You get what you expect? A critical appraisal of imaging methodology in endosonographic cancer staging

Linear EUS Accuracy in Preoperative Staging of Gastric Cancer: A Retrospective Multicenter Study

INTRODUCTION

Preoperative gastric cancer (GC) staging is the most reliable prognostic factor that affects therapeutic strategies. Contrast-enhanced computed tomography (CECT) and radial endoscopic ultrasound (R-EUS) scans are the most commonly used staging tools for GC. The accuracy of linear EUS (L-EUS) in this setting is still controversial. The aim of this retrospective multicenter study was to evaluate the accuracy of L-EUS and CECT in preoperative GC staging, with regards to depth of tumor invasion (T staging) and nodal involvement (N staging).

MATERIALS AND METHODS

191 consecutive patients who underwent surgical resection for GC were retrospectively enrolled. Preoperative staging had been performed using both L-EUS and CECT, and the results were compared to postoperative staging by histopathologic analysis of surgical specimens.

RESULTS

L-EUS diagnostic accuracy for depth of invasion of the GC was 100%, 60%, 74%, and 80% for T1, T2, T3, and T4, respectively. CECT accuracy for T staging was 78%, 55%, 45%, and 10% for T1, T2, T3, and T4, respectively. L-EUS diagnostic accuracy for N staging of GC was 85%, significantly higher than CECT accuracy (61%).

CONCLUSIONS

Our data suggest that L-EUS has a higher accuracy than CECT in preoperative T and N staging of GC.

Endoscopic Submucosal Dissection for Upper Gastrointestinal Neoplasia-a North American Perspective

OBJECTIVES

Organ-sparing endoscopic submucosal dissection (ESD) is an acceptable treatment strategy for superficial neoplastic lesions of the esophagus and stomach. The adoption of this technique has lagged in North America compared with Asia, and we sought to report on our experiences with ESD for upper GI neoplasia.

METHODS

A prospectively entered database of all patients undergoing endoscopic resection of esophageal and gastric neoplasia at McGill University from 2009 to 2019 was queried for those who received ESD.

RESULTS

A total of 103 consecutive ESDs were identified from 2009 to 2019. Seventy-one (69%) patients were male and the median age was 72 (range: 38-90). Sixty-one (59%) cases were esophageal and 42 (41%) gastric. Forty-nine (48%) were performed in the endoscopy suite under local sedation only. Perforation occurred in 9 patients (7 esophageal and 2 stomach), of which 3 required operative repair. Histology was principally invasive carcinoma (79, 77%), with 17 (16%) dysplastic lesions (e.g., HGD), 1 (1%) neuroendocrine tumor, and 7 (7%) benign lesions. En bloc resection was achieved in 90 (87%), and the complete resection rate was 74 (72%), with 51 (50%) of procedures fulfilling the criteria for curative resection. At medium of 23-month (2-199) follow-up of these 51 curative resections, one case of recurrent carcinoma was found at follow-up and was managed with repeat endoscopic resection. Non-curative ESDs were found 45 (R1 resection = 29: risk of lymph node metastasis = 16), 21 had active surveillance, and 24 were resected.

CONCLUSION

ESD is a viable, effective, and safe therapeutic and staging modality for superficial lesions of the stomach and esophagus.

Prognostic Implications of Tumor Differentiation in Clinical T1N0 Gastric Adenocarcinoma

Background

Current guidelines recommend neoadjuvant chemotherapy in patients with locoregional gastric adenocarcinoma. Patients diagnosed with early stage gastric adenocarcinoma are usually managed with upfront surgical intervention. However, pathologic staging in a subset of these clinically staged patients identifies more advanced locoregional disease requiring adjuvant treatment. Therefore, identifying these patients prior to surgical intervention is critical to ensure employment of the appropriate treatment paradigm. The aim of the current study was to define patient characteristics associated with clinical understaging in early gastric cancer.

Methods

Using the National Cancer Database (2004–2014) we identified 3,892 individuals with clinical T1N0 gastric adenocarcinoma who underwent upfront definitive surgery, had negative surgical margins, and did not receive preoperative chemotherapy or radiotherapy. Patient characteristics were compared between those with pathologic stage T1N0 disease and those who were upstaged upon surgery.

Results

Twenty‐seven percent of clinical T1N0 gastric adenocarcinomas had a change in stage because of pathologically defined ≥T2 disease or positive lymph nodes. Individuals who were upstaged had a higher tumor grade compared with those with pathologic stage T1N0 disease. Specifically, 41.9% (530/1,264) of individuals with a poorly differentiated tumor were upstaged, compared with only 10.7% (70/656) with a well‐differentiated tumor. Approximately 75% of cases involved upstaging because of T misclassification. The highest percentage of upstaging was shown for tumors located at the fundus and body of the stomach.

Conclusion

Upstaging of clinical T1N0 gastric adenocarcinoma is characterized by higher tumor grade and is mostly a result of a change in T stage. These findings mandate thorough workup in order to identify patients with clinically staged T1N0 disease requiring preoperative chemotherapy.

Implications for Practice

Upstaging of clinical T1N0 gastric adenocarcinoma is characterized by higher tumor grade and is mostly a result of a change in T stage. These findings mandate thorough workup in order to identify patients with clinically staged T1N0 disease requiring preoperative chemotherapy.

This article evaluates the frequency of upstaging following surgery among cT1N0 gastric cancer and defines the corresponding patient characteristics, with the goal of better identifying those patients who require preoperative chemotherapy.

What should be known prior to performing EUS?

Direct referral of patients for EUS – instead of preprocedural consultation with the endosonographer – has become standard practice (like for other endoscopic procedures) as it is time- and cost-effective. To ensure appropriate indications and safe examinations, the endosonographer should carefully consider what information is needed before accepting the referral. This includes important clinical data regarding relevant comorbidities, the fitness of the patient to consent and undergo the procedure, and the anticoagulation status. In addition, relevant findings from other imaging methods to clarify the clinical question may be necessary. Appropriate knowledge and management of the patients’ anticoagulation and antiplatelet therapy, antibiotic prophylaxis, and sedation issues can avoid unnecessary delays and unsafe procedures. Insisting on optimal preparation, appropriate indications, and clear clinical referral questions will increase the quality of the outcomes of EUS. In this paper, important practical issues regarding EUS preparations are raised and discussed from different points of view.

