Role of endoscopic ultrasonography in preoperative staging of gastric carcinoma

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.

Margin diagnosis for endoscopic submucosal dissection of early gastric cancer using multiphoton microscopy

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has become the primary option for the treatment of early gastric cancer (EGC). Thus, it is necessary to diagnose whether residual cancer cells exist in the ESD specimen margins, which can affect tumor recurrence and survival rates in the future. Multiphoton microscopy (MPM) can be suitably used for nondestructive imaging of biological tissue on a cellular level to enable real-time guidance during endoscopic therapy. Considering this, the objective of this study is to explore the practicality of MPM for the diagnosis of ESD specimen margins in the case of EGC.

METHODS

First, a total of 20 surgical samples was imaged using the proposed MPM technique to obtain two-photo excited fluorescence signal from the intrinsic fluorescent substances within cells and second-harmonic generation signal from collagen; these signals were used to determine MPM pathological features for margin diagnosis. Then, a double-blind study of 50 samples was conducted to evaluate the diagnosis results based on the obtained MPM pathological features.

RESULTS

Multiphoton microscopy can accurately identify the cytological and morphological differences between tissue in the negative and positive margin. The sensitivity, specificity, accuracy, negative predictive, and positive predictive values of MPM in the diagnosis of ESD specimen margins were 97.62, 75.00, 94.00, 95.35, and 85.71%, respectively.

CONCLUSION

These results indicate that MPM can be used as an effective, real-time, and label-free novel method to determine intraoperative resection margins.

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.

Enhanced intensity on preoperative double contrast-enhanced sonography as a useful indicator of lymph node metastasis in patients with gastric cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of enhanced intensity on double contrast-enhanced sonography in assessing lymph node metastasis of gastric cancer.

METHODS

A total of 357 patients with gastric cancer were enrolled in this study. Double contrast-enhanced sonography, in which an oral ultrasound contrast agent is combined with an intravenous contrast agent, was performed preoperatively, and the data were analyzed quantitatively. The predictive ability of enhanced intensity, a quantitative double contrast-enhanced sonographic measure, for lymph node metastasis was evaluated retrospectively.

RESULTS

Compared to negative lymph node metastasis cases, the presence of thicker lesions, deeper invasion, poorer differentiation, and higher enhanced intensity were found in positive cases (P< .05). An enhanced intensity cutoff value of 16.91 dB was the best point for balancing the sensitivity and specificity (71.50% and 79.30%, respectively) for prediction of lymph node metastasis, with the highest Youden index of 0.508. The area under the receiver operating characteristic curve was 0.828 (P < .001; 95% confidence interval, 0.786-0.870). In cases in which the lesions were hyperenhanced (enhanced intensity >16.91 dB), the lesions were significantly thicker and had deeper invasion, poorer differentiation, and more positive metastasis findings compared to non-hyperenhanced cases (enhanced intensity ≤16.91 dB; P < .05). On logistic regression analysis, the enhanced intensity of primary tumors and the invasion depth were significantly associated with lymph node metastasis.

CONCLUSIONS

Double contrast-enhanced sonography with quantitative analysis may be considered a novel alternative imaging modality for noninvasive preoperative evaluation of lymph node metastasis with good reliability.

Endoscopic ultrasonography (EUS) in preoperative staging of gastric cancer--demand and reality

Exact pretherapeutic staging is considered to be essential for decision-making in the therapeutic algorithm of gastric cancer. THE AIM OF THE STUDY was to characterize the role and value of EUS in the diagnostic and therapeutic management of gastric cancer in daily surgical practice.

MATERIAL AND METHODS

Thousand one hundred thirty nine patients with primary gastric cancer from 80 hospitals of each profile of care were enrolled in this systematic clinical prospective multicenter observational study over a time period of 12 months. The characteristics of the diagnostic management, in particular, of EUS were documented. The preoperative EUS findings were compared with the T stage (T1 to T4) and the N category (N+ or N-) revealed by the histopathologic investigation of the surgical specimen. By the mean of χ² test, the impact of EUS on the therapeutic decision-making was determined.

RESULTS

Pretherapeutic EUS was only performed in 27.4% (n=312) of all patients. Overall, the diagnostic accuracy for the T stage was 42.6% in average. The subgroup analysis showed the following results: T1, 31.5%; T2, 42.6%; T3, 65.2%; T4, 17.6%. The correct predictive value of the N category was 71.3% reaching a sensitivity of 69.7% and a specificity of 73.3%. Overstaging was observed in 45.8%, understaging in only 10.8%. Additional diagnostic information by EUS was only provided in 4.7% of subjects.

CONCLUSIONS

The present study indicates the variability, limited reliability and only moderate acceptance of EUS in diagnosing gastric cancer in daily practice. In particular, the prediction of the T stage does not reach the data reported in the literature, which were mostly achieved in specific EUS studies.

Low accuracy of endoscopic ultrasonography for detailed T staging in gastric cancer

Background

The accuracy of endoscopic ultrasonography (EUS) for preoperative staging of gastric cancer varies. The aim of this study was to investigate the accuracy of EUS tumor (T) and node (N) staging, and to identify the histopathological factors influencing accuracy based on the detailed tumor depth of gastric cancer.

Methods

In total, 309 patients with gastric cancer with confirmed pathological staging underwent EUS examination for preoperative staging at Seoul St. Mary’s Hospital, Korea, between January and December 2009. The T and N staging of EUS and the pathologic report were compared.

Results

The overall accuracies of EUS for T stage and the detailed T stages were 70.2% and 43.0%, respectively. In detailed stage, tumors greater than 50 mm in diameter were significantly associated with T overstaging (odds ratio (OR) = 2.094). The overall accuracy of EUS for N staging was 71.2%. Tumor size (20 mm ≤ size < 50 mm, OR = 4.389; and 50 mm ≤ size, OR = 8.170), cross-sectional tumor location (circumferential, OR = 4.381) and tumor depth (submucosa, OR = 3.324; muscular propria, OR = 6.923; sub-serosa, OR = 4.517; and serosa-exposed, OR = 6.495) were significant factors affecting incorrect nodal detection.

Conclusions

Careful attention is required during EUS examination of large-sized gastric cancers to increase accuracy, especially for T staging.

A systematic review and meta-analysis of the utility of EUS for preoperative staging for gastric cancer

BACKGROUND

Accurate preoperative staging is important in determining the appropriate treatment of gastric cancer. Recently, endoscopic ultrasound (EUS) has been introduced as a staging modality. However, reported test characteristics for EUS in gastric cancer vary. Our purpose in this study was to identify, synthesize, and evaluate findings from all articles on the performance of EUS in the preoperative staging of gastric cancer.

METHODS

Electronic literature searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1 January 1998 to 1 December 2009. All search titles and abstracts were independently rated for relevance by a minimum of two reviewers. Meta-analysis for the performance of EUS was analyzed by calculating agreement (Kappa statistic), and pooled estimates of accuracy, sensitivity, and specificity for all EUS examinations, using histopathology as the reference standard. Subgroup analyses were also performed.

RESULTS

Twenty-two articles met our inclusion criteria and were included in the review. EUS pooled accuracy for T staging was 75% with a moderate Kappa (0.52). EUS was most accurate for T3 disease, followed by T4, T1, and T2. EUS pooled accuracy for N staging was 64%, sensitivity was 74%, and specificity was 80%. There was significant heterogeneity between the included studies. Subgroup analyses found that annual EUS volume was not associated with EUS T and N staging accuracy (P = 0.836, 0.99, respectively).

CONCLUSION

EUS is a moderately accurate technique that seems to describe advanced T stage (T3 and T4) better than N or less advanced T stage. Stratifying by EUS annual volume did not affect EUS performance in staging gastric cancer.

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.

Endoscopic ultrasonography is valuable for identifying early gastric cancers meeting expanded-indication criteria for endoscopic submucosal dissection

BACKGROUND

Endoscopic ultrasonography (EUS) has become a reliable method for predicting the invasion depth of early gastric cancer (EGC). This study evaluated the accuracy of EUS in identifying lesions meeting expanded-indication criteria for endoscopic submucosal dissection (ESD) and analyzed clinicopathologic factors influencing the diagnostic accuracy of EUS in assessing tumor invasion depth.

METHODS

This study investigated 542 EGCs of 515 patients who underwent EUS pretreatment. The pretreatment EUS-determined diagnosis was compared with the final histopathologic evaluation of resected specimens, and the impact of various clinicopathologic parameters on diagnostic accuracy was analyzed.

RESULTS

The diagnostic accuracy of EUS in identifying lesions meeting expanded-indication criteria for ESD was 87.8% (259/295) for differentiated adenocarcinoma (D-type) 30 mm in diameter or smaller, 43.5% (10/23) for D-type tumor larger than 30 mm in diameter, and 75% (42/56) for undifferentiated adenocarcinoma (UD-type) 20 mm in diameter or smaller. Using multivariate analysis, the diagnostic accuracy of EUS in predicting tumor invasion depth was determined to be decreased significantly by ulcerous change and large tumor size (diameter, ≥30 mm).

CONCLUSION

For patients with EGC, D-type lesions 30 mm in diameter or smaller and UD-type lesions 20 mm in diameter or smaller can be diagnosed with high accuracy by EUS, but larger D-type lesions (diameter, >30 mm) should be considered carefully in terms of EUS-based treatment decisions. Findings of ulceration and large tumors are associated with incorrect diagnosis of tumor invasion depth by EUS.

Imaging in assessing lymph node status in gastric cancer

BACKGROUND

Accurate assessment of lymph node status is of crucial importance for appropriate treatment planning and determining prognosis in patients with gastric cancer. The aim of this study was to systematically review the current role of imaging in assessing lymph node (LN) status in gastric cancer.

METHODS

A systematic literature search was performed in the PubMed/MEDLINE and Embase databases. The methodological quality and diagnostic performance of the included studies was assessed.

RESULTS

Six abdominal ultrasonography (AUS) studies, 30 endoscopic ultrasonography (EUS) studies, 10 multidetectorrow computed tomography (MDCT) studies, 3 conventional magnetic resonance imaging (MRI) studies, 4 (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) studies, and 1 FDG-PET/CT fusion study were included. In general, the included studies had moderate methodological quality. The sensitivity and specificity of AUS varied between 12.2% and 80.0% (median, 39.9%) and 56.3% and 100% (median, 81.8%). The sensitivity and specificity of EUS varied between 16.7% and 95.3% (median, 70.8%) and 48.4% and 100% (median, 84.6%). The sensitivity and specificity of MDCT varied between 62.5% and 91.9% (median, 80.0%) and 50.0% and 87.9% (median, 77.8%). The sensitivity and specificity of MRI varied between 54.6% and 85.3% (median, 68.8%) and 50.0% and 100% (median, 75.0%). The sensitivity and specificity of FDG-PET varied between 33.3% and 64.6% (median, 34.3%) and 85.7% and 97.0% (median, 93.2%). The sensitivity and specificity of the FDG-PET/CT fusion study were 54.7% and 92.2%. For all the imaging modalities, there were no significant differences between the mean sensitivities and specificities of high- and low-quality studies.

CONCLUSION

AUS, EUS, MDCT, conventional MRI, and FDG-PET cannot reliably be used to confirm or exclude the presence of LN metastasis. The performance of highresolution PET/CT fusion and functional MRI techniques still has to be determined.

Diagnostic accuracy of T and N stages with endoscopy, stomach protocol CT, and endoscopic ultrasonography in early gastric cancer

BACKGROUND

Preoperative accurate diagnosis of the T and N stages in early gastric cancer (EGC) is important in determining the application of various limited treatments. The aim of this study is to analyze the accuracy of T and N staging of EGC with esophagogastroduodenoscopy (EGD), Stomach protocol CT (S-CT), and endoscopic ultrasonography (EUS), and the factors influencing the accuracy.

METHODS

Four hundred and thirty-four patients preoperatively diagnosed as EGC using EGD or S-CT and undergoing curative gastrectomy at Seoul National University Hospital in 2005 were included. The T and N stage reviewed by experienced personnel were compared with the surgical pathology.

RESULTS

The predictive values for EGC of EGD, S-CT, and EUS were 87.4%, 92.2%, and 94.1%, respectively. The predictive values for node negativity of S-CT, and EUS were 90.1% and 92.6%, respectively. The factors leading to underestimation of T stage with EGD were the upper third location, the size greater than 2 cm, and diffuse type of tumor. Those with S-CT were female sex, the upper third location and lesion size greater than 2 cm.

CONCLUSIONS

Before applying limited treatment for EGC, a surgeon should consider the risk factors of underestimation of T stage with EGD or S-CT.

How good is endoscopic ultrasound for TNM staging of gastric cancers? A meta-analysis and systematic review

AIM: To evaluate the accuracy of endoscopic ultrasound (EUS) for staging of gastric cancers.

METHODS: Only EUS studies confirmed by surgery were selected. Only studies from which a 2 × 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Articles were searched in Medline, Pubmed, Ovid journals, Cumulative index for nursing & allied health literature, International pharmaceutical abstracts, old Medline, Medline nonindexed citations, and Cochrane control trial registry. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. 2 × 2 tables were constructed with the data extracted from each study. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio. Pooling was conducted by both the Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran’s Q test based upon inverse variance weights.

RESULTS: Initial search identified 1620 reference articles and of these, 376 relevant articles were selected and reviewed. Twenty-two studies (n = 1896) which met the inclusion criteria were included in this analysis. Pooled sensitivity of T1 was 88.1% (95% CI: 84.5-91.1) and T2 was 82.3% (95% CI: 78.2-86.0). For T3, pooled sensitivity was 89.7% (95% CI: 87.1-92.0). T4 had a pooled sensitivity of 99.2% (95% CI: 97.1-99.9). For nodal staging, the pooled sensitivity for N1 was 58.2% (95% CI: 53.5-62.8) and N2 was 64.9% (95% CI: 60.8-68.8). Pooled sensitivity to diagnose distant metastasis was 73.2% (95% CI: 63.2-81.7). The P for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10.

CONCLUSION: EUS results are more accurate with advanced disease than early disease. If EUS diagnoses advanced disease, such as T4 disease, the patient is 500 times more likely to have true anatomic stage of T4 disease.

Clinicopathologic factors influence accurate endosonographic assessment for early gastric cancer

BACKGROUND AND OBJECTIVE

EUS has become a valuable tool for the selection of patients who are suitable for EMR of early gastric cancer (EGC). The aim of this study was to evaluate the various clinicopathologic factors affecting the diagnostic accuracy of EUS in EGC.

DESIGN AND SETTING

A retrospective, single-center study.

PATIENTS

A total of 206 patients suspected of EGC endoscopically who underwent EUS examination and curative treatment for EGC at Severance Hospital, Seoul, Korea, from October 2001 to May 2005 were included.

INTERVENTIONS

We reviewed the medical records of 206 patients and compared preoperative EUS staging with final histopathologic staging of the resected specimen according to the clinicopathologic parameters.

MAIN OUTCOME MEASUREMENTS AND RESULTS

The diagnostic accuracy of EUS for predicting tumor invasion depth was significantly affected by the histopathologic differentiation and the size of tumor. The differentiated cell types were associated with higher diagnostic accuracy in predicting the tumor invasion. Lesions located in the mid one third of the stomach larger than 3 cm had significantly higher probability of overstaging. Poorly differentiated histologic diagnosis had a significantly higher probability of understaging. There was no significant factor associated with the endosonographic prediction of lymph node metastasis.

CONCLUSIONS

EGC with undifferentiated histopathologic features or large tumor size is more frequently associated with an incorrect diagnosis in tumor invasion depth by EUS. EGC with a size larger than 3 cm and poorly differentiated histologic diagnosis should be cautiously considered in the decision on treatment modality by pretreatment EUS staging.

Imaging in local staging of gastric cancer: a systematic review

PURPOSE

Endoscopic ultrasound (EUS) has been established as the diagnostic modality of choice in local (T) staging of gastric cancer. Multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) are promising alternatives. The aim of this study was to systematically review the literature regarding the performance of each of these imaging modalities.

METHODS

A systematic search for relevant studies was performed in the PubMed/MEDLINE and EMBASE databases. Two reviewers independently assessed the methodological quality of each study. Local staging performance of included studies was calculated.

RESULTS

Twenty-two EUS studies, five MDCT studies, one combined EUS and MDCT study, and three MRI studies met the inclusion criteria. The studies were of moderate methodological quality. Diagnostic accuracy of overall T staging for EUS, MDCT, and MRI varied between 65% to 92.1%, 77.1% to 88.9%, and 71.4% to 82.6%, respectively. Sensitivity for assessing serosal involvement for EUS, MDCT, and MRI varied between 77.8% to 100%, 82.8% to 100%, and 89.5% to 93.1%, respectively. Specificity for assessing serosal involvement for EUS, MDCT, and MRI varied between 67.9% to 100%, 80% to 96.8%, and 91.4% to 100%, respectively.

CONCLUSION

EUS, MDCT, and MRI achieve similar results in terms of diagnostic accuracy in T staging and in assessing serosal involvement. Most experience has been gained with EUS. Few MDCT studies and even fewer MRI studies are available. Thus, EUS remains the first-choice imaging modality in preoperative T staging of gastric cancer.

CURRENT CLINICAL APPLICATIONS OF ENDOSCOPIC ULTRASOUND

Endoscopic ultrasound (EUS) has been developed since the early 1980s. Its clinical role in the diagnosis of gastrointestinal wall lesions and staging of gastrointestinal and lung cancer has evolved over the last two decades. Initially, it was either used as an imaging tool for gastrointestinal wall lesions or for staging of gastrointestinal tumours. However, in combination with fine-needle aspiration under real-time scanning, EUS is now being used in tissue sampling for diagnosis. In addition, EUS may be used therapeutically in coeliac plexus neurolysis or pseudocyst drainage. This review concentrates on the current applications of EUS.

Gene expression profile of primary gastric cancer: towards the prediction of lymph node status

BACKGROUND

The identification of gastric tumors associated with a higher risk of lymph node metastasis could help surgeons select patients who may benefit from extended lymph node dissection. The aim of this study was to screen the genome in the search of primary gastric cancer gene expression profiles that might predict lymph node status.

METHODS

The gene expression profile was evaluated in frozen tumor samples obtained from 32 patients with primary gastric adenocarcinomas. The array consisted of a duplicated spot panel of 5,541 human genes. To classify node-positive (N+) and node-negative (N-) cases, a logistic regression model was fitted optimizing the Akaike Information Criteria after a stepwise gene selection. The accuracy was evaluated by means of leave-one-out cross validation.

RESULTS

All patients underwent radical gastrectomy and extended lymphadenectomy. Of all the cases, 21 were N+ and 11 demonstrated no lymph node involvement (N-). After quality filtering, the analysis of variance selected a set of 136 genes potentially correlated with nodal involvement (P value <.05). Of these 136 genes, 5 were differentially expressed (adjusted P value <.05). After a stepwise gene selection, only three genes (Bik, aurora kinase B, eIF5A2) were retained in the logistic model, which could correctly predict lymph node status in 30 of 32 cases.

CONCLUSIONS

If our findings were confirmed, the identified gene pattern might be used to tailor the extent of lymph node dissection on a single patient basis.

Does endoscopic ultrasound staging already allow individual treatment regimens in gastric cancer

AIM

The aim of our study was to evaluate the accuracy of preoperative TNM staging with endoscopic ultrasound (EUS) in gastric cancer patients in comparison with the pathohistological stage of the resected specimen, and to determine the possible implications of EUS for individualized treatment of gastric cancer patients at our institution.

PATIENTS AND METHODS

The study included 82 patients operated for resectable gastric cancer between January 1(st) 2001 and July 1(st) 2003 at the Maribor Teaching Hospital Department of Abdominal and General Surgery. The EUS stage was assessed preoperatively at the Endoscopical Unit, and the pathohistological stage in the resected specimen was determined postoperatively at the Department of Pathologic Morphology according to recommended standards.

RESULTS

Comparison of EUS and pathohistological assessments revealed accuracy of EUS staging for locoregional tumor infiltration (category T) in 68% of patients. The accuracy of EUS staging was 68% for T1, 69% for T2, 69% for T3 and 60% for T4. Lymph nodes (category N) were correctly staged with EUS in 57% of cases. The EUS stage was correct for lymph nodes with no metastases (N-) in 40% of cases, and for lymph nodes with metastases (N+) in 90%. There was no significant difference in accuracy of EUS staging with regard to tumor site (P = 0.768) or tumor size (P = 0.766).

CONCLUSIONS

According to our results the accuracy of EUS staging matched pathohistological staging with regard to tumor infiltration and lymph node stage in 68% and 57% of cases respectively. Underestimation of the final T2 and T3 stages as T1 stage by EUS presents a problem regarding the consistency of EUS examination at our institution, particularly with respect to individual treatment for early gastric cancer. The present uncertainty in EUS stage reliability makes it necessary to have a strategy of radical resection with D2 lymphadenectomy in patients within EUS stages T1-T3, with additional CT examinations in more advanced EUS stages in order to visualize the circumstances of tumor growth. Nevertheless, EUS provides an opportunity for the surgeon to gain more insight into the loco-regional circumstances of the gastric tumor process. For development of individual modes of treatment based on EUS staging, a more reliable assessment of EUS stage is mandatory.

Surgical outcome of laparoscopy-assisted gastrectomy with extraperigastric lymph node dissection for gastric cancer

AIM

The aim of this study was to determine the feasibility of laparoscopy-assisted gastrectomy (LAG) with extraperigastric lymph node dissection for gastric cancer.

METHODS

The authors attempted LAG with extraperigastric lymph node dissection in 117 consecutive gastric cancer patients between May 1998 and January 2004. The clinico-pathologic characteristics, operative outcomes, post-operative morbidities and mortalities, and follow-up findings of patients with advanced gastric cancer were evaluated.

RESULTS

LAG with extraperigastric lymph node dissection were successfully performed in 114 of 117 patients (success rate, 97%). Of these 114 successful cases, 100 cases were early gastric cancers and 14 cases were advanced gastric cancers. The mean operation time for the 114 cases was 259 (range 150-415) min, and the mean number of retrieved lymph nodes was 23 (range 6-66). Operative mortality, hospital death, and overall post-operative complication rates were 0, 1.7 and 14.7%, respectively. Follow-up was available in 110 of the 112 patients (two post-operative hospital deaths were excluded from the 114). Follow-up ranged from 6 to 74 months (median: 19). 108 patients remain alive without recurrence or port-site metastasis.

CONCLUSIONS

LAG with extraperigastric lymph node dissection is a technically feasible and acceptable method for the surgical treatment of gastric cancer.

Technology Insight: current status of endoscopic ultrasonography

Endoscopic ultrasound (EUS) has become the most accurate imaging modality for locoregional cancer staging of the gastrointestinal tract. Fine-needle aspiration (FNA) has added a new level of accuracy for EUS in nodal staging, with reported numbers in the 90% range for luminal and pancreaticobiliary disease. In addition, new non-gastrointestinal applications are being evaluated, such as the role of EUS-FNA for the staging of non-small-cell lung cancer and exploration of the posterior mediastinum. Furthermore, the same techniques that make safe tissue sampling possible are being explored for their use as interventional applications, such as EUS-guided celiac plexus neurolysis, fine-needle injection, EUS-guided pseudocyst drainage, and EUS-guided cholangiography and pancreatography. This review describes the current clinical status of EUS in gastrointestinal oncology, as well as future and novel indications and therapeutic strategies for this technology.