion is unavoidable in traditional TUR. Furthermore, pathological diagnosis is often difficult due to heat-related denaturation of tissues in TUR. Although transurethral en-bloc resection is useful for judging tumor invasion, it is associated with a prolonged operative duration. We attempted to show the safety and usefulness of combined endoscopic mucosal resection (EMR) and en-bloc resection in NMIBC patients.

Methods

We investigated 39 patients with clinical NMIBC who were treated using our original EMR + en-bloc resection technique, which involved removal of the tumor mass that protruded from the mucosa, using a polypectomy snare similar to that used for EMR. The residual lesion was removed using en-bloc resection. The operative period, duration of hospitalization, and recurrence rates were compared with those of conventional TUR (n = 31).

Results

The mean (standard deviation, range) time interval for EMR and total operative duration were 1.6 (1.1, 1–5) min and 18.3 (10.5, 3–48) min, respectively. The total operative duration was comparable to that of TUR (17.3 min, p = 0.691). The mean duration of catheterization in the EMR + en-bloc resection group (4.2 days) was also similar to that in the TUR group (3.7 days; p = 0.285). No severe complications were observed with EMR + en-bloc resection. The pathologists were able to determine tumor invasiveness with considerable certainty in all specimens obtained via the EMR + en-bloc procedure than via TUR, and the difference in the ease of diagnosis was statistically significant (p = 0.016). Recurrence rates were comparable (p = 0.662) between the EMR + en-bloc (15.4%) and TUR groups (19.4%).

Conclusions

Our results demonstrated that the EMR + en-bloc resection technique is feasible, safe, and useful for treating patients with NMIBC. Furthermore, this technique helps provide a more accurate pathological diagnosis.

Clinical outcomes of endoscopic submucosal dissection for lesions on the proximal location between remnant and entire stomach

BACKGROUND

Tumors located on the proximal stomach are associated with a longer procedure time and lower en-block resection of endoscopic submucosal dissection (ESD). Additionally, it is more difficult to perform ESD for lesions after distal gastrectomy because of the narrow inner space. We aimed to evaluate the therapeutic outcomes of ESD for lesions on the remnant stomach compared with those on the upper third of the entire stomach.

METHODS

A total of 135 patients with a neoplasm located on the proximal stomach who received ESD between Aug 2008 and Dec 2016 were enrolled. We retrospectively reviewed en-bloc resection rate, complete resection rate, and complication rate according to whether distal gastrectomy was performed. Clinical outcomes were compared among the 1:2 propensity-matched groups.

RESULTS

Between the remnant stomach and entire stomach, the en-bloc [92% (23/25) and 92.0% (46/50), respectively; P = 1.000] and complete resection [84% (21/25) and 88.0 (44/50), respectively; P = 0.723] rates were not significantly different. In patients with lesions that indicated ESD, there was no significant difference in en-bloc and complete resection rates. In a multivariable analysis, submucosal fibrosis [odds ratio (OR) 5.9, 95% confidence interval (CI) 1.1-30.7] and submucosa invasive cancer (OR 10.1, 95% CI 1.4-74.3) were independent risk factors for incomplete resection.

CONCLUSIONS

ESD is a feasible therapeutic option for lesions located on the proximal stomach regardless the operation history of distal gastrectomy. However, the complete resection rate decreases for lesions with submucosal fibrosis or the submucosa invasion.

Multimodality management of locally advanced gastric cancer-the timing and extent of surgery

The optimal treatment for patients with locally advanced gastric adenocarcinoma is multimodal. Surgery is the cornerstone of therapeutic strategies with curative intent. The addition of chemotherapy or chemoradiation decreases rate of recurrence and prolongs survival. Guidelines differ between countries and there is no universal standard of care. Modern studies of patients with locally advanced gastric cancer showed that adjuvant chemotherapy improves survival over surgery alone in Asia. These studies could not be replicated in Europe. Peri-operative chemotherapy strategies, conversely, have been effective in Europe for improving overall and disease free survival. Adjuvant chemoradiation has also demonstrated improved survival when compared to surgery alone, but studies comparing chemotherapy with chemoradiation have not shown significant difference. Trials are ongoing to examine the role of chemoradiation in a neoadjuvant fashion. A D2 extent of lymphadenectomy improves cancer related survival for those who do not undergo distal pancreatectomy/splenectomy. Survival is also associated not only with the extent but also the number of lymph nodes examined. There are ongoing trials related to immunotherapy and targeted therapies, which may also impact or change the treatment paradigm for locally advanced gastric cancer.