Endoscopic diagnosis and treatment of esophageal adenocarcinoma: introduction of Japan Esophageal Society classification of Barrett's esophagus

Endoscopic surveillance of Barrett's esophagus has become a foundation of the management of esophageal adenocarcinoma (EAC). Surveillance for Barrett's esophagus commonly involves periodic upper endoscopy with biopsies of suspicious areas and random four-quadrant biopsies. However, targeted biopsies using narrow-band imaging can detect more dysplastic areas and thus reduce the number of biopsies required. Several specific mucosal and vascular patterns characteristic of Barrett's esophagus have been described, but the proposed criteria are complex and diverse. Simpler classifications have recently been developed focusing on the differentiation between dysplasia and non-dysplasia. These include the Japan Esophageal Society classification, which defines regular and irregular patterns in terms of mucosal and vascular shapes. Cancer invasion depth is diagnosed by endoscopic ultrasonography (EUS); however, a meta-analysis of EUS staging of superficial EAC showed favorable pooled values for mucosal cancer staging, but unsatisfactory diagnostic results for EAC at the esophagogastric junction. Endoscopic resection has recently been suggested as a more accurate staging modality for superficial gastrointestinal cancers than EUS. Following endoscopic resection for gastrointestinal cancers, the risk of metastasis can be evaluated based on the histology of the resected specimen. European guidelines describe endoscopic resection as curative for well- or moderately differentiated mucosal cancers without lymphovascular invasion, and these criteria might be extended to lesions invading the submucosa (≤ 500 μm), i.e., to low-risk, well- or moderately differentiated tumors without lymphovascular involvement, and < 3 cm. These criteria were confirmed by a recent study in Japan.

Prospective evaluation of the short access cholangioscopy for stone clearance and evaluation of indeterminate strictures

BACKGROUND

Peroral cholangioscopy facilitates diagnosis and therapy of biliary disorders. This study prospectively evaluated a new short access cholangioscopy.

METHODS

Consecutive patients were included as follows: difficult stones (group 1) underwent cholangioscopy with electrohydraulic lithotripsy and indeterminate biliary strictures (group 2) were evaluated with macroscopic assessment and cholangioscopy guided biopsy sampling. We evaluated the complete stone clearance rate (group 1) and diagnostic accuracy (group 2). Follow-up was performed over a median of 13 and 16 months, respectively.

RESULTS

Group 1 (n=21): complete stone clearance defined as lack of stones in cholangiography and stone removal during cholangioscopy was achieved in 15 (71.4%) patients. Clinical stone clearance defined as lack of symptoms, laboratory abnormalities and hospital visits during follow-up, irrespective of stone clearance was evident in 17 (81.0%) patients. One serious adverse event occurred (bile duct perforation). Group 2 (n=28): malignancy was confirmed in 15 patients. Sensitivity, specificity and diagnostic accuracy of cholangioscopy were 85.7%, 75.0% and 80.7%, respectively. Sensitivity, specificity and diagnostic accuracy of biopsies were 54.5%, 100.0% and 72.2%, respectively. No serious adverse events occurred, and one patient was lost to follow-up.

CONCLUSIONS

The novel system enabled complex stone treatment and biliary stricture diagnosis. Cholangioscopy outperformed direct biopsy regarding characterization of indeterminate strictures.

Applications of contrast-enhanced harmonic endoscopic ultrasound on biliary, focal liver lesions and vascular diseases

Over the last decade, the clinical applications of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) have increased steadily. The development of second-generation ultrasound contrast agents has allowed superior visualization of the microvasculature and tissue perfusion of the target lesion. This methodology has proven useful in the differential diagnosis of solid pancreatic masses and lymph nodes. In addition, the applicability of CH-EUS has expanded to nonpancreas structures such as biliary, focal liver lesions, and vascular disease. This article focuses primarily on the novel applications of CH-EUS in biliary tract and visceral vascular diseases.

The Expanding Role of Contrast-Enhanced Endoscopic Ultrasound in Pancreatobiliary Disease

Since its introduction into clinical practice in the 1980s, endoscopic ultrasound (EUS) has been described as a good imaging modality for the diagnosis of pancreatobiliary diseases. However, differential diagnosis of certain lesions based only on B-mode ultrasound images can be challenging. Clinical use of ultrasound contrast agents has expanded the utility of EUS from that of detection to characterization of pancreatobiliary lesions based on the enhancement features of contrast-enhanced EUS (CE-EUS). Current low mechanical index techniques for CE-EUS using second-generation contrast agents have a number of distinct advantages over conventional diagnostic modalities in evaluating pancreatobiliary lesions, including real-time assessment of perfusion pattern, availability, and the absence of exposure to radiation. This article describes the technical aspects of CE-EUS and reviews the expanding indications in pancreatobiliary diseases and further development of this technique.

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.

Fetal aortic valvuloplasty: investigating institutional bias in surgical decision-making

OBJECTIVES

Fetal aortic valvuloplasty may prevent the progression of aortic stenosis to hypoplastic left heart syndrome and allow biventricular rather than univentricular postnatal treatment. This study aimed to investigate whether blinded simulation of a multidisciplinary team approach aids interpretation of multicenter data to uncover institutional bias in postnatal decision-making following fetal cardiac intervention for aortic stenosis.

METHODS

The study included 109 cases of prenatally diagnosed aortic stenosis from 13 European countries, of which 32 had undergone fetal cardiac intervention. The multidisciplinary team, blinded to fetal cardiac intervention, institutional location and postnatal treatment, retrospectively assigned a surgical pathway (biventricular or univentricular) based on a review of recorded postnatal imaging and clinical characteristics. The team's decisions were the numerical consensus of silent voting, with case review when a decision was split. Funnel plots showing concordance between the multidisciplinary team and the local team's surgical choice (first pathway) and with outcome (final pathway) were created.

RESULTS

In 105 cases the multidisciplinary team reached a consensus decision regarding the surgical pathway, with no decision in four cases because the available imaging records were inadequate. Blinded multidisciplinary team consensus for the first pathway matched the decision of the surgical center in 93/105 (89%) cases, with no difference in agreement between those that had undergone successful fetal cardiac intervention (n = 32) and no (n = 74) or unsuccessful (n = 3) valvuloplasty (no fetal cardiac intervention) (κ = 0.73 (95% CI, 0.38-1.00) vs 0.74 (95% CI, 0.51-0.96)). However, funnel plots comparing multidisciplinary team individual decisions with those of the local teams displayed more discordance (meaning biventricular-univentricular conversion) for the final surgical pathway following fetal cardiac intervention than they did for cases without such intervention (36/74 vs 34/130; P = 0.002), and identified one outlying center.

CONCLUSIONS

The use of a blinded multidisciplinary team to simulate decision-making and presentation of data in funnel plots may assist in the interpretation of data submitted to multicenter studies and permit the identification of outliers for further investigation. In the case of aortic stenosis, a high level of agreement was observed between the multidisciplinary team and the surgical centers, but one outlying center was identified.

