EUS for the staging of gastric cancer: a meta-analysis

Low Absolute Lymphocyte Count Correlates with Lymph Node Metastases and Worse Survival of Patients with Gastric Cancer

BACKGROUND

Several studies have found that the absolute lymphocyte (ALC) or neutrophil count predicts the survival of patients with solid tumors, and that the neutrophil-to-lymphocyte ratio and the prognostic nutritional index are useful markers of gastric cancer prognosis. However, it remains unclear whether the ALC is prognostic of lymph node (LN) metastasis in patients with gastric cancer. In this study, we aimed to explore the impact of ALC on prognosis and distinctive clinical characteristics in patients with gastric cancer.

PATIENTS AND METHODS

The medical records of patients with gastric adenocarcinomas who underwent radical gastrectomy with curative intent at Seoul St. Mary's Hospital and Yeouido St. Mary's Hospital between January 2010 and December 2017 were reviewed. Of these, 4149 patients for whom preoperative white blood cell, neutrophil, and lymphocyte counts were available were enrolled.

RESULTS

In all 4149 patients, ALC gradually decreased as the pN stage increased. Those with an ALC of less than 1360 cells/μL were defined as a low-ALC group, and advanced cT and cN stages were the strongest risk factors for LN metastasis in both univariate and multivariate analyses; undifferentiated tumor histology and a low ALC were also significant risk factors. Patients of all stages in the ALC-low group exhibited poorer prognoses. The ALC-low group also exhibited a higher recurrence rate in a greater proportion of LNs.

CONCLUSIONS

In patients with gastric cancer, as the preoperative ALC decreases, the incidence of LN metastasis increases. A low ALC is associated with a high recurrence rate, particularly in LNs.

Establishment and validation of a risk score model based on EUS: assessment of lymph node metastasis in early gastric cancer

BACKGROUND AND AIMS

Lymph node metastasis significantly affects the prognosis of early gastric cancer patients. EUS plays a crucial role in the preoperative assessment of early gastric cancer. This study evaluated the efficacy of EUS in identifying lymph node metastasis in early gastric cancer patients and developed a risk score model to aid in choosing the best treatment options.

METHODS

We retrospectively analyzed the effectiveness of EUS for detecting lymph node metastasis in early gastric cancer patients. A risk score model for predicting lymph node metastasis preoperatively was created using independent risk factors identified through binary logistic regression analysis and subsequently validated. Receiver operating characteristic curves were generated for both the development and validation cohorts.

RESULTS

The overall accuracy of EUS in identifying lymph node metastasis was 85.3%, although its sensitivity (29.2%) and positive predictive value (38.7%) were relatively low. Patients were categorized based on preoperative risk factors for lymph node metastasis, including tumor size of ≥20 mm, lymph nodes of ≥10 mm, body mass index of ≥24 kg/m2, and lymph node metastasis on CT scans. A 7-point risk score model was developed to assess the likelihood of lymph node metastasis. The areas under the receiver operating characteristic curve for the development and validation sets were 0.842 and 0.837, respectively, with sensitivities of 64% and 79%, respectively.

CONCLUSIONS

We developed a practical risk score model based on preoperative factors to help EUS predict lymph node metastasis in early gastric cancer patients, guiding the selection of optimal treatment approaches for these patients.

Predictive nomogram for lymph node metastasis and survival in gastric cancer using contrast-enhanced computed tomography-based radiomics: a retrospective study

Background

Lymph node involvement significantly impacts the survival of gastric cancer patients and is a crucial factor in determining the appropriate treatment. This study aimed to evaluate the potential of enhanced computed tomography (CT)-based radiomics in predicting lymph node metastasis (LNM) and survival in patients with gastric cancer before surgery.

Methods

Retrospective analysis of clinical data from 192 patients diagnosed with gastric carcinoma was conducted. The patients were randomly divided into a training cohort (n = 128) and a validation cohort (n = 64). Radiomic features of CT images were extracted using the Pyradiomics software platform, and distinctive features were further selected using a Lasso Cox regression model. Features significantly associated with LNM were identified through univariate and multivariate analyses and combined with radiomic scores to create a nomogram model for predicting lymph node involvement before surgery. The predictive performance of radiomics features, CT-reported lymph node status, and the nomogram model for LNM were compared in the training and validation cohorts by plotting receiver operating characteristic (ROC) curves. High-risk and low-risk groups were identified in both cohorts based on the cut-off value of 0.582 within the radiomics evaluation scheme, and survival rates were compared.

Results

Seven radiomic features were identified and selected, and patients were stratified into high-risk and low-risk groups using a 0.582 cut-off radiomics score. Univariate and multivariate analyses revealed that radiomics features, diabetes mellitus, Nutrition Risk Screening (NRS) 2002 score, and CT-reported lymph node status were significant predictors of LNM in patients with gastric cancer. A predictive nomogram model was developed by combining these predictors with the radiomics score, which accurately predicted LNM in gastric cancer patients before surgery and outperformed other models in terms of accuracy and sensitivity. The AUC values for the training and validation cohorts were 0.82 and 0.722, respectively. The high-risk and low-risk groups in both the training and validation cohorts showed significant differences in survival rates.

Conclusion

The radiomics nomogram, based on contrast-enhanced computed tomography (CECT ), is a promising non-invasive tool for preoperatively predicting LNM in gastric cancer patients and postoperative survival.

Application of artificial intelligence in endoscopic gastrointestinal tumors

With an increasing number of patients with gastrointestinal cancer, effective and accurate early diagnostic clinical tools are required provide better health care for patients with gastrointestinal cancer. Recent studies have shown that artificial intelligence (AI) plays an important role in the diagnosis and treatment of patients with gastrointestinal tumors, which not only improves the efficiency of early tumor screening, but also significantly improves the survival rate of patients after treatment. With the aid of efficient learning and judgment abilities of AI, endoscopists can improve the accuracy of diagnosis and treatment through endoscopy and avoid incorrect descriptions or judgments of gastrointestinal lesions. The present article provides an overview of the application status of various artificial intelligence in gastric and colorectal cancers in recent years, and the direction of future research and clinical practice is clarified from a clinical perspective to provide a comprehensive theoretical basis for AI as a promising diagnostic and therapeutic tool for gastrointestinal cancer.

Diagnostic value of conventional endoscopic ultrasound for lymph node metastasis in upper gastrointestinal neoplasia: A meta-analysis

BACKGROUND

Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer, both of which have high morbidity and mortality. Lymph node metastasis (LNM), as the most common metastasis mode of both diseases, is an important factor affecting tumor stage, treatment strategy and clinical prognosis. As a new fusion technology, endoscopic ultrasound (EUS) is becoming increasingly used in the diagnosis and treatment of digestive system diseases, but its use in detecting LNM in clinical practice remains limited.

AIM

To evaluate the diagnostic value of conventional EUS for LNM in upper gastrointestinal neoplasia.

METHODS

Using the search mode of "MeSH + Entry Terms" and according to the predetermined inclusion and exclusion criteria, we conducted a comprehensive search and screening of the PubMed, EMBASE and Cochrane Library databases from January 1, 2000 to October 1, 2022. Study data were extracted according to the predetermined data extraction form. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool, and the results of the quality assessment were presented using Review Manager 5.3.5 software. Finally, Stata14.0 software was used for a series of statistical analyses.

