A non-randomized confirmatory trial of an expanded indication for endoscopic submucosal dissection for intestinal-type gastric cancer (cT1a): the Japan Clinical Oncology Group study (JCOG0607)

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

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

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

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

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

Objectives

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

Methods

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

Results

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

Conclusions

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

The safety and feasibility of endoscopic submucosal dissection using a flexible three-dimensional endoscope for early gastric cancer and superficial esophageal cancer: A prospective observational study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is performed as one of standard treatments for patients with early gastric cancer (EGC) and superficial esophageal squamous cancer (SESCC). A prototype of a flexible endoscope with a 3-D system has been recently developed. This study aimed to investigate the safety and feasibility of ESD using a 3-D flexible endoscope (3-D ESD) for EGC and SESCC.

METHODS

This single-center, prospective, observational study enrolled patients who underwent planned 3-D ESD. The clinical outcomes, including the incidence of adverse events and treatment results, were analyzed. Visibility and manipulation during 3-D ESD were evaluated using a visual analog scale (VAS). We also evaluated the effect of the 3-D system on the endoscopist using VAS and the critical flicker fusion frequency (CFFF).

RESULTS

We analyzed 47 EGC and 20 SESCC cases. There are no bleeding cases that required transfusion and perforation during 3-D ESD in both EGC and SESCC patients. However, the incidence of delayed bleeding and delayed perforation was 1.5% (one case) each. The mean VAS scores for recognizing the submucosal layer during the submucosal dissection, visual perception of blood vessel, and depth perception were 72.7 ± 22.2, 74.7 ± 21.8, and 78.2 ± 19.9, respectively. In contrast, the mean VAS score for manipulation was 25.4 ± 19.7. Among endoscopists, there was no significant difference in the VAS of eyestrain and headache before and after ESD, and there was no significant difference in the CFFF.

CONCLUSION

The safety and feasibility of 3-D ESD for EGC and SESCC are acceptable in both patients and endoscopists.

Second gastric cancer after curative endoscopic resection of differentiated-type early gastric cancer: post-hoc analysis of a single-arm confirmatory trial

BACKGROUND AND AIMS

Endoscopic resection (ER) for early gastric cancer (EGC) can preserve the stomach; however, the remaining stomach can develop second gastric cancer. Few reports have prospectively investigated the incidence and treatment outcomes of second gastric cancer.

METHODS

This post-hoc analysis used the dataset of the single-arm confirmatory trial, JCOG0607. The key inclusion criteria for JCOG0607 were solitary differentiated-type EGC and no previous gastrectomy or endoscopic treatment for EGC. Three hundred seventeen patients who underwent curative ER were included in this study. Surveillance endoscopy was performed 1 to 3 months after the initial ER and subsequently annually for at least 5 years. A lesion detected ≤1 year and >1 year after the initial ER was defined as overlooked gastric cancer (OGC) and metachronous gastric cancer (MGC), respectively.

RESULTS

During a median follow-up period of 6.0 years (interquartile range, 5.1-7.0), 30 OGCs and 61 MGCs were detected in 24 and 48 patients, respectively. The cumulative incidence of OGC at 1 year and MGC at 5 years was 7.6% and 12.7%, respectively. ER and gastrectomy were performed in 85 lesions and 6 lesions, respectively. Pathologic evaluation showed 78 mucosal cancers, 12 submucosal cancers, and 1 advanced cancer. Eventually, 28 OGCs and 52 MGCs fulfilled the pathologic criteria for curative ER.

CONCLUSIONS

Our study was the first to reveal the actual incidence of second gastric cancer after curative ER for differentiated-type gastric cancer. Most lesions could be treated with ER. Continuous endoscopic surveillance after curative ER is important to detect second gastric cancer.

Pretreatment risk factors for endoscopic noncurative resection of gastric cancers with undifferentiated-type components

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is recommended for the treatment of early gastric cancers with an undifferentiated-type component, clinically diagnosed as intramucosal lesions ≤ 2 cm, without ulceration. In the JCOG1009/1010 trial, ESD could be performed with stomach preservation in 70% of such patients whose pathological findings met the curative resection criteria. However, additional gastrectomy was required for the remaining 30%. We identified the pretreatment risk factors for noncurative resection.

METHODS

Post-hoc analysis indicated that 336 patients were identified in the JCOG1009/1010 trial; among them, 243 and 93 patients were categorized into the curative or noncurative resection groups, respectively, based on the pathological findings of the resected specimens. We explored the pretreatment risk factors for noncurative resection and investigated their associated pathological findings.

RESULTS

Multivariable analysis revealed that a pretreatment tumor size > 1 cm was an independent risk factor for noncurative resection (odds ratio, 3.538; 95% confidence interval, 2.020-6.198, P < 0.0001). Patients with a pretreatment tumor size > 1 cm (n = 172) had a histological tumor size > 2 cm (22.1% vs 4.3%, odds ratio, 6.313; 95% confidence interval, 2.73-14.599, P < 0.0001) and submucosal invasion (17.4% vs 9.1%, odds ratio, 2.000; 95% confidence interval, 1.032-3.877, P = 0.040) more frequently as noncurative resection findings compared with those with a tumor size < 1 cm (n = 164).

CONCLUSIONS

Because pretreatment tumor size > 1 cm is an independent risk factor for noncurative resection, endoscopists should be aware that noncurative resection is not uncommon in ESD and fully explain the potential necessity for additional gastrectomy to patients before the procedure.

Comparable long-term outcomes after endoscopic therapy and gastrectomy of early adenocarcinoma of esophagogastric junction: a population-based study

BACKGROUND AND AIMS

Current guidelines recommend consideration of endoscopic therapy (ET) when treating selected early gastric cancers. However, clinical decision-making on ET versus gastrectomy for early adenocarcinoma of esophagogastric junction (AEGJ) remains challenging because of uncertain long-term outcomes.

METHODS

We performed a retrospective cohort study using the Surveillance, Epidemiology, and End Results database from 2004 to 2017 of early AEGJ patients underwent ET or gastrectomy. Multivariate models were used to compare cancer-specific survival (CSS).

RESULTS

Of 881 included early AEGJ patients, 227 (36.2%) patients underwent ET and 654 (63.8%) patients underwent gastrectomy. Early AEGJ patients who underwent ET experienced a similar hazard of cancer-specific death compared with those underwent gastrectomy in both multivariate Cox regression (HR [hazard ratio], 0.93; 95% CI [confidence interval], 0.55-1.56; P = 0.78) and the multivariate competing risk model (subdistribution HR [SHR], 0.86; 95% CI 0.50-1.45; P = 0.56). Propensity score matching was used, 210 patients underwent ET were matched with 210 patients underwent gastrectomy. Patients underwent ET experienced a similar hazard of cancer-specific death compared with those underwent gastrectomy in both multivariate Cox regression (HR, 0.97; 95% CI 0.53-1.77; P = 0.92) and the multivariate competing risk model (SHR, 0.96; 95% CI 0.52-1.77; P = 0.89).

CONCLUSION

Early AEGJ patients who received ET or gastrectomy had comparable long-term outcomes, which lend support to the role of ET in the treatment of these patients.

