Efficacy of endoscopic ultrasonography for prediction of tumor depth in gastric cancer

Coexistence of early gastric cancer and benign submucosal lesions mimic invasive cancer: a retrospective multicenter experience

OBJECTIVE

To present a study to identify the characteristics of coexisting early gastric cancer (EGC) and benign submucosal lesions, with the aim of reducing the adverse consequences of overdiagnosis and overtreatment.

METHODS

In this retrospective study, we searched the endoscopic databases of three tertiary centers. We screened of patients suspected of early gastric cancer submucosal infiltration by conventional endoscopy and ultimately selected for endoscopic submucosal dissection treatment after endoscopic ultrasonography and magnifying endoscopy with narrow-band imaging examination. Patients with coexisting EGC and benign submucosal lesions in histological sections were included. Clinical data and endoscopic images were reviewed. To evaluate the precision of endoscopists' diagnoses for this type of lesion, eight endoscopists with different experiences were recruited to judge the infiltration depth of these lesions and analyze the accuracy rate.

RESULTS

We screened 520 patients and retrospectively identified 18 EGC patients with an invasive cancer-like morphology. The most common lesion site was the cardia (12/18, 66.67%). The coexisting submucosal lesions could be divided into solid (5/18, 27.78%) and cystic (13/18, 72.22%). The most common type of submucosal lesion was gastritis cystica profunda (12/18, 66.67%), whereas leiomyoma was the predominant submucosal solid lesion (3/18, 16.67%). Ten (55.56%) patients < underwent endoscopic ultrasonography; submucosal lesions were definitively diagnosed in 6 patients (60.00%). The accuracy of judgement of the infiltration depth was significantly lower in cases of coexistence of EGC with benign submucosal lesions (EGC-SML) than in EGC (38.50% versus 65.60%, P = 0.0167). The rate of over-diagnosis was significantly higher within the EGC-SML group compared to the EGC group (59.17% versus 10.83%, P < 0.0001).

CONCLUSIONS

We should be aware of the coexistence of EGC and benign submucosal lesions, the most common of which is early cardiac-differentiated cancer with gastritis cystica profunda.

The future of endoscopic resection for early gastric cancer

Endoscopic resection for early gastric cancer is recommended when the risk of lymph node metastasis is negligible and should be performed through submucosal dissection due to well-established short- and long-term results. To overcome technical difficulties and decrease adverse events some techniques have been studied. This review outlines current strategies for improving patient selection and highlights innovative techniques that help minimize adverse events. Moreover, we discuss how to improve management after curative and noncurative resections.

[Clinical Value of White Light Image, Endoscopic Ultrasonography and Magnifying Endoscopy with Narrow Band Imaging in Evaluation of Indications for Endoscopic Treatment of Early Gastric Cancer]

OBJECTIVE

To explore the application value of white light image (WLI), endoscopic ultrasonography (EUS) and magnifying endoscopy with narrow band imaging (ME-NBI) in the endoscopic treatment of early gastric cancer (EGC), and to provide basis for decision-making in clinical diagnosis and treatment.

METHODS

The clinicopathological data of EGC patients who underwent endoscopic submucosal dissection (ESD) at West China Hospital, Sichuan University between December 2013 and October 2020 were included. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of EGC invasive depth were compared between WLI and EUS. The role of ME-NBI in predicting the differentiation types of EGC was analyzed.

RESULTS

A total of 280 patients (291 lesions) were enrolled in the study. Among them, 199 patients (207 lesions) received EUS and 160 patients (168 lesions) received ME-NBI. The overall accuracy of WLI in diagnosing the invasive depth of EGC was 87.0%, significantly higher than that of EUS (46.4%, P<0.001). When WLI was combined with EUS, the diagnostic accuracy (87.4%) was not significantly improved. The overall accuracy of determining the differentiation degree of EGC with ME-NBI was 92.3% (155/168), and the accuracy of determining undifferentiated EGC with ME-NBI was significantly lower than that of differentiated EGC (41.2% vs. 98.0%, P<0.001).