RESULTS

A total of 22 studies were included in our study, including 2986 patients. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic score and diagnostic odds ratio of conventional EUS in the diagnosis of upper gastrointestinal neoplasia LNM were 0.62 [95% confidence interval (CI): 0.50-0.73], 0.80 (95%CI: 0.73-0.86), 3.15 (95%CI: 2.46-4.03), 0.47 (95%CI: 0.36-0.61), 1.90 (95%CI: 1.51-2.29) and 6.67 (95%CI: 4.52-9.84), respectively. The area under the summary receiver operating characteristic curve was 0.80 (95%CI: 0.76-0.83). Sensitivity analysis indicated that the results of the meta-analysis were stable. There was considerable heterogeneity among the included studies, and the threshold effect was an important source of heterogeneity. Univariable meta-regression and subgroup analysis showed that tumor type, sample size and EUS diagnostic criteria were significant sources of heterogeneity in specificity (P < 0.05). No significant publication bias was found.

CONCLUSION

Conventional EUS has certain clinical value and can assist in the detection of LNM in upper gastrointestinal neoplasia, but it cannot be used as a confirmatory or exclusionary test.

Endoscopic advances in the management of gastric cancer and premalignant gastric conditions

Gastric cancer is the fifth most common cancer and in 2018, it was the third most common cause of cancer-related deaths worldwide. Endoscopic advances continue to be made for the diagnosis and management of both early gastric cancer and premalignant gastric conditions. In this review, we discuss the epidemiology and risk factors of gastric cancer and emphasize the differences in early vs late-stage gastric cancer outcomes. We then discuss endoscopic advances in the diagnosis of early gastric cancer and premalignant gastric lesions. This includes the implementation of different imaging modalities such as narrow-band imaging, chromoendoscopy, confocal laser endomicroscopy, and other experimental techniques. We also discuss the use of endoscopic ultrasound in the diagnosis and staging of early gastric cancer. We then discuss the endoscopic advances made in the treatment of these conditions, including endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid techniques such as laparoscopic endoscopic cooperative surgery. Finally, we comment on the current suggested recommendations for surveillance of both gastric cancer and its premalignant conditions.

Gastric cancer in 2022: Is there still a role for endoscopic ultrasound?

Gastric cancer (GC) represents the fourth leading cause of cancer death worldwide and many factors can influence its development (diet, geographic area, genetic, Helicobacter pylori or Epstein-Barr virus infections). High quality endoscopy represents the modality of choice for GC diagnosis. The correct morphologic classification during a high-resolution endoscopy is fundamental for oncologic diagnosis, staging and therapeutic decisions. Since its initial introduction in clinical practice the endoscopic ultrasound (EUS) has been considered a valuable tool for tumor (T-) and lymph nodes (N-) staging also in GC, in order to establish the best therapeutic strategy for the patient (e.g., upfront surgery vs neoadjuvant treatments). EUS tools as elastography, Doppler and contrast administration can improve diagnosis mainly in case of malignant lymph node evaluation. EUS has a marginal role in disease staging but has a fundamental role in case of a pre-endoscopic resection management and in the new era of endoscopic mucosal resection or submucosal dissection as minimally invasive surgery. Diagnosis and locoregional staging of GC with EUS are a method of inarguable value for the assessment of gastric wall involvement and presence of infiltrated paragastric lymph nodes. EUS can also have a role in disease restaging in those patients who have undergone neoadjuvant treatment. EUS can also have a role in the advanced phases of the disease, in facilitating palliative, minimally-invasive treatments, such as gastroenterostomy or biliary drainages. This review intends to discuss the modern role of EUS in GC topic.

Endoscopic Submucosal Dissection in the Stomach and Duodenum: Techniques, Indications, and Outcomes

Gastric endoscopic submucosal dissection (ESD) is established for management of early gastric cancer (EGC). Diagnosis of EGC relies on adequate endoscopic assessment involving lesion size, histopathology, presence of ulceration, and depth of invasion. Absolute indications for endoscopic resection of EGC are if patients are presumed to have a less than 1% risk of lymph node metasta endoscopic submucosal dissectionsis, and long-term outcomes are similar to those with surgical gastrectomy. Duodenal ESD is more technically difficult and requires expertise in ESD in other locations.

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

Prophylactic surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC CO2) versus standard surgery for gastric carcinoma at high risk of peritoneal carcinomatosis: short and long-term outcomes (GOETH STUDY)-a collaborative randomized controlled trial by ACOI, FONDAZIONE AIOM, SIC, SICE, and SICO

INTRODUCTION

At the time of diagnosis, 15-20% of gastric carcinomas are in stage T4 or T4b. Furthermore, 5-20% of patients undergoing potentially curative surgery suffer from synchronous or metachronous peritoneal metastases. To date, neither surgery nor systemic chemotherapy successfully controls peritoneal dissemination, offering a limited impact on survival. Peritoneal metastases are in fact responsible for death in around 60% of gastric cancer patients. Several Eastern studies in the past have focused on hyperthermic intraperitoneal chemotherapy (HIPEC) as a prophylactic measure in patients with serosal extension, nodal involvement, and positive peritoneal fluid cytology. Therefore, a new multimodal therapeutic strategy based on aggressive surgery plus new locoregional treatment may prolong survival in this particular clinical scenario.

METHODS

This study compares the efficacy of prophylactic surgery (radical gastric resection, appendectomy, resection of the round ligament of the liver, and bilateral adnexectomy) plus hybrid CO2 HIPEC system versus standard surgery in patients with T3-T4 N0-N + gastric adenocarcinoma. Patients will be randomly assigned (1:1 ratio) to the experimental arm or standard surgery. The primary endpoint is to establish the difference in disease-free survival between the groups. The secondary objective is to compare the safety and tolerability of prophylactic surgery plus HIPEC CO₂ versus standard surgery.

DISCUSSION

Considering the poor prognosis of patients with peritoneal dissemination from gastric cancer, a prophylactic strategy to prevent peritoneal metastases may be beneficial. In patients with gastric cancer at high risk of peritoneal carcinomatosis, we propose aggressive surgical treatment with radical gastrectomy, removal of organs at risk of harbouring tumour cells, and HIPEC.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03917173. Registered on 16 April 2019.

PROTOCOL VERSION

v1, March 27, 2019. Protocol number: IRFMN-GCC-7813. EudraCT number: 2019-001478-27.

Clinical outcomes of gastroduodenal neuroendocrine tumors according to their WHO grade: A single-institutional retrospective analysis

The management of gastroduodenal neuroendocrine tumor (NET) has been controversial between radical surgical resection and local excision including endoscopic resection. A gastroduodenal NET grade (G), measured by their mitotic rate and Ki67 proliferation index, is important to predict prognosis. In this study, we aimed to compare the clinical outcomes of gastroduodenal NET according to grades in order to identify poor prognostic factors of gastroduodenal NETs. Fifty-four gastroduodenal NETs diagnosed between December 2008 and December 2020 in a tertiary referral hospital were retrospectively reviewed. The clinical outcomes of gastroduodenal NETs, according to tumor grades and factors associated with NET G2-3, were analyzed. A total of 52 gastroduodenal NET patients was enrolled. The mean follow-up period was 56.2 ± 40.1 months. The mean size of gastric and duodenal NET was 7.9 ± 11.0 mm and 9.8 ± 7.6 mm, respectively. During the study period, 72.7% (16/22) of gastric NETs and 83.3% (25/30) of duodenal NETS were G1. All G1 gastroduodenal NETs showed no lymph node or distant metastasis during the study periods. All G3 gastroduodenal NETs showed metastasis (one lymph node metastasis and 3 hepatic metastases). Among metastatic NETs, the smallest tumor size was a 13 mm gastric G3 NET. Factors associated with G2-3 NETs were larger tumor size, mucosal ulceration, proper muscle or deeper invasion, and lymphovascular invasion. A small-sized gastroduodenal NET confined to submucosa without surface ulceration may be suitable for endoscopic resection. After local resection of a gastroduodenal NET (G1) without lymphovascular and muscle proper invasion, follow-up examination without radical surgical resection can be recommended. G3 NETs may be treated by radical surgical resection, regardless of tumor size.