Effect of Tailored Perigastric Lymph Node Dissection on Gastric Motility in a Canine Model

BACKGROUND

Combination laparoscopic lymph node (LN) dissection and endoscopic resection is a promising treatment for early gastric cancer. However, LN dissection could cause nerve injury and deterioration of motility in the preserved stomach. This experimental study aims to evaluate changes in gastric motility after tailored perigastric regional lymph node dissection without gastrectomy.

MATERIALS AND METHODS

We identified four most frequently involved LN combinations considering tumor location from retrospective reviews of 4697 gastrectomy patients. We randomly assigned 55 dogs to five groups: control (laparotomy only) and four experimental groups with LN dissection without gastrectomy: group 1 (LNs 3, 7, and 8), group 2 (LNs 3, 4, and 6), group 3 (LNs 1, 3, and 7), and group 4 (LNs 3, 4, and 11). Gastric emptying time (GET) was measured using barium-impregnated polyethylene spheres. GET₅₀ and GET₇₅ were the time points when 50% and 75% of the markers, respectively, had emptied from the stomach.

RESULTS

On postoperative days (PODs) 2 and 3, GET_50, GET_75, and proportion of GET₅₀ <4 h in groups 1 and 2 were comparable with controls. However, group 3 showed delayed GET₅₀ and GET₇₅, and groups 3 and 4 demonstrated significantly smaller proportions of GET₅₀ <4 h compared with controls on PODs 2 and 3. This effect resolved by POD 6 and there were no significant differences in GET_50, GET_75, or proportion of GET₅₀ <4 h between the groups.

CONCLUSIONS

Tailored perigastric LN resection without gastrectomy was feasible and acceptable in terms of postoperative motility in the preserved stomach.

Clinicopathological Characteristics and Prognosis of cT1N0M1 Gastric Cancer: A Population-Based Study

Background

Distant metastasis of early gastric cancer is a rare subgroup and poorly understood. The present study is aimed at summarizing the clinicopathological characteristics, prognosis, and management of clinical T1N0M1 (cT1N0M1) gastric cancer.

Method

Between 2004 and 2015, patients diagnosed with cT1N0M1 gastric cancer were retrospectively analyzed using the Surveillance, Epidemiology, and End Results (SEER) database.

Results

A total of 1093 cT1N0M1 gastric cancer patients were identified. 49 patients (4.5%) received cancer-directed surgery, and 113 patients (10.4%) were managed with radiotherapy. Compared with the other stage IV diseases, a relatively high proportion of black population (19.9% vs. 15.8%), patients older than 60 years (63.1% vs. 57.8%), and adenocarcinoma (59.5% vs. 55.9%) were observed in the cT1N0M1 gastric cancer subgroup. Besides that, patients with cT1N0M1 had the characteristics of less poor differentiated or undifferentiated (54.3% vs. 61.7%). Patients with cT1N0M1 had worse cancer-specific survival (CSS) and overall survival (OS) as compared to the other metastatic gastric cancer patients (CSS: p = 0.002, OS: p = 0.001 for log-rank test). Intriguingly, patients with cT1N0M1 had poor prognosis as compared to patients with cT1N+M1 (CSS: p = 0.015, OS: p = 0.007 for log-rank test). The 3-year and 5-year CSS for patients with cT1N0M1 were 5.7% and 4.0%, respectively. The addition of surgery resulted in improved CSS (p < 0.001 for log-rank test) while radiotherapy was not associated with CSS (p = 0.756 for log-rank test) in patients with cT1N0M1. A multivariate Cox analysis showed that surgery (HR = 0.378, 95% CI: 0.255-0.562) and patients younger than 60 (HR = 0.745, 95% CI: 0.647-0.858) years were independent protective factors for these subgroup patients.