Management of elderly patients with early gastric cancer in Japan

Management of elderly patients with early gastric cancer is an important issue in an aging society such as Japan. While endoscopic resection is recommended as the standard treatment for early gastric cancers with extremely low risk of lymph node metastasis (<1%), gastrectomy with lymphadenectomy is recommended for the other early gastric cancers as the standard treatment even in elderly patients. Endoscopic submucosal dissection is the most recommended endoscopic resection procedure because of its high ability for 'en bloc' resection. Endoscopic submucosal dissection can reportedly provide favorable short-term outcomes in elderly patients. In terms of patient prognosis, the importance of considering patients' physical and nutritional conditions before endoscopic submucosal dissection has recently attracted attention. With respect to gastrectomy, the nationwide data in Japan have demonstrated relatively low 5-year overall survival and non-negligible post-operative 90-day mortality in men aged ≥75 years and women aged ≥80 years compared with those in younger patients. Among these elderly patients, 20% or more reportedly died within 5 years after gastrectomy mostly due to other diseases. These facts suggested the necessity of a less invasive management option for the elderly patients. Efforts are being made to provide a non-invasive follow-up option without gastrectomy following endoscopic resection in elderly patients. To avoid the increase in gastric cancer-related deaths, the selection of patients with relatively low lymph node metastasis risk is essential, and several tools to estimate the lymph node metastasis risk from early gastric cancers have been developed. To avoid overtreatment with gastrectomy in more elderly early gastric cancer patients, new endoscopic submucosal dissection indications for them are also warranted.

Clinical efficacy and prognostic risk factors of endoscopic radiofrequency ablation for gastric low-grade intraepithelial neoplasia

BACKGROUND

The use of radiofrequency ablation (RFA) has been reported in the treatment of gastric low-grade intraepithelial neoplasia (LGIN). However, its efficacy and prognostic risk factors have not been well analyzed.

AIM

To explore the efficacy and prognostic risk factors of RFA for gastric LGIN in a large, long-term follow-up clinical study.

METHODS

The clinical data of 271 consecutive cases from 198 patients who received RFA for treatment of gastric LGIN at the Chinese PLA General Hospital from October 2014 to October 2020 were reviewed in this retrospective study. Data on operative parameters, complications, and follow-up outcomes including curative rates were recorded and analyzed.

RESULTS

The curative rates of endoscopic RFA for gastric LGIN at 3 mo, 6 mo, and 1-5 years after the operation were 93.3%, 92.8%, 91.5%, 90.3%, 88.5%, 85.7%, and 83.3%, respectively. Multivariate analyses revealed that Helicobacter pylori (H. pylori) infection and disease duration > 1 year had a significant effect on the curative rate (P < 0.001 and P = 0.013, respectively). None of patients had bleeding, perforation, infection, or other serious complications after RFA, and the main discomfort was postoperative abdominal pain.

CONCLUSION

RFA was safe and effective for gastric LGIN during long-term follow-up. H. pylori infection and disease course > 1 year may be the main risk factors for relapse of LGIN after RFA.

Incidence and risk factors for postoperative pancreatic fistula in 2089 patients treated by radical gastrectomy: A prospective multicenter cohort study in China

OBJECTIVE

To determine the incidence of clinically relevant postoperative pancreatic fistula (CR-POPF) following radical gastrectomy and to identify independent risk factors of CR-POPF.

BACKGROUND

CR-POPF and its sequelae are potential complications following radical gastrectomy. The reported incidence of CR-POPF was quite different across various regions, and no consensus was reached.

METHODS

Between December 2017 to November 2018, patients who underwent radical gastrectomy from 22 centers across 13 regions in China were prospectively recruited. The primary endpoint was the occurrence of CR-POPF, defined by the International Study Group of Pancreatic Fistula (ISGPF) in 2016. Clinically relevant change and short-term outcomes were recorded to diagnose and grade the POPF. Multivariate regression analyses were performed to identify independent risk factors of clinically relevant postoperative pancreatic fistula (CR-POPF).

RESULTS

A total of 2089 cases were analyzed. The incidence of biochemical leakage (BL) and CR-POPF were 19.6% and 1.1% respectively. All CR-POPF patients recovered well after appropriate treatment and no Grade C POPF were recorded. Logistic regression analysis showed pTNM III (OR, 2.940; 95% CI 1.180-7.325; P = 0.021) and LigaSure usage (OR, 6.618; 95% CI 1.847-23.707; P = 0.004) were independent risk factors of CR-POPF. LigaSure usage (OR, 4.817; 95% CI 1.184-19.598; P = 0.028), the drain amylase content (D-AMY) on postoperative day 3 (POD3) ≥5 times the upper limit of normal amylase (OR, 3.476; 95% CI 1.240-9.744; P = 0.018) and open surgery (OR, 2.463; 95% CI 1.003-6.050; P = 0.049) were independent predictors for identifying CR-POPF from BL.

CONCLUSION

In rich-experienced gastric cancer centers, there is high prevalence of BL secondary to radical gastrectomy without clinical impact. Fewer patients suffered Grade B POPF, and Grade C POPF was less common. The patients with pTNM III or LigaSure usage were prone to suffer CR-POPF. Surgery procedure, LigaSure usage combined with D-AMY measurement on POD3 are promising for early identification of CR-POPF.

Quantifying the cell morphology and predicting biological behavior of signet ring cell carcinoma using deep learning

Signet ring cell carcinoma (SRCC) is a malignant tumor of the digestive system. This tumor has long been considered to be poorly differentiated and highly invasive because it has a higher rate of metastasis than well-differentiated adenocarcinoma. But some studies in recent years have shown that the prognosis of some SRCC is more favorable than other poorly differentiated adenocarcinomas, which suggests that SRCC has different degrees of biological behavior. Therefore, we need to find a histological stratification that can predict the biological behavior of SRCC. Some studies indicate that the morphological status of cells can be linked to the invasiveness potential of cells, however, the traditional histopathological examination can not objectively define and evaluate them. Recent improvements in biomedical image analysis using deep learning (DL) based neural networks could be exploited to identify and analyze SRCC. In this study, we used DL to identify each cancer cell of SRCC in whole slide images (WSIs) and quantify their morphological characteristics and atypia. Our results show that the biological behavior of SRCC can be predicted by quantifying the morphology of cancer cells by DL. This technique could be used to predict the biological behavior and may change the stratified treatment of SRCC.

What's New with Endoscopic Treatments for Early Gastric Cancer in the "Post-ESD Era"?

BACKGROUND

Endoscopic treatments for gastric cancers have still been progressing even after the great success of endoscopic submucosal dissection (ESD).

SUMMARY

In further advancements of ESD, safe and less-invasive procedures are challenged by managing postoperative bleeding, one of the major adverse events in ESD. Covering the mucosal defect after removal of lesions appears reasonable and effective for preventing delayed bleeding from the post-ESD ulcers. Shielding with biodegradable sheets is attempted on clinical trials, which show equivocal results. Although suturing of the mucosal rims is technically challenging, pilot studies demonstrate favorable outcomes for avoiding post-ESD bleeding even in cases at high risk. In cases after noncurative resection of ESD, the selection of patients who truly require additional gastrectomy with lymph node dissection is important to provide necessary surgery. Risk stratification of lymph node metastases and surgery has been developed, which offers tailor-made management to each patient considering the risks and benefits. In surgery, function-preserving gastrectomy to minimize the resection area in both lymphadenectomy and the primary site is clinically introduced. The sentinel node navigation surgery is promising to realize the minimally invasive gastrectomy, and it should strongly fit ESD as well as laparoscopic endoscopic cooperative surgery or endoscopic full-thickness resection, although nonexposure approaches are desirable. Key Message: Development for less-invasive managements on gastric cancer will be continued in step with the advancement of endoscopic treatments.