Current and future imaging modalities in gastric cancer

Gastric adenocarcinoma treatment can include endoscopic mucosal resection, surgery, chemotherapy, radiation, and palliative measures depending on staging. Both invasive and noninvasive staging techniques have been used to dictate the best treatment pathway. Here, we review the current imaging modalities used in gastric cancer as well as novel techniques to accurately stage and screen these patients.

Significance of Lymph Node Metastasis in the Treatment of Gastric Cancer and Current Challenges in Determining the Extent of Metastasis

The stomach exhibits abundant lymphatic flow, and metastasis to lymph nodes is common. In the case of gastric cancer, there is a regularity to the spread of lymph node metastasis, and it does not easily metastasize outside the regional nodes. Furthermore, when its extent is limited, nodal metastasis of gastric cancer can be cured by appropriate lymph node dissection. Therefore, identifying and determining the extent of lymph node metastasis is important for ensuring accurate diagnosis and appropriate surgical treatment in patients with gastric cancer. However, precise detection of lymph node metastasis remains difficult. Most nodal metastases in gastric cancer are microscopic metastases, which often occur in small-sized lymph nodes, and are thus difficult to diagnose both preoperatively and intraoperatively. Preoperative nodal diagnoses are mainly made using computed tomography, although the specificity of this method is low because it is mainly based on the size of the lymph node. Furthermore, peripheral nodal metastases cannot be palpated intraoperatively, nodal harvesting of resected specimens remains difficult, and the number of lymph nodes detected vary greatly depending on the skill of the technician. Based on these findings, gastrectomy with prophylactic lymph node dissection is considered the standard surgical procedure for gastric cancer. In contrast, several groups have examined the value of sentinel node biopsy for accurately evaluating nodal metastasis in patients with early gastric cancer, reporting high sensitivity and accuracy. Sentinel node biopsy is also important for individualizing and optimizing the extent of uniform prophylactic lymph node dissection and determining whether patients are indicated for function-preserving curative gastrectomy, which is superior in preventing post-gastrectomy symptoms and maintaining dietary habits. Notably, advancements in surgical treatment for early gastric cancer are expected to result in individualized surgical strategies with sentinel node biopsy. Chemotherapy for advanced gastric cancer has also progressed, and conversion gastrectomy can now be performed after downstaging, even in cases previously regarded as inoperable. In this review, we discuss the importance of determining lymph node metastasis in the treatment of gastric cancer, the associated difficulties, and the need to investigate strategies that can improve the diagnosis of lymph node metastasis.

Life prognosis of sentinel node navigation surgery for early-stage gastric cancer: Outcome of lymphatic basin dissection

BACKGROUND

Lymphatic basin dissection is a sentinel node biopsy method that is specific for gastric cancer. In this method, the dyed lymphatic system is dissected en bloc, and sentinel nodes are identified at the back table (ex vivo). Even with lymphatic basin dissection, blood flow to the residual stomach can be preserved, and function-preserving curative gastrectomy can be performed. The oncological safety of function-preserving curative gastrectomy combined with lymphatic basin dissection has not yet been fully investigated. We hypothesized that the oncological safety of sentinel node navigation surgery (SNNS) is not inferior to that of the guidelines.

AIM

To investigate the life prognosis of SNNS for gastric cancer in comparison with guidelines surgery.

METHODS

This was a retrospective cohort study. Patients were selected from gastric cancer patients who underwent sentinel node biopsy from April 1999 to March 2016. Patients from April 1999 to August 2008 were from the Department of Surgery II, Kanazawa University Hospital, and patients from August 2009 to March 2016 were from the Department of Surgical Oncology, Kanazawa Medical University Hospital. Patients who were diagnosed with gastric cancer, which was preoperatively diagnosed as superficial type (type 0), 5 cm or less in length, clinical T1-2 and node negative, and underwent various gastrectomies guided by sentinel node navigation were retrospectively collected. The overall survival (OS) and relapse-free survival (RFS) of these patients (SNNS group) were investigated. Patients with gastric cancer of the same stage and who underwent guidelines gastrectomy with standard nodal dissection were also selected as the control group.

RESULTS

A total of 239 patients in the SNNS group and 423 patients in the control group were included. Pathological nodal metastasis was observed in 10.5% and 10.4% of the SNNS and control groups, respectively. The diagnostic abilities of sentinel node biopsy were 84% and 98.6% for sensitivity and accuracy, respectively. In the SNNS group, 81.6% of patients underwent modified gastrectomy or function-preserving curative gastrectomy with lymphatic basin dissection, in which the extent of nodal dissection was further reduced compared to the guidelines. The OS rate in the SNNS group was 96.8% at 5 years and was significantly better than 91.3% in the control group (P = 0.0014). The RFS rates were equal in both groups. After propensity score matching, there were 231 patients in both groups, and the cumulative recurrence rate was 0.43% at 5 years in the SNNS group and 1.30% in the control group, which was not statistically different.

CONCLUSION

The oncological safety of patients who undergo gastrectomy guided by sentinel node navigation is not inferior to that of the guidelines surgery.

Diagnostic Efficacy and Decision-Making Role of Preoperative Endoscopic Ultrasonography in Early Gastric Cancer

Objectives: Endoscopic ultrasonography (EUS) is the most commonly used method for T staging of early gastric cancer (EGC). However, the studies pertaining to EUS for staging EGC reported widely varied sensitivities and specificities. This study aimed to estimate the overall diagnostic accuracy of EUS for staging the depth of EGCs and to explore the influential factors. Methods: We retrospectively reviewed data from 208 consecutive patients with EGC, and all patients underwent EUS for estimating tumor invasion depth, followed by either curative surgery or endoscopic submucosal dissection (ESD). The diagnostic accuracy of EUS was evaluated by comparing the final histologic results of resected specimens. The correlation between accuracy of EUS and characteristics of EGC lesion was analyzed. Results: A total of 211 EGC lesions in 208 patients were included. The overall diagnostic accuracy of EUS in assessing the tumor invasion depth of EGC was 55.9%. Multivariate analysis showed that submucosal invasion (OR 2.615; 95% CI 1.203-5.684, P = 0.015) was independently associated with misdiagnosis of the depth of EGC and 0-III type lesions (OR 31.495; 95% CI 2.083-476.256, P = 0.013) were an independent risk factor for over-diagnosis of invasion depth by EUS. However, EUS was only suitable for lesions within absolute indications for endoscopic resection. Conclusions: The overall accuracy of EUS in diagnosing invasion depth of EGC was relatively low. Thus, EUS is not necessary routinely for determining the therapeutic strategy for EGC.

[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.