Conclusion

Patients with cT1N0M1 gastric cancer had distinctive clinicopathological characteristics and presented poor prognosis. Knowledge of these differences contributes to guiding clinical evaluation for metastatic gastric cancer patients. More aggressive therapeutic strategy should be highlighted for this subgroup.

Update on the Diagnosis and Management of Gastric Intestinal Metaplasia in the USA

Gastric intestinal metaplasia (GIM) is a premalignant condition that can lead to intestinal-type gastric adenocarcinoma. It is characterized by a change in the gastric mucosa to a small-intestinal phenotype. Infection with Helicobacter pylori is the most common factor associated with GIM. Although GIM is typically a histologic diagnosis, various techniques have been developed to enable the endoscopic identification of GIM. There are presently no widely accepted guidelines on screening and surveillance strategies in patients with GIM in the USA. The aim of this review is to provide an update regarding the problem, diagnosis, and management of GIM in the USA.

Endoscopic management of patients with early gastric cancer before and after endoscopic resection: A review

With the wide application of endoscopic resection for early gastric cancer (EGC) by not only Asian endoscopists but also those from Western countries, reviews on standardized treatment processes before and after endoscopic resection are nevertheless lacking. In this article we provide a narrative review of studies on the selection of appropriate EGC for endoscopic resection and the follow-up strategies for those with histologically confirmed EGC after endoscopic resection. EGC should be comprehensively assessed before endoscopic resection, including its exact margin, invasive depth and risk of lymph node metastasis (LNM). While the curative resection status of EGC may be evaluated after endoscopic resection based on the newly developed eCura system, although this needs to be further verified. Surveillance with endoscopy and computed tomography scan is necessary for patients with an EGC level A or B. An additional endoscopic resection is recommended for patients with a level-C1 EGC. For patients with a level-C2 EGC, close follow-up is suggested for low-risk tumors of level C2 and additional surgery for those at high risks. Further postoperative strategy is suggested based on comprehensive assessment of the risk of LNM, patient's quality of life and wishes.

Different risk factors between early and late cancer recurrences in patients without additional surgery after noncurative endoscopic submucosal dissection for early gastric cancer

BACKGROUND AND AIMS

Cancer recurrence is observed in some patients without additional radical surgery after endoscopic submucosal dissection (ESD) that does not fulfill the curability criteria for early gastric cancer (EGC), categorized as "noncurative resection" or "curability C-2" in the guidelines. However, time to cancer recurrence is different in such patients. Thus, we aimed to identify the risk factors of early and late cancer recurrences in these patients.

METHODS

Between 2000 and 2011, this multicenter study analyzed 905 patients who were followed up without additional radical surgery after ESD for EGC categorized as curability C-2. We evaluated the risk factors for early and late cancer recurrences, separately, after ESD. The cut-off value was defined at 2 years.

RESULTS

Time to cancer recurrence in the enrolled patients showed a bimodal pattern, and the 5-year cancer recurrence rate was 3.2%. Multivariate Cox analyses revealed that lymphatic invasion (hazard ratio [HR], 8.56; P = .003) was the sole independent risk factor for early cancer recurrence. Regarding late cancer recurrence, vascular invasion (HR, 4.50; P = .039) was an independent risk factor, and lymphatic invasion tended to be a risk factor (HR, 3.63; P = .069).

CONCLUSIONS

This multicenter study with a large cohort demonstrated that lymphatic invasion is mainly associated with early cancer recurrence; however, vascular invasion was a risk factor only for late recurrence in patients without additional treatment after ESD for EGC categorized as curability C-2. This finding may contribute to decision making for treatment strategies after ESD, especially for patients with a relatively short life expectancy.

