Accuracy of high-frequency catheter-based endoscopic ultrasonography according to the indications for endoscopic treatment of early gastric cancer

Value of quantitative microsurface structure analysis for evaluating the invasion depth of type 0-II early gastric cancer

Background and Aim

The microsurface structure reflects the degree of damage to the glands, which is related to the invasion depth of early gastric cancer. To evaluate the diagnostic value of quantitative microsurface structure analysis for estimating the invasion depth of early gastric cancer.

Methods

White-light imaging and narrow-band imaging (NBI) endoscopy were used to visualize the lesions of the included patients. The area ratio and depth-predicting score (DPS) of each patient were calculated; meanwhile, each lesion was examined by endoscopic ultrasonography (EUS).

Results

Ninety-three patients were included between 2016 and 2019. Microsurface structure is related to the histological differentiation and progression of early gastric cancer. The receiver operating characteristic curve showed that when an area ratio of 80.3% was used as a cut-off value for distinguishing mucosal (M) and submucosal (SM) type 0-II gastric cancers, the sensitivity, specificity, and accuracy were 82.9%, 80.2%, and 91.6%, respectively. The accuracies for distinguishing M/SM differentiated and undifferentiated early gastric cancers were 87.4% and 84.8%, respectively. The accuracy of EUS for distinguishing M/SM early gastric cancer was 74.9%. DPS can only distinguish M-SM1 (SM infiltration <500 μm)/SM (SM infiltration ≥500 μm) with an accuracy of 83.8%. The accuracy of using area ratio for distinguishing 0-II early gastric cancers was better than those of using DPS and EUS (P < 0.05).

Conclusion

Quantitative analysis of microsurface structure can be performed to assess M/SM type 0-II gastric cancer and is expected to be effective for judging the invasion depth of 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.

Endoscopic submucosal dissection for early gastric cancer: It is time to consider the quality of its outcomes

Endoscopic resection, particularly endoscopic submucosal dissection (ESD), is widely used as a standard treatment modality for early gastric cancer (EGC) when the risk of lymph node metastasis is negligible. Compared with surgical gastrectomy, ESD is a minimally invasive procedure with additional advantages, such as preservation of the entire stomach and maintenance of the patient's quality of life. However, not all patients achieve curative resection after ESD of EGC. Several patients require surgical gastrectomy after ESD to achieve a curative treatment. Additional surgery after ESD, owing to non-curative resection, places considerable emotional and financial burdens on patients. Recently, as the number of endoscopists performing ESD has increased, the rate of non-curative resection after ESD has increased correspondingly. In order to decrease the non-curative resection rate, as well as determine the ideal rate of non-curative resection after ESD, it is time to consider quality indicators for the outcomes of ESD for EGC.

FDG-avid antrum-pylorus ulcer, adjacent lymph node, and abdominal wall nodule mimicking gastric cancer with metastases

Gastric cancer presents with similar clinical symptoms as gastric ulcer, and the morphologic features of gastroscopy overlap considerably. We report a 58-year-old man with the clinical presentation of recurrent gastric discomfort and black stools. A suspected malignant tumor of the gastric antrum-pylorus was observed on gastroscopy. Contrast-enhanced CT showed enhancement of the lesion. PET/CT revealed an FDG-avid lesion at the gastric antrum-pylorus, an intense FDG-uptake perigastric lymph node, and an enlarged nodule with high FDG uptake in the right abdominal wall. Subsequent surgical pathology revealed an inflammatory ulcer of the gastric antrum-pylorus with reactive hyperplastic lymph node, while the lesion in the right abdominal wall was a scar nodule. This case suggests that when multiple FDG-avid lesions accompany an atypical gastric ulcer, it can easily lead to misdiagnosis, and therefore more emphasis should be placed on histopathological analysis.

Effect of administration of a proton pump inhibitor for ulcerative differentiated early gastric cancer prior to endoscopic submucosal dissection

OBJECTIVES

Predicting the depth of invasion for early gastric cancer (EGC) with ulcerative findings may prove difficult. The purpose of this study was to evaluate the extent of ulcer healing and clinical effectiveness of proton pump inhibitor (PPI) administration for ulcerative differentiated EGC prior to endoscopic submucosal dissection (ESD).

METHODS

A total of 214 patients with ulcerative differentiated EGC who were treated by ESD were retrospectively analyzed, among whom 129 had been administered a PPI prior to ESD and 85 patients had not. The degree of ulcer healing following administration of PPI and the clinical outcome were compared between the PPI and non-PPI groups.

