Diagnostic utility of 20-megahertz linear endoscopic ultrasonography in early gastric cancer

Diagnostic Endoscopic Ultrasound (EUS) of the Luminal Gastrointestinal Tract

The purpose of this review is to focus on the diagnostic endoscopic ultrasound of the gastrointestinal tract. In the last decades, EUS has gained a central role in the staging of epithelial and sub-epithelial lesions of the gastrointestinal tract. With the evolution of imaging, the position of EUS in the diagnostic work-up and the staging flow-chart has continuously changed with two extreme positions: some gastroenterologists think that EUS is absolutely indispensable, and some think it is utterly useless. The truth is, as always, somewhere in between the two extremes. Analyzing the most up-to-date and strong evidence, we will try to give EUS the correct position in our daily practice.

Comparison of Endoscopic Ultrasonography and Conventional Endoscopy for Prediction of Tumor Depth in Superficial Nonampullary Duodenal Epithelial Tumors

BACKGROUND

The utility of endoscopic ultrasonography (EUS) in predicting tumor depth among superficial nonampullary duodenal epithelial tumors (SNADETs) is unclear. The aim was to compare EUS with conventional endoscopy (CE) for the evaluation of tumor invasion of SNADETs.

METHODS

A retrospective analysis was performed on consecutive 174 lesions/169 patients with duodenal dysplasia or adenocarcinoma with invasion up to submucosa who underwent both CE and EUS before endoscopic (n = 133) or surgical (n = 41) treatment. Endoscopic staging by CE was performed based on the characteristic endoscopic criteria of submucosal invasion (irregular surface, submucosal tumor [SMT]-like marginal elevation, and fusion of converging folds). The diagnostic performance of each test was compared with the final histology.

RESULTS

The sensitivity and accuracy of estimating the depth were higher for CE compared to that of EUS (99.4% vs. 89.4%, p < 0.01 and 97.7% vs. 87.9%, p < 0.01, respectively). Univariate analysis of endoscopic factors revealed that tumor diameter, red color, SMT-like appearance, and hypoechogenicity were factors related to advanced histology. Multivariate analysis revealed that the presence of SMT-like appearance based on CE was an independent factor to predict submucosal invasion (p = 0.025). Gross morphology of the combined type was associated to incorrect diagnosis of EUS (p = 0.007). Among 3 cases in which EUS overestimated the tumor depth, carcinoma extension in submucosal Brunner's gland or nontumorous submucosal cystic dilation was observed.

CONCLUSION

EUS may not be necessary, and CE may be sufficient for determining the optimal therapeutic strategy for SNADETs.

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

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

Controversies in EUS: Do we need miniprobes?

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

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

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

Background

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

Aim

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

Methods

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

Results

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

Conclusion

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

Double Contrast-Enhanced Ultrasonography in Preoperative T Staging of Gastric Cancer: A Comparison With Endoscopic Ultrasonography

Objective: To compare the precision of double contrast-enhanced ultrasonography (DCEUS) to endoscopic ultrasonography (EUS) in preoperative T staging of gastric cancers.

Methods: This retrospective study consisted of 158 pathologically confirmed gastric cancer patients. All patients underwent DCEUS (intravenous contrast-enhanced ultrasonography combined with oral contrast-enhanced ultrasonography) and endoscopic ultrasonography (EUS) preoperatively. The histopathological findings of resected specimens were compared with the results of DCEUS and EUS retrospectively.

Results: The accuracy of DCEUS and EUS in evaluating the T staging of gastric cancer were 82.3% (T1 62.5%,T2 84.4%,T3 87.9%,T4 91.3%) and 76.6% (T1 84.4%,T2 82.2%,T3 72.4%,T4 65.2%), respectively. There were no significant differences between the methods for the overall T staging accuracy (χ² = 1.569, P = 0.210). But EUS was superior to DCEUS for T1 stage (χ² = 3.925, P = 0.048) and DCEUS was superior to EUS for T3 stage (χ² = 4.393, P = 0.036) and T4 stage (χ² = 4.600, P = 0.032).

Conclusion: DCEUS is a convenient and noninvasive method with high precision, which can be used as the primary imaging technique for advanced gastric cancer T staging. In early gastric cancer, we should prefer EUS. Two methods are complementary for assessing tumor invasion depth of gastric cancer.

Comparing single oral contrast-enhanced ultrasonography and double contrast-enhanced ultrasonography in the preoperative Borrmann classification of advanced gastric cancer

Objectives

To evaluate the accuracy of double contrast-enhanced ultrasonography (DCEUS) in preoperative Borrmann classification of advanced gastric cancer (AGC).

Materials and Methods

A total of 162 patients histologically confirmed AGC were enrolled into this study. Single oral contrast-enhanced ultrasonography (SOCEUS) were performed in 80 patients and DCEUS (intravenous microbubbles combined with oral contrast-enhanced ultrasound) were performed in 82 patients preoperatively. The findings of the histopathologic examination of resected specimens after surgery were considered as gold standard. The accuracy of SOCEUS was compared with the accuracy of DCEUS in determining Borrmann classification. Interobserver agreement between two sonographyers of SOCEUS and DCEUS had also been assessed.