Topographic mapping of a specimen after endoscopic submucosal dissection

Background and study aims  Mapping of pathologic specimens after endoscopic submucosal dissection (ESD) is common practice in Asian countries, especially in Japan. However, there is a lack of awareness for this technique in Europe. In this report, we demonstrate the feasibility and benefits of topographic mapping in a Western setting.

Implementation of endoscopic submucosal dissection for early upper gastrointestinal tract cancer after primary experience in colorectal endoscopic submucosal dissection

Background  Current guidelines recommend endoscopic submucosal dissection (ESD) as a treatment option for early cancers of the upper gastrointestinal tract with absent or minimal risk of lymph node metastasis. However, due to the low prevalence of these entities, it is difficult to achieve a competence level for ESD of upper gastrointestinal tract cancers in the Western World. Here, we present single-center data on the implementation of upper gastrointestinal ESD after previous experience with 89 colorectal ESD cases. Methods  Retrospective case series of 39 consecutive patients with early cancers of the esophagus (n = 13) or cardia and stomach (n = 26) treated with ESD over a 4-year period. Results  ESD was technically feasible in all cases with en bloc, R0, and curative resection rates of 100 %, 76.9 %, and 71.8 %, respectively, and a mean procedure time of 100 minutes (30 - 360 minutes). After an initial 20 procedures, the R0 and curative resection rates increased from 65.0 % to 89.5 %, and from 60.0 % to 84.2 %, respectively. Complications were observed in four patients (10.3 %): three perforations, one case of delayed bleeding, and one esophageal stricture. No case required emergency surgery; the 30-day mortality rate was 0 %. Conclusion  In this modest case series from Europe, we observed an effectiveness and complication rate for ESD for early esophageal and gastric cancer that are comparable to other series from Europe but also to more abundant data from Asia. The results indicate that even small numbers of upper gastrointestinal cancers can be managed adequately in centers with expertise in colorectal ESD.

Management of adverse events related to endoscopic resection of upper gastrointestinal neoplasms: Review of the literature and recommendations from experts

Prevention therapy is recommended for lesions >1/2 of the esophageal circumference. Locoregional steroid injection is recommended for lesions >1/2-3/4 of the esophageal circumference and oral steroids are recommended for lesions >1/2 of the subtotal circumference. For lesions of the entire circumference, oral steroid combined with injection steroid is considered. Endoscopic balloon dilatation (EBD) is the first choice of treatment for stricture after esophageal endoscopic submucosal dissection (ESD). Radical incision and cutting or self-expandable metallic stent can be considered for refractory stricture after EBD. In case of intraoperative perforation during esophageal ESD, endoscopic clip closure should be initially attempted. Surgery is considered for treatment of delayed perforation. Current standard practice for prevention of delayed bleeding after gastric ESD includes prophylactic coagulation of vessels on post-ESD ulcers and giving proton pump inhibitors. Chronic kidney disease stage 4 or 5, multiple antithrombotic drug use, anticoagulant use, and heparin bridging therapy are high-risk factors for delayed bleeding after gastric ESD. Intraoperative perforation during gastric ESD is initially managed by endoscopic clip closure. If endoscopic clip closure is difficult, other methods such as over-the-scope clip (OTSC), polyglycolic acid (PGA) sheet shielding etc. are attempted. Delayed perforation usually requires surgical intervention, but endoscopic closure by OTSC or PGA sheet may be considered. Resection of three-quarters of the circumference is a risk factor for stenosis after gastric ESD. Giving prophylactic local steroid injection and/or oral steroid is reported, but effectiveness has not been fully verified as has been done for esophageal stricture. The main management method for gastric stenosis is EBD but it may cause perforation.