RESULTS

The ulcer healing rate (80.7 vs. 30.6%, P < 0.001) and complete ulcer healing rate (45.0 vs. 16.5%, P < 0.001) differed significantly between the PPI and non-PPI groups, respectively. The ESD procedure time was 86.0 (73) vs. 100.0 (68.0) min (P = 0.044). However, no significant differences were observed in the en bloc resection rate, complete resection rate, or the incidence of adverse events. Based on the multivariate regression analysis, PPI administration [odds ratio (OR) = 4.909, 95% confidence interval (CI) 2.459-9.799, P < 0.001] and mucosal cancer (OR = 9.336, 95% CI 2.693-32.362, P < 0.001) were independent predictive factors for complete ulcer healing. Partial or complete ulcer healing following PPI administration had a better predictive ability than EUS for mucosal invasion (kappa value 0.553 vs. 0.101; Youden index 0.553 vs. 0.132).

CONCLUSIONS

Partial or complete ulcer healing following PPI administration predicts differentiated EGC that is confined to the mucosa.

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

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

Controversies in EUS: Do we need miniprobes?

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

Endoscopic 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.

Factors Affecting the Accuracy of Endoscopic Ultrasonography in the Diagnosis of Early Gastric Cancer Invasion Depth: A Meta-analysis

Background

Endoscopic ultrasonography (EUS) is the first imaging modality for investigating the depth of invasion in early gastric cancer (EGC). However, there is presently no consensus on the accuracy of EUS in diagnosing the invasion depth of EGC.

Aim

This study is aimed at systematically evaluating the accuracy of EUS in diagnosing the invasion depth of EGC and its affecting factors.

Methods

The literatures were identified by searching PubMed, SpringerLink, Cochrane Library, Web of Science, Nature, and Karger knowledge databases. Two researchers extracted the data from the literature and reconstructed these in 2 × 2 tables. The Meta-DiSc software was used to evaluate the overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic advantage ratio, and 95% confidence interval (CI). The SROC was drawn, and the area under the curve (AUC) was calculated to evaluate the diagnostic value.

Results

A total of 17 articles were selected, which included 4525 cases of lesions. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic dominance ratio, and 95% CI of EUS for diagnosing EGC was 0.87 (95% CI: 0.86-0.88), 0.67 (95% CI: 0.65-0.70), 2.90 (95% CI: 2.25-3.75), 0.17 (95% CI: 0.13-0.23), and 18.25 (95% CI: 12.61-26.39), respectively. The overall overstaging rate of mucosa/submucosa 1 (M/SM1) and SM by EUS was 13.31% and 32.8%, respectively, while the overall understaging rate of SM was 29.7%. The total misdiagnosis rates for EUS were as follows: 30.4% for lesions ≥ 2 cm and 20.9% for lesions < 2 cm, 27.7% for ulcerative lesions and 21.4% for nonulcerative lesions, and 22% for differentiated lesions and 26.9% for undifferentiated lesions.

Conclusion

EUS has a moderate diagnostic value for the depth of invasion of EGC. The shape, size, and differentiation of lesions might be the main factors that affect the accuracy of EUS in diagnosing EGC.

A Meta-Analysis And Systematic Review Of Accuracy Of Endoscopic Ultrasound For N Staging Of Gastric Cancers

BACKGROUND

Endoscopic ultrasonography (EUS) is widely used as a staging modality for gastric cancer. However, the results of studies on the use of EUS for N staging in gastric cancer vary. This study aimed at studying the overall diagnostic accuracy of EUS for N staging of gastric cancer.

METHODS

Published studies were identified through searching the MEDLINE, Web of Science, EMBASE, SpringerLink and ScienceDirect databases. A bivariate random effect model was used to estimate the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). A hierarchical summary receiver operating characteristic curves (HSROC) based on the pooled data was also computed.

RESULTS

Fifty studies (5223 patients) were included in this analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of EUS for N staging were 0.82 (95% CI 0.78 to 0.85), 0.68 (0.63 to 0.73), 2.6 (2.2 to 3.0), 0.27 (0.22 to 0.32), and 10 (8 to 12), respectively. The area under the HSROC was 0.83.

CONCLUSION

The EUS may provide a clinically useful tool to guide physicians in the N staging of gastric cancer. However, physicians must note that the EUS has a relatively low specificity.

The distribution pattern of metastatic lymph nodes after non-curative endoscopic resection in early gastric cancer

BACKGROUND AND OBJECTIVES

Additional surgery should be done after non-curative endoscopic resection (ER) in early gastric cancer (EGC) due to the risk of lymph node metastasis (LNM). However, the distribution pattern of LNM in these patients is complicated and unpredictable. The aim of this study is to identify any different distribution patterns of LNM in patients with EGC who underwent additional surgery after non-curative (ER) comparing to those without ER.

METHODS

Patients who underwent surgery for EGC between 2001 and 2016 were included. Enrolled patients were divided into two groups, those who underwent additional surgery after non-curative ER and those who underwent direct surgery without a history of ER. Demographics, tumor characteristics and LNM distribution pattern were analyzed.