Application of artificial intelligence-driven endoscopic screening and diagnosis of gastric cancer

The landscape of gastrointestinal endoscopy continues to evolve as new technologies and techniques become available. The advent of image-enhanced and magnifying endoscopies has highlighted the step toward perfecting endoscopic screening and diagnosis of gastric lesions. Simultaneously, with the development of convolutional neural network, artificial intelligence (AI) has made unprecedented breakthroughs in medical imaging, including the ongoing trials of computer-aided detection of colorectal polyps and gastrointestinal bleeding. In the past demi-decade, applications of AI systems in gastric cancer have also emerged. With AI’s efficient computational power and learning capacities, endoscopists can improve their diagnostic accuracies and avoid the missing or mischaracterization of gastric neoplastic changes. So far, several AI systems that incorporated both traditional and novel endoscopy technologies have been developed for various purposes, with most systems achieving an accuracy of more than 80%. However, their feasibility, effectiveness, and safety in clinical practice remain to be seen as there have been no clinical trials yet. Nonetheless, AI-assisted endoscopies shed light on more accurate and sensitive ways for early detection, treatment guidance and prognosis prediction of gastric lesions. This review summarizes the current status of various AI applications in gastric cancer and pinpoints directions for future research and clinical practice implementation from a clinical perspective.

A comprehensive update on early gastric cancer: defining terms, etiology, and alarming risk factors

INTRODUCTION

Early gastric cancer (EGC) is a well-defined gastric malignancy that is limited to the mucosa or submucosa, irrespective of lymph node metastasis. At an early stage, gastric cancer often does not cause symptoms until it becomes advanced, and it is a heterogeneous disease and usually encountered in its late stages.

AREA COVERED

This comprehensive review will provide a novel insight into the evaluation of EGC epidemiology, defining terms, extensive etiology and risk factors, and timely diagnosis since prevention is an essential approach for controlling this cancer and reducing its morbidity and mortality.

EXPERT OPINION

The causative manner of EGC is complex and multifactorial. In recent years, researchers have made significant contributions to understanding the etiology and pathogenesis of EGC, and standardization in the evaluation of disease activity. Though the incidence of this cancer is steadily declining in some advanced societies owing to appropriate interventions, there remains a serious threat to health in developing nations. Early detection of resectable gastric cancer is crucial for better patient outcomes.

Endoscopic Ultrasound Quality Metrics in Clinical Practice

Recent advances in endoscopic ultrasound (EUS), particularly EUS-guided tissue acquisition, may have affected EUS procedural performance as measured by current American Society for Gastrointestinal Endoscopy (ASGE)/American College of Gastroenterology (ACG) quality indicators. Our study aims to assess how these quality metrics are met in clinical practice. We retrospectively analyzed 732 EUS procedures; data collected were procedural indications, technical aspects and outcomes, completeness of documentation, and malignancy staging. EUS was performed in 660 patients for a variety of indications. All ASGE/ACG EUS procedural quality metrics were met or exceeded. Intervention was successful in 97.7% (715/732) of cases, with complication rate of 0.4% (3/732). EUS outcomes changed clinical management in 58.7% of all cases and in 91.2% of malignancy work-up cases; in 26.0% of suspected choledocholithiasis cases, endoscopic retrograde cholangiopancreatography (ERCP) was avoided after EUS. Locoregional EUS staging was accurate in 61/65 (93.8%) cases of non-metastatic disease and in 15/22 (68.2%) cases of metastatic disease. Pancreatic mass malignancy detection rate with EUS-guided fine needle aspiration (FNA) or fine needle biopsy (FNB) was 75.8%, with a sensitivity of 96.2%; a significant increase in detection rate from 46.2% (6/13) to 95.0% (19/20) (p = 0.0026) was observed with a transition to the predominant use of FNB for tissue acquisition. All ASGE/ACG EUS quality metrics were met or exceeded for EUS procedures performed for a wide variety of indications in a diverse patient population. EUS was instrumental in changing clinical management, with a low complication rate. The malignancy detection rate in pancreatic masses significantly increased with FNB use.

Hierarchical Analysis of Factors Associated with T Staging of Gastric Cancer by Endoscopic Ultrasound

BACKGROUND

Size, ulcer, differentiation, and location are known to be factors affecting the T stage accuracy of EUS in gastric cancer. However, whether an interaction exists among recognized variables is poorly understood. The aim of this study was to identify the combinatorial characteristics of group with high overestimation rate to determine which group should be considered carefully for EUS-based treatment plans.

METHODS

We retrospectively analyzed early gastric cancer patients who underwent EUS from 2005 to 2016. The accuracy of EUS T stage and factors affecting over-/underestimation were examined by using decision tree analysis, the CHAID method.

RESULTS

The most significant factor affecting the accuracy of the EUS T stage was the size. The rate of overestimation was higher in lesions > 3 cm (37.2% vs. 28.8% vs. 17.1%, p < 0.001). In lesions > 3 cm, the rate of overestimation was higher in lesions with an ulcer (62.1% vs. 35.0%, p < 0.001). Moreover, for lesions ≤ 3 cm, the accuracy of the EUS T stage was more affected by differentiation and location. The rate of overestimation was higher in undifferentiated-type lesions ≤ 2 cm (24.5% vs. 13.9%, p < 0.001) and 2-3 cm (33.3% vs. 25.7%, p = 0.011). In the differentiated type, the location affected the accuracy of the EUS T stage.

CONCLUSION

In this hierarchical analysis, the rate of overestimation was higher in lesions > 3 cm with ulcer, lesions > 3 cm irrespective of ulcer, and undifferentiated-type lesions measuring 2-3 cm.

Inaccurate Clinical Stage Is Common for Gastric Adenocarcinoma and Is Associated with Undertreatment and Worse Outcomes

BACKGROUND

Accurate clinical staging (CS) of gastric cancer is critical for appropriate treatment selection and prognostication, but CS remains highly imprecise. Our study evaluates factors associated with inaccurate CS, the impact of inaccurate CS on outcomes, and utilization of adjuvant therapy in patients who are understaged.

METHODS

We conducted a retrospective review of NCDB patients diagnosed with clinical early stage gastric adenocarcinoma (cT1-2N0M0) between 2004 and 2016. Patients not undergoing upfront gastrectomy or with missing pathologic staging were excluded. Patients were classified as accurately staged, inaccurately staged with receipt of adjuvant therapy (IS+), and inaccurately staged with no receipt of adjuvant therapy (IS-). Logistic regression was utilized to assess the impact of factors on CS accuracy and receipt of adjuvant therapies. Kaplan-Meier and Cox proportional hazard methods were used for survival analysis.

RESULTS

Approximately 40% of patients were inaccurately staged (IS). cT2, moderately/poorly differentiated, and site-overlapping tumors were associated with increased likelihood of being IS. Treatment at an academic facility was associated with decreased likelihood of understaging. Only 54% of patients who were IS received adjuvant therapy.

CONCLUSION

Accurate CS of gastric cancer remains inadequate. Understaging is associated with detrimental effects on receiving guideline-concordant care and, possibly, patient outcomes. Targeted interventions reducing the proportion of understaged patients and ensuring receipt of appropriate therapy is needed to optimize outcomes. Patients with high-risk disease that are frequently understaged may benefit from selective neoadjuvant therapy. Centralization of gastric cancer care may also be a key strategy in improving receipt of guideline-concordant therapies.

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 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.

Gastric cancer: development and validation of a CT-based model to predict peritoneal metastasis

BACKGROUND

The sensitivity of computed tomography (CT) for the detection of peritoneal metastasis (PM) of advanced gastric cancer (AGC) is relatively low.

PURPOSE

To develop a predictive model to improve the sensitivity of PM detection and to externally validate this model.