CONCLUSION

In the evaluation of indications for endoscopic treatment of EGC, WLI showed better performance in predicting the invasive depth of EGC, while EUS demonstrated limited value. ME-NBI showed better accuracy for predicting the differentiation degree of most EGC, especially for differentiated EGC.

Clinical significance of endoscopic ultrasonography in diagnosing invasion depth of early gastric cancer prior to endoscopic submucosal dissection

BACKGROUND AND AIM

Endoscopic ultrasonography is a reliable diagnostic modality for determining indications of endoscopic submucosal dissection for early gastric cancer. We aimed to clarify the clinical significance of endoscopic ultrasonography in the invasion depth diagnosis of early gastric cancer.

METHODS

We retrospectively assessed 1598 consecutive patients with 2001 early gastric cancers who underwent EUS before ESD or surgery between October 2010 and April 2019 at our institution. Lesions were classified according to endoscopic ultrasonography-determined invasion depth as EUS-M/SM1 (lesions confined to sonographic layers 1 and 2 or lesions with changes in sonographic layer 3; depth, < 1 mm) and EUS-SM2 (lesions with changes in sonographic layer 3; depth, ≥ 1 mm). We evaluated the invasion depth determination accuracy of endoscopic ultrasonography and analyzed the clinicopathological features of misdiagnosed early gastric cancer cases.

RESULTS

The invasion depth determination accuracy was as follows: EUS-M/SM1: pathological T1a/T1b1 early gastric cancer, 97%; EUS-SM2: pathological T1b2 early gastric cancer, 79%. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 95%, 98%, 69%, 97%, and 79%, respectively. In EUS-M/SM1 early gastric cancer, tumor size of ≥ 15 mm, presence of ulceration, and undifferentiated histological type were significantly associated with endoscopic ultrasonography accuracy. In EUS-SM2 early gastric cancer, tumor size of ≥ 30 mm was significantly associated with endoscopic ultrasonography accuracy.

CONCLUSIONS

Endoscopic ultrasonography is a useful modality in accurately determining the invasion depth of early gastric cancer before endoscopic submucosal dissection.

Endoscopic Ultrasonography Miniature Probe Performance for Depth Diagnosis of Early Gastric Cancer with Suspected Submucosal Invasion

Background/Aims

The accurate assessment of the depth of invasion of early gastric cancer (EGC) is critical to determine the most appropriate treatment option. However, it is difficult to distinguish shallow submucosal (SM1) invasion from deeper submucosal (SM2) invasion. We investigated the diagnostic performance of endoscopic ultrasonography (EUS) using a miniature probe for EGC with suspected SM invasion.

Methods

From April 2008 to June 2018, EGCs with suspected SM invasion were analyzed retrospectively. The EGCs examined by a 20 MHz high-frequency miniature probe was included in our study. Esophago-gastric junction cancers and patients treated by chemotherapy before resection were excluded. The sensitivity and specificity for the detection of SM2 invasion by EUS were compared with those of white light imaging (WLI). Additionally, factors related to depth underestimation or overestimation were investigated using multivariate analysis.

Results

A total of 278 EGCs in 259 patients were included in the final analysis. The sensitivity and specificity for SM2 or deeper by EUS were 73.7% (87/118) and 74.4% (119/160), respectively. The sensitivity and specificity by WLI were 47.5% (56/118) and 68.1% (109/160), respectively. The sensitivity of EUS was significantly superior to that of conventional endoscopy (p<0.01). Multivariate analysis revealed that an anterior location of the EGC was an independent risk factor for underestimation by EUS (odds ratio, 3.3; 95% confidence interval, 1.1 to 9.8; p=0.03).