RESULTS

Among 4295 patients with EGC, 404 patients had a history of preoperative ER, and 3891 patients did not. After the application of exclusion criteria, 23 (7.1%) of 322 patients undergoing additional surgery had LNM. The additional surgery group showed less LNM, fewer nodal stations and more restricted distribution pattern of LNM.

CONCLUSIONS

The distribution pattern of LNM in EGC is complicated. However, more restricted locoregional LNM could be expected in cases of additional surgery after non-curative ER than after direct surgery.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 diagnosing ulcerative early gastric cancers

Although endoscopic ultrasonography (EUS) is the first-choice imaging modality for predicting the invasion depth of early gastric cancer (EGC), the prediction accuracy of EUS is significantly decreased when EGC is combined with ulceration.The aim of present study was to compare the accuracy of EUS and conventional endoscopy (CE) for determining the depth of EGC. In addition, the various clinic-pathologic factors affecting the diagnostic accuracy of EUS, with a particular focus on endoscopic ulcer shapes, were evaluated.We retrospectively reviewed data from 236 consecutive patients with ulcerative EGC. All patients underwent EUS for estimating tumor invasion depth, followed by either curative surgery or endoscopic treatment. The diagnostic accuracy of EUS and CE was evaluated by comparing the final histologic result of resected specimen. The correlation between accuracy of EUS and characteristics of EGC (tumor size, histology, location in stomach, tumor invasion depth, and endoscopic ulcer shapes) was analyzed. Endoscopic ulcer shapes were classified into 3 groups: definite ulcer, superficial ulcer, and ill-defined ulcer.The overall accuracy of EUS and CE for predicting the invasion depth in ulcerative EGC was 68.6% and 55.5%, respectively. Of the 236 patients, 36 patients were classified as definite ulcers, 98 were superficial ulcers, and 102 were ill-defined ulcers, In univariate analysis, EUS accuracy was associated with invasion depth (P = 0.023), tumor size (P = 0.034), and endoscopic ulcer shapes (P = 0.001). In multivariate analysis, there is a significant association between superficial ulcer in CE and EUS accuracy (odds ratio: 2.977; 95% confidence interval: 1.255-7.064; P = 0.013).The accuracy of EUS for determining tumor invasion depth in ulcerative EGC was superior to that of CE. In addition, ulcer shape was an important factor that affected EUS accuracy.

Efforts to increase image quality during endoscopy: The role of pronase

Clear visualization of the gastrointestinal mucosal surface is essential for thorough endoscopy. An unobstructed assessment can reduce the need for additional time-consuming manipulations such as frequent washing and suction, which tend to prolong total procedure time. However, mucus, foam, and bubbles often hinder clear visibility during endoscopy. Premedication with pronase, a compound of mixed proteolytic enzymes, has been studied in order to improve mucosal visibility during endoscopy. Although its effects differ according to the location in the stomach, premedication with pronase 10 to 20 min before endoscopy significantly improves mucosal visibility without affecting the accuracy of Helicobacter pylori identification. The effects of pronase as premedication also extend to chromoendoscopy, narrow-band imaging, magnifying endoscopy, and endoscopic ultrasonography. In addition, endoscopic flushing with pronase during endoscopy may improve the quantity and the quality of a biopsy to some degree. Although improved mucosal visibility does not necessarily improve clinical outcomes, premedication with pronase may be helpful for increasing the detection rate of early cancers.

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.

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

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society (JGES), in collaboration with the Japanese Gastric Cancer Association (JGCA), has produced 'Guidelines for ESD and EMR for Early Gastric Cancer', as a set of basic guidelines in accordance with the principles of evidence-based medicine. These Guidelines cover the present state of knowledge and are divided into the following seven categories: Indications, Preoperative diagnosis, Techniques, Evaluation of curability, Complications, Long-term postoperative surveillance, and Histology. Twenty-three statements were finally accepted as guidelines, and the majority of these were obtained from descriptive studies with lower evidence levels. A number of statements had to be created by consensus (the lowest evidence level), as evidence levels remain low for many specific areas in this field.

Is It Reasonable to Treat Early Gastric Cancer with Mucosal Infiltration and Well Differentiation by Endoscopic Submucosal Resection?

BACKGROUND

While limited endoscopic submucosal dissection (ESD) is increasingly applied in the treatment of early gastric cancer, preoperative prediction of lymph node metastasis is very critical for determining treatment strategies preoperatively. Thus, the aim of this study was to accurately assess the prevalence and pattern of lymph node metastasis in early gastric cancer patients and to identify the best candidates for ESD.

METHODS

From September 2008 to December 2013, a total of 539 patients with early gastric cancer were retrospectively analyzed in the present study. Of them, 503 patients underwent radical gastrectomy and 36 patients underwent ESD. The clinicopathological features were collected and correlations with lymph node metastasis were analyzed. The survival rates of patients were also analyzed.