Bleeding After Gastric Endoscopic Submucosal Dissection Focused on Management of Xa Inhibitors

Purpose

The use of direct oral Xa inhibitors (DXaIs) to prevent venothrombotic events is increasing. However, gastrointestinal bleeding, including that related to endoscopic resection, is a concern. In this study, we evaluated bleeding and coagulation times during the perioperative period of gastric endoscopic submucosal dissection (ESD).

Materials and Methods

Patients who consecutively underwent gastric ESD from August 2016 to December 2018 were analyzed. Bleeding rates were compared among the 3 groups (antiplatelet, DXaIs, and control). DXaI administration was discontinued on the day of the procedure. Prothrombin time (PT), activated partial thromboplastin time, and the ratio of inhibited thrombin generation (RITG), which was based on dilute PT, were determined before and after ESD.

Results

During the study period, 265 gastric ESDs were performed in 239 patients, where 23 and 50 patients received DXaIs and antiplatelets, respectively. Delayed bleeding occurred in 17 patients (7.4%) and 21 lesions (7.1%). The bleeding rate in the DXaI group was significantly higher than that in the other groups (30.4%, P<0.01), and the adjusted odds ratio of bleeding was 5.7 (95% confidence interval, 1.4–23.7; P=0.016). In patients using DXaIs, there was a significant (P=0.046) difference in the median RITG between bleeding cases (18.6%) and non-bleeding cases (3.8%).

Conclusions

A one-day cessation of DXaIs was related to a high incidence of bleeding after gastric ESD, and monitoring of residual coagulation activity at trough levels might enable the predicted risk of delayed bleeding in patients using DXaIs.

Vonoprazan versus proton pump inhibitors for postendoscopic submucosal dissection bleeding in the stomach: a multicenter population-based comparative study

BACKGROUND AND AIMS

The effectiveness of vonoprazan relative to that of proton pump inhibitors (PPIs) after gastric endoscopic submucosal dissection (ESD) is unclear. Although previous studies used post-ESD ulcer healing as the outcome measure, post-ESD bleeding rate is the most objective and appropriate outcome measure because it has less ascertainment bias. We aimed to compare the post-ESD bleeding rates between vonoprazan and PPIs.

METHODS

This nationwide population-based retrospective cohort study was conducted between 2014 and 2018 and involved 9 hospitals. After 2 days of intravenous PPI administration, either vonoprazan or PPI was administrated from postoperative day 2 to 30.

RESULTS

Overall, data of 1715 patients (627 patient pairs) were analyzed through propensity score matching. The vonoprazan group had significantly lower post-ESD bleeding rates than the PPI group (overall, 11.9% vs 17.2%, P = .008; bleeding between days 2 and 30, 7.8% vs 11.8%, P = .015). The readmission rate because of post-ESD bleeding was lower in the vonoprazan group (2.4% vs 4.1%, P = .081). Blood transfusion (2.1% vs 3.0%, P = .15) and additional surgery because of delayed perforation (.5% vs 1.0%, P = .32) were not significantly different between the 2 groups. No deaths within 30 days occurred in both groups. On Cox regression analysis, vonoprazan use, lesion location (antrum), aspirin use, direct oral anticoagulant use, and Charlson Comorbidity Index (≥2) were associated with an increased risk of post-ESD bleeding within 30 days.

CONCLUSIONS

Vonoprazan has a lower post-ESD bleeding rate than PPIs. Further prospective studies are required to confirm these results.

Development of a predictive model for extragastric recurrence after curative resection for early gastric cancer

BACKGROUND

Stratification of patients who undergo curative resection for early gastric cancer (EGC) is warranted due to the heterogeneity in the risk of developing extragastric recurrence (EGR). Therefore, we aimed to stratify the need for postoperative surveillance for EGR detection in patients with EGC by developing a model for predicting EGR-free survival.

METHODS

This retrospective cohort study included patients who underwent postoperative surveillance after curative resection of EGC (n = 4149). Cox proportional hazard models were used to identify predictors to build a model for predicting EGR-free survival. Bootstrap-corrected c-index and calibration plots were used for internal and external (n = 2148) validations.

RESULTS

A risk-scoring system was constructed using variables significantly associated with EGR-free survival: pathologic T stage (pT1b[sm1], hazard ratio [HR] 4.928; pT1b[sm2], HR 5.235; pT1b[sm3], HR 7.748) and N stage (pN1, HR 4.056; pN2, HR 9.075; pN3, HR 30.659). Patients were dichotomized into a very-low-risk group or a low-or-greater-risk group. The 5-year EGR-free survival rates differed between the two groups (99.9 vs. 97.3%). The discriminative performance of the model was 0.851 (Uno's c-index) and 0.751 in the internal and external cohorts, respectively. The calibration slope was 0.916 and 1.131 in the internal and external cohorts, respectively.

CONCLUSIONS

Our model for predicting EGR-free survival based on the pathologic T and N stages may be useful for stratifying patients who have undergone curative surgery for EGC. The results suggest that patients in the very-low-risk group may be spared from postoperative surveillance considering their extremely high EGR-free survival rate.

Long-term endoscopic submucosal dissection with postoperative lung injury: a case report

BACKGROUND

Endoscopic submucosal dissection (ESD) has been recognized as a safe and minimally invasive technique for the removal of early gastric cancer. Here, we describe a case of extended-duration ESD for a gastric tumor associated with intraoperative perforation and bleeding. Unfortunately, the patient developed acute lung injury (ALI) after the operation.

CASE PRESENTATION

A 72-year-old woman received ESD for a gastric tumor under general anesthesia. Preoperatively, endoscopic ultrasonography (EUS) showed a 3.1 × 3.5 cm hypoechoic, well-defined mass at the junction of the antrum and body of the stomach on the greater curvature, originating in the muscularis propria layer. During the ESD procedure, when the submucosal mass was stripped, it was found to be closely adhered to the muscular layer and serosa layer, and a full-thickness incision was performed. The abdominal cavity was gradually filled with carbon dioxide gas, and abdominal puncture was performed to reduce intra-abdominal hypertension (IAH). Because the mass adhered to the greater omentum and there was more bleeding during the operation, a long duration of hemostasis and suturing of the wound was required. The whole operation lasted nearly 9 h, and total blood loss was 800 ml. After surgery, acute lung injury was suspected, and the patient was sent to the intensive care unit (ICU) for further treatment.

CONCLUSIONS

The operation time of ESD and IAH caused by perforation are closely related to a poor prognosis. We should pay attention to the impact of operation time on patients and improve awareness regarding protecting important organ functions.

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

Simple Summary

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

Abstract

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

Efficacy and Safety of Endoscopic Submucosal Dissection for Superficial Gastric Neoplasms: A Latin American Cohort Study

Background/Aims

Endoscopic submucosal dissection (ESD) is the preferred technique for treating early gastric cancer (EGC). However, very few studies have been conducted in South America. This study aimed to assess the efficacy and safety of ESD for EGC.

Methods

We analyzed data from a prospective cohort from 2013 to 2020. A total of 152 superficial gastric neoplasms that fulfilled the absolute or expanded criteria for ESD were included. Outcomes were en bloc, R0, and curative resection rates, incidence of adverse events, and length of procedure.

Results

The age of the enrolled patients was 68.4±11.3 years. The number of included patients based on the absolute and expanded indications was 150 and 2, respectively. En bloc, R0, and curative resections were achieved in 98.0%, 96.1%, and 89.5% of the cases, respectively. Bleeding and perforation were reported in 5.9% and 6.6% of the cases, respectively. Histopathological examination revealed low-grade dysplasia, high-grade dysplasia, well-differentiated adenocarcinoma, and poorly differentiated adenocarcinoma in 13, 20, 117, and 2 cases, respectively.