Conclusions

The depth diagnostic performance for EGCs with suspected SM invasion using EUS was satisfactory and superior to that of conventional endoscopy. Additionally, it is important to recognize factors that may lead to misdiagnosis in those lesions.

Clinical Efficacy of Single-Channel Gastroscopy, Double-Channel Gastroscopy, and Double Gastroscopy for Submucosal Tumors in the Cardia and Gastric Fundus

OBJECTIVE

To determine the feasibility and efficacy of single-channel gastroscopy, double-channel gastroscopy, and double gastroscopy in treating submucosal tumors in the cardia and gastric fundus.

METHODS

The data of 77 patients with submucosal tumors (SMTs) in the cardia and gastric fundus parts of the stomach who underwent single-channel gastroscopy, double-channel gastroscopy, and double gastroscopy were retrospectively analyzed. The observed therapeutic effect, complications, and local recurrence from these three groups were then compared.

RESULTS

All lesions were completely taken out under endoscopy, and the operation time for single-channel gastroscopy group was 20-90 min with an average of 44.5 min, and the postoperative hospitalization time was 5-9 days with an average of 7.5 days. The operation time for the double-channel gastroscopy group was 40-110 min with an average of 60.5 min, and the postoperative hospitalization time was 7-10 days with an average of 8.3 days, whereas the operation time of double gastroscopy group was 35-120 min with an average of 66.3 min, and the postoperative hospitalization time was 7-10 days with an average of 8.5 days. No patient was required to be transferred to the General Surgery Department for continuous treatment. Bleeding was noted from all the patients during operation, and hemostasis was performed successfully. Postoperative bleeding was not observed in any of the cases. Full-thickness resection was performed in all the three groups. No residual or recurrent lesions were detected via reexamination of gastroscopy in all the patients.

CONCLUSION

Single-channel gastroscopy, double-channel gastroscopy, and double gastroscopy present potential capability with distinctive advantages in the endoscopic treatment of submucosal tumors of the cardia and gastric fundus, and it also shows that appropriate operation methods should be selected based on the situation of an individual patient.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of World Health Organization (WHO) Histological Classification on Predicting Lymph Node Metastasis and Recurrence in Early Gastric Cancer

Background

The World Health Organization (WHO) histological classification for gastric cancer is widely accepted and used. However, its impact on predicting lymph node metastasis and recurrence in early gastric cancer (EGC) is not well studied.

Material/Methods

From 1987 to 2005, 2873 EGC patients with known WHO histological type who had undergone curative resection were enrolled in this study. In all, 637 well-differentiated adenocarcinomas (WD), 802 moderately-differentiated adenocarcinomas (MD), 689 poorly-differentiated adenocarcinomas (PD), and 745 signet-ring cell adenocarcinomas (SRC) were identified.

Results

The distribution of demographic and clinical features in early gastric cancer among WD, MD, PD, and SRC were significantly different. Lymph node metastasis was observed in 317 patients (11.0%), with the lymph node metastasis rate being 5.3%, 14.8%, 17.0%, and 6.3% in WD, MD, PD, and SRC, respectively. Univariate and multivariate analyses indicated that gender, tumor size, gross appearance, depth of invasion, and WHO classification were significantly associated with lymph node metastasis. Recurrence was observed in 83 patients (2.9%), with the recurrence rate being 2.2%, 4.5%, 3.0%, and 1.6% in WD, MD, PD, and SRC, respectively. Multivariate analysis confirmed that MD, elevated gross type, and lymph node metastasis were independent risk factors for recurrence in EGC. MD patients showed worse disease-free survival than non-MD patients (P=0.001).

Conclusions

WHO classification is useful and necessary to evaluate during the perioperative management of EGC. Treatment strategies for EGC should be made prudently according to WHO classification, especially for MD patients.

What types of early gastric cancer are indicated for endoscopic ultrasonography staging of invasion depth?