Application of convolutional neural network in the diagnosis of the invasion depth of gastric cancer based on conventional endoscopy

BACKGROUND AND AIMS

According to guidelines, endoscopic resection should only be performed for patients whose early gastric cancer invasion depth is within the mucosa or submucosa of the stomach regardless of lymph node involvement. The accurate prediction of invasion depth based on endoscopic images is crucial for screening patients for endoscopic resection. We constructed a convolutional neural network computer-aided detection (CNN-CAD) system based on endoscopic images to determine invasion depth and screen patients for endoscopic resection.

METHODS

Endoscopic images of gastric cancer tumors were obtained from the Endoscopy Center of Zhongshan Hospital. An artificial intelligence-based CNN-CAD system was developed through transfer learning leveraging a state-of-the-art pretrained CNN architecture, ResNet50. A total of 790 images served as a development dataset and another 203 images as a test dataset. We used the CNN-CAD system to determine the invasion depth of gastric cancer and evaluated the system's classification accuracy by calculating its sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

The area under the receiver operating characteristic curve for the CNN-CAD system was .94 (95% confidence interval [CI], .90-.97). At a threshold value of .5, sensitivity was 76.47%, and specificity 95.56%. Overall accuracy was 89.16%. Positive and negative predictive values were 89.66% and 88.97%, respectively. The CNN-CAD system achieved significantly higher accuracy (by 17.25%; 95% CI, 11.63-22.59) and specificity (by 32.21%; 95% CI, 26.78-37.44) than human endoscopists.

CONCLUSIONS

We constructed a CNN-CAD system to determine the invasion depth of gastric cancer with high accuracy and specificity. This system distinguished early gastric cancer from deeper submucosal invasion and minimized overestimation of invasion depth, which could reduce unnecessary gastrectomy.

Impact of gastric endoscopic submucosal dissection in elderly patients: The latest single center large cohort study with a review of the literature

With the increase in the elderly population, we are witnessing an increase in the rate of patients with underlying diseases and those under treatment with antithrombotic drugs.In this study, we compared the treatment outcomes of endoscopic submucosal dissection (ESD) and other parameters in the following 3 groups: super-elderly, elderly, and nonelderly.Compared with the other groups, the super-elderly group showed a significantly higher incidence of underlying diseases and the rate of antithrombotic treatment (P < .05). However, we observed no significant difference in the rate of curative resection or incidence of complications among the 3 groups. ESD is a relatively safe technique when performed on super-elderly patients. However, we have identified some cases in the super-elderly group, for which ESD was selected as a minimally invasive treatment for lesions that did not meet the inclusion criteria for open surgery as well as for which follow-up observations were selected rather than additional surgery for noncurative resections.Further investigations concerning ESD are required, focusing on aspects such as indications, additional surgery, and informed consent of the patient or family, particularly when ESD is performed for super-elderly patients.

Exploring the possibility of endoscopic submucosal dissection for clinical submucosal invasive early gastric cancers

BACKGROUND

The current standard treatment modality for clinical submucosal invasive (cT1b) early gastric cancer (EGC) is surgery. However, there are discrepancies in T staging between pre- and post-operative findings, and in cases of overestimation, patients may lose the opportunity to preserve the stomach. The aim of this study was to analyze surgical outcomes of cT1b EGC and determine the pre-treatment factors favoring ESD.

METHODS

Patients who underwent gastrectomy for cT1b EGC with a tumor size of 30 mm or less in diameter and differentiated-type histology were retrospectively reviewed from January 2010 to December 2014. According to the final surgical pathologic results, two groups were classified: patients whose pathologic results qualified for current ESD indication (ESD-qualified group, n = 203) and patients whose pathologic results made them ineligible for ESD (ESD-disqualified group, n = 261). The preoperative clinical characteristics were compared.

RESULTS

Forty-three percent of the patients (203/464) who underwent gastrectomy for cT1b EGC qualified for ESD; their endoscopic lesion tended to be smaller than 20 mm in size and located in the distal part of stomach. In addition, the ESD-qualified group showed a significantly higher proportion of well-differentiated tubular adenocarcinoma on endoscopic biopsy and of the flat/depressed type in the endoscopic evaluation.