Conclusions

Our study shows that ESD performed by properly trained endoscopists in reference centers is safe and effective, with comparable therapeutic outcomes to those reported in the Eastern series.

Indications of Endoscopic Submucosal Dissection for Undifferentiated Early Gastric Cancer: Current Status and Future Perspectives for Further Expansion

BACKGROUND

Endoscopic submucosal dissection (ESD) is a widely accepted and minimally invasive treatment for early gastric cancer (EGC) without the risk of lymph node metastasis (LNM). However, undifferentiated-type EGC (UD-EGC) is considered to have a relatively high risk of LNM. Recently, the Japan Clinical Oncology Group conducted a nonrandomized confirmatory trial (JCOG1009/1010) to evaluate the efficacy and safety of ESD for UD-EGC. Herein, we review the results of JCOG1009/1010 and the possibility of further expanding the indications for ESD.

SUMMARY

JCOG1009/1010 showed excellent technical results and 5-year overall survival in patients with UD-EGC. Based on the results, ESD for UD-EGC (cT1a) of ≤2 cm without ulceration was technically feasible and acceptable for standard treatment instead of gastrectomy with lymph node dissection. A review of the EGC of mixed histological type (mixed EGC) suggested that the mixed EGC might have worse biological behavior than the pure histological type. In cases of intramucosal EGC with pure signet-ring cell carcinoma or presenting a double-layer structure, the risk of LNM might be relatively low. Thus, there is a possibility of further expanding the indications or curative evaluations. In the case of UD-EGC after noncurative resection, the data suggest that the eCura system may be applicable to UD-EGC; however, due to the small number of cases, further study is warranted. Key Message: This review summarizes the present knowledge regarding indications for UD-EGC and the possibility of further expanding them.

Clinical Research of Combined Application of DCEUS and Dynamic Contrast-Enhanced MSCT in Preoperative cT Staging of Gastric Cancer

Purpose

To investigate the clinical value of double contrast-enhanced ultrasound (DCEUS) combined with dynamic contrast-enhanced multislice CT (MSCT) in preoperative T staging of gastric cancer (GC).

Methods

206 patients with GC confirmed by preoperative gastroscopy from February 2019 to February 2021 were collected, all patients were examined by DCEUS and dynamic contrast-enhanced MSCT before operation, and the invasion depth (T staging) of GC was evaluated. The diagnosis results of DCEUS, dynamic contrast-enhanced MSCT, and combined diagnosis of DCEUS and MSCT methods (D&M method) were compared with the pathological staging results (gold standard).

Results

The correct diagnosis rate of MSCT was 27.27% in T1 staging, 55.56% in T2 staging, 42.11% in T3 staging, 59.29% in T4 staging, and 55.34% in summation. The correct diagnosis rate of DCEUS was 90.91% in T1 staging, 88.89% in T2 staging, 78.95% in T3 staging, 82.86% in T4 staging, and 83.98% in summation. The correct diagnosis rate of the D&M method was 100.00% in T1 staging, 94.44% in T2 staging, 89.47% in T3 staging, 93.57% in T4 staging, and 93.69% in summation. The D&M method had higher correct diagnosis rate than MSCT or DCEUS alone, the correct diagnosis rate of the D&M method in T1, T2, T3, and T4 staging was significantly higher than that of MSCT (P < 0.05). The correct diagnosis rate of the D&M method in T1, T3, and T4 was significantly higher than that of DCEUS (P < 0.05). The Youden index of preoperative T1, T2, T3, and T4 staging of GC by the D&M method was 99.49%, 94.44%, 84.13%, and 90.54%, respectively, and the Kappa values of these were 0.954, 0.966, 0.707, and 0.881, respectively.

Conclusions

Dynamic contrast-enhanced MSCT combined with DCEUS in the diagnosis of preoperative cT staging of GC has more validity, reliability, and revenue than the using of MSCT or DCEUS alone, which is an image evaluation method worthy of clinical promotion.

Current Status of Photodynamic Diagnosis for Gastric Tumors

Although the recent development and widespread use of image-enhanced endoscopy and magnifying endoscopy have improved endoscopic diagnosis of gastric cancer, it is somewhat complicated, requires a higher level of expertise, and is still subjective. Photodynamic endoscopic diagnosis (PDED) is based on the fluorescence of photosensitizers that accumulate in tumors, which enables objective evaluation independent of the endoscopist’s experience, and is useful for tumor detection. The objective of this work was to perform a narrative review of PDED for gastric tumors and to introduce our approach to PDED in gastric tumors in our hospital. In our review there have been case reports of PDED for gastric cancer, but its usefulness has not been established because no prospective studies evaluating its usefulness have been performed. In our previous study, 85.7% (42/49) of gastric tumors exhibited fluorescence in PDED. PDED may be useful in the diagnosis of early gastric cancer. Our previous studies were pilot studies in cancer patients; therefore, future prospective studies are required to verify the usefulness of PDED.

Polysaccharide hemostatic powder to prevent bleeding after endoscopic submucosal dissection in high risk patients: a randomized controlled trial

BACKGROUND : Bleeding after endoscopic submucosal dissection (ESD) is a severe adverse event. Several methods to prevent post-ESD bleeding (PEB) have been introduced; however, they have not been widely used because of technical difficulties. We aimed to investigate whether polysaccharide hemostatic powder (PHP), which is very easy to apply, can prevent early post-ESD bleeding, especially in patients with a high risk of post-ESD bleeding. METHODS : This was a prospective, multicenter, randomized, open-label, controlled trial. Patients with a high risk for post-ESD bleeding were enrolled. Patients with gastric neoplasms in whom the resected specimen size was expected to be > 40 mm and those who were regularly taking antithrombotic agents were defined as high risk patients. Patients were randomly assigned to the PHP or control groups. RESULTS:  Between May 2017 and September 2018, 143 patients were enrolled (PHP group, 73; control group, 70). The total post-ESD bleeding rate was 6.3 % (PHP group, 5.5 % vs. control group, 7.1 %; P = 0.74). There was no bleeding within 7 days after ESD in the PHP group. Continued antithrombotic use was an independent risk factor for post-ESD bleeding. In subgroup analysis excluding the patients who continued to take antithrombotic agents (n = 129) during ESD, the rate of post-ESD bleeding tended to be lower in the PHP group than in the control group (0 % vs. 6.3 %; P = 0.06). CONCLUSION : PHP did not demonstrate a significant effect on the prevention of post-ESD bleeding in this study. Further larger scale, randomized controlled trials are needed to confirm this.

Endoscopic instruments and techniques in endoscopic submucosal dissection for early gastric cancer

Introduction: Endoscopic submucosal dissection (ESD) is a less invasive local treatment for early gastric cancer (EGC).Areas covered: Japanese guidelines have recently expanded the endoscopic treatment indications for EGC. ESD is sometimes performed for lesions with a relative indication that has not previously been considered for ESD. ESD procedures are technically difficult, especially for larger and more invasive lesions. Complete resection and accurate histological assessment of EGC lesions are essential to evaluate endoscopic curability. Various endoscopic instruments, including three types of endoscopic knives and specific hemostatic forceps, have been developed, and endoscopic techniques, including the traction method, have been modified to simplify the procedure.Expert opinion: An insulated-tip knife with large tissue contact allows us to perform faster incisions, while a needle-type knife with minimal tissue contact allows us to perform precise incisions. Furthermore, a scissor-type knife with grasping tissues allows us to perform more secure incision. The traction method enables the operator to proceed with submucosal dissection procedures. In cases with small lesions, snaring can be used, as well as knife dissection. Understanding the features of each endoscopic instrument and technique is essential because appropriate selection and usage contribute to successful and safe ESD procedures.