AIM

To clarify the diagnostic efficacy and limitations of endoscopic ultrasonography (EUS) and the characteristics of early gastric cancers (EGCs) that are indications for EUS-based assessment of cancer invasion depth.

METHODS

We retrospectively investigated the cases of 153 EGC patients who underwent conventional endoscopy (CE) and EUS (20 MHz) before treatment.

RESULTS

We found that 13.7% were “inconclusive” cases with low-quality EUS images, including all nine of the cases with protruded (0-I)-type EGCs. There was no significant difference in the diagnostic accuracy between CE and EUS. Two significant independent risk factors for misdiagnosis by EUS were identified-ulcer scarring [UL(+); odds ratio (OR) = 4.49, P = 0.003] and non-indication criteria for endoscopic resection (ER) (OR = 3.02, P = 0.03). In the subgroup analysis, 23.1% of the differentiated-type cancers exhibiting SM massive invasion (SM2) invasion (submucosal invasion ≥ 500 μm) by CE were correctly diagnosed by EUS, and 23.1% of the undifferentiated-type EGCs meeting the expanded-indication criteria for ER were correctly diagnosed by EUS.

CONCLUSION

There is no need to perform EUS for UL(+) EGCs or 0-I-type EGCs, but EUS may enhance the pretreatment staging of differentiated-type EGCs with SM2 invasion without UL or undifferentiated-type EGCs revealed by CE as meeting the expanded-indication criteria for ER.

Accuracy of endoscopic ultrasonography for determination of tumor invasion depth in gastric cancer

BACKGROUND

Gastric cancer (GC) is one the common lethal cancers in Iran. Detection of GC in the early stages would assesses to improve the survival of patients. In this study, we attempt to evaluate the accuracy of EUS in detection depth of invasion of GC among Iranian Patients.

MATERIALS AND METHODS

This study is a retrospective study of patients with pathologically confirmed GC. They underwent EUS before initiating the treatment. The accuracy of EUS and agreement between the two methods was evaluated by comparing pre treatment EUS finding with post operative histopathological results.

RESULTS

The overall accuracy of EUS for T and N staging was 67.9% and 75.47, respectively. Underestimation and overestimation was seen in 22 (14.2%) and 40 (25.6%) respectively. The EUS was more accurate in large tumors and the tumors located in the middle and lower parts of the stomach. The EUS was more sensitive in T3 staging. The values of weighted Kappa from the T and N staging were 0.53 and 0.66, respectively.

CONCLUSIONS

EUS is a useful modality for evaluating the depth of invasion of GC. The accuracy of EUS was higher if the tumor was located in the lower parts of the stomach and the size of the tumor was more than 3 cm. Therefore, judgments made upon other criteria evaluated in this study need to be reconsidered.

Is endoscopic ultrasonography useful for endoscopic submucosal dissection?

Endoscopic submucosal dissection (ESD) is an innovative advance in the treatment of early gastrointestinal (GI) cancer without lymph node metastases and precancerous lesions as it is an effective and safe therapeutic method. ESD has also been a promising therapeutic option for removal of submucosal tumors (SMTs) for improving the completeness of resection of a large lesion. Endoscopic ultrasonography (EUS) can be used to detect the depth of invasion during the preoperative evaluation because of its close proximity to the lesion. EUS-guided fine-needle aspiration can be used to increase the diagnostic accuracy of EUS in determining the malignant lymph node. EUS is considered to be a useful imaging procedure to characterize early GI cancer, which is suspicious for submucosal invasion, and the most accurate procedure for detecting and diagnosing SMTs for further treatment. In the process of ESD, EUS can also be used to detect surrounding blood vessels and the degree of fibrosis; this may be helpful for predicting procedure time and decreasing the risk of bleeding and perforation. EUS-guided injection before ESD renders the endoscopic resection safe and accurate. Therefore, EUS plays an important role in the use of ESD. However, compared to conventional endoscopic staging, EUS sometimes can under or overstage the lesion, and the diagnostic accuracy is controversial. In this review, we summarize the latest research findings regarding the role of EUS in ESD.