Results

The accuracy of SOCEUS and DCEUS in Borrmann classification of advanced gastric cancer were 78.75% and 91.46% respectively. There was a significant difference between two methods (χ² = 5.186, P < 0.05). The interobserver agreement of two methods was both excellent for assessing the Borrmann classification with a Kappa value of 0.777 by SOCEUS and 0.844 by DCEUS.

Conclusions

DCEUS is a valuable method for Borrmann classification with its high accuracy preoperatively. It should be used widely.

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

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

Tissue engineering of the stomach

Tissue engineering combines engineering principles with the biological sciences to create functional replacement tissues. The underlying principle of tissue engineering is that isolated cells combined with biomaterials can form new tissues and organs in vitro and in vivo. This review focuses on stomach tissue engineering, which is a promising approach to the treatment of gastric cancer, the fourth most common malignancy in the world and the second-leading cause of cancer mortality worldwide. Although gastrectomy is a reliable intervention to achieve complete removal of cancer lesions, the limited capacity for food intake after resection results in lower quality of life for patients. To address this issue, we have developed a tissue-engineered stomach to increase the capacity for food intake by creating a new food reservoir. We have transplanted this neo-stomach as a substitute for the original native stomach in a rat model and confirmed functional adaptation. Furthermore, we have demonstrated the feasibility of transplanting a tissue-engineered gastric wall patch in a rat model to alleviate the complications after resection of a large area of the gastric wall. Although progress has been achieved, significant challenges remain to bring this approach to clinical practice. Here, we summarize our work and present the state of the art in stomach tissue engineering.

Early gastric cancer and dysplasia

Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.

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

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

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

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

Is endoscopic ultrasonography indispensable in patients with early gastric cancer prior to endoscopic resection?

BACKGROUND

Endoscopic resection as curative treatment of early gastric cancer (EGC) requires accurate staging for depth of invasion (T) before therapy. This study aimed to compare T staging of EGC using a miniprobe with that of conventional endoscopy (CE).

METHODS

A total of 388 patients with suspected of EGC by CE were prospectively enrolled in the study. After miniprobe staging by an experienced endosonographer, CE staging was performed by another endoscopist who was blinded to the miniprobe assessment. Patients underwent either endoscopic resection (n = 325) or surgery (=63) according to staging results. Results of each method were compared with the histology of the resected specimen. Clinicopathological factors affecting accuracy of each test were also evaluated.

RESULTS

Overall accuracy of miniprobe and CE staging was 78.9% (306/388) and 81.4% (316/388), respectively (p = 0.052). Sensitivity for T1m was more than 95% (miniprobe 98.7%, CE 97.7%), whereas sensitivity for T1sm was lower at 6.6% for miniprobe and 23.7% for CE (p = 0.002). Among nine lesions identically considered submucosal invasion by both methods, three were T1sm cancer. Diagnostic accuracy of the miniprobe was lower than that of CE with respect to lesions located in the lower third of the stomach, differentiated histology, or massive submucosal invasion.

CONCLUSIONS

Overall accuracy of the miniprobe and CE for T staging in EGC was approximately 80% with no significant difference. Accurate prediction of both techniques for submucosal invasion was poor, even by using a combination of the two methods. The use of the miniprobe may not increase the positive predictive value for T staging over the use of CE alone.

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

BACKGROUND AND AIM

The development of endoscopic treatment, such as endoscopic submucosal dissection, extends the indications for endoscopic resection in patients with early gastric cancer (EGC). Endoscopic ultrasonography (EUS) is the first-choice imaging modality for determining the depth of invasion of gastric cancer. The aim of the present study was to prospectively assess the accuracy of EUS for determining the depth of EGC, according to the accepted/extended indications.

METHODS

We prospectively included a total of 181 lesions in 178 patients, with an endoscopic diagnosis of EGC, who underwent EUS for staging the depth of tumor invasion using a 20-MHz catheter probe. We investigated the accuracy of EUS for determining the depth of endoscopically-suspected EGC and then analyzed the difference in the accuracy of EUS according to the accepted/extended indications.

RESULTS

Of the 178 patients, five patients were dropped because of the absence of final histological results. For the 176 lesions in 173 patients, the accuracy of EUS assessment for the depth of tumor invasion was 80.7% (142 of 176 lesions). The accuracy of EUS for the lesions with accepted indications and with extended indications was 97.6% (40 of 41 lesions) and 83.6% (46 of 57 lesions), respectively (P = 0.040). Of the lesions with extended indications, the accuracy of EUS decreased especially for the lesions with ulceration and those with minute submucosal invasion (79.2% and 42.9%, respectively).