Incidence and treatment outcomes of metachronous gastric cancer occurring after curative endoscopic submucosal dissection of undifferentiated-type early gastric cancer: Japan Clinical Oncology Group study-post hoc analysis of JCOG1009/1010

BACKGROUND AND AIMS

A drawback of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is the development of metachronous gastric cancer (MGC). While MGC after ESD for differentiated-type (D-) EGC was well understood, little is known about MGC occurring after ESD for undifferentiated-type (UD-) EGC, because ESD had not been indicated. We evaluated the incidence and treatment outcomes of MGC after ESD of UD-EGC.

METHODS

This study is a post hoc analysis of JCOG1009/1010, a multicenter trial to evaluate the efficacy and safety of ESD for UD-EGC. The patients who underwent curative ESD of index solitary UD-EGC were analyzed. Surveillance endoscopy was performed biannually for the first 3 years and thereafter annually. We assessed the time to MGC occurrence after ESD, lesion characteristics, and treatment outcomes of MGC. Time to MGC occurrence was estimated by cumulative incidence function, with death and total gastrectomy as competing risks.

RESULTS

A total of 198 patients were included in this study. During a median follow-up period of 5.8 years, 4 patients (2%) developed MGC. Median time to MGC occurrence was 4.5 years (range: 3.1-5.4). Five-year cumulative incidence of MGC was 1.0% (95% CI: 0.2-3.3%). Two MGCs were histologically D-EGC, and the remaining two were UD-EGC. The median tumor size of MGCs was 1.0 cm (range: 0.7-1.7), and the depth of invasion (M/SM1/SM2) was 2/1/1, respectively. Three patients achieved curative resection with repeated ESD.

CONCLUSIONS

MGC does not occur commonly after curative ESD of UD-EGC, and repeated ESD could contribute to stomach preservation.

Predictive Factors for Short-Term Survival after Non-Curative Endoscopic Submucosal Dissection for Early Gastric Cancer

BACKGROUND/AIMS

For early gastric cancer (EGC) treated using endoscopic submucosal dissection (ESD) with poor curability defined by the Japanese Guidelines (non-curative EGC, N-EGC), additional gastrectomy has been recommended. However, N-EGC patients without additional gastrectomy often die of other diseases within a relatively short interval after ESD. It has been unclear whether additional gastrectomy is beneficial or not for such patients. The aim of this study was to clarify predictors for short-term survival of N-EGC patients without additional gastrectomy after ESD.

METHODS

One hundred six N-EGC patients without additional gastrectomy were included in this study. Factors related to short-term survival, defined as death within 3 years after ESD, were evaluated using uni- and multivariate analyses by comparing patients with and without short-term survival (Groups S and C, respectively).

RESULTS

During the mean follow-up period of 89 months, 39 patients died (14 patients died within 3 years, being Group S). The cause of death was gastric cancer for only 1 patient in the Group C. The 3- and 5-year overall survival rates were 86.8 and 81.8%, respectively, and the 3- and 5-years disease-specific survival rates were 100 and 98.9%, respectively. Univariate analyses showed that short-term survival was statistically associated with elevated morphology, high-risk status for lymph node metastases as defined by the eCura system, severe comorbidity (Charlson Comorbidity Index [CCI] ≥3), low level of activity in daily living (being unable to go out by oneself), habitation (a nursing home), and several poor nutritional prognostic indices (neutrophil to lymphocyte ratio ≥2.5, geriatric nutritional risk index <92, C-reactive protein ≥1.0). In the multivariate analysis, a high CCI (≥3) was the independent predictor for short-term survival after ESD (odds ratio, 8.1; 95% confidence interval, 1.53-43.0; p = 0.014).

CONCLUSIONS

Severe comorbidity indicated by a high CCI score (≥3) was the independent predictor for short-term survival for EGC patients without additional gastrectomy after non-curative ESD. Since the cause of death for most patients was not gastric cancer, observational follow-ups without additional gastrectomy might be a reasonable option for patients with a poor general status indicated by a CCI ≥3.

The Chinese Society of Clinical Oncology (CSCO): Clinical guidelines for the diagnosis and treatment of gastric cancer, 2021

There exist differences in the epidemiological characteristics, clinicopathological features, tumor biological characteristics, treatment patterns, and drug selections between gastric cancer patients from the Eastern and Western countries. The Chinese Society of Clinical Oncology (CSCO) has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually. Taking into account regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China. The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis, treatment, follow-up, and screening of gastric cancer. Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines, this updated guideline integrates the results of major clinical studies from China and overseas for the past year, focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations. For the comprehensive treatment of non-metastatic gastric cancer, attentions were paid to neoadjuvant treatment. The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated. For the comprehensive treatment of metastatic gastric cancer, recommendations for immunotherapy were included, and immune checkpoint inhibitors from third-line to the first-line of treatment for different patient groups with detailed notes are provided.

Long- and short-term outcomes of early gastric cancer after endoscopic resection: a retrospective study from China

Background and study aims  The aim of the study was to evaluate short- and long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in China because no study has yet been conducted to confirm its effectiveness in EGC in China. Patients and methods  A total of 570 EGC samples from 537 patients were collected for evaluation of en bloc, complete, and curative resection using ESD. Data from 302 patients with at least 3 years of active follow-up were collected for analysis of recurrence of EGC and occurrence of metachronous GC (MGC). Short- and long-outcomes of mixed-type and pure differentiated EGC were also compared. Results  En bloc resection rates of 96.0 %, 98.7 %, and 95.2 %, complete resection rates of 91.2 %, 96.6 % and 90.8 %, and curative resection rates of 83.0 %, 96.2 % and 88.2 % were achieved in all EGCs included in the study, those with absolute indication, and those with expanded indication, respectively. As a long-term outcome, recurrence was observed in 1.3 % of patients, 3-year and 5-year recurrence rates being 0.7 % and 1.2 %, respectively. Thirteen patients (4.3 %) exhibited MGCs during follow-up, all of which were resected in a second ESD. Conclusions  The effectiveness of ESD for EGC in China was confirmed, with satisfactory short- and long-term outcomes. With scheduled follow-up, the outcomes for mixed-type EGC can be similar to those for pure differentiated EGC after complete resection without development of lymphovascular invasion.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Endoscopic Closure Utilizing Endoloop and Endoclips After Gastric Endoscopic Submucosal Dissection for Patients on Antithrombotic Therapy

OBJECTIVES

Antithrombotic therapy is a well-known independent risk factor for bleeding after endoscopic submucosal dissection (ESD) of early gastric cancer (EGC). A novel method of ulcer base closure using an endoloop and endoclips has been reported. This study aimed to evaluate the effectiveness of endoscopic closure using an endoloop and endoclips in preventing post-ESD bleeding in patients undergoing gastric ESD on antithrombotic therapy.

METHODS

This was a single center, retrospective study. Patients on antithrombotic therapy who underwent gastric ESD were divided into two groups, the closure group and the non-closure group. We analyzed procedural outcomes, post-ESD bleeding rate and factors associated with post-ESD bleeding.