Diagnostic group classifications of gastric neoplasms by endoscopic resection criteria before and after treatment: real-world experience

BACKGROUND AND STUDY AIMS

There are often discrepancies between the pretreatment evaluation of gastric neoplasms by endoscopy with biopsy and the final diagnosis of resected specimen in terms of pathology and depth of invasion. We evaluated the spectrum of discrepancies between pretreatment and posttreatment diagnosis which may deliver significant differences on clinical practice.

PATIENTS AND METHODS

A total of 2041 patients with gastric dysplasia or cancer who underwent curative endoscopic resections or surgeries in 2012 were enrolled. Patients were classified into five different diagnostic groups: low-grade dysplasia (LGD), high-grade dysplasia (HGD), absolute indication early gastric cancer (AI-EGC), beyond absolute indication early gastric cancer (BAI-EGC), and advanced gastric cancer (AGC). The choice of initial treatment and final pathologic diagnosis was analyzed.

RESULTS

The study patients belonged to the following pretreatment diagnostic groups: LGDs in 162, HGDs in 164, AI-EGCs in 396, BAI-EGCs in 824, and AGCs in 495 cases. Posttreatment diagnostic groups were LGDs in 140, HGDs in 121, AI-EGCs in 322, BAI-EGCs in 947, AGCs in 505, and no residual tumor in 6 cases. In general, 6.9 % (141/2041) of cases were downgraded and 15.9 % (324/2041) were upgraded. Thirty-four percent of pretreatment HGDs (56/164) were changed to cancers after endoscopic resection. Thirty-three percent of pretreatment AI-EGCs (131/396) were regrouped as posttreatment BAI-EGCs. The additional surgery rate in each pretreatment group was 0.6 % in LGD, 4.3 % in HGD, 15.7 % in AI-EGC, 23.6 % in BAI-EGC among the patients with initial endoscopic resection (p < 0.01).

CONCLUSIONS

Twenty-three percent of gastric neoplasms changed in their final diagnostic group after endoscopic resection or surgery. This discrepancy should be considered when the initial treatment strategy is being selected.

Integrated diagnostic strategy for the invasion depth of early gastric cancer by conventional endoscopy and EUS

BACKGROUND

Although conventional endoscopy (CE) and EUS are considered useful for predicting the invasion depth (T-staging) in early gastric cancer (EGC), no effective diagnostic strategy has been established.

OBJECTIVE

To produce simple CE criteria and to elucidate an efficient diagnostic method by combining CE and EUS for accurate T-staging.

DESIGN

Single-center retrospective analysis.

SETTING

Academic university hospital.

PATIENTS

Consecutive patients with EGC from April 2007 to March 2012 who underwent CE and EUS before treatment.

INTERVENTIONS

Recorded endoscopic images were independently reviewed by 3 observers. The CE criteria for massive invasion were defined, and their utility and the additional value of EUS were assessed.

MAIN OUTCOME MEASUREMENTS

The accuracy of CE based on the criteria and the accuracy of EUS.

RESULTS

Two hundred thirty patients were enrolled: 195 with mucosal cancer or cancer in the submucosa less than 500 μm from the muscularis mucosae and 35 with invasive cancers. Multivariate analysis of the CE findings by 1 observer revealed that an irregular surface and a submucosal tumor-like marginal elevation were significantly associated with massive invasion. The simple CE criteria, consisting of those 2 features, had an overall accuracy of 73% to 82% and no significant differences in the diagnostic yield compared with EUS in all observers. CE accurately revealed mucosal cancer, and EUS efficiently salvaged the lesions that were over-diagnosed by CE. With our strategy, which involved the CE criteria and the optimal use of EUS, the comprehensive accuracy exceeded 85% in each observer.

LIMITATIONS

Retrospective, single-center study.

CONCLUSIONS

We demonstrated a practical strategy for T-staging in EGC using simple CE criteria and EUS.

Endoscopic prediction of tumor margin and invasive depth in early gastric cancer

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related deaths in the world. The prognosis of GC is clearly associated with the tumor stage, with a 5-year overall survival rate for early gastric cancer (EGC) exceeding 90%, which is significantly higher than that of advanced gastric cancer. Endoscopic resection, including endoscopic mucosal resection and endoscopic submucosal dissection, has been adopted in recent decades as the first treatment option of EGC in many countries for its minimal invasion and high curative rate. However, the horizontal and vertical margins are related to the curative resection of EGC and the prognosis of patients. Thus the accurate prediction of the tumor boundary and its invasive depth before treatment counts for much in planning the most appropriate treatment strategy and promising curative resection. To date, various endoscopic techniques have been identified to play a role in pretreatment evaluation, such as white light endoscopy, chromoendoscopy, narrow band imaging and endoscopic ultrasonography. This article aimed to summarize the diagnostic methods, applications and limitations of these different endoscopic techniques for identifying tumor horizontal and vertical margins in EGC, helping to increase preoperative evaluation of capabilities and to improve the curative resection rate of EGC.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

Undiagnosed Borrmann type II gastric cancer due to necrosis and regenerative epithelium

Endoscopic biopsy is essential to the proper diagnosis and treatment of gastric cancer. Unfortunately, the results of endoscopic biopsy are not always the same as what is expected based on gross endoscopic findings. The results of endoscopic biopsy can be negative for malignancy in Borrmann type IV advanced gastric cancer (AGCa) or gastric lymphoma. However, in the case of type II AGCa, repeated biopsies negative for malignancy have not been reported. A 49-year-old male patient underwent esophagogastroduodenoscopy three times due to large gastric ulcer suspected to be Borrmann type II cancer. However, three repeat endoscopic biopsies with multiple specimens showed necrosis and superficial regenerative epithelium without malignant findings. The patient underwent laparoscopic distal gastrectomy with D2 lymph node dissection. The surgical specimen revealed that the mucosal layer was completely replaced with regenerative epithelium without cancer cells.

Diagnostic value of clinical T staging assessed by endoscopy and stomach protocol computed tomography in gastric cancer: the experience of a low-volume institute

Purpose

Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute.

Materials and Methods

We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging.

Results

The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm.

Conclusions

Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.

Accuracy of endoscopic ultrasonography for determining the treatment method for early gastric cancer

Background. Endoscopic resection (ER) for early gastric cancer (EGC) is a minimally invasive and curative treatment. The value of endoscopic ultrasonography (EUS) in determining the therapeutic strategy for EGC was assessed in this study. Materials and Methods. Pretreatment EUS was performed on 406 EGCs. The lesions were divided into the histological categories m/sm1 and sm2. The EUS-determined depths of invasion were classified as EUS-M/SM1, EUS-SM2, and EUS-MP or deeper. An analysis of the factors influencing the EUS-based depth determination was then conducted. Results. Most (92.8%) of the EUS-M/SM1 group belonged to the m/sm1 histological category. Ulcerated lesions, tumor size of larger than 2 cm, and the use of an ultrasound endoscope were independently associated with misdiagnosis of the depth of EGC by EUS. The ulcerated lesions had a significantly higher probability of overestimation. Conclusions. EUS is a useful method for determining the therapeutic strategy for EGC. Special attention should be paid not to overestimate the depth of cancer invasion when determining the ulcerated lesions and the type of curative procedure to be used.