Gastric cancer staging: EUS and CT

INTRODUCTION

Gastric cancer is the fourth most common cancer and the second leading cause of death from cancer. Only complete resection of all gross disease with negative microscopic margins (R0 resection) provides a long-term survival benefit, and the overall 5-year relative survival rate is approximately 20%. To improve survival and quality of life, new therapeutic approaches have been introduced.

MATERIAL AND METHODS

A total of 277 patients (171 men, 106 women) were included in this analysis. The results from the preoperative EUS and MDCT were compared to the postoperative pathological findings. A radial scanning ultrasonic endoscope was used. In patients with early gastric cancer, especially in cases confined to mucosa, endoscopic resection is performed to avoid unnecessary surgical procedures. To achieve R0 resection for locally-advanced gastric cancer, neoadjuvant treatments have been investigated.

RESULTS AND DISCUSSION

Laparoscopic surgery has been shown to improve quality of life for both early and locally advanced gastric cancer. Endoscopic ultrasonography (EUS), which is considered to be the most precise method for locoregional staging, was commonly used for differentiating mucosal lesions from submucosal lesions. By contrast, computed tomography (CT) was used to detect the presence of distant metastasis. The difference in accuracy between the < or = 20-mm group and other groups was statistically significant for both EUS and MDCT (P = 0.026 and P = 0.044, respectively).

CONCLUSION

However, recent technological advances with the helical and multi-detector scanners have provided better CT performance.

Clinical controversies in endoscopic ultrasound

The field of diagnostic and therapeutic endoscopic ultrasound (EUS) is growing rapidly. Although EUS has enhanced our ability to diagnose and treat a wide variety of GI conditions, there are many controversial issues regarding the appropriate application of EUS techniques. In this review we discuss five controversial topics in EUS: the utility of EUS in staging of esophageal and gastric cancer; selection of appropriate needle gauge for fine needle aspiration (FNA); use of the stylet in FNA; and the emerging role of contrast agents in endoscopic ultrasound.

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.

Estimation by gross findings in early gastric cancer

Endoscopic resection has been accepted as both minimally invasive and curative treatment modality for early gastric cancer (EGC). The widely accepted indication of endoscopic resection for EGC is small sized, differentiated mucosal cancer in which the risk of lymph node metastasis is negligible. Tumor size can be measured by conventional endoscopy, and chromoendoscopy, magnifying endoscopy, narrow band imaging, autofluorescence imaging can also be helpful for accurate estimation of tumor size. Pretreatment tumor histology can be assessed with endoscopic biopsy, and also be measured by confocal endomicroscopy (so called "virtual biopsy"). Although endoscopic ultrasonography may be helpful for the assessment of tumor depth in EGC, the accurate assessment of tumor depth can be performed by the typical findings in the conventional endoscopy, by which treatment modality can be decided according to the depth of tumor invasion.

[Gastric cancer and adenocarcinoma of the esophagogastric junction: principles of neoadjuvant therapy]

According to the current European and German S3 guidelines, neoadjuvant chemotherapy is now an integral part of the treatment of locally advanced gastric cancer and adenocarcinoma of the esophagogastric junction. Neoadjuvant therapy seeks to achieve downsizing of the primary tumor, lowering of the T and N categories and eradication of micrometastases. As the indications for neoadjuvant treatment are based on pretherapeutic information alone, a sophisticated clinical staging plays a central role. Despite all progress made in the field of diagnostic work-up, clinical staging often fails. Despite this fact, controlled randomized trials showed that neoadjuvant chemotherapy enhances the rate of curative (R0) resections and reduces the likelihood of systemic relapse. Overall, survival can be improved by neoadjuvant chemotherapy. The current research is focused on the molecular prediction of response and early response monitoring with functional imaging. New targeted drugs are being integrated into the peri-operative treatment.

Efficacy of endoscopic ultrasound guided fine needle aspiration in patients with solid pancreatic neoplasms

BACKGROUND/AIM

Endosonography is a distinct method for evaluating the structural lesions of the gastrointestinal (GI) tract, particularly the pancreatobilliary region. This procedure has made a fundamental change in the diagnosis of pancreatic mass lesion through providing fine needle aspiration. This study aims at evaluating the results and efficacy of endoscopic ultrasound fine needle aspiration (EUS-FNA) in patients with pancreatic solid mass.

PATIENTS AND METHODS

The present study is an observational, prospective case series nature, evaluated patients with pancreatic solid mass referred to Imam Khomeini educational hospital in Tehran for a duration of one year since November 2010. In order to determine the false negative cases, the patients were followed-up from 6 to 12 months.

RESULTS

EUS-FNA was conducted on all 53 patients without any complication. The majority of patients included in the study were males (68%) and 81% of patients had a mass in the head of pancreas. The result of cytopathology revealed 36 adenocarcinomas (68%), 7 other malignancies (13%), benign lesions (6%) and 7 non-diagnostic cases (13%). The frequency of non-diagnostic results was significantly high in masses smaller than 3 cm (6 vs. 1, P < 0.002). Patients with non-diagnostic result were younger than those with malignant cytopathology (52 ± 7.5 vs. 66 ± 7.5 years, P < 0.001).. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this procedure concerning Adenocarcinoma were 88%, 100%, 100%, 70% and 90%, respectively.

CONCLUSION

EUS - FNA is an effective and safe procedure in histopathologic diagnosis of pancreatic tumors. This procedure is useful in all pancreatic mass cases including resectable and non-resectable ones.

Management of cancer risk in Barrett's esophagus

The importance of Barrett's esophagus (BE) lies in its potential to give rise to esophageal adenocarcinoma (EAC), postulated to be through a series of progressive degrees of dysplasia; from intestinal metaplasia to low-grade dysplasia, high-grade dysplasia, and subsequently, to cancer. The management strategies for the detection and treatment of dysplasia and early esophageal cancer on a background of BE have changed significantly in the last few decades, with the emergence of newer and less invasive non-operative alternatives. This review aims to outline BE and its relation to EAC, the rationale and cost-effectiveness of both screening and surveillance programs, methods of diagnosing and identifying dysplasia and early cancer in Barrett's, and approaches to individualizing their endoscopic and surgical management based on best-available staging techniques.

Systematic review: bias in imaging studies - the effect of manipulating clinical context, recall bias and reporting intensity

OBJECTIVES

To perform a systematic review of diagnostic test accuracy studies which manipulate or investigate the context of interpretation. In particular, those which modify or conceal sample characteristics (e.g. disease prevalence or reporting intensity) or research setting ("laboratory" versus "field"). We also investigated recall bias.

METHODS

We searched the biomedical literature to March 2010 using 3 complementary strategies. Inclusion criteria were: imaging studies quantifying the effect on diagnosis of modifying the context of observers' interpretations, varying disease prevalence, concealing sample characteristics, reporting intensity and recall bias.