RESULTS

Lymph node metastasis was observed in 80 of 503 patients (15.9 %). Among these, the rate for mucosal cancer was 8.3 %, and 20.1 % for submucosal cancer. By univariate analysis, risk factors for lymph node metastasis were growth pattern, tumor size, pathological type, depth of invasion, lymphatic-vascular invasion, and neural invasion. By multivariate analysis, risk factors for lymph node metastasis were tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. The incidence of lymph node metastasis was 0 % in the well-differentiated mucosal cancers, irrespective of tumor size. For the well-differentiated mucosal cancers, the overall survival rates were comparable between patients underwent gastrectomy with lymph node dissection and patients underwent ESD (100 vs 100 %).

CONCLUSIONS

The most important factors for predicting lymph node metastasis in early gastric cancer are tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. Well-differentiated mucosal gastric cancers could be candidates for ESD.

Endoscopic ultrasonography for staging depth of invasion in early gastric cancer: A meta-analysis

BACKGROUND AND AIM

Endoscopic ultrasonography (EUS) is a widely used imaging modality for detecting the depth of early gastric cancer (EGC) invasion. However, the studies pertaining to EUS for staging early gastric cancer have reported widely varied sensitivities and specificities. This study was conducted to estimate the overall diagnostic accuracy of EUS for staging the depth in EGCs.

METHODS

The literatures were identified by searching in PubMed, Embase, and Web of Knowledge databases. Two reviewers independently extracted the information from the literatures for constructing 2 × 2 table. A random-effect model or a fixed-effect model was used to estimate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve also was constructed. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity.

RESULTS

The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EUS for M staging were 76% (95% confidence interval [CI], 74-78%), 72% (95% CI, 69-75%), 3.67 (95% CI, 2.48-5.44), and 0.31 (95% CI, 0.24-0.40), respectively. For SM staging, these results were 62% (95% CI, 59-66%), 78% (95% CI, 76-80%), 2.99 (95% CI, 2.26-3.96), and 0.43 (95% CI, 0.32-0.57), respectively. For M/SM1 staging, they were 90% (95% CI, 88-92%), 67% (95% CI, 61-72%), 3.14 (95% CI, 2.08-4.73), and 0.12 (95% CI, 0.07-0.22), respectively. The area under the curve for mucosal, submucosal, and mucosal/minimal submucosal invasion staging were 0.85, 0.82, and 0.81, respectively.

CONCLUSIONS

Endoscopic ultrasonography only has a relatively low accuracy for staging the depth of invasion in EGCs. Accordingly, EUS may be not indispensable in the staging of EGCs.

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.

Current status of endoscopic ultrasound for the upper gastrointestinal tract in Asia

We summarize the current status of endoscopic ultrasound (EUS) for the upper gastrointestinal (GI) tract solely in Asia, focusing on the staging of superficial cancers and the diagnosis of submucosal tumors (SMT), by analysis of questionnaire responses and a literature review. EUS for assessing the depth of superficial cancers of the upper GI tract is useful; however, evidence is lacking to support that EUS is superior to other modalities. The current status of EUS varies across different Asian countries, and standardization of the methods used both during the procedure and for depth subclassification is necessary to evaluate the diagnostic accuracy. Although EUS alone is limited in the diagnosis of SMT, EUS-guided fine-needle aspiration is an effective and safe diagnostic tool. Although there is a role for EUS, there are still many limitations both technically and in terms of accessibility.

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.

Clinicopathologic factors influencing the accuracy of EUS for superficial esophageal carcinoma

AIM: To identify clinicopathologic factors influencing the accuracy of a high-frequency catheter probe endoscopic ultrasonography (EUS) for superficial esophageal carcinomas (SECs).

METHODS: A total of 126 patients with endoscopically suspected SEC, who underwent EUS and curative treatment at Pusan National University Hospital during 2005-2013, were enrolled. We reviewed the medical records of the 126 patients and compared EUS findings with histopathologic results according to clinicopathologic factors.

RESULTS: A total of 114 lesions in 113 patients were included in the final analysis. The EUS assessment of tumor invasion depth was accurate in 78.9% (90/114) patients. Accuracy did not differ according to histologic type, tumor differentiation, tumor location, or macroscopic shape. However, accuracy significantly decreased for tumors ≥ 3 cm in size (P = 0.002). Overestimation and underestimation of the invasion depth occurred for 11 (9.6%) and 13 lesions (11.4%), respectively. In multivariate analyses, tumor size ≥ 3 cm was the only factor significantly associated with EUS accuracy (P = 0.031), and was specifically associated with the underestimation of invasion depth.