RESULTS

Among 400 ESDs with EGCs in 311 patients, 131 ESDs in 110 patients were in the closure group, and 269 ESDs in 217 patients were in the non-closure group (16 patients were overlapped in both groups). Post-ESD bleeding rate was 11.5% (15/131) in the closure group, and 11.9% (32/269) in the non-closure group (p = 0.89). Total sustained closure rate during second look endoscopy was 47.8% (33/69). Post-ESD bleeding rate tended to be lower in the closure group than in the non-closure group for lesions located in the greater curvature (3.6% vs. 11.1%, p = 0.11). In addition, sustained closure rate was significantly higher in the greater curvature than in the lesser curvature (72.0% vs. 34.1%, p < 0.01). Multivariate analysis revealed resection size > 40 mm and heparin bridge were the independent risk factor for post-ESD bleeding.

CONCLUSION

Ulcer base closure using endoloop and endoclips did not prevent post-ESD bleeding in patients on antithrombotic therapy.

Endoscopic Resection of Gastric Cancer

With improvements in the early detection of early gastric cancer (EGC) and advances in therapeutic techniques, endoscopic resection (ER) for EGC has become widely adopted in East Asian and Western countries. Endoscopic submucosal dissection has higher rates of en bloc, complete, and curative resections with lower rates of local recurrence than that of endoscopic mucosal resection. ER is a minimally invasive method with low morbidity that provides excellent outcomes. ER for EGC is a safe, effective method, preserving organ function and thus maintaining the patient's quality of life, and is recognized as the first-line treatment of EGC in selected patients.

Current indications for endoscopic submucosal dissection of early gastric cancer

The development of endoscopic treatment technology has further promoted the minimally invasive treatment of early gastric cancer (EGC). Endoscopic treatment has achieved better therapeutic effects in terms of safety and prognosis and is the preferred treatment method for patients who meet the indications for endoscopic treatment. However, the consequent problem is that some patients receiving endoscopic treatment may undergo non-curative resection, and the principle of follow-up management for non-curative resection patients deserves further attention. In addition, there are still debates on how to improve the accuracy of clinical staging, select a reasonable treatment method for patients who meet the expanded indications for endoscopic treatment, manage patients with positive endoscopic surgical margins, conduct research on function-preserving surgery, and manage the treatment of EGC under the current situation in China. Consequently, we aim to review current indications for endoscopic submucosal dissection of EGC in order to better inform treatment options.

Risk for lymph node metastasis in Epstein-Barr virus-associated gastric carcinoma with submucosal invasion

OBJECTIVES

Epstein-Barr virus-associated gastric cancer (EBVGC) has been reported to be associated with a low risk for lymph node metastasis (LNM). However, the curative criteria for endoscopic submucosal dissection (ESD) for submucosal EBVGC (pT1b-EBVGC) remain unclear. Our study aimed to investigate the risk factors for LNM in pT1b-EBVGC.

METHODS

This was a retrospective multicenter study at five institutes in Japan. We reviewed medical records and extracted all pT1b-EBVGC cases that met the following criteria: (i) histologically proven submucosal gastric cancer; (ii) surgical or endoscopic resection between January 2000 and December 2016; and (iii) presence of Epstein-Barr virus (EBV) in tumor cells verified by EBV-encoded small RNA in situ hybridization (EBER-ISH). The association between clinicopathological factors and LNM were assessed using multivariable logistic regression analysis.

RESULTS

A total of 185 pT1b-EBVGC cases were included in the analysis. LNM was found in nine cases (4.9%). Multivariable logistic regression analysis demonstrated that lymphatic invasion (OR 9.1; 95% CI 2.1-46.1) and submucosal invasion ≥4000 μm (OR 9.2; 95% CI 1.3-110.3) were significant risk factors for LNM. When we focused on pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 μm, the rate of LNM was 0% (0/96, 95% CI 0-3.8%).

CONCLUSIONS

Our findings indicated that lymphatic invasion and submucosal invasion ≥4000 μm were significant risk factors for LNM. ESD could be an appropriate option for pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 μm.

Factors associated with overall survival in early gastric cancer patients who underwent additional surgery after endoscopic submucosal dissection

BACKGROUND

Controversy exists about the benefit of additional surgery after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC).

AIM

To examine risk factors for overall survival (OS) after additional surgery in patients with EGC who initially underwent ESD.

METHODS

This was a retrospective analysis of patients with EGC who underwent additional surgery after ESD at the Beijing Friendship Hospital affiliated to Capital Medical University between August 2012 and August 2019. OS was the primary outcome. Lymph node metastasis and residual tumor were secondary outcomes. Logistic regression models and Kaplan-Meier curves were used for further analysis.

RESULTS

Forty-two patients were evaluated, including 35 (83.3%) males and 7(16.7%) females. The mean age was 62 (range, 32-82) years. Male sex [hazard ratio (HR) = 21.906, 95% confidence interval (CI): 3.762-229.250; P = 0.039), T1b invasion (HR = 3.965, 95%CI: 1.109-17.432; P = 0.047), undifferentiated tumor (HR = 9.455, 95%CI: 0.946-29.482; P = 0.049), lymph node metastasis (HR = 2.126, 95%CI: 0.002-13.266; P = 0.031), and residual tumor (HR = 4.275, 95%CI: 1.049-27.420; P = 0.043) were independently associated with OS. The follow-up duration was 4-81 mo (median: 50.7 mo). OS was 77.0 ± 12.1 mo (95%CI: 53.3-100.7 mo). The 3-year and 5-year OS rates were 94.1% and 85%, respectively.

CONCLUSION

Male sex, T1b invasion, undifferentiated tumor, lymph node metastasis, and residual tumor are independently associated with OS in patients with EGC who underwent additional surgery after ESD.

Recurrence rate of intramucosal gastric cancer with positive vertical margin due to lesion damage during endoscopic submucosal dissection

BACKGROUND AND STUDY AIM

In principle, additional surgery is performed after endoscopic submucosal dissection for early gastric cancer if the vertical margin is positive, regardless of lesion damage. The recurrence rate of vertical margin-positive lesions due to lesion damage after endoscopic submucosal dissection is unknown, and unnecessary surgeries may be performed. In this study, we investigated whether there was a difference in the recurrence rate between vertical margin-positive lesions due to lesion damage and vertical margin-negative lesions.

PATIENTS AND METHODS

We included 1,294 intramucosal gastric cancer lesions that were resected by endoscopic submucosal dissection between January 2008 and December 2016, without additional surgery. The lesions were divided into the Damage and No damage groups based on vertical margin status. The Damage group had only one non-curative indication: a positive vertical margin due to lesion damage. The No damage group had no non curative indications. We compared the recurrence rate between the Damage and No damage groups.

RESULTS

The recurrence rates of the Damage and No damage groups were 0% (0/23; 95% confidence interval: 0-14.8%) and 0% (0/1,271; 95% confidence interval: 0-0.003%), respectively, with no statistically significant difference.

CONCLUSIONS

In intramucosal gastric cancer, the recurrence rate of vertical margin-positive lesions due to lesion damage was 0%, which did not differ from that of vertical margin-negative lesions with curative resection. Follow-up, instead of additional surgery, may be an option for patients with non-curative resection when the only non-curative indication is a positive vertical margin due to lesion damage.

Clinical feasibility and oncologic safety of primary endoscopic submucosal dissection for clinical submucosal invasive early gastric cancer

PURPOSE

This study aimed to evaluate the clinical feasibility and oncologic safety of primary endoscopic submucosal dissection for cT1bN0M0 gastric cancer by identifying patients who had undergone curative resection after endoscopic submucosal dissection and patients who had undergone primary surgery but could be treated with endoscopic submucosal dissection.