MATERIAL AND METHODS

We analyzed data from 78 patients with PM, who had undergone preoperative CT and subsequent surgery between January 2012 and December 2014, and 101 controls to form a derivation set, retrospectively. The following CT findings were evaluated: tumor size; Bormann type 4; enlarged lymph node; indirect findings of PM (peritoneal thickening, fat stranding, plaques or nodules on the peritoneum, and ascites); and definitive findings of PM (omental cake and rectal shelf). A predictive model was created using multivariate logistic regression. Receiver operating characteristic (ROC) analyses were performed to assess the diagnostic performance of the model. The accuracy was externally validated at other hospitals on 31 patients with PM and 48 patients without PM.

RESULTS

Tumor size >5.2 cm, Bormann type 4, enlarged lymph node, peritoneal plaques or nodules, and ascites were independently associated with PM. It was able to predict PM with a higher area under the ROC curve (AUC) and sensitivity than definitive findings of PM (AUC 0.903 vs. 0.647, sensitivity 92.3% vs. 38.3%). External validation confirmed the predictive power with good inter-observer agreement.

CONCLUSION

The CT-driven model shows higher AUC and sensitivity for prediction of PM and may help decision-making with the aim of improving care for patients with AGC.

Gastric Cancer Staging: Is It Time for Magnetic Resonance Imaging?

Gastric cancer (GC) is a common cancer worldwide. Its incidence and mortality vary depending on geographic area, with the highest rates in Asian countries, particularly in China, Japan, and South Korea. Accurate imaging staging has become crucial for the application of various treatment strategies, especially for curative treatments in early stages. Unfortunately, most GCs are still diagnosed at an advanced stage, with the peritoneum (61-80%), distant lymph nodes (44-50%), and liver (26-38%) as the most common metastatic locations. Metastatic disease is limited to the peritoneum in 58% of cases; in nonperitoneal distant metastases, the most involved GC metastasization site is the liver (82%). The eighth edition of the tumor-node-metastasis staging system is the most commonly used system for determining GC prognosis. Endoscopic ultrasonography, computed tomography, and 18-fluorideoxyglucose positron emission tomography are historically the most accurate imaging techniques for GC staging. However, studies have recently shown renewed interest in magnetic resonance imaging (MRI) as a useful tool in GC staging, especially for distant metastasis assessment. The technical improvement of diffusion-weighted imaging and the increasing use of hepatobiliary contrast agents have been shown to increase the diagnostic performance of MRI, particularly for detecting peritoneal and liver metastasis. However, no principal oncological guidelines have included the use of MRI as a first-line technique for distant metastasis evaluation during the GC staging process, such as the National Comprehensive Cancer Network Guidelines. This review analyzed the role of the principal imaging techniques in GC diagnosis and staging, focusing on the potential role of MRI, especially for assessing peritoneal and liver metastases.

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.

A Lesion-Based Convolutional Neural Network Improves Endoscopic Detection and Depth Prediction of Early Gastric Cancer

In early gastric cancer (EGC), tumor invasion depth is an important factor for determining the treatment method. However, as endoscopic ultrasonography has limitations when measuring the exact depth in a clinical setting as endoscopists often depend on gross findings and personal experience. The present study aimed to develop a model optimized for EGC detection and depth prediction, and we investigated factors affecting artificial intelligence (AI) diagnosis. We employed a visual geometry group(VGG)-16 model for the classification of endoscopic images as EGC (T1a or T1b) or non-EGC. To induce the model to activate EGC regions during training, we proposed a novel loss function that simultaneously measured classification and localization errors. We experimented with 11,539 endoscopic images (896 T1a-EGC, 809 T1b-EGC, and 9834 non-EGC). The areas under the curves of receiver operating characteristic curves for EGC detection and depth prediction were 0.981 and 0.851, respectively. Among the factors affecting AI prediction of tumor depth, only histologic differentiation was significantly associated, where undifferentiated-type histology exhibited a lower AI accuracy. Thus, the lesion-based model is an appropriate training method for AI in EGC. However, further improvements and validation are required, especially for undifferentiated-type histology.

Role of D2 gastrectomy in gastric cancer with clinical para-aortic lymph node metastasis

BACKGROUND

Owing to the technical difficulty of pathological diagnosis, imaging is still the most commonly used method for clinical diagnosis of para-aortic lymph node metastasis (PALM) and evaluation of therapeutic effects in gastric cancer, which leads to inevitable false-positive findings in imaging. Patients with clinical PALM may have entirely different pathological stages (stage IV or not), which require completely different treatment strategies. There is no consensus on whether surgical intervention should be implemented for this group of patients. In particular, the value of D2 gastrectomy in a multidisciplinary treatment (MDT) approach for advanced gastric cancer with clinical PALM remains unknown.

AIM

To investigate the value of D2 gastrectomy in a MDT approach for gastric cancer patients with clinical PALM.

METHODS

In this real-world study, clinico-pathological data of all gastric cancer patients treated at the Cancer Hospital, Chinese Academy of Medical Sciences between 2011 and 2016 were reviewed to identify those with clinically enlarged PALM. All the clinico-pathological data were prospectively documented in the patient medical record. For all the gastric cancer patients with advanced stage disease, especially those with suspicious distant metastasis, the treatment methods were determined by a multidisciplinary team.

RESULTS

In total, 48 of 7077 primary gastric cancer patients were diagnosed as having clinical PALM without other distant metastases. All 48 patients received chemotherapy as the initial treatment. Complete or partial response was observed in 39.6% (19/48) of patients in overall and 52.1% (25/48) of patients in the primary tumor. Complete response of PALM was observed in 50.0% (24/48) of patients. After chemotherapy, 45.8% (22/48) of patients received D2 gastrectomy, and 12.5% (6/48) of patients received additional radiotherapy. The postoperative major complication rate and mortality were 27.3% (6/22) and 4.5% (1/22), respectively. The median overall survival and progression-free survival of all the patients were 18.9 and 12.1 mo, respectively. The median overall survival of patients who underwent surgical resection or not was 50.7 and 12.8 mo, respectively. The 3-year and 5-year survival rates were 56.8% and 47.3%, respectively, for patients who underwent D2 resection. Limited PALM and complete response of PALM after chemotherapy were identified as favorable factors for D2 gastrectomy.

CONCLUSION

For gastric cancer patients with radiologically suspicious PALM that responds well to chemotherapy, D2 gastrectomy could be a safe and effective treatment and should be adopted in a MDT approach for gastric cancer with clinical PALM.

Endoscopic ultrasonography for pretreatment T-staging of gastric cancer: An in vitro accuracy and discrepancy analysis

In the current era of multi-disciplinary treatment, precise and detailed diagnosis prior to treatment is crucial for clinical practice. For different lesions that fit different indications, the optimum approach for treatment differs significantly. Thus, the recent 8th American Joint Committee on Cancer classification system has introduced 'clinical stage' as a criterion. Endoscopic ultrasonography (EUS) has been the first-line choice for pretreatment staging; however, there is no standardization of the depth classification nor a standard EUS method. Additionally, the accuracy for this diagnostic test has ranged between <40 and 90% in previous studies. The aim of the present study was to determine the accuracy of EUS, identify the discrepancies between EUS and histological results, and analyze the underlying causes. Between June 2014 and February 2016, EUS was performed on gastric carcinoma specimens from 60 consecutive patients. EUS was performed on the resected specimens following surgery, but prior to fixation in formalin, invasion of the gastric wall was determined and the deepest location was marked with sutures. The ultrasound images were independently interpreted, and the quality of the images was scored by two endoscopists. Subsequently, the ultrasound images were compared with the pathological results of the same section. The overall accuracy of EUS was 75%. For locally advanced gastric cancers, EUS had a relatively high accuracy (33/43, 86%). The EUS results corresponded well with the pathological hematoxylin and eosin staining results, and the deepest points determined by EUS were confirmed by pathology in the majority of cases (85%). In total, 50 and 10 cases were scored as having high/moderate and low quality, associated with accuracies of 86% (43/50) and 20% (2/10), respectively. EUS is valuable for pretreatment T-staging, particularly for advanced cases. Proximal stomach cancer exhibited a tendency for improved accuracy. Overall, the results of the present study suggest that standardized scanning processes, particularly including all-encompassing scanning, proper probe-placement and high image quality, lead to improved accuracy of EUS.