Evaluation of endoscopic ultrasound image quality is necessary in endosonographic assessment of early gastric cancer invasion depth

We evaluated whether endoscopic ultrasonography (EUS) image quality affects the accuracy of diagnosing the vertical invasion depth of early gastric cancer (EGC). A total of 75 lesions in 75 patients suspected of having EGC were enrolled. All patients underwent EUS examination. Findings of EUS were compared with histopathologic results. We evaluated the effect of the following clinicopathologic factors: location, diameter, surface pattern, concomitant ulceration, histology type, and EUS image quality score. EUS image quality was scored based on detection repeatability, appropriate probe placement, and clarity of the five gastric wall layers including the lesion. Sixty-three lesions (84%) were pathologically mucosal and 12 lesions (16%) were submucosal cancer. Overall accuracy was 82.7%. Significantly more lesions in the upper and middle portions of the stomach were incorrectly diagnosed than in the lower portion (P = 0.0019). Lesion diameter was significantly larger among incorrectly diagnosed lesions (P = 0.0257). Low-quality images were significantly more often associated with incorrectly diagnosed lesions than with correctly diagnosed lesions (P = 0.0001). Multivariate analysis revealed that EUS image quality was associated with EUS staging accuracy (odds ratio, 21.8; 95% confidence interval, 4.5–137.6). Low-quality EUS images led to an incorrect diagnosis of invasion depth of EGC, independent of tumor location or size.

Endoscopic ultrasound, where are we now in 2012?

Topics related with endoscopic ultrasound (EUS) made up considerable portion among many invited lectures presented in International Digestive Endoscopy Network 2012 meeting. While the scientific programs were divided into the fields of upper gastrointestinal (UGI), lower gastrointestinal, and pancreato-biliary (PB) categories, UGI and PB parts mainly dealt with EUS related issues. EUS diagnosis in subepithelial lesions, estimation of the invasion depth of early gastrointestinal cancers with EUS, and usefulness of EUS in esophageal varices were discussed in UGI sessions. In the PB part, pancreatic cystic lesions, EUS-guided biliopancreatic drainage, EUS-guided tissue acquisition, and improvement of diagnostic yield in indeterminate biliary lesions by using intraductal ultrasound were discussed. Advanced techniques such as contrast-enhanced EUS, EUS elastography and forward-viewing echoendoscopy were also discussed. In this paper, I focused mainly on topics of UGI and briefly mentioned about advanced EUS techniques since more EUS related papers by other invited speakers were presented afterwards.

Trends and outcomes of minimally invasive surgery for gastric cancer: 750 consecutive cases in seven years at a single center

BACKGROUND

The aims of this study were to investigate trends in minimally invasive surgery (MIS) for gastric cancer through the experience of a single center and to predict the direction of the development of MIS.

METHODS

During a 7-year period, 2,160 patients underwent curative gastric cancer surgery. Changes in the proportion and pathologic features of a total of 750 cases that involved MIS, as well as the surgical methods and outcomes of MIS, were analyzed.

RESULTS

An analysis of the patient population treated by MIS revealed that the proportion of patients with T2 or greater tumors on the basis of pathologic findings was initially <5.0% but had recently increased to 24.3%. Although the proportions of intracorporeal anastomosis and robotic surgery had recently increased, the complication rate and operative time had stabilized 2 years after the 1st MIS.

CONCLUSIONS

Given these results, the application of MIS for gastric cancer is expected to become more frequent. In addition, new modalities will be preferred by both surgeons and patients to reduce the invasiveness of gastric cancer surgery.

Endoscopic ultrasound-guided fine needle aspiration in hollow viscus cancer

Accurate cancer staging is essential in patients with hollow viscus malignancy to decide therapeutic modalities. Endoscopic ultrasound (EUS) is considered as the best modality for local staging of hollow viscus cancer. EUS-guided fine needle aspiration (FNA) is a minimally invasive and effective sampling method. EUS-FNA should be applied when positive diagnosis of malignancy can possibly change the choice of therapeutic options. EUS in conjunction with EUS-FNA can optimize stage-directed therapy which is helpful in selecting minimally invasive treatment option including endoscopic treatment and avoiding unnecessary surgery in advanced cases.