CONCLUSION

Forty-three percent of the patients with cT1b EGC who underwent gastrectomy had a chance to preserve their stomach by ESD. Therefore, pre-treatment factors such as endoscopic lesion size, location, histology, and gross type should be considered for treatment modality selection for cT1b EGC.

Endoscopic Indication of Endoscopic Submucosal Dissection for Early Gastric Cancer Is Not Compatible with Pathologic Criteria in Clinical Practice

BACKGROUND

The inappropriate selection of patients with early gastric cancer (EGC) for endoscopic submucosal dissection (ESD) may lead to additional surgery because of a non-curative resection. This study was performed to assess the accuracy of clinical decisions in ESD for EGC.

METHODS

A total of 607 cases of EGC treated by ESD were prospectively enrolled from January 2011 to June 2014 at a single academic hospital. The 607 EGCs were divided into three groups (overestimated, same-estimated, and underestimated) based on pre-procedure endoscopic findings (indication) and pathological diagnosis after ESD (criteria). We evaluated the discrepancy rates between pre-procedure indication and pathological criteria, and then analyzed the pre-procedure factors that could influence the occurrence of the discrepancies.

RESULTS

The absolute, expanded, and beyond the expanded indication has its accuracy on curability criteria in 87%, 77.6%, and 55.6% of cases, respectively. The ratio of overall indication-criteria discrepancies was 250/607 (41.2%). The curability was significantly lower in the underestimated group compared to the overestimated and same-estimated groups (41.6% vs. 94.6%, 94.4%, p < 0.001). In multivariate analysis examining the predictive factors for discrepancies in the 598 EGCs with absolute/expanded indications, the endoscopic size ≥ 20 mm [odds ratio (OR) 2.493, confidence interval (CI) 1.546-4.022, p < 0.001], presence of ulcers (OR 1.712, CI 1.070-2.738, p = 0.025), patient age < 60 years (OR 1.689, CI 1.044-2.733, p = 0.033), and undifferentiated type EGC on forceps biopsy (OR 5.397, CI 2.027-14.369, p = 0.001) were all associated with discrepancies.

CONCLUSIONS

Indication judged by pre-procedural endoscopy is not sufficiently accurate to be used as a good measurement for post-procedural criteria.

Multicenter prospective study on the histological diagnosis of gastric cancer by narrow band imaging-magnified endoscopy with and without acetic acid

Background and study aims  The usefulness of endoscopy for diagnosing histological type remains unclear. This study aimed to examine the diagnostic accuracy of white light endoscopy (WLE), magnified endoscopy with narrow band imaging (NBI-ME), and NBI-ME with acetic acid enhancement (NBI-AA) for histological type of gastric cancer. Patients and methods  Patients with depressed-type gastric cancers resected by endoscopic submucosal dissection were prospectively enrolled, and 221 cases were analyzed. Histological type was diagnosed by WLE, followed by NBI-ME and NBI-AA. Histological type was classified into differentiated adenocarcinoma and undifferentiated adenocarcinoma. Histological type was diagnosed based on lesion color in WLE, surface patterns (pit, villi, and unclear) and vascular irregularities in NBI-ME, and surface patterns in NBI-AA. Results  Histological types of target areas were differentiated adenocarcinoma and undifferentiated adenocarcinoma in 206 and 15 cases, respectively. Diagnostic accuracy of WLE, NBI-ME, and NBI-AA for the histological type was 96.4 % (213/221), 96.8 % (214/221), and 95.5 % (211/221), respectively. No significant differences were observed among modalities. Positive predictive value based on endoscopic findings in NBI-ME was 98.0 % (149/152) for the villi pattern, 100 % (19/19) for the irregular pit pattern, 100 % (9/9) for the unclear surface pattern with a vascular network, 90.3 % (28/31) for the unclear surface pattern with mild vascular irregularity, and 88.9 % (8/9) for the unclear surface pattern with severe vascular irregularity. Conclusions  NBI-ME and NBI-AA did not show any advantages over WLE for diagnostic accuracy. Villi pattern, irregular pit pattern, and vascular network may be useful for identifying differentiated adenocarcinoma.