A Single-Center Experience of Endoscopic Resection for Early Gastric Cancer with Lymphoid Stroma

Purpose

This study aimed to evaluate immediate outcomes and clinical courses of patients with early gastric carcinoma with lymphoid stroma (GCLS) who underwent endoscopic resection.

Materials and Methods

We retrospectively reviewed the medical records of 40 patients (mean age, 56.9 years; 90.0% male) who underwent endoscopic resection and were pathologically diagnosed with GCLS confined to the mucosa or to the submucosa between March 1998 and December 2017.

Results

Forty GCLS lesions in 40 patients were treated using endoscopic resection. Only 4 (10%) patients received diagnosis of GCLS before endoscopic resection. Fourteen (35.0%) lesions were intramucosal cancers and 26 (65.0%) exhibited submucosal invasion. En bloc resection (97.5%) was achieved for all lesions except one, with no significant complications. The complete resection rate was 85.0% (34 of 40 lesions). After endoscopic resection, 17 patients were referred for surgery and underwent gastrectomy with lymph node (LN) dissection because of deep submucosal invasion (n=16) and misclassification as undifferentiated cancer (n=1). No LN metastasis was determined in the specimens obtained during surgery. During a mean follow-up period of 49.7 months for 23 patients without surgical treatment, no regional LN enlargements, distant metastases, or gastric cancer-related deaths were found, although 1 metachronous lesion (undifferentiated adenocarcinoma, follow-up duration: 7 months) was observed.

Conclusions

In patients with early GCLS, endoscopic resection is technically feasible and has favorable clinical outcomes. Therefore, endoscopic resection might represent an alternative treatment modality in patients with early GCLS with a low likelihood of LN metastasis.

Accuracy of endoscopic ultrasound in gastric adenocarcinoma patient selection for neoadjuvant therapy

Background

Recent studies demonstrated the positive impact of neoadjuvant treatment in locally advanced gastric cancer.

Objective

To assess the accuracy of endoscopic ultrasound (EUS) in the selection of patients with gastric adenocarcinoma for neoadjuvant therapy (T ≥ 2 and/or N+).

Methods

Retrospective analysis of patients with an anatomopathological diagnosis of gastric adenocarcinoma between January 2011 and June 2017, who had EUS for staging and underwent surgery as a first therapeutic attempt. The concordance (k) and accuracy (area under the curve (AUC)) of EUS for T ≥ 2 and/or N+ were assessed using the anatomopathological staging of the resected surgical specimen as the gold standard.

Results

The final sample included 152 patients (66.4% male, 67.1 ± 12.2 years). The concordance, accuracy, sensitivity and specificity of the EUS for T ≥ 2 and/or N+ were 0.72, 0.86 ± 0.03, 88.5% and 83.1%, respectively. The results were higher in proximal (k = 0.93, AUC = 0.96 ± 0.05, sensitivity (S) = 99.0% and specificity (E) = 90.9%) compared with distal lesions (k = 0.67, AUC = 0.84 ± 0.04, S = 85.7% and E = 81.5%), and in intestinal subtype (k = 0.77, AUC = 0.88 ± 0.04, S = 92.6% and E = 84.1%) compared with diffuse (k = 0.58, AUC = 0.79 ± 0.10, S = 85.0% and E = 72.7%) or mixed-subtype tumours (k = 0.65, AUC = 0.84 ± 0.10, S = 76.9% and E = 90.0%).

Conclusion

In one of the largest series of patients, we showed that EUS has overall high agreement and accuracy in the selection of patients with gastric adenocarcinoma for neoadjuvant therapy, although the agreement and accuracy are greater for proximal and intestinal lesions.

Clinical efficacy of endoscopic ultrasonography for decision of treatment strategy of gastric cancer

BACKGROUND

Accurate preoperative tumor staging of gastric cancer is indispensable with expansion of indications for laparoscopic surgery and endoscopic resection. It is important to distinguish mucosal cancer (T1a) in smaller lesion and differentiate early gastric cancer (EGC) in larger lesion considering endoscopic resection indication and laparoscopic surgery indication. We evaluated the clinical outcomes of endoscopic ultrasonography (EUS) for the decision of treatment strategy of gastric cancer compared with pathological staging.

METHODS

The patients who underwent EUS and surgical or endoscopic resection for gastric cancer were retrospectively reviewed between September 2005 and February 2016. The depth of tumor invasion (T staging) by EUS was compared with the pathological staging after endoscopic or surgical resection.

RESULTS

A total of 6084 patients were finally analyzed. The accuracy rates for T1a and EGC were 75.0 and 89.4%, respectively. The overall accuracy of T staging by EUS was 66.3% when divided by T1a, T1b, and over T2. The accuracy of EUS prior to endoscopic resection was 75.1% in absolute indication and 73.1% in expanded criteria, respectively. The accuracy rates for T1a with lesion ≤ 2 cm in miniprobe EUS and EGC with lesion > 2 cm in conventional EUS were 84.6 and 83.2%, respectively. In multivariate analysis, presence of ulcer, large tumor size, and radial EUS were associated with overestimation, and small tumor size and miniprobe were associated with underestimation in T staging.

CONCLUSIONS

EUS showed the high accuracy of 84.6% for T1a in lesion ≤ 2 cm in miniprobe EUS and 83.2% for EGC in lesion > 2 cm in conventional EUS, respectively. EUS can be a complementary diagnostic method to determine endoscopic or surgical treatment modality.

Accuracy of Computed Tomographic Enterography for Obscure Gastrointestinal Bleeding: A Diagnostic Meta-analysis

RATIONALE AND OBJECTIVES

Obscure gastrointestinal bleeding (OGIB) is the bleeding from the gastrointestinal tract without definite source that persists and recurs after a negative endoscopic evaluation. The study aimed to systematically evaluate the diagnostic accuracy of computed tomography enterography on OGIB detection by meta-analysis.

MATERIALS AND METHODS

Studies were searched in relevant databases. With predefined inclusion criteria, eligible studies were included, followed by quality assessment using the Quality Assessment of Diagnostic Accuracy Studies scoring system. The Meta-DiSc software was used to implement the meta-analysis, and sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio with their 95% confidence intervals (CIs) were used as the effect size. Publication bias was determined by Egger test.

RESULTS

A set of nine studies was included in this meta-analysis, having a relatively high quality. Under the random effects model, the pooled sensitivity and specificity were 0.724 (95% CI: 0.651-0.789) and 0.752 (95% CI: 0.691-0.807), respectively. Under the fixed effects model, the pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 2.949 (95% CI: 2.259-3.850), 0.393 (95% CI: 0.310-0.497), and 9.452 (95% CI: 5.693-15.692), respectively. The area under curve of the summary receiver operating characteristic curve was 0.7916 (95% CI: 0.723-0.860). No obvious publication bias was detected (t = 1.62, P = .181).