RESULTS

11247 abstracts were reviewed, 201 full texts examined and 12 ultimately included. There were 5 to 9520 patients and 2 to 129 observers per study. Nine studies investigated clinical review bias of sample level information. Only 3 studies investigated prevalence, 2 of which investigated maximum enrichment well below the levels often used by researchers. We identified no research specifically directed at concealing disease prevalence. Available research found no evidence of recall bias or "washout" on study results.

CONCLUSIONS

Several sources of bias central to the design of diagnostic test accuracy studies are poorly researched; the implications for evidence-based-practice remain uncertain. Research is suggested to guide methodological design, particularly in the context of screening.

KEY POINTS

Imaging research studies often ignore the possible effect of disease prevalence It is unclear how the expectation of disease influences radiological interpretation The potential effect of observer recall bias is poorly researched Such factors might introduce bias into radiological research methodology This systematic review attempts to illustrate these points.

How radical should surgery be for early esophageal cancer?

BACKGROUND

We have compared the oncologic effectiveness of limited resection (LR) techniques such as transhiatal (TH) or limited resection of the esophagogastric junction with intestinal interposition (LREGJ) in the treatment of early esophageal carcinoma with that of the extended resection such as the classical thoracoabdominal (TA) en bloc esophagectomy.

METHODS

We performed a retrospective analysis of prospectively collected data of 113 patients with T1 esophageal cancer (57 adeno- and 56 squamous cell carcinomas) who had surgical resection with systematic lymphadenectomy. Forty-one underwent extensive (TA) and 72 limited resection (51 TH and 21 LREGJ).

RESULTS

Complete resection (R0) was achieved in all cases. Lymphatic metastases were seen in none of the mucosal but in 26.8% of the submucosal T1 cancers. The median lymph node yield was significantly higher in patients with extensive resection (24 vs. 15 lymph nodes; p=0.036), but this did not affect the overall survival (median=88 vs. 102 months, 5-year survival probability=57.8 vs. 67.7%; log rank=0.578). The median hospital stay and ICU stay were significantly shorter in the LR group (p=0.039 and p = 0.044, respectively).

CONCLUSION

Limited resection leads to lower lymph node yield but similar oncologic effectiveness as the extensive surgery. It may represent a valuable alternative in the treatment of patients with early (submucosal) esophageal carcinoma.

Double contrast-enhanced ultrasonography for the preoperative evaluation of gastric cancer: a comparison to endoscopic ultrasonography with respect to histopathology

BACKGROUND

This study was designed to compare the accuracy of endoscopic ultrasound (EUS) with double contrast-enhanced ultrasound (DCUS) in the staging of gastric malignancies. DCUS is a transabdominal ultrasound technique using both intravenous and intraluminal contrast to enhance sonographic visualization.

METHODS

This retrospective study included 162 patients with biopsy-proven gastric cancer who underwent DCUS and EUS preoperatively with the ultrasound results compared with the pathologic findings of the resected specimens.

RESULTS

The overall accuracy of DCUS and EUS for tumor (T) staging was 77.2% and 74.7%, respectively. Comparison of ultrasound techniques for T staging revealed that DCUS was superior to EUS only for a tumor depth of T3 (chi-square, P = .025). Lymph nodes were staged correctly with DCUS and EUS in 78.4% and 57.4% of cases, respectively (chi-square, P = .001).

CONCLUSIONS

DCUS offers a noninvasive approach for the staging of gastric cancer. DCUS was comparable to EUS in tumor depth evaluation but offered an advantage in lymph node detection.

Lymph node metastasis of gastric cancer

Despite a decrease in incidence in recent decades, gastric cancer is still one of the most common causes of cancer death worldwide [1]. In areas without screening for gastric cancer, it is diagnosed late and has a high frequency of nodal involvement [1]. Even in early gastric cancer (EGC), the incidence of lymph node (LN) metastasis exceeds 10%; it was reported to be 14.1% overall and was 4.8 to 23.6% depending on cancer depth [2]. It is important to evaluate LN status preoperatively for proper treatment strategy; however, sufficient results are not being obtained using various modalities. Surgery is the only effective intervention for cure or long-term survival. It is possible to cure local disease without distant metastasis by gastrectomy and LN dissection. However, there is no survival benefit from surgery for systemic disease with distant metastasis such as para-aortic lymph node metastasis [3]. Therefore, whether the disease is local or systemic is an important prognostic indicator for gastric cancer, and the debate continues over the importance of extended lymphadenectomy for gastric cancer. The concept of micro-metastasis has been described as a prognostic factor [4-9], and the biological mechanisms of LN metastasis are currently under study [10-12]. In this article, we review the status of LN metastasis including its molecular mechanisms and evaluate LN dissection for the treatment of gastric cancer.

Do we still need EUS in the workup of patients with early esophageal neoplasia? A retrospective analysis of 131 cases

BACKGROUND

EUS is often used for locoregional staging of early esophageal neoplasia. However, its value compared with that of endoscopic examination and diagnostic endoscopic resection (ER) may be questioned because diagnostic ER allows histological assessment of submucosal invasion and other risk factors for lymph node metastasis, eg, poor differentiation/lymphovascular invasion.

OBJECTIVE

To evaluate how often patients were excluded from endoscopic treatment of esophageal neoplasia based on EUS findings.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care institution.

PATIENTS

Patients with early esophageal neoplasia.

INTERVENTIONS

EUS, diagnostic ER.

MAIN OUTCOME MEASUREMENTS

Number of patients excluded from endoscopic treatment based on EUS results.

RESULTS

A total of 131 patients were included (98 men, 33 women; age 66 ± 13 years). In 105 of 131 patients (80%), EUS findings were unremarkable. In 25 of 105 patients (24%), diagnostic ER showed submucosal invasion (n = 17), deep resection margins positive for cancer (n = 2, confirmed at surgery), or poor differentiation/lymphovascular invasion (n = 6). In 26 of 131 patients (20%), EUS findings raised the suspicion of submucosal invasion and/or lymph node metastasis. In the 14 of 26 patients (54%) with abnormal EUS findings, endoscopy results were unremarkable. Diagnostic ER showed submucosal invasion in 7 of 14 (50%) patients, whereas no lymph node metastasis risk factors were found in 7 of 14 patients (50%), who subsequently underwent curative endoscopic treatment. In 12 of 26 patients (46%) with abnormal EUS, endoscopy also raised doubts on whether curative endoscopic treatment could be achieved. After diagnostic ER, no risk factors for lymph node metastasis were found in 3 of 12 patients (25%).

LIMITATION

Retrospective study.

CONCLUSIONS

This study shows that EUS has virtually no clinical impact on the workup of early esophageal neoplasia and strengthens the role of diagnostic ER as a final diagnostic step.