CONCLUSION: EUS using a high-frequency catheter probe generally provides highly accurate assessments of SEC invasion depth, but its accuracy decreases for tumors ≥ 3 cm.

Unveiling lymph node metastasis in early gastric cancer

With respect to gastric cancer treatment, improvements in endoscopic techniques and novel therapeutic modalities [such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD)] have been developed. Currently, EMR/ESD procedures are widely accepted treatment modalities for early gastric cancer (EGC). These procedures are most widely accepted in Asia, including in Korea and Japan. In the present era of endoscopic resection, accurate prediction of lymph node (LN) metastasis is a critical component of selecting suitable patients for EMR/ESD. Generally, indications for EMR/ESD are based on large Japanese datasets, which indicate that there is almost no risk of LN metastasis in the subgroup of EGC cases. However, there is some controversy among investigators regarding the validity of these criteria. Further, there are currently no accurate methods to predict LN metastasis in gastric cancer (for example, radiologic methods or methods based on molecular biomarkers). We recommend the use of a 2-step method for the management of early gastric cancer using endoscopic resection. The first step is the selection of suitable patients for endoscopic resection, based on endoscopic and histopathologic findings. After endoscopic resection, additional surgical intervention could be determined on the basis of a comprehensive review of the endoscopic mucosal resection/endoscopic submucosal dissection specimen, including lymphovascular tumor emboli, tumor size, histologic type, and depth of invasion. However, evaluation of clinical application data is essential for validating this recommendation. Moreover, gastroenterologists, surgeons, and pathologists should closely collaborate and communicate during these decision-making processes.

Management of gastric epithelial neoplasia in patients requiring esophagectomy for esophageal cancer

Esophageal squamous cell carcinoma is occasionally associated with malignancies located in other regions of the alimentary tract, as well as in the head, neck, and upper respiratory tract. The stomach is most commonly used for reconstruction of the alimentary tract after esophagectomy for esophageal cancer. When synchronous tumors are located in the stomach, it is often unsuitable for use in esophageal reconstruction. In such cases, an invasive procedure involving anastomosis between the esophagus and the colon must be performed. However, this procedure is associated with a high incidence of mortality and morbidity. Seven patients with synchronous esophageal cancer and gastric epithelial neoplasia were encountered. First, endoscopic submucosal dissection (ESD) was performed for the gastric epithelial neoplasia. Then, following successful ESD, Ivor-Lewis esophagectomy for esophageal cancer was planned 1 to 2 weeks later. A total of 11 gastric epithelial lesions were found in seven patients. En bloc resection by ESD was possible in all 11 lesions and histologically complete resection was achieved in all 11 lesions. Follow-up endoscopy was done 1-2 weeks after ESD; six patients with well-healing ulcers underwent esophagectomy the next day (8 or 15 days after ESD). In one patient with a poorly healed ulcer, a second follow-up endoscopy was done 1 week later and then esophagectomy was performed the next day (22 days after ESD). Post-surgical complications related to ESD, such as bleeding or mediastinal leak, were not seen in any of the seven patients. In patients with synchronous esophageal cancer and gastric epithelial neoplasia, ESD for gastric epithelial neoplasia followed by Ivor-Lewis esophagectomy 1 to 2 weeks later is an effective choice of treatment.

Pathologic definition and number of lymphovascular emboli: impact on lymph node metastasis in endoscopically resected early gastric cancer

Endoscopic submucosal dissection (ESD) is widely accepted as an appropriate treatment modality for early gastric cancer (EGC). Accepted indications for ESD are mostly based on the risk of lymph node (LN) metastasis in EGC. The presence of lymphovascular emboli (LVEs) is the most important risk factor for predicting LN metastasis, but the criteria for diagnosing LVEs are inconsistent and controversial. Here, we defined LVE as the presence of tumor cells within a space according to the following criteria: (1) red cells or lymphocytes surrounding the tumor cells, (2) an endothelial cell lining, and (3) attachment to the vascular wall. We reviewed a series of 102 patients with EGC who underwent gastrectomy after ESD, evaluated the definition of LVE, counted the number of LVEs in ESD specimens, and validated the significance of the definition and number of LVEs with regard to the presence of LN metastasis in gastrectomy specimens using receiver operating characteristic (ROC) curve analysis. Overall, 13 instances (12.7%) of LN metastasis were identified among 102 patients with EGC who underwent gastrectomy after ESD. The LN metastasis-positive group showed higher numbers of definite (4.46 ± 2.45 versus 0.19 ± 0.07), suspicious (3.15 ± 0.76 versus 0.62 ± 0.14), and probable (1.62 ± 0.43 versus 0.43 ± 0.10) LVEs in ESD specimens than the LN metastasis-negative group. In ROC analysis, the area under the ROC curve was 0.851 (95% confidence interval [CI], 0.711-0.991) for definite LVEs, compared with 0.82 (95% CI, 0.698-0.960) for suspicious LVEs and 0.72 (95% CI, 0.549-0.891) for probable LVEs. We recommend the use of strict LVE criteria to predict LN metastasis and determine the need for surgical intervention after ESD.