The Role of an Undifferentiated Component in Submucosal Invasion and Submucosal Invasion Depth After Endoscopic Submucosal Dissection for Early Gastric Cancer

BACKGROUND/AIMS

The role of an undifferentiated component in submucosal invasion and submucosal invasion depth (SID) for lymph node metastasis (LNM) of early gastric cancer (EGC) with deep submucosal invasion (SID ≥500 μm from the muscularis mucosa) after endoscopic submucosal dissection (ESD) has not been fully understood. This study aimed to clarify the risk factors (RFs), including these factors, for LNM in such patients.

METHODS

We enrolled 513 patients who underwent radical surgery after ESD for EGC with deep submucosal invasion. We evaluated RFs for LNM, including an undifferentiated component in submucosal invasion and the SID, which was subdivided into 500-999, 1,000-1,499, 1,500-1,999, and ≥2,000 µm.

RESULTS

LNM was detected in 7.6% of patients. Multivariate analysis revealed that an undifferentiated component in submucosal invasion (OR 2.22), in addition to tumor size >30 mm (OR 2.51) and lymphatic invasion (OR 3.07), were the independent RFs for LNM. However, the SID was not significantly associated with LNM.

CONCLUSION

An undifferentiated component in submucosal invasion was one of the RFs for LNM, in contrast to SID, in patients who underwent ESD for EGC with deep submucosal invasion. This insight would be helpful in managing such patients.

Pitfalls in the Interpretation of Publications about Endoscopic Submucosal Dissection of Early Gastric Cancer with Undifferentiated-Type Histology

Endoscopic submucosal dissection (ESD) is a standard treatment for patients with gastrointestinal neoplasms with a negligible risk of lymph node metastasis. ESD enables en bloc resection of gastrointestinal neoplasms and organ preservation, thereby, avoiding surgical treatment. Although small (<2 cm) intramucosal early gastric cancer with undifferentiated-type histology (EGC-UH) without ulceration is included in the expanded criteria for ESD, controversies remain due to different biology and characteristics compared to EGC with differentiated-type histology. The authors previously presented studies about the technical feasibility of ESD for these lesions using a meta-analysis and retrospective multicenter analysis. However, many pitfalls were identified in the interpretation of studies analyzing histologic discrepancy, mixed-type histology, criteria-based analysis of therapeutic outcomes, interpretation of curative resection, and long-term clinical outcomes. In this review, the authors discuss pitfalls in the interpretation of publications on ESD for EGC-UH.

Endoscopic foregut surgery and interventions: The future is now. The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic, the content will progress as follows: "lessons learned", "technical considerations" and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years. Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver, pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease (GERD), achalasia, esophageal diverticula, Barrett's esophagus (BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors. For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy (POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique (Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection (ESD) which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies (radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy. Importantly, in regard to early gastric cancer and submucosal tumors (SMTs) of the stomach, ESD and full thickness resection (FTR) can excise these lesions en-bloc and endoscopic suturing is now used to close large defects and perforations. For treatment of patients with malignant gastric outlet obstruction (GOO), endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty (ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound (EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

Risk factors for lymph node metastasis in non-sentinel node basins in early gastric cancer: sentinel node concept

BACKGROUND

Sentinel node (SN) concept is being applied to early gastric cancer. However, when SNs are positive for metastasis, it is unclear how often LNs in other LN basins show metastasis. We aimed to investigate LN metastasis possibility in LN basins without SNs (non-SN basins). We determined risk factors for metastasis in non-SN basins and identified a prediction model for non-SN basin metastasis using classification and regression tree (CART) analysis.

METHODS

We enrolled 550 patients who were diagnosed with cT1N0M0 or cT2N0M0 gastric cancer with a single lesion and underwent SN mapping. We adopted a dual-tracer method using a radioactive colloid and blue dye to detect SNs.