EUS in the management of gastric cancer

In this review we summarize latest data on the role of endoscopic ultrasonography (EUS) in the diagnosis and management of gastric carcinoma. Since its initial introduction in clinical practice, EUS has been considered a valuable tool for the diagnosis and locoregional staging of gastric cancer and a method of inarguable value for the assessment of gastric wall involvement and presence of infiltrated paragastric lymph nodes. Moreover, another application of EUS, i.e. its role in the assessment of early gastric cancer has come into focus, especially nowadays in the era of endoscopic mucosal resection and endoscopic submucosal dissection. These topics, together with other aspects of EUS in gastric cancer are discussed. On the other hand, despite its indisputable value, EUS for gastric cancer evaluation is "threatened" nowadays by other modern cross-sectional imaging methods (including trans-abdominal ultrasound, CT, MRI and PET), whose quality has lately improved. A brief comparison between the available imaging methods, attempts to show that their role ismore complementary than competitive.

Contrast-enhanced harmonic EUS with novel ultrasonographic contrast (Sonazoid) in the preoperative T-staging for pancreaticobiliary malignancies

OBJECTIVE

Sonazoid is a new second-generation microbubble contrast for ultrasonography. In this pilot study, the diagnostic role of contrast-enhanced harmonic imaging endoscopic ultrasonography (CH-EUS) with Sonazoid was prospectively evaluated in preoperative T-staging of pancreaticobiliary malignancies.

PATIENTS AND METHODS

Patients with suspected pancreaticobiliary malignancies underwent CH-EUS by a single examiner. After the lesions were observed carefully with conventional harmonic imaging EUS (H-EUS), CH-EUS was performed with intravenous injection of Sonazoid. A reviewer who was blinded reviewed the recordings of H-EUS and CH-EUS and assessed the T-staging. The accuracy of H-EUS and CH-EUS for T-staging was compared to the results of surgical histopathology in patients who underwent surgery.

RESULT

Twenty-six patients underwent surgical resection and could be included in the study. The final diagnosis were pancreatic cancer in 11, bile duct cancer in 7, gallbladder cancer in 4 and ampullary cancer in 4. The overall accuracy of H-EUS and CH-EUS for T-staging were 69.2 (18/26) and 92.4% (24/26), respectively (p < 0.05). There were disagreement in six cases between H-EUS and CH-EUS. CH-EUS staged correctly in all of these six cases, whereas H-EUS misdiagnosed the depth of invasion in one case of gallbladder cancer and one case of ampullary cancer, and invasion of portal vein in two cases of pancreatic cancer and two cases of bile duct cancer.

CONCLUSION

The depth of invasion of biliary cancer and vascular invasion of pancreatic and biliary cancer could be demonstrated more clearly with CH-EUS compared to H-EUS. CH-EUS has the potential to improve the diagnostic accuracy of preoperative T-staging of pancreaticobiliary malignancies.

Preoperative staging of gastric cancer by endoscopic ultrasonography and multidetector-row computed tomography

BACKGROUND AND AIM

The aim of this study was to determine the accuracy of endoscopic ultrasonography (EUS) and multidetector-row computed tomography (MDCT) for the locoregional staging of gastric cancer. EUS and computed tomography (CT) are valuable tools for the preoperative evaluation of gastric cancer. With the introduction of new therapeutic options and the recent improvements in CT technology, further evaluation of the diagnostic accuracy of EUS and MDCT is needed.

METHODS

In total, 277 patients who underwent EUS and MDCT, followed by gastrectomy or endoscopic resection at Bundang Hospital, Seoul National University, from July 2006 to April 2008, were analyzed. The results from the preoperative EUS and MDCT were compared to the postoperative pathological findings.

RESULTS

Among the 277 patients, the overall accuracy of EUS and MDCT for T staging was 74.7% and 76.9%, respectively. Among the 141 patients with visualized primary lesions on MDCT, the overall accuracy of EUS and MDCT for T staging was 61.7% and 63.8%, respectively. The overall accuracy for N staging was 66% and 62.8%, respectively. The performance of EUS and MDCT for large lesions and lesions at the cardia and angle had significantly lower accuracy than that of other groups. For EUS, the early gastric cancer lesions with ulcerative changes had significantly lower accuracy than those without ulcerative changes.

CONCLUSIONS

For the preoperative assessment of individual T and N staging in patients with gastric cancer, the accuracy of MDCT was close to that of EUS. Both EUS and MDCT are useful complementary modalities for the locoregional staging of gastric cancer.

Clinical staging of adenocarcinoma of the esophagogastric junction

Tumors of the esophagogastric junction are among the most frequent and cause lethal cancers. Patients often do not present until late in the disease when the tumor is sufficiently large to cause obstruction or invasion of the adjacent structures, and thus becomes symptomatic. Preoperative staging is critical to select those patients whose disease is still locally confined for curative surgery. Ideally, clinical staging should accurately predict tumor invasion, lymph node involvement, and distant metastases. Upper endoscopy establishes the tumor diagnosis by multiple biopsies and defines the tumor type (Siewert I-III), based on tumor localization in relation to the endoscopic cardia. Preoperative TNM staging has a strong impact on treatment strategy. Endoscopic Ultrasound (EUS) determines the T category, and to a lesser extent, the presence of lymph node metastases. Multislice Computed Tomography (CT) and 18Fluorode-ocx-glucose Positron Emission Computed Tomography (18FDG-PET-CT) provide further information, especially about systemic metastases. Diagnostic laparascopy is suggested in advanced (CT3/4) Siewert type II-III tumors to exclude peritoneal carcinomatosis. This chapter summarizes current staging modalities and their accuracy in clinical practice.

Translational advances and novel therapies for pancreatic ductal adenocarcinoma: hope or hype?

Biological complexity, inaccessible anatomical location, nonspecific symptoms, lack of a screening biomarker, advanced disease at presentation and drug resistance epitomise pancreatic ductal adenocarcinoma (PDA) as a poor-prognosis, lethal disease. Twenty-five years of research (basic, translational and clinical) have barely made strides to improve survival, mainly because of a fundamental lack of knowledge of the biological processes initiating and propagating PDA. However, isolation of pancreas cancer stem cells or progenitors, whole-genome sequencing for driver mutations, advances in functional imaging, mechanistic dissection of the desmoplastic reaction and novel targeted therapies are likely to shed light on how best to treat PDA. Here we summarise current knowledge and areas where the field is advancing, and give our opinion on the research direction the field should be focusing on to better deliver promising therapies for our patients.

[Principles of neoadjuvant therapy]

Neoadjuvant therapy is now an integral part in the treatment of locally advanced cancer of the esophagus and stomach. The mechanisms of action comprise downsizing of the primary tumor, improvement of the T and N categories and the earliest possible eradication of micrometastases. Several controlled clinical studies could show that these principles can indeed augment the rate of curative (R0) resections and can reduce the likelihood of systemic recurrences. As a consequence overall survival is improved by neoadjuvant therapy. This article summarizes how the basic principles of neoadjuvant therapy translate into clinical practice and gives a review of current developmental perspectives in this field.

Newly developed surface coil for endoluminal MRI, depiction of pig gastric wall layers and vascular architecture in ex vivo study

BACKGROUND

The purpose of this study was to visualize the gastric wall layers and to depict the vascular architecture in vitro by using resected porcine stomachs studied with high-spatial resolution magnetic resonance (MR) imaging.

METHODS

Normal dissected porcine stomach samples (n = 4) were examined with a 3 Tesla MR system using a newly developed surface coil. MR images were obtained by the surface coil as receiver and a head coil as transmitter. High-spatial-resolution spin-echo MR images were obtained with a field of view of 8 x 8 cm, a matrix of 256 x 128 and slice thicknesses of 3 and 5 mm.

RESULTS

T1 and T2-weighted MR images clearly depicted the normal porcine gastric walls as consisting of four distinct layers. In addition, vascular architectures in proper muscle layers were also visualized, which were confirmed by histological examinations to correspond to blood vessels.

CONCLUSIONS

High-spatial-resolution MR imaging using a surface coil placed closely to the gastric wall enabled the differentiation of porcine gastric wall layers and the depiction of the blood vessels in proper muscle layer in this experimental study.

Highly sensitive detection of early-stage pancreatic cancer by multimodal near-infrared molecular imaging in living mice

Pancreatic cancer is a serious disease with poor patient outcome, often as a consequence of late diagnosis in advanced stages. This is in large part due to the lack of diagnostic tools for early detection. To address this deficiency, we have investigated novel molecular near-infrared fluorescent (NIRF) in vivo imaging techniques in clinically relevant mouse models of pancreatic cancer. Genome wide gene expression profiling was used to identify cathepsin cystein proteases and matrix metalloproteinases (MMP) as targets for NIRF imaging. Appropriate protease activatable probes were evaluated for detection of early-stage pancreatic cancer in mice with orthotopically implanted pancreatic cancer cell lines. Mice with pancreatitis served as controls. Whole body in vivo NIRF imaging using activatable cathepsin sensitive probes specifically detected pancreatic tumors as small as 1-2 mm diameter. Imaging of MMP activity demonstrated high specificity for MMP positive tumors. Intravital flexible confocal fluorescence lasermicroscopy of protease activity enabled specific detection of pancreatic tumors at the cellular level. Importantly, topical application of NIRF-probes markedly reduced background without altering signal intensity. Taken together, macroscopic and confocal lasermicroscopic molecular in vivo imaging of protease activity is highly sensitive, specific and allows discrimination between normal pancreatic tissue, inflammation and pancreatic cancer. Translation of this approach to the clinic could significantly improve endoscopic and laparoscopic detection of early-stage pancreatic cancer.

Improved differentiation of pancreatic tumors using contrast-enhanced endoscopic ultrasound

BACKGROUND & AIMS

Endoscopic ultrasound is a widely accepted imaging method for staging of ductal adenocarcinoma and the localization of neuroendocrine tumors of the pancreas. We prospectively evaluated conventional color Doppler imaging and contrast-enhanced endoscopic Doppler ultrasound (CE-EDUS) as a new imaging technique for further characterization and differentiation of solid pancreatic tumors.

METHODS

From 300 patients with pancreatic lesions investigated using contrast-enhanced endoscopic ultrasound we could finally include 93 patients with an undetermined, solitary, predominantly solid, lesion 40 mm or less, and a definite histologically proven diagnosis. After bolus injection of the contrast agent SHU 508A 4 g (400 mg/dL) the vascular pattern of the lesion during the arterial phase was compared with the vascularity of the residual pancreatic parenchyma.

RESULTS

Color Doppler imaging did not reveal vascularity of the pancreatic parenchyma in any of the patients, and therefore tumor hypovascularity could not be determined in contrast to all CE-EDUS-examined patients revealing at least some degree of parenchymal vascularity. Fifty-seven of 62 patients with ductal adenocarcinoma of the pancreas showed a hypovascularity of the tumor using CE-EDUS. All other pancreatic lesions revealed an isovascular or hypervascular pattern using contrast-enhanced endoscopic ultrasound (20 neuroendocrine tumors, 10 serous microcystic adenomas, and 1 teratoma). Hypovascularity as a sign of malignancy in contrast-enhanced endoscopic ultrasound obtained 92% (82%-97%) sensitivity and 100% specificity (89%-100%).

CONCLUSIONS

Contrast-enhanced endoscopic ultrasound is effective in differentiating small solid pancreatic tumors of different origin in most cases. Hypovascularity indicates malignancy of pancreatic tumors.

CT and endoscopic ultrasound in comparison to endoluminal MRI: preliminary results in staging gastric carcinoma

PURPOSE

To prospectively compare diagnostic parameters of a newly developed endoluminal MRI (endo-MRI) concept with endoscopic ultrasound (EUS) and hydro-computer tomography (Hydro-CT) in T-staging of gastric carcinoma on one patient collective.

MATERIAL AND METHODS

28 consecutive patients (11 females, 17 males, age range 46-87 years, median 67 years) referred for surgery due to a gastric malignancy were included. Preoperative staging by EUS was performed in 14 cases and by Hydro-CT in 14 cases within a time frame of 2 weeks. Ex vivo endo-MRI examination of gastric specimens was performed directly after gastrectomy within a time interval of 2-3h. EUS data were acquired from the clinical setting whereas Hydro-CT and endo-MRI data were evaluated in blinded fashion by two experienced radiologists and one surgeon well experienced in EUS on gastric carcinomas.

RESULTS

Histopathology resulted in 4 pT1, 17 pT2, 3 pT3 and 2 pT4 carcinomas with 2 gastric lymphomas which were excluded. Overall accuracy for endo-MRI was 75% for T-Staging of the 26 carcinomas. EUS achieved 42.9% accuracy; endo-MRI in this subgroup was accurate in 71.4%. Hydro-CT was correct in 28.6%, accuracy for endo-MRI in this subgroup was 71.4%.

CONCLUSION

The direct comparison of all three modalities on one patient collective shows that endo-MRI is able to achieve adequate staging results in comparison with clinically accepted methods like EUS and Hydro-CT in classifying the extent of tumor invasion into the gastric wall. However the comparison is limited as we compared in vivo routine clinical data with experimental ex vivo data. Future investigations need to show if the potential of endo-MRI can be transferred into a clinical in vivo setting.