Prediction of risk factors for lymph node metastasis in early gastric cancer

AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.

METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.

RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ² = 122.901, P = 0.001; χ² = 7.14, P = 0.008; χ² = 79.523, P = 0.001; χ² = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ² = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN₁ (P = 0.008).

CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.

The current state of diagnosis and treatment for early gastric cancer

The prognosis for gastric cancer depends on its stage; so, detection in the early stage of disease is important, when complete and curative removal is possible. Accurate diagnosis can be facilitated by a sound understanding of the basic findings of white light endoscopy of early gastric cancer, and diagnosis can be refined further by the combined use of other imaging modalities such as image-enhanced endoscopy including chromoendoscopy and endoscopic ultrasonography. Minimally invasive endoscopic treatment has come to be the preferred therapeutic approach for early gastric cancer. In addition to conventional endoscopic mucosal resection, a new technique known as endoscopic submucosal dissection (ESD) has spread rapidly worldwide. Indeed, strategies for ESD have been established, devices developed, its indications expanded, and its safety and long-term results extensively reported. Some unique combination therapies involving endoscopy and surgical treatment have also been reported. It is anticipated that the number of patients undergoing endoscopic therapy will continue to increase, and the ongoing developments in endoscopic treatment are expected not only to improve gastric cancer prognosis but also to maintain good quality of life after treatment.

Indication for endoscopic treatment of ulcerative early gastric cancer according to depth of ulcer and morphological change

BACKGROUND AND AIM

This study was conducted to determine the clinicopathologic factors affecting the stage of ulcerative early gastric cancer (EGC), focusing on the relationships between cancer stage and degree of endoscopic ulcer depth and morphologic changes.

METHODS

Medical records of 183 cases of ulcerative EGC who had received endoscopic examination two or more times with a minimum interval of one week, and who underwent either curative surgery or endoscopic treatment were retrospectively reviewed.

RESULTS

Change in ulcer morphology at follow-up endoscopy was observed in 84 cases (45.9%) with improvement and exacerbation of ulcer in 65 (35.5%) and 19 (13.8%) cases, respectively. The presence of type III ulcer (P < 0.01), and endoscopic findings suggesting submucosal cancer invasion (tumorous bank, fusion of converging folds, hardness or decreased flexibility) (P < 0.01), and incomplete ulcer healing (P = 0.036) were independently associated with a higher incidence of submucosal cancer invasion. The incidence of lymph node metastasis was 14.1%, and undifferentiated histology and presence of lymphovascular invasion were significantly associated with a higher incidence of lymph node metastasis (P = 0.018 and P = 0.005, respectively).

CONCLUSIONS

Endoscopic resection with curative intent may be an acceptable option for EGC combined with endoscopic ulcer or ulcer scar, but should be restricted to cases showing significant improvement in the size and depth of ulcer at follow-up endoscopy, and which are not accompanied with deep ulcer more than the thickness of adjacent mucosal surface and prominent surrounding mucosal fold change. In addition, histologic criteria should meet the conditions of differentiated intramucosal cancer without lymphovascular invasion.

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.

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.

Endoscopic ultrasound using ultrasound probes for the diagnosis of early esophageal and gastric cancers

Endoscopic ultrasound (EUS) devices were first designed and manufactured more than 30 years ago, and since then investigators have reported EUS is effective for determining both the staging and the depth of invasion of esophageal and gastric cancers. We review the present status, the methods, and the findings of EUS when used to diagnose and stage early esophageal and gastric cancer. EUS using high-frequency ultrasound probes is more accurate than conventional EUS for the evaluation of the depth of invasion of superficial esophageal carcinoma. The rates of accurate evaluation of the depth of invasion by EUS using high-frequency ultrasound probes were 70%-88% for intramucosal cancer, and 83%-94% for submucosal invasive cancer. But the sensitivity of EUS using high-frequency ultrasound probes for the diagnosis of submucosal invasive cancer was relatively low, making it difficult to confirm minute submucosal invasion. The accuracy of EUS using high-frequency ultrasound probes for early gastric tumor classification can be up to 80% compared with 63% for conventional EUS, although the accuracy of EUS using high-frequency ultrasound probes relatively decreases for those patients with depressed-type lesions, undifferentiated cancer, concomitant ulceration, expanded indications, type 0-I lesions, and lesions located in the upper-third of the stomach. A 92% overall accuracy rate was achieved when both the endoscopic appearance and the findings from EUS using high-frequency ultrasound probes were considered together for tumor classification. Although EUS using high-frequency ultrasound probes has limitations, it has a high depth of invasion accuracy and is a useful procedure to distinguish lesions in the esophagus and stomach that are indicated for endoscopic resection.