METHODS

A single-center retrospective cohort study was conducted on patients with cT1bN0M0 gastric cancer (size: ≤ 30 mm) and differentiated histology from January 2007 to May 2017. Submucosal invasion was evaluated using conventional endoscopy and endoscopic ultrasonography. Patients were divided into the primary endoscopic submucosal dissection and primary surgery groups according to initial treatment.

RESULTS

Curative resection rate was 65.0% (91/140) in the primary endoscopic submucosal dissection group. Of patients in the primary surgery group, 49.1% (82/167) were considered eligible for endoscopic submucosal dissection. No differences in en bloc resection rate were observed between pT1a and pT1b gastric cancers after endoscopic submucosal dissection (97.8 vs. 97.9%). However, the negative horizontal margin rate was higher in pT1a gastric cancer than pT1b gastric cancer (98.9 vs. 91.3%). There was no difference in overall survival among the curative treatment groups (log rank P = 0.310).

CONCLUSION

In this study, 173 (56.4%) out of 307 patients with cT1bN0M0 gastric cancer could avoid unnecessary surgery if primary endoscopic submucosal dissection was used. Based on these findings, it is necessary to add an appropriate indication for endoscopic submucosal dissection in patients with cT1b gastric cancer. Further management could be determined based on pathologic findings after primary endoscopic submucosal dissection.

Progress of Gastric Cancer Surgery in the era of Precision Medicine

With the development of genomics, the update of modern imaging technology and the advent of artificial intelligence and big data, the surgical treatment of gastric cancer has gradually stepped into precision medicine. Precision surgery treatment of gastric cancer is based on accurate molecular typing and staging using modern molecular diagnostic technology and imaging, and the formulation of precise and individualized surgical treatment plans, with the concept of minimally invasive and accelerated rehabilitation surgery running through it. For intermediate-stage gastric cancer, we have adopted a comprehensive treatment approach including traditional radiotherapy and chemotherapy, targeted therapy and immunotherapy. Utilize artificial intelligence and big data technology to improve the standardization and interconnectivity of specialty data and realize the transformation of evidence-based medicine. Promoting the standardization, standardization and individualization of gastric cancer surgical treatment, providing patients with precise diagnosis and treatment, and further improving patients' prognosis are the opportunities and challenges in the development of gastric cancer surgery.

Long-term outcomes after endoscopic submucosal dissection for differentiated-type early gastric cancer that fulfilled expanded indication criteria: A prospective cohort study

BACKGROUND AND AIM

Endoscopic resection for early gastric cancer (EGC) is widely performed. However, there is still a paucity of strong evidence regarding long-term outcomes after endoscopic submucosal dissection (ESD) for the expanded indication criteria of the Japanese guidelines (ver. 2010).

METHODS

Endoscopic submucosal dissection was performed in patients with EGC that met the expanded indication criteria: (i) cT1a, differentiated-type EGC of 2 to 5 cm, ulcer negative or (ii) cT1a, differentiated-type EGC of ≤3 cm, ulcer positive. Patients whose pathological examination fulfilled the curative resection criteria were then enrolled in this cohort study: negative vertical margin, negative lymphovascular invasion, and (i) pT1a, differentiated-type, and ulcer negative; (ii) pT1a, differentiated-type, ≤3 cm, and ulcer positive; or (iii) pT1b1 (<500-μm submucosal invasion), differentiated-type, and ≤3 cm. Patients with only a positive horizontal margin as a noncurative factor were included for follow-up.

RESULTS

From September 2003 to February 2012, a total of 356 patients underwent ESD, and 214 were enrolled in the survival analysis. One hundred twenty patients (56%) had >2 cm in diameter and ulcer-negative lesions, and 94 (44%) had ≤3 cm and ulcer-positive lesions. The vital status at 5 years after ESD was confirmed in all (100%) patients. No local or metastatic recurrence was detected; however, 26 metachronous gastric cancers developed, and 1 patient died of metachronous gastric cancer. The 5-year disease-specific and overall survival rates were 99.5% (95% confidence interval [CI], 97.2%-100%) and 93.9% (95% CI, 89.8%-96.4%), respectively.

CONCLUSION

ESD for EGC that fulfills the expanded criteria is feasible and shows favorable long-term outcomes.

A nonrandomized, single-arm confirmatory trial of expanded endoscopic submucosal dissection indication for undifferentiated early gastric cancer: Japan Clinical Oncology Group study (JCOG1009/1010)

BACKGROUND

While endoscopic submucosal dissection (ESD) is recognized as a minimally invasive standard treatment for differentiated early gastric cancers (EGCs), it has not been indicated for undifferentiated EGC (UD-EGC) because of a relatively high risk of lymph node metastasis (LNM). However, patients with surgically resected mucosal (cT1a) UD-EGC ≤ 2 cm in size with no lymphovascular invasion or ulceration are reported to be at a very low risk of LNM. This multicenter, single-arm, confirmatory trial was conducted to evaluate the efficacy and safety of ESD for UD-EGC.

METHODS

The key eligibility criteria were endoscopically diagnosed cT1a/N0/M0, single primary lesion, size ≤ 2 cm, no ulceration and histologically proven components of undifferentiated adenocarcinoma on biopsy. Based on the histological findings after ESD, additional gastrectomy was indicated if the criteria for curative resection were not satisfied. The subjects of the primary analysis were patients with UD-EGC as the dominant component. The primary endpoint was 5-year overall survival (OS) of patients with UD-EGC.

RESULTS

Three hundred 46 patients were enrolled from 49 institutions. The proportion of en bloc resection was 99%. No ESD-related Grade 4 adverse events were noted. Delayed bleeding and intraoperative and delayed perforation occurred in 25 (7.3%), 13 (3.8%), and 6 (1.7%) patients, respectively. Among the 275 patients who were the subjects of the primary analysis, curative resection was achieved in 195 patients (71%), and 5-year OS was 99.3% (95% CI: 97.1-99.8).

CONCLUSIONS

ESD can be a curative and less invasive treatment for UD-EGC for patients meeting the eligibility criteria of this study.

Incidence of metachronous cancer after endoscopic submucosal dissection: a comparison between undifferentiated-type and differentiated-type early gastric cancer

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has become an important and minimally invasive treatment for early gastric cancer (EGC) with a negligible risk of metastasis not only for differentiated-type (D-type) cancer but also for undifferentiated-type (UD-type) cancer. We aimed to investigate the incidence and characteristics of metachronous cancer after ESD for UD-type cancer, which has not yet been elucidated.

METHODS

In total, 175 patients who underwent ESD for UD-type EGC were enrolled. For comparison, 350 patients who underwent ESD for D-type EGC during the same period were randomly selected. These patients underwent a follow-up EGD annually. The median observation period was 6.0 years and 5.4 years, respectively.

RESULTS

The annual incidence of metachronous cancer after ESD for UD-type and D-type cancer was .9% and 5.3%, respectively. Among the patients who underwent ESD for UD-type cancer, 30.9% of patients were uninfected with Helicobacter pylori, whereas all patients who underwent ESD for D-type cancer were infected with H pylori. All patients who developed metachronous cancer were infected with H pylori. UD-type metachronous cancer developed more frequently in patients after ESD for UD-type cancer than after ESD for D-type cancer, and the curative resection rate of ESD was significantly lower in these cases.

CONCLUSIONS

Metachronous cancers developed only in H pylori-infected patients in this cohort. Although metachronous cancer incidence was significantly less frequent in patients after ESD for UD-type cancer, the curative resection rate of ESD was significantly lower. Routine surveillance should be conducted more carefully after ESD for UD-type cancer, especially in H pylori-infected patients.