CONCLUSIONS

Computed tomography enterography might be used as a complementary to video capsule endoscopy instead of an alternative for the detection of OGIB.

Evaluation of the American Joint Committee on Cancer 8th edition staging system for gastric cancer patients after preoperative therapy

BACKGROUND

The American Joint Committee on Cancer (AJCC) recently released its 8th edition staging system, which created a separate staging system for gastric cancer patients who have undergone preoperative therapy (ypStage). The objective of this retrospective study was to apply the new ypStage to patients who have undergone preoperative therapy and potentially curative gastrectomy.

METHODS

We collected data from a prospectively maintained institutional database of gastric cancer patients who underwent potentially curative gastrectomy after preoperative therapy (1995-2015). Kaplan-Meier survival estimations and log-rank tests were performed to compare survival. Univariable and multivariable analyses were performed to determine risk factors for overall survival.

RESULTS

A total of 354 patients met our criteria. Most patients completed planned preoperative therapy (94%; 332/354) and received chemoradiation therapy (75%; 265/354). Although clinical stage (cStage) provided a poor discrimination of survival, postneoadjuvant pathological stage (ypStage) identified significant variation in survival (p < 0.001). Multivariable analysis showed the following factors were associated with survival after adjustment for ypStage: Asian race (HR 0.52; p = 0.028), linitis plastica (HR 1.66; p = 0.037), and R1 resection (HR 1.91; p = 0.016). Survival was not longer in ypT0N0 patients than in ypStage I patients (HR 1.29; p = 0.377).

CONCLUSIONS

The AJCC 8th edition staging system for gastric cancer demonstrated reasonable survival prediction by ypStage, but not cStage, in patients who had undergone preoperative therapy. ypT0N0 patients, although not defined in the 8th edition, may be considered for inclusion in the ypStage I group.

Preoperative accuracy of gastric cancer staging in patient selection for preoperative therapy: race may affect accuracy of endoscopic ultrasonography

Background

Over the last 15 years, large randomized controlled studies have validated the benefit of preoperative therapy for patients with resectable gastric cancer. Computed tomography (CT) and endoscopic ultrasonography (EUS) are commonly used to select patients for preoperative treatment, but studies of preoperative staging accuracy that focus on patient selection for preoperative therapy are rare; therefore, whether CT or EUS can reliably identify patients eligible for preoperative therapy is still unclear. Our purpose was to determine the accuracy of EUS and CT for preoperative staging of gastric cancer and to identify factors that may affect their usefulness in selecting patients for preoperative therapy.

Methods

We reviewed the medical records of 8,260 patients with gastric or gastroesophageal adenocarcinoma treated at our institution from 1995 to 2013, identifying those who underwent gastrectomy without preoperative treatment. We compared T stage and N status from preoperative EUS and CT reports with those drawn from surgical pathology reports. Clinicopathologic and demographic variables associated with incorrect preoperative staging were investigated using univariate and multivariate analyses.

Results

We identified 187 patients who underwent preoperative staging by EUS (n=145) and/or CT (n=134) before gastrectomy. The accuracy, sensitivity, and specificity of EUS in distinguishing stage T1 from more advanced tumors were 82%, 78%, and 85%, respectively. Variables associated with underestimation of EUS T stage were lymphovascular invasion [odds ratio (OR), 7.51; 95% confidence interval (CI), 1.91-29.50; P<0.01] and white race (OR, 3.75; 95% CI, 1.31-10.75; P=0.01). The accuracies, sensitivities, and specificities for determining N status were, respectively, 65%, 49%, and 79% with CT and 66%, 29%, and 95% with EUS. Lymphovascular invasion was associated with a false negative result (OR, 3.79; 95% CI, 1.34-10.70; P=0.01), and well- or moderately differentiated histology was associated with a false positive result for CT N status (OR, 7.14; 95% CI, 2.00-25.44; P<0.01).

Conclusions

EUS is accurate in distinguishing T1 from T2-T4 lesions; both CT and EUS have low sensitivities and high specificities in determining N status. These accuracies and variables associated with inaccurate staging, including race, should be considered when selecting gastric cancer patients for preoperative therapy.

Clinical application of early gastric carcinoma with lymphoid stroma based on lymph node metastasis status

BACKGROUND

Gastric carcinoma with lymphoid stroma (GCLS) is characterized by undifferentiated carcinoma mixed with prominent lymphoid infiltration. GCLS has unique clinicopathological features and a better prognosis compared to other types of gastric cancer. We analyzed the clinicopathological features of early GCLS in relation to lymph node metastasis (LNM).

METHODS

We performed a retrospective analysis of 241 patients diagnosed with GCLS confined to the mucosa or the submucosa between March 1998 and December 2015. Their data were compared with those from 1219 patients who underwent resection for differentiated early gastric cancer (EGC).

RESULTS

Of the 241 patients analyzed, 33 (13.7%) had intramucosal cancers and 208 (86.3%) had cancers that penetrated the submucosa. Compared to differentiated EGC, early GCLS was more prevalent in younger individuals and in men, tended to be proximally located, was highly associated with Epstein-Barr virus (EBV) infection (89.2%), and had a lower risk of LNM. The 5-year disease-specific survival rate of patients with early GCLS was 98.3% but depended significantly on LNM status (p < 0.001) and EBV infection status (p = 0.039). The risk of LNM from mucosal GCLS and submucosal GCLS was 0% [95% confidence interval (CI) 0-9.1] and 10% (95% CI 6.8-15.2), respectively. On multivariate analysis, LNM was found to be associated with tumor size (p = 0.022) and lymphovascular invasion (p = 0.002) in addition to tumor depth.

CONCLUSIONS

Early GCLS has distinct clinicopathological features depending on age, sex, tumor location, EBV infection status, and LNM status. Tailored therapies, including endoscopic treatment, are needed based on the distinct clinicopathological features of early GCLS.

Hyperechoic demarcation line between a tumor and the muscularis propria layer as a marker for deciding the endoscopic treatment of gastric submucosal tumor

Minimally invasive endoscopic resection has been rapidly adopted as a new technique for treating patients with gastric submucosal tumors (SMTs) originating in the muscularis propria (MP) layer. This study was conducted to evaluate the information obtained from endoscopic ultrasonography (EUS) to determine the appropriate endoscopic dissection method for treating SMTs originating in the MP layer. Between February 2014 and May 2016, a total of 50 patients with gastric SMTs originating in the MP layer were enrolled in this study. The clinical features of the patients and their endoscopic, EUS, and histopathologic findings, as well as their postoperative follow-up data, were analyzed in this retrospective study. The mean age of the patients was (55.0±10.2) years, and the male/female ratio was 17:33. Endoscopic submucosal dissection (ESD) was performed on 43 patients and an endoscopic full-thickness resection (EFR) was performed on seven patients. The most frequent location for an SMT was in the upper body region of the stomach (n=16), and the most common pathological diagnosis was a gastrointestinal stromal tumor (GIST) (n=32). The overall rates for complete resection were 95.3% (41/43) and 100.0% (7/7) when the SMTs were treated by ESD and EFR, respectively. The presence of a complete tumor capsule was significantly associated with a complete resection (P=0.001). Of the cases treated by ESD, nine patients developed perforation, one of whom required laparoscopic surgery. The remaining patients were closed with clips or purse-string sutures. The presence of an MP2-type tumor (P=0.018) and a wide connection with the MP layer (P=0.044) were significantly associated with perforation. A preoperative evaluation of the integrity and the location of a tumor capsule and the length of the tumor connection with the MP layer by EUS can improve the complete resection rate and reduce the occurrence of intraoperative complications. Tumors with a complete capsule originating from the superficial MP layer or with a narrow connection with the MP layer are appropriate candidates for treatment by ESD.