Endoscopic ultrasound with conventional probe and miniprobe in preoperative staging of esophageal cancer

BACKGROUND

Using an endoscopic ultrasound (EUS) miniprobe, even highly stenotic esophageal cancers precluding the passage of a conventional probe can be examined without prior dilatation.

OBJECTIVE

To assess: (1) staging accuracy of conventional EUS probe and miniprobe, (2) variables influencing staging accuracy, (3) endoscopic features predicting tumor stage.

METHODS

Ninety-seven consecutive patients with esophageal cancer undergoing complete surgical resection were included. Preoperative EUS was performed using a conventional probe in nonstenotic tumors and a miniprobe in stenotic tumors. Accuracy of EUS for T and N stages was compared to pathohistological staging.

RESULTS

Overall EUS staging accuracy was 73.2% for T stage and 74.2% for N stage. It was similar for the miniprobe used in stenotic tumors vs the conventional probe used in nonstenotic tumors. Based on EUS, 84.5% of the patients would have been assigned to the appropriate therapy protocol (primary surgery vs neoadjuvant therapy). Endoscopic tumor features had no influence on staging accuracy. Tumor length >5 cm predicted advanced T and nodal positive stages.

CONCLUSIONS

The miniprobe allows adequate EUS staging of stenotic esophageal tumors precluding the passage of a conventional probe. Therefore, dilatation therapy of stenotic cancers to conduct conventional EUS should be avoided.

R1-Resektion in der Chirurgie des oberen Gastrointestinaltrakts

Microscopically involved tumor margins are an important problem in the surgery of locally advanced esophageal and gastric carcinomas. We conducted a systematic review of the literature and a specific analysis of our own patient database. This article summarizes current knowledge of the incidence and prognosis of R1 resections in upper gastrointestinal cancers. Preoperative strategies for reducing the rate of R1 resections are presented, and the surgical options in case of R1 resection are discussed.

Information bias in endoscopic assessment

OBJECTIVE

Endoscopic assessment is observer dependent and patient history may influence the interpretation of images. This study assessed the impact of knowledge bias in a large sample of endoscopists.

DESIGN

The same 2-minute video sequence of a normal gastroscopy was shown twice as part of a diagnostic quiz. The 129 endoscopists were unaware that they participated in a validation experiment. Two fictional patient histories accompanied the videos. The first case suggested reflux-like symptoms. The second case described epigastric pain in an elderly woman. Endoscopists gave diagnoses in free writing. The diagnostic suggestions were categorized into five classes: (a) normal findings; (b) reflux-related findings (e.g., erosions, hiatal hernia, Barrett's metaplasia); (c) peptic ulcer or atrophic gastritis; (d) other specified pathology; (e) no diagnostic suggestion.

RESULTS

Only 30/129 (23%) endoscopists gave the same diagnosis for the two identical video cases. The patient history had a major impact on the diagnostic suggestions: In case 1 (reflux symptoms) 54/129 (42%) of the diagnoses were related to reflux disease compared with only six diagnoses of ulcer or atrophic gastritis (P < 0.0001). In case 2 (epigastric pain) 56 endoscopists (43%) diagnosed ulcer or atrophic gastritis whereas only 16 (12%) suggested reflux-related findings (P < 0.0001).

CONCLUSION

Endoscopists are biased by the patient history when they interpret endoscopic images.

Endoscopic ultrasound predicts outcomes for patients with adenocarcinoma of the gastroesophageal junction

BACKGROUND

Endoscopic ultrasound (EUS) is the most accurate locoregional staging tool for gastroesophageal junction (GEJ) adenocarcinoma, and it may allow pretreatment risk stratification. The purpose of this study was to compare preoperative EUS staging with postoperative pathologic staging and to assess the ability of EUS to predict survival after resection for GEJ adenocarcinoma.

STUDY DESIGN

Patients with GEJ adenocarcinoma, who had preoperative staging with EUS followed by resection, were identified from a prospectively maintained database. Patients receiving neoadjuvant therapy were excluded. EUS stage was compared with pathologic stage. Survival analyses were performed in patients who underwent complete gross resection.

RESULTS

From 1985 through 2003, 209 patients underwent preoperative EUS followed by surgery without neoadjuvant therapy for GEJ adenocarcinoma. EUS correlated with pathologic T stage in 128 of 209 (61%) patients and with pathologic nodal stage in 154 of 206 (75%) patients. EUS accurately stratified patients into "early" (T0-2 N0) or "advanced" (T3-4 or N1) disease categories in 173 (83%) patients. Curative (R0) resection was performed in 184 patients: EUS "early" (n=84) and "advanced" (n=122) stages were associated with R0 rates of 100% and 82%, respectively (p=0.001). EUS "early" versus "advanced" stage was highly predictive of outcomes (p < 0.0001). The 5-year disease-specific survival for EUS "early" patients was 65% compared with 34% for EUS "advanced" stage.

CONCLUSIONS

EUS accurately predicts pathologic stage. In addition, EUS is predictive of outcomes after complete gross resection without neoadjuvant treatment for GEJ adenocarcinoma and identifies a high-risk population that might benefit from preoperative therapy.

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.

[Oesophageal tumours--what does the surgeon need from the radiologist?]

Surgery is the most important therapeutic discipline for oesophageal cancers and the surgeon has specific questions for the radiologist which can require various imaging procedures. The radiological presentation is, for example, necessary for the topographic imaging of larger space occupying processes, the localization and axial spread of which are important for the surgical procedure chosen. Imaging diagnostics helps with the identification of R0 resectable patients. High resolution computed tomography (CT) of the mediastinum is used to clarify the spatial relationship between oesophageal cancer and the tracheobronchial system. This method also helps demonstrate the presence of fistulas in the tracheobronchial system or mediastinum. Using a neck or thorax CT, or a PET-CT distant metastases can be documented and a second tumour excluded. Imaging procedures gain additional significance for the evaluation of the T stage of the oesophageal tumour or the response to neoadjuvant therapy concepts, for which an earliest possible response evaluation is of great importance. Imaging procedures are also of importance in aftercare as it is sometimes possible and valuable to carry out surgery for local relapses.

Accuracy of endoscopic ultrasound staging of gastric cancer in routine clinical practice in Singapore

OBJECTIVE

Endoscopic ultrasound has emerged as the leading modality to assess the T and N stage in gastric cancer. This study aimed to assess the accuracy of TN staging by endoscopic ultrasound in routine clinical practice in Singapore.

METHODS

Over a period of 7 years, 77 patients (male: 70%; median age 62.8 years) with gastric cancer underwent preoperative staging with endoscopic ultrasound. Fifty-seven patients eventually underwent surgery with tissues available for histopathological staging and comparison.