CONCLUSIONS

The accuracy of EUS for the lesions with the extended indications was lower than that for the lesions with the accepted indications. In particular, lesions with ulceration and minute submucosal invasion should be carefully considered prior to endoscopic treatment by pretreatment EUS staging.

Large endoscopic mucosal resection for colorectal tumors exceeding 4 cm

AIM: To evaluate the feasibility and the outcome of endoscopic mucosal resection (EMR) for large colorectal tumors exceeding 4 cm (LCRT) undergoing piecemeal resection.

METHODS: From January 2005 to April 2008, 146 digestive tumors larger than 2 cm were removed with the EMR technique in our department. Of these, 34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal tumors. The mean age of the patients was 71 years. The mean follow-up duration was 12 mo.

RESULTS: LCRTs were located in the rectum, left colon, transverse colon and right colon in 58%, 15%, 4% and 23% of cases, respectively. All were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm). According to the Paris classification, 34% of the tumors were type Is, 58% type IIa, 4% type IIb and 4% type IIc. Pathological examination showed tubulous adenoma in 31%, tubulo-villous adenoma in 27%, villous adenoma in 42%, high-grade dysplasia in 38%, in situ carcinoma in 19% of the cases and mucosal carcinoma (m2) in 8% of the cases. The two cases (7.7%) of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with clips. During follow-up, recurrence of the tumor occurred in three patients (12%), three of whom received endoscopic treatment.

CONCLUSION: EMR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection, despite providing incomplete histological assessment.

Ulcerous change decreases the accuracy of endoscopic ultrasonography diagnosis for the invasive depth of early gastric cancer

BACKGROUND

With the development of endoscopic submucosal dissection, an expansion of the criteria for local treatment was suggested for lesions with ulcerous changes or undifferentiated-type adenocarcinoma.

AIM OF THE STUDY

To determine the efficacy of endoscopic ultrasonography for such lesions, we retrospectively analyzed factors that influenced accurate diagnosis by endoscopic ultrasonography of the depth of tumor invasion.

METHODS

We investigated 267 gastric adenocarcinomas for which histopathological results were obtained by endoscopic mucosal resection or gastrectomy. The lesions were divided into four groups by histological type and the presence of ulcerous changes. Five clinicopathological factors were assessed for their possible associations with incorrect diagnosis.

RESULTS

The positive predictive value (PPV) for cancer limited within the mucosa (endoscopic ultrasonography, EUS-M) and cancer invaded into the submucosal layer (EUS-SM) were 88.0% (125 of 142 lesions) and 60.0% (30 of 50 lesions), respectively. The lesions diagnosed as EUS-M/SM borderline (37 lesions) included 19 lesions (51.4%) of M cancer and 17 lesions (45.9%) of SM cancer. In logistic analysis, ulcerous changes (p < 0.0001) and macroscopic classification (p = 0.0284) were factors that caused incorrect diagnosis by endoscopic ultrasonography. In the group having differentiated-type adenocarcinoma with ulcerous changes, the PPV of EUS-SM was 25% (3 of 12), and there was a significant difference (p < 0.05) between the EUS-SM of this group and that of the differentiated-type adenocarcinoma without ulcerous changes.

CONCLUSION

The accuracy of endoscopic ultrasonography tumor staging was not sufficient for the lesions with ulcerous changes in our study. Therefore, we should be careful to perform endoscopic submucosal dissection for lesions with ulcerous changes.

The accuracy of endoscopic ultrasonography in differentiating mucosal from deeper gastric cancer

BACKGROUND AND AIM

With the advent of endoscopic mucosal resection and endoscopic submucosal dissection techniques, pretreatment differentiation between mucosal and deeper gastric cancer has become increasingly important. The aim of this study was to systematically review published data on the diagnostic performance of endoscopic ultrasonography (EUS) in differentiating between mucosal and deeper gastric cancer.

METHODS

A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Two reviewers independently assessed the methodological quality of each study. Sensitivity and specificity of EUS were calculated for each study and a summary receiver operating characteristic curve (sROC) was constructed. Subgroup analyses were performed if results of individual studies were heterogeneous.

RESULTS

The inclusion criteria were met by 18 studies. The studies had poor methodological quality. Sensitivity and specificity of EUS in detecting cancerous extension beyond the mucosa ranged from 18.2 to 100% (median 87.8%) and from 34.7 to 100% (median 80.2%), with an area under the sROC of 0.8924. There was significant heterogeneity in both sensitivities and specificities among the included studies (P < 0.0001). Studies which only included patients endoscopically suspected of having EGC and studies which only used transducer frequencies > or =15 MHz were homogeneous in sensitivities (P= 0.1828 and 0.4501, respectively).

CONCLUSION

It is unclear yet whether EUS can accurately differentiate between mucosal and deeper gastric cancer. Factors that may influence its diagnostic performance should be further explored.

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.

Endoscopic mucosal resection: an improