The value of diagnostic endoscopic submucosal dissection for patients with clinical submucosal invasive early gastric cancer

Diagnostic evaluation of endoscopic ultrasonography with submucosal saline injection for differentiating between T1a and T1b early gastric cancer

BACKGROUND

Endoscopic ultrasonography (EUS) has become a reliable method for predicting the invasion depth of early gastric cancer (EGC). However, diagnostic accuracy of EUS is affected by several factors. In particular, it is difficult to differentiate between T1a and T1b EGC through EUS.

AIM

To confirm whether submucosal saline injection (SSI) could improve the accuracy of EUS in distinguishing T1a and T1b lesions in EGC.

METHODS

Twenty-four patients with EGC were examined by EUS and subsequently by SSI combined EUS to compare the degree of tumor invasion. Then, they underwent endoscopic or surgical resection within 7 d. The diagnostic accuracy of EUS and SSI combined EUS was evaluated based on the final pathological findings postoperatively. Saline injected into the submucosa acted as an echoic contrast enhancing agent and had the effect of distinguishing the mucosal and submucosal layers clearly.

RESULTS

Of total 24 patients, 23 were diagnosed with EGC (T1 cancer: 13 as T1a, and 10 as T1b). Standard EUS identified 6 of 13 T1a cancer patients and 3 of 10 T1b cancer patients. Whereas, EUS-SSI identified 12 of 13 T1a cancer patients and 6 of 10 T1b cancer patients. In this study, SSI combined EUS was more accurate than EUS alone in diagnosing T1a and T1b lesions of EGC (75.0% and 37.5%, respectively).

CONCLUSION

SSI improved the diagnostic accuracy of EUS in distinguishing between the T1a and T1b stages in EGC.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preoperative evaluation of endoscopic submucosal dissection for early gastric cancer

OBJECTIVE

To retrospectively analyze the preoperative endoscopic evaluation of the size, nature, and depth of lesions in endoscopic submucosal dissection (ESD) for early gastric cancer and precancerous lesions, determine whether the lesions can be completely resected, and reduce the risk of additional surgery after ESD.

METHODS

A total of 114 patients with high-grade intraepithelial neoplasia(HGIN) and early gastric cancer treated with ESD in Hebei General Hospital from January 2016 to April 2021 were enrolled in this study. The lesions were evaluated preoperatively according to the endoscopic findings of white light, magnifying endoscopy, endoscopic features of narrow band imaging, and preoperative pathology. Lesion size, positive resection margin, lesion depth, and vascular invasion of postoperative pathology were used as criteria.

RESULTS

There were 121lesions in 114 patients. The coincidence rates of preoperative and postoperative pathology were 87.21% (75/86) for HGIN and 92.1% (35/38) for adenocarcinoma. There was no significant difference in the coincidence rate between preoperative pathological evaluation and postoperative pathology among the 3 lesions (χ2 = 10.614, P = .005). The type and malignancy of the lesion were not related to its location or size. Magnifying endoscopy combined with narrow-band imaging showed that HGIN and early gastric cancer had clear borders, irregular microvessels, and irregular surface microarchitecture on endoscopic features. Lesions > 3 cm, surface ulcers and spontaneous bleeding may be risk factors for deeper lesions.

CONCLUSION

ESD is not only a method for the treatment of early gastric cancer and precancerous lesions, but is also an important method for definite pathological diagnosis. Accurate preoperative assessment of lesion type, lesion extent and depth of invasion is helpful to improve the complete resection rate of ESD and reduce the risk of additional surgery.

Predicting the depth of superficial adenocarcinoma of the esophagogastric junction

BACKGROUND AND AIM

Preoperative determination of the invasion depth of superficial adenocarcinoma of the esophagogastric junction is important for appropriate endoscopic or surgical resection. There are no objective criteria regarding this; therefore, we investigated the factors associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction.

METHODS

This retrospective study evaluated patients with superficial adenocarcinoma of the esophagogastric junction who had undergone endoscopic or surgical resection at a Japanese tertiary cancer center between April 2004 and December 2017. We analyzed endoscopic features of intramucosal to slight submucosal (M-SM1; < 500 μm) and deep submucosal (SM2; ≥ 500 μm) adenocarcinoma of the esophagogastric junction and extracted significant factors associated with and assessed the diagnostic performance of endoscopic features for SM2 lesion.