RESULTS

The tumor locations were: cardia: 13; corpus: 20; incisura: 19; antrum: 25. The majority was poorly differentiated (57.1%); 26% were moderately differentiated and 16.9% were well differentiated adenocarcinoma. Compared to pathological staging, the overall accuracy of T staging by endoscopic ultrasound was 77.2% (17.5% under-staged: 5.3% over-staged). The staging accuracy of T1 (92.9%) and T3 (81.8%) was higher than T2 (57.1%) and T4. For N staging, the accuracy of endoscopic ultrasound was 59.6% (26.3% under-staged; 14% over-staged); this was significantly superior to computer tomography (43.9%).

CONCLUSION

Endoscopic ultrasound is useful for the T staging of gastric cancer, with an overall accuracy rate of 77%, and up to 93% for T1 lesions. Under-staging may occur due to microscopic tumor infiltration, while over-staging may arise due to inflammatory reactions. The accuracy of N staging is lower at 60%, but could be further improved with the use of fine needle aspiration.

Preoperative 18[F]-fluorodeoxyglucose positron emission tomography standardized uptake values predict survival after esophageal adenocarcinoma resection

BACKGROUND

Clinical staging modalities for esophageal cancer are inaccurate at determining prognosis, especially in early-stage patients. We performed a retrospective review of patients with esophageal adenocarcinoma imaged by positron emission tomography before surgical resection to determine whether 18[F]-fluorodeoxyglucose uptake predicted overall survival independently of clinical and pathologic stage.

METHODS

The study is a retrospective review of patients with adenocarcinoma of the esophagus treated by surgery. All patients were imaged with computed tomography and positron emission tomography imaging, and most patients had an endoscopic ultrasound. We compared positron emission tomography standardized uptake values (SUVmax) with clinical and pathologic stage and survival. Prognostic variables were assessed by log-rank test, and survival by the method of Kaplan and Meier.

RESULTS

From January 1996 through June 2004, 50 patients meeting study eligibility criteria were analyzed. Median follow-up for surviving patients was 27 months. The median SUVmax was 4.5. Stratification of patients by the median SUVmax predicted survival. The 3-year survival was 57% for patients with an SUVmax greater than 4.5 and 95% for patients with an SUVmax of 4.5 or less (p = 0.02). The survival advantage of the SUVmax 4.5 or less group was also seen in clinically early-stage patients (defined as no adenopathy on computed tomography and positron emission tomography, and by endoscopic ultrasound T1-2 N0), as well as in patients with pathologically early-stage disease (T-2 N0).

CONCLUSIONS

In surgically managed esophageal adenocarcinoma patients, SUVmax predicts overall survival. Moreover, SUVmax identifies patients who have a poor prognosis from a subset of patients that would otherwise be considered to have early-stage disease.

New coil concept for endoluminal MR imaging: initial results in staging of gastric carcinoma in correlation with histopathology

Our aim was to conduct a prospective study to evaluate staging accuracy of a new coil concept for endoluminal magnetic resonance imaging (MRI) on ex vivo gastric carcinomas. Twenty-eight consecutive patients referred to surgery with a clinically proven primary gastric malignancy were included. Surgical specimens were examined with a foldable and self-expanding loop coil (8-cm diameter) at 1.5 Tesla immediately after total gastrectomy. T1- and T2-weighted and opposed-phase sequences (axial, frontal sections; 3- to 4-mm slice thickness) were acquired. Investigators blinded to any patient information analyzed signal intensity of normal gastric wall, gastric tumor, and lymph nodes. Findings were compared with histopathological staging. On surgical specimens, 2-5 gastric wall layers could be visualized. All gastric tumors (26 carcinomas, two lymphomas) were identified on endoluminal MR data (100%). Overall accuracy for T staging was 75% (18/24); sensitivity to detect serosal involvement was 80% and specificity 89%. N staging correlated in 58% (14/24) with histopathology (N+ versus N-). The endoluminal coil concept is feasible and applicable for an ex vivo setting. Endoluminal MR data provided sufficient detail for gastric wall layer differentiation, and therefore, identification of T stages in gastric carcinoma is possible. Further investigations in in vivo settings should explore the potential of our coil concept for endoluminal MR imaging.

Usefulness of endoscopic ultrasonography in preoperative TNM staging of gastric cancer

AIM: To evaluate the value of endoscopic ultrasono-graphy (EUS) in the preoperative TNM staging of gastric cancer.

METHODS: Forty-one patients with gastric cancer (12 early stage and 29 advanced stage) proved by esophagogastroduodenoscopy and biopsies preoperatively evaluated with EUS according to TNM (1997) classification of International Union Contrele Cancer (UICC). Pentax EG-3630U/Hitachi EUB-525 echo endoscope with real-time ultrasound imaging linear scanning transducers (7.5 and 5.0 MHz) and Doppler information was used in the current study. EUS staging procedures for tumor depth of invasion (T stage) were performed according to the widely accepted five-layer structure of the gastric wall. All patients underwent surgery. Diagnostic accuracy of EUS for TNM staging of gastric cancer was determined by comparing preoperative EUS with subsequent postoperative histopathologic findings.

RESULTS: The overall diagnostic accuracy of EUS in preoperative determination of cancer depth of invasion was 68.3% (41/28) and 83.3% (12/10), 60% (20/12), 100% (5/5), 25% (4/1) for T1, T2, T3, and T4, respectively. The rates for overstaging and understaging were 24.4% (41/10), and 7.3% (41/3), respectively. EUS tended to overstage T criteria, and main reasons for overstaging were thickening of the gastric wall due to perifocal inflammatory change, and absence of serosal layer in certain areas of the stomach. The diagnostic accuracy of metastatic lymph node involvement or N staging of EUS was 100% (17/17) for N0 and 41.7% (24/10) for N+, respectively, and 66% (41/27) overall. Misdiagnosing of the metastatic lymph nodes was related to the difficulty of distinguishing inflammatory lymph nodes from malignant lymph nodes, which imitate similar echo features. Predominant location and distribution of tumors in the stomach were in the antrum (20 patients), and the lesser curvature (17 patients), respectively. Three cases were found as surgically unresectable (T4 N+), and included as being correctly diagnosed by EUS.

CONCLUSION: EUS is a useful diagnostic method for preoperative staging of gastric cancer for T and N criteria. However, EUS evaluation of malignant lymph nodes is still unsatisfactory.

[Imaging of pancreatic adenocarcinoma]

Pancreatic cancer remains the fourth most common cause of cancer death. Surgery remains the only option for cure. Accurate diagnosis and staging are essential for appropriate management of patients with pancreatic cancer. This paper reviews the state of the art for imaging modalities in the diagnosis and staging of pancreatic adenocarcinoma. The crucial role of CT has increased with the new generation of multidetector CT.