The efficacy of the application of the curative criteria of the 5rd edition Japanese gastric cancer treatment guidelines for early adenocarcinoma of the esophagogastric junction treated by endoscopic submucosal dissection

BACKGROUND

The curative criteria after endoscopic submucosal dissection for early gastric carcinoma were updated by the Japanese Gastric Cancer Association. No study has shown promising results with endoscopic submucosal dissection for early adenocarcinoma of esophagogastric junction based on the new curative criteria. The purpose of this study was to validate clinical efficacy of the application of the curative criteria of the 5th edition Japanese gastric cancer treatment guidelines for early adenocarcinoma of esophagogastric junction after endoscopic submucosal dissection.

METHODS

Patients who underwent endoscopic submucosal dissection for Siewert type II adenocarcinoma between January 2013 and June 2018 were eligible for this study. Clinical and pathological features and treatment outcomes were retrospectively reviewed using medical records.

RESULTS

The success rate for en-bloc resection was 97.2% (172/177) and the curative resection rate was 71.2% (126/177). Additional endoscopic submucosal dissection or radical surgery was conducted in 10 patients (5.6%) who did not fulfil the curative resection criteria, while one patient with curative resection remedied with endoscopic submucosal dissection because of recurrence. According to eCura scoring system, 94 patients (53.1%) were categorized into eCura A, 34 patients (19.2%) into eCura B, 11 patients (6.2%) into eCura C-1, and 38 patients (21.5%) into eCura C-2. Five patients categorized as eCura C-2 underwent radical surgery, two of whom have lymph node metastasis.

CONCLUSIONS

Endoscopic submucosal dissection for early adenocarcinoma of esophagogastric junction that met the expanded criteria of the 5th edition Japanese gastric cancer treatment guidelines were acceptable and should be the standard treatment instead of surgical resection.

Machine learning predicts lymph node metastasis of poorly differentiated-type intramucosal gastric cancer

To construct a machine learning algorithm model of lymph node metastasis (LNM) in patients with poorly differentiated-type intramucosal gastric cancer. 1169 patients with postoperative gastric cancer were divided into a training group and a test group at a ratio of 7:3. The model for lymph node metastasis was established with python machine learning. The Gbdt algorithm in the machine learning results finds that number of resected nodes, lymphovascular invasion and tumor size are the primary 3 factors that account for the weight of LNM. Effect of the LNM model of PDC gastric cancer patients in the training group: Among the 7 algorithm models, the highest accuracy rate was that of GBDT (0.955); The AUC values for the 7 algorithms were, from high to low, XGB (0.881), RF (0.802), GBDT (0.798), LR (0.778), XGB + LR (0.739), RF + LR (0.691) and GBDT + LR (0.626). Results of the LNM model of PDC gastric cancer patients in test group : Among the 7 algorithmic models, XGB had the highest accuracy rate (0.952); Among the 7 algorithms, the AUC values, from high to low, were GBDT (0.788), RF (0.765), XGB (0.762), LR (0.750), RF + LR (0.678), GBDT + LR (0.650) and XGB + LR (0.619). Single machine learning algorithm can predict LNM in poorly differentiated-type intramucosal gastric cancer, but fusion algorithm can not improve the effect of machine learning in predicting LNM.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Early gastric cancer detection in high-risk patients: a multicentre randomised controlled trial on the effect of second-generation narrow band imaging

OBJECTIVE

Early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2G-NBI) can improve early detection, is unknown.

DESIGN

This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (WLI) followed by secondary 2G-NBI (WLI group: n=2258) and primary 2G-NBI followed by secondary WLI (2G-NBI group: n=2265) performed by the same examiner. Suspected early gastric cancer (EGC) lesions in both groups were biopsied. Primary endpoint was the rate of EGC patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for EGC in suspicious lesions detected (primary examination).

RESULTS

EGCs were found in 44 (1.9%) and 53 (2.3%; p=0.412) patients in the WLI and 2G-NBI groups, respectively, during primary EGD. In a post hoc analysis, the overall rate of lesions detected at the second examination was 25% (n=36/145), with no significant differences between groups. PPV for EGC in suspicious lesions was 13.5% and 20.9% in the WLI (50/371 target lesions) and 2G-NBI groups (59/282 target lesions), respectively (p=0.015).

CONCLUSION

The overall sensitivity of primary endoscopy for the detection of EGC in high-risk patients was only 75% and should be improved. 2G-NBI did not increase EGC detection rate over conventional WLI. The impact of a slightly better PPV of 2G-NBI has to be evaluated further.

TRIAL REGISTRATION NUMBER

UMIN000014503.

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.

Somatic alterations and mutational burden are potential predictive factors for metachronous development of early gastric cancer

The risk of developing metachronous gastric cancer (MGC) following curative endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) remains even after eradicating Helicobacter pylori (HP) successfully. We screened initial EGC and adjacent non-cancerous mucosa ESD-resected specimens for somatic variants of 409 cancer-related genes, assessing their mutational burden (MB) to predict molecular markers for metachronous post-ESD development. We compared variants between ten patients diagnosed with MGC more than 3 years after ESD and ten age-matched patients who did not have MGC developments after successful HP eradication. We found no significant background differences between the two groups. In adjacent non-cancerous mucosa, the MB tended to be higher in the patients with metachronous developments than in the others. Somatic genomic alterations of RECQL4, JAK3, ARID1A, and MAGI1 genes were significantly associated with MGC development. The criteria including both the MB and their variants, which had potential significant values for predicting MGC. In conclusion, combined of assessing specific somatic variants and MB may be useful for predicting MGC development. This study included a limited number of subjects; however, our novel findings may encourage further exploration of the significance of the molecular features of EGC that predict MGC development, thereby promoting focused follow-up strategies and helping elucidate the mechanisms.

Highly accurate artificial intelligence systems to predict the invasion depth of gastric cancer: efficacy of conventional white-light imaging, nonmagnifying narrow-band imaging, and indigo-carmine dye contrast imaging

BACKGROUND AND AIMS

Diagnosing the invasion depth of gastric cancer (GC) is necessary to determine the optimal method of treatment. Although the efficacy of evaluating macroscopic features and EUS has been reported, there is a need for more accurate and objective methods. The primary aim of this study was to test the efficacy of novel artificial intelligence (AI) systems in predicting the invasion depth of GC.

METHODS

A total of 16,557 images from 1084 cases of GC for which endoscopic resection or surgery was performed between January 2013 and June 2019 were extracted. Cases were randomly assigned to training and test datasets at a ratio of 4:1. Through transfer learning leveraging a convolutional neural network architecture, ResNet50, 3 independent AI systems were developed. Each system was trained to predict the invasion depth of GC using conventional white-light imaging (WLI), nonmagnifying narrow-band imaging (NBI), and indigo-carmine dye contrast imaging (Indigo).

RESULTS

The area under the curve of the WLI AI system was .9590. The lesion-based sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the WLI AI system were 84.4%, 99.4%, 94.5%, 98.5%, and 92.9%, respectively. The lesion-based accuracies of the WLI, NBI, and Indigo AI systems were 94.5%, 94.3%, and 95.5%, respectively, with no significant difference.

CONCLUSIONS

These new AI systems trained with multiple images from different angles and distances could predict the invasion depth of GC with high accuracy. The lesion-based accuracy of the WLI, NBI, and Indigo AI systems was not significantly different.