Endoscopy and role of endoscopic resection in gastric cancer

Patient selection for endoscopic resection is based on meticulous endoscopic examination and histological assessment so as to avoid performing this procedure on patients with a high risk of lymph node involvement or metastatic disease. Currently, endoscopic mucosal resection (EMR) is used for tumors <2 cm, and endoscopic submucosal dissection (ESD) should be considered for tumors >2 cm. The advantage of ESD is that it achieves en-bloc resection of larger tumors, potentially reducing the risk of disease recurrence.

[Diagnostic endoscopic ultrasonography in the gastrointestinal tract]

Endoscopic ultrasonography is a relatively new technology that combines the use of flexible fiberoptic endoscopes with high-resolution ultrasound technology. It proved to be highly accurate and useful in the staging of gastrointestinal malignancies, as well as in characterizing the nature of subepithelial lesions and disorders of the pancreaticobiliary system. In this overview the variety of current evidence based diagnostic options of endoscopic ultrasonography are discussed.

Diagnosis of the invasion depth of gastric cancer using MDCT with virtual gastroscopy: comparison with staging with endoscopic ultrasound

OBJECTIVE

The objectives of this study were to retrospectively evaluate the lesion detection rate of gastric cancer using only virtual gastroscopy generated from MDCT images and the accuracy of invasion depth diagnosis (T staging) using virtual gastroscopy together with contrast-enhanced MDCT with multiplanar reconstruction (MPR) images (virtual gastroscopy with MPR), and to compare the diagnostic performance between virtual gastroscopy with MPR images and endoscopic ultrasound.

MATERIALS AND METHODS

The subjects consisted of 175 patients with a total of 186 endoscopically proven gastric cancer lesions. All patients underwent dynamic MDCT (arterial and venous phase) for preoperative staging and underwent surgery or endoscopic treatment. In 129 patients (135 lesions) who were also examined using endoscopic ultrasound, the T staging accuracy was also compared between the two modalities. Two endoscopists independently evaluated the lesion detection rate on virtual gastroscopy images alone and determined the T stage on virtual gastroscopy with MPR images. The T staging included the ability to differentiate T1a from T1b lesions.

RESULTS

The overall lesion detection rate was 67.7% (126/186). The detection rates of T1a, T1b, and T2 or deeper were 37.8% (28/74), 75.0% (39/52), and 98.3% (59/60), respectively, showing statistically significant differences (p < 0.001). The T staging accuracies were 82.2% (111/135) using virtual gastroscopy with MPR images and 83.7% (113/135) using endoscopic ultrasound, showing no statistically significant difference (p = 0.850). The main causes of over- and understaging were an ulcer or ulcer scar and poorly differentiated adenocarcinomas, non-solid type, respectively.

CONCLUSION

Virtual gastroscopy with MPR imaging is a useful modality in the T staging of gastric cancer.

Benefit of pronase in image quality during EUS

BACKGROUND

EUS is useful for diagnosis of GI disease. However, artifacts caused by gastric mucus may worsen visibility during EUS.

OBJECTIVE

To investigate the efficacy of premedication with pronase, the proteolytic enzyme, for improving imaging during EUS.

DESIGN

Blinded, randomized, prospective study.

SETTING

Tertiary-care referral center.

PATIENTS

This study involved 183 patients scheduled for EUS.

INTERVENTION

Patients were assigned to oral premedication with saline solution (group A), pronase and bicarbonate (group B), or pronase, bicarbonate, and simethicone (group C). Either conventional EUS or high-frequency catheter EUS (HFUS) was selected. Gastric cavity and gastric mucosal surface obscurity grades were assessed by using visibility scores from ultrasonographic images of each patient.

MAIN OUTCOME MEASUREMENTS

Means of visibility scores and proportion of images with better visibility scores of the gastric cavity and gastric mucosal surface. Lower scores indicate better visibility of the gastric mucosal surface and fewer artifacts within the gastric cavity on conventional EUS and HFUS.

RESULTS

Group B had significantly lower mean gastric cavity and gastric mucosal surface visibility scores than did groups A and C in both conventional EUS and HFUS. Group B also had a high proportion of images that had better gastric cavity and gastric mucosal surface visibility scores than did the other two groups in conventional EUS and HFUS.

LIMITATIONS

Small number of patients and no assessment of the amount of mucus before oral premedication.

CONCLUSION

Premedication for conventional EUS and HFUS by using a mixture of pronase and bicarbonate seems to decrease the number of gastric wall and lumen hyperechoic artifacts observed in patients given either saline solution or pronase/bicarbonate/simethicone.