RESULTS

Of all, 45 (8.2%) patients had SN metastasis; we divided them into two groups: LN metastasis positive and LN metastasis negative in non-SN basins. Univariate analysis showed that the groups differed significantly regarding lymphatic invasion (p = 0.007), number of identified SNs (p = 0.032), and macrometastasis in SN basins (p = 0.005). The CART decision tree for predicting LN metastasis in non-SN basins had area under the curve value of 0.86. Moreover, there were significantly differences in cancer-specific survival (CSS) between the two groups (p = 0.028).

CONCLUSIONS

Macrometastasis in SN basins, lymphatic invasion, and number of identified SNs ≥ 5 are risk factors for LN metastasis in non-SN basins among gastric cancer patients. We identified a prediction model with CART analysis; patients with macrometastasis in SN basins and lymphatic invasion were considered to be at the highest risk for LN metastasis.

The search, coagulation, and clipping (SCC) method prevents delayed bleeding after gastric endoscopic submucosal dissection

BACKGROUND

Delayed bleeding is an important complication after gastric endoscopic submucosal dissection (ESD). The search, coagulation, and clipping (SCC) method can be used to prevent delayed bleeding after ESD. However, its safety and efficacy are unclear. We compared the SCC method with post-ESD coagulation (PEC) to clarify the safety and efficacy of the SCC method for preventing delayed bleeding after gastric ESD.

METHODS

This retrospective study included 438 patients (478 lesions) who underwent gastric ESD. Multivariate logistic regression analysis was performed to identify the significant independent factors associated with delayed bleeding and we performed propensity-score matching (PSM) to reduce the effect of procedure-selection bias of SCC method.

RESULTS

Of the 438 patients, 216 underwent PEC and 222 underwent SCC. Delayed bleeding was significantly less common in the SCC than in the PEC (2.6% vs. 7.2%; P = 0.013). Among patients treated with antithrombotic therapy, the delayed bleeding rate was lower in the SCC group than in the PEC group; however, the difference was not significant (P = 0.15). The SCC method was found to be a significant independent factor for the prevention of delayed bleeding. PSM was performed in 156 patients in the PEC group and SCC group. There was a significant difference in the incidence of bleeding in the PEC and SCC groups (P = 0.013). No patient had perforation/bleeding associated with the SCC method.

CONCLUSIONS

Our findings suggest that the SCC method is a simple, safe, and effective approach for preventing delayed bleeding after gastric ESD.

Over-the-scope clip system: A review of 1517 cases over 9 years

Rescue therapy for gastrointestinal (GI) refractory bleeding, perforation, and fistula has traditionally required surgical interventions owing to the limited performance of conventional endoscopic instruments and techniques. An innovative clipping system, the over-the-scope clip (OTSC), may play an important role in rescue therapy. This innovative device is proposed as the final option in endoscopic treatment. The device presents several advantages including having a powerful sewing force for closure of GI defects using a simple mechanism and also having an innovative feature, whereby a large defect and fistula can be sealed using accessory forceps. Consequently, it is able to provide outstanding clinical effects for rescue therapy. This review clarifies the current status and limitations of OTSC according to different indications of GI refractory disease, including refractory bleeding, perforation, fistula, and anastomotic dehiscence. An extensive literature search identified studies reported 10 or more cases in which the OTSC system was applied. A total of 1517 cases described in 30 articles between 2010 and 2018 were retrieved. The clinical success rates and complications were calculated overall and for each indication. The average clinical success rate was 78% (n = 1517) overall, 85% for bleeding (n = 559), 85% (n = 351) for perforation, 52% (n = 388) for fistula, 66% (n = 97) for anastomotic dehiscence, and 95% (n = 122) for other conditions, respectively. The overall and severe OTSC-associated complications were 1.7% (n = 23) and 0.59% (n = 9), respectively. This review concludes that the OTSC system may serve as a safe and productive device for GI refractory diseases, albeit with limited success for fistula.