Gastric Adenocarcinoma: A Multimodal Approach

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Endoscopic ultrasound in oncology: An update of clinical applications in the gastrointestinal tract

An accurate staging is necessary to select the best treatment and evaluate prognosis in oncology. Staging usually begins with noninvasive imaging such as computed tomography, magnetic resonance imaging or positron emission tomography. In the absence of distant metastases, endoscopic ultrasound plays an important role in the diagnosis and staging of gastrointestinal tumors, being the most accurate modality for local-regional staging. Its use for tumor and nodal involvement in pre-surgical evaluation has proven to reduce unnecessary surgeries. The aim of this article is to review the current role of endoscopic ultrasound in the diagnosis and staging of esophageal, gastric and colorectal cancer.

Current practice for gastric cancer treatment in Ukraine

Ukraine registers more than 8,000 new cases of gastric cancer (GC) annually. The disease is usually diagnosed at stage III-IV (65% of cases) and 62.2% of patients die within 1 year. About 70% of patients with GC need chemotherapy, and for most of them, this is the only way to increase their life expectancy. An unsolved problem of nationwide importance is achieving the early diagnosis of GC, which predetermines the treatment outcome. The 5-year survival rate for GC patients in Ukraine is only 13%, while early diagnosed GC is almost totally curable using surgery. Another important task is the development of national diagnosis and treatment standards, which will be based on national breakthroughs and will meet modern international requirements.

Potential diagnostic and prognostic significance of plasma prolidase activity in gastric cancer

Aim: Plasma prolidase activities (PPAs) in cases of gastric cancer. Methodology/results: This study was based on a prospective design. 60 patients with gastric cancer (operable cases: 48; inoperable: 12) and 60 healthy controls were included in the study. Prolidase activity was analyzed. The mean PPA levels in the operable, inoperable and control groups were 45.60 ± 4.20, 54.35 ± 4. 9 and 10.92 ± 0.79 U/l, respectively (p < 0.001). PPA decreased significantly after tumor resection. PPA level was significant in differentiating operable cases from inoperable (sensitivity: 91.7%; specificity: 85.2%). Discussion/conclusion: PPA was significantly higher in patients with inoperable gastric cancer than in operable cases and the control group. A strong correlation was found between tumor volume and PPA.

Preoperative staging of nodal status in gastric cancer

An accurate preoperative staging of nodal status is crucial in gastric cancer, because it has a great impact on prognosis and therapeutic decision-making. Different staging methods have been evaluated for gastric cancer in order to predict nodal involvement. So far, no technique could meet the necessary requirements, which include a high detection rate of infiltrated lymph nodes and a low frequency of false-positive results. This article summarizes different staging methods used to assess lymph node status in patients with gastric cancer, evaluates the evidence, and proposes to establish new methods.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Endoscopic ultrasound in gastric cancer staging before and after neoadjuvant chemotherapy. A comparison with PET-CT in a clinical series

BACKGROUND

Treatment of gastric cancer is based on accurate staging. Emerging methods, such as PET-CT, are increasingly being used for this purpose. Our aim was to analyze the results of EUS and PET-CT in staging and restaging our patients with gastric cancer, comparing both of them with the histological results.

METHODS

Patients with confirmed gastric cancer were prospectively enrolled. Inclusion criteria for the final analysis included only patients who finally received a surgical resection. All patients underwent preoperative TNM staging by means of EUS and PET-CT within 21 days prior to the surgical treatment.

RESULTS

A total of 256 patients were included. The overall EUS accuracy for T staging was 78% and 80.2% in restaging. EUS showed its best accuracy when distinguishing T1-T2 tumors vs. T3-T4, with an increased accuracy in restaging. Regarding N staging, the overall accuracy of EUS was 76.2%, and 72.5% for PET-CT (p = 0.02). With regards to restaging, accuracy of EUS and PET-CT for N staging was 88.5% and 69%, respectively, with significant differences (p < 0.0001).

CONCLUSIONS

EUS performed better than PET-CT in gastric cancer N staging and restaging. EUS accuracy in this setting is still suboptimal and probably more than one single diagnostic procedure should be used.

Therapeutic Decision-Making Using Endoscopic Ultrasonography in Endoscopic Treatment of Early Gastric Cancer

Background/Aims

We evaluated the effectiveness of an endoscopic ultrasonography (EUS)-based treatment plan compared to an endoscopy-based treatment plan in selecting candidates with early gastric cancer (EGC) for endoscopic submucosal dissection based on the prediction of invasion depth.

Methods

We reviewed 393 EGCs with differentiated histology from 380 patients who underwent EUS from July 2007 to April 2010. The effectiveness of the EUS-based and endoscopy-based plans was evaluated using a simplified hypothetical treatment algorithm.

Results

The numbers of endoscopically determined mucosal, indeterminate, and submucosal cancers were 253 (64.4%), 56 (14.2%), and 84 (21.4%), respectively. Overall, the appropriate treatment selection rates were 75.3% (296/393) in the endoscopy-based plan and 71.5% (281/393) in the EUS-based plan (p=0.184). For endoscopic mucosal cancers, the appropriate treatment selection rates in the endoscopy-based plan were 88.1% (223/253), while the use of an EUS-based plan significantly decreased this rate to 81.4% (206/253) (p=0.036). For endoscopic submucosal cancers, the appropriate selection rates did not differ between the endoscopy-based plan (46.4%, 39/84) and the EUS-based plan (53.6%, 45/84) (p=0.070).

Conclusions

EUS did not increase the likelihood of selecting the appropriate treatment in differentiated-type EGC. Therefore, EUS may not be necessary before treating differentiated-type EGC, especially in endoscopically presumed mucosal cancers.

Role of endoscopic ultrasonography in TNM staging of gastric cancer

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

The role of endoscopic ultrasound on the preoperative T staging of gastric cancer: A retrospective study

Endoscopic ultrasonography (EUS) is used for preoperative assessment of gastric cancer. However, recent studies suggested that EUS staging accuracy is lower than previously thought. We aimed to assess EUS efficacy and image characteristics in preoperative gastric cancer T staging.A retrospective review of clinical and imaging features of 232 gastric carcinoma patients who underwent preoperative EUS assessment of T stage was performed. Only cases with tumor-free resection margin status and no metastases were enrolled. Comparisons of preoperative EUS and postoperative histopathological stagings were also performed to identify vital EUS image features for evaluating gastric carcinoma.EUS accuracy for T staging was 64.2% (149/232) with the highest accuracy for T3 (75.0%). Enlarged lymph nodes, well differentiated histological type and Borrmann IV type were associated with diagnostic accuracy in predicting tumor invasion. Although no factors were associated with overstaging, circumferential lesions ≥1/2, signet ring cell adenocarcinoma, and Borrmann IV type had significantly higher risks of understaging. Gastric wall outer edge irregularity was also an indicator of serosal involvement with a sensitivity of 82.0%. The pancreas and colon were more frequent disease extension sites than previously predicted.Although EUS is likely the best and most accurate option that we have used to stage gastric cancer, the finding that factors including circumferential lesions, signet ring cell adenocarcinoma, and Borrmann IV type carcinoma were more frequently related to incorrect staging warrants attention.