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

PURPOSE

As the proportion of early gastric cancer (EGC) has recently been increased, minimally invasive treatment is currently accepted as main therapy for EGC. Accurate preoperative staging is very important in determining treatment options. To know the accuracy of endoscopic ultrasonography (EUS), we compared the depth of invasion of the tumor with preoperative EUS and postoperative pathologic findings.

MATERIALS AND METHODS

We retrospectively analyzed 152 patients who underwent EUS before laparoscopic gastrectomy. The preoperative EUS results were compared with the pathological findings.

RESULTS

The overall proportion of coincidence for depth of invasion between EUS and pathologic results was 41.4%. Univariate analysis showed that the rate of corrected prediction of EUS for tumor depth significantly decreased for the lesions more than 3cm in diameter (P=0.033), and those with a depressed morphology (P=0.035). In multivariate analysis, the depressed type (P=0.029, OR=2.873) and upper lesion (P=0.035, OR=2.151) was the significantly independent factors influencing the inaccurate prediction of EUS for tumor depth.

CONCLUSIONS

When we decide the treatment modality considering the clinical depth of invasion by EUS, the possibility of discordance with pathologic results should be considered for the lesions located in the upper third of the stomach and with a depressed morphology.

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

PURPOSE

As the proportion of early gastric cancer (EGC) has recently been increased, minimally invasive treatment is currently accepted as main therapy for EGC. Accurate preoperative staging is very important in determining treatment options. To know the accuracy of endoscopic ultrasonography (EUS), we compared the depth of invasion of the tumor with preoperative EUS and postoperative pathologic findings.

MATERIALS AND METHODS

We retrospectively analyzed 152 patients who underwent EUS before laparoscopic gastrectomy. The preoperative EUS results were compared with the pathological findings.

RESULTS

The overall proportion of coincidence for depth of invasion between EUS and pathologic results was 41.4%. Univariate analysis showed that the rate of corrected prediction of EUS for tumor depth significantly decreased for the lesions more than 3cm in diameter (P=0.033), and those with a depressed morphology (P=0.035). In multivariate analysis, the depressed type (P=0.029, OR=2.873) and upper lesion (P=0.035, OR=2.151) was the significantly independent factors influencing the inaccurate prediction of EUS for tumor depth.

CONCLUSIONS

When we decide the treatment modality considering the clinical depth of invasion by EUS, the possibility of discordance with pathologic results should be considered for the lesions located in the upper third of the stomach and with a depressed morphology.

Endoscopic submucosal dissection for early gastric cancer: Quo vadis?

The diagnosis of early gastric cancer (EGC) is of great interest because its endoscopic and surgical treatment presents the best chance for a cure. With technical development, endoscopic submucosal dissection (ESD) has been widely performed for the curative treatment of EGC in Korea. Multinational studies of ESD for EGC will be the next missions that overcome these limitations and global guidelines will be processed for ESD for EGC.

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

BACKGROUND

The role of EUS in the locoregional staging of gastric carcinoma is undefined.

OBJECTIVE

We aimed to comprehensively review and quantitatively summarize the available evidence on the staging performance of EUS.

DESIGN

We systematically searched the MEDLINE, Cochrane, CANCERLIT, and EMBASE databases for relevant studies published until July 2010.

SETTING

Formal meta-analysis of diagnostic accuracy parameters was performed by using a bivariate random-effects model.

PATIENTS

Fifty-four studies enrolling 5601 patients with gastric cancer undergoing disease staging with EUS were eligible for the meta-analysis.

MAIN OUTCOME MEASUREMENTS

EUS staging accuracy across eligible studies was measured by computing overall sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR).

RESULTS

EUS can differentiate T1-2 from T3-4 gastric cancer with high accuracy, with overall sensitivity, specificity, PLR, NLR, and DOR of 0.86 (95% CI, 0.81-0.90), 0.91 (95% CI, 0.89-0.93), 9.8 (95% CI, 7.5-12.8), 0.15 (95% CI, 0.11-0.21), and 65 (95% CI, 41-105), respectively. In contrast, the diagnostic performance of EUS for lymph node status is less reliable, with overall sensitivity, specificity, PLR, NLR, and DOR of 0.69 (95% CI, 0.63-0.74), 0.84 (95% CI, 0.81-0.88), 4.4 (95% CI, 3.6-5.4), 0.37 (95% CI, 0.32-0.44), and 12 (95% CI, 9-16), respectively. Results regarding single T categories (including T1 substages) and Bayesian nomograms to calculate posttest probabilities for any target condition prevalence are also provided.

LIMITATIONS

Statistical heterogeneity was generally high; unfortunately, subgroup analysis did not identify a consistent source of the heterogeneity.

CONCLUSIONS

Our results support the use of EUS for the locoregional staging of gastric cancer, which can affect the therapeutic management of these patients. However, clinicians must be aware of the performance limits of this staging tool.