RESULTS

A total of 106 cases were included in this study. Multivariate analysis indicated that depressed or protruded type (odds ratio [OR], 11.1), lesion size ≥ 15 mm (OR, 3.11), uneven surface (OR, 6.31), and subsquamous extension (OR, 5.41) were significantly associated with SM2 adenocarcinomas of the esophagogastric junction. When the macroscopic type was depressed or protruded, high sensitivity (97%) but fair specificity (46%) were observed for SM2 adenocarcinoma of the esophagogastric junction, whereas uneven surface and subsquamous extension showed high specificity (96% and 87%) but fair sensitivity (36% and 46%).

CONCLUSIONS

Depressed or protruded type, lesion size ≥ 15 mm, uneven surface, and subsquamous extension were significantly associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction. These endoscopic features are useful in determining the treatment method preoperatively.

[Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer]

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Discrepancy between endoscopic and pathological ulcerative findings in clinical intramucosal early gastric cancer

BACKGROUND

Ulcerative finding (UL) is one of the factors that define the indication and curability of endoscopic resection (ER) in early gastric cancer (EGC). Discrepancies between endoscopic UL (cUL) and pathological UL (pUL) sometimes occur in clinical practice. The aim of this study was to investigate the discrepancy rate in UL diagnosis and the risk factors associated with such discrepancies.

METHODS

Patients with clinical intramucosal (cT1a) EGC who underwent ER or surgery between September 2002 and December 2017 were analyzed. The proportion of cUL-negative (cUL0) lesions that were identified as pUL-positive (pUL1) and that of cUL-positive (cUL1) lesions that were identified as pUL-negative (pUL0) were calculated. Logistic regression analysis was performed to estimate the associations between discrepancy in UL diagnosis and clinical variables of the lesion, such as the size, histology, location, and macroscopic type.

RESULTS

In total, 5382 lesions were evaluated; 5.5% of cUL0 lesions (256/4619) were identified as pUL1, while 38.7% of cUL1 lesions (295/763) were pUL0. Multivariate analysis indicated that in cUL1 lesions, tumor location in the lower third of the stomach (odds ratio 3.11, 95% confidence interval 1.90-5.08) was identified as an independent risk factor for overestimation.

CONCLUSIONS

Endoscopic diagnosis of UL in cT1a EGC was overestimated in 38.7% of lesions, especially for lesions located in the lower third of the stomach. This discrepancy should be considered in the management of cT1a EGC with UL.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

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.

Clinical outcomes of endoscopic resection for undifferentiated intramucosal early gastric cancer larger than 2 cm

BACKGROUND

This study investigated the long-term clinical outcomes of endoscopic resection (ER) for undifferentiated-type (UD) early gastric cancer (EGC), with tumor size > 2 cm as the only non-curative factor.

METHODS

From among 1123 patients who underwent ER for UD EGC at 18 tertiary hospitals in Korea between 2005 and 2014, we identified 216 patients with UD intramucosal EGC > 2 cm, which was completely resected, with negative resection margins, and absence of ulceration and lymphovascular invasion. The patients were divided into the additional surgery (n = 40) or observation (n = 176) groups, according to post-ER management and were followed up for a median duration of 59 months for recurrence and 90 months for overall survival.

RESULTS

Lymph node (LN) or distant metastasis or cancer-related mortality was not observed in the surgery group. In the observation group, two (1.1%) patients developed LN or distant metastasis with a 5-year cumulative risk of 0.7%, and one (0.6%) patient died of gastric cancer. The 5- and 8-year overall survival rates were 94.1% and 89.9%, respectively, in the observation group and 100.0% and 95.2%, respectively, in the surgery group (log-rank P = 0.159). Cox regression analysis did not reveal an association between the observation group and increased mortality.

CONCLUSION

The risk of LN or distant metastasis was not negligible, but as low as 1% for patients undergoing non-curative ER for UD EGC, with tumor size > 2 cm as the only non-curative factor. Close observation may be an alternative to surgery, especially for older patients or those with poor physical status.

Risk-Scoring System for Prediction of Non-Curative Endoscopic Submucosal Dissection Requiring Additional Gastrectomy in Patients with Early Gastric Cancer

Purpose

When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required.

Materials and Methods

Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set.

Results

Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%.

Conclusions

We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Laparoscopic approach to early gastric cancer in a patient with a prior history of open right hepatectomy: a case report

Background

Laparoscopic gastrectomy is regarded a standard treatment procedure for early gastric cancer and is widely used in clinical practice. However, the feasibility of laparoscopic gastrectomy for patients with a prior history of open surgery, especially in the case of a complicated operation, remains unclear. Here, we report a laparoscopic gastrectomy case with a prior history of right hepatectomy.

Case presentation

A 70-year-old man was diagnosed with early gastric cancers preceding a right hepatectomy for a solitary hepatocellular carcinoma at risk of rupture. An additional gastrectomy, after non-curative endoscopic submucosal dissection, was planned after the hepatectomy. Extensive adhesions were found around the liver. Rigid adherence of the duodenum to the adjacent hepatoduodenal ligament had formed. In addition, identification of the hepatic artery was difficult due to stiffening of the mesentery. Peeling off the adhesions from the ventral side of the duodenum revealed the supra-pyloric vessels and enabled us to transect the duodenum safely. Further, exposing the proper hepatic artery via the dorsal side of the mesentery and subsequent supra-pancreatic dissection on the outermost layer allowed effective identification of the right gastric artery. The postoperative course was uneventful.

Conclusions

We successfully performed total laparoscopic distal gastrectomy on a patient with a prior history of major hepatectomy.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by <i>en bloc</i> fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

RAB43 Promotes Gastric Cancer Cell Proliferation and Metastasis via Regulating the PI3K/AKT Signaling Pathway

BACKGROUND

Ras-related GTP-binding protein 43 (RAB43) plays a key part in the progression of many human cancers. However, the role and functional mechanisms of RAB43 in gastric cancer (GC) remain unknown.

PURPOSE

To elucidate the function and mechanism of RAB43 in the progression of GC.

PATIENTS AND METHODS

One hundred patients with histologically confirmed GC were recruited for this study. Tumor samples and GC cell lines were used to detect RAB43 levels. Cell Counting Kit8 (CCK8) and colony formation assays were used to analyze cell proliferation. Cell migration and invasion ability were examined by wound healing and transwell assays. Western blot assays and quantitative real‑time PCR (qRT-PCR) were performed to examine related mRNA and protein expression. In vivo experiments were used to examine the effect of RAB43.

RESULTS

Patients with RAB43-positive tumors had worse overall survival than patients with RAB43-negative tumors. Downregulation of RAB43 significantly inhibited cell proliferation and cell metastasis. In contrast, RAB43 overexpression promoted proliferation and metastasis in normal gastric epithelial GES‑1 cells. In vivo studies confirmed that RAB43 promoted tumor growth. In addition, the knockdown of RAB43 significantly inhibited cell proliferation and metastasis via phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway.

CONCLUSION

RAB43 promotes GC cells proliferation and migration in vivo and in vitro and probably served as a novel potential therapeutic biomarker for GC.

Comparison of Long-Term Outcomes of Endoscopic Submucosal Dissection and Surgery for Early Gastric Cancer: a Systematic Review and Meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is an endoscopic alternative to surgical resection of early gastric cancer (EGC). Besides offering both diagnostic and therapeutic capability, it has the benefits of reducing post-operative complications and provides fast recovery and better quality of life compared to surgical resection of neoplastic lesions. However, due to limitations of the procedure, its long-term outcomes are rather controversial.

METHODS

This study has been carried out to investigate the long-term outcomes of ESD which includes the overall survival (OS), disease-free survival (DFS), and recurrence rate. The following databases were used to search for articles published until February 2018: Medline, Cochrane Library, PubMed, Web of Science, and EBSCO.

RESULTS

A total of 13 eligible studies covering 4986 patients were selected for a meta-analysis based on specified inclusion and exclusion criteria. The difference of OS and disease-specific survival (DSS) between ESD and surgical treatment was not statistically significant (RR = 0.90, 95% CI = 0.68-1.19, p = 0.46; RR = 0.40, 95% CI = 0.15-1.03, p = 0.06, respectively). However, DFS in the ESD group was much lower than that in the surgery group (RR = 3.40, 95% CI = 2.39-4.84, p < 0.001). In terms of the treatment after recurrence, the proportion of patients who could receive radical treatment was significantly higher in the ESD than that in the gastrectomy (OR = 5.27, 95% CI = 2.35-11.79, p < 0.001).

CONCLUSIONS

This meta-analysis showed that ESD might be an alternative treatment option to surgery for patients with EGC in Asian countries. But a close surveillance program after ESD is of necessity, considering the higher possibility of tumor recurrence after ESD.

Morphologic pattern analysis of submucosal deformities identified by endoscopic ultrasonography for predicting the depth of invasion in early gastric cancer

BACKGROUND

The aims of this study are to evaluate the usefulness of submucosal deformity pattern analysis with endoscopic ultrasonography (EUS) for predicting the depth of invasion in early gastric cancer (EGC) and the treatment results of endoscopic submucosal dissection (ESD).

METHODS

The endoscopic and EUS parameters of 345 patients with endoscopically suspected EGC who underwent endoscopic or surgical resection between July 2012 and May 2017 were retrospectively reviewed. All patients were classified into three categories as follows according to the morphologic type of submucosal deformity identified by EUS: (1) no submucosal deformity, (2) wedge-shaped deformity, and (3) arch-shaped deformity. The presence of an arch-shaped submucosal deformity on EUS and an active endoscopic ulcer or surrounding mucosal fold convergence/clubbing on conventional endoscopy were defined as suggestive of deep submucosal cancer invasion (SCI).

RESULTS

Upper location (p = 0.034) and the presence of an arch-shaped submucosal deformity on EUS (p < 0.001) were significant predictors of deep submucosal invasion, with the presence of an arch-shaped submucosal deformity showing the highest predictive value (odds ratio of 26.27). The overall diagnostic accuracy of EUS for predicting deep SCI was 83.5%, with a sensitivity of 84.0% and a specificity of 83.3%, which were significantly higher than those of conventional endoscopy. A larger lesion size and the presence of an arch-shaped submucosal deformity were significant factors associated with noncurative resection after ESD.

CONCLUSIONS

Submucosal deformity pattern analysis with EUS can provide more accurate information than conventional endoscopy for predicting deep SCI. The presence of an arch-shaped submucosal deformity on EUS was an effective predictor of deep SCI and noncurative resection.

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.

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.

Technical feasibility and oncologic safety of diagnostic endoscopic resection for superficial esophageal cancer

BACKGROUND AND AIMS

Active use of endoscopic resection (ER) for cM3-SM2 esophageal cancer may enable sufficient extent of esophageal resection and help determine the need for lymph node dissection based on histopathologic findings. However, ER preceding esophagectomy may have an adverse impact on outcomes. This study was designed to determine the technical feasibility and oncologic safety of diagnostic ER.

METHODS

A single-institution retrospective cohort study was performed between July 2008 and June 2014. During this period, 135 consecutive patients with clinical T1a-M3N0M0, T1b-SM1N0M0, and T1b-SM2N0M0 primary esophageal cancer were referred to our division. Eight patients who underwent chemoradiotherapy as primary treatment were excluded because of inadequate pathologic findings. Based on oncologic and physical factors, we categorized the remaining 127 patients into 2 groups: primary esophagectomy (n = 54) and primary ER (n = 73).

RESULTS

In all 127 patients, the 3-year overall survival (OS) and disease-free survival (DFS) rates were 95.7% and 87.6%, respectively. No adverse event requiring surgical intervention was observed after ER. Diagnostic ER had no negative impact on surgical outcomes, DFS, and OS after esophagectomy. Fourteen patients (19.2%) of those who received primary ER underwent curative resection, whereas 11 (20.4%) who had pT1a disease, no lymphovascular invasion, and no pathologic lymph node metastasis underwent primary esophagectomy.

CONCLUSIONS

Diagnostic ER for cM3-SM2 esophageal cancer with or without subsequent esophagectomy was feasible and safe, not only from a surgical perspective but also an oncologic perspective. Approximately 20% of cM3-SM2N0M0 patients can potentially avoid undergoing additional treatment including esophagectomy using diagnostic ER.

Via mucosa incision EUS-guided sampling for the diagnosis of conventional endoscopic biopsy-negative gastric wall thickening

Abnormal thickened lesions of the gastric wall are usually covered with normal mucosa. Conventional endoscopic biopsies often do not yield sufficient positive histological results for clinical treatment. To increase the rate of diagnosis of conventional endoscopic biopsy-negative gastric wall thickening, we used an endoscopic submucosal dissection (ESD)-like sampling method under endoscopic ultrasound (EUS) guidance to obtain tissue of gastric wall-thickening lesions. Between 2012 and 2016, patients with gastric wall thickening (as identified by computed tomography (CT), EUS or other imaging methods that showed no positive findings in repeating conventional endoscopic biopsy) underwent via mucosa incision EUS-guided sampling. Final diagnosis was determined after surgical or biopsy pathology. A total of 10 patients with gastric wall thickening were included in this study. Eight cases received definite results, whereas in two cases the biopsy results were ambiguous and in these two patients poorly differentiated adenocarcinoma was determined by postoperative pathology. The results of the cases presented in this study demonstrated that via mucosa incision EUS-guided sampling provided a complementary option for the diagnosis of conventional endoscopic biopsy-negative gastric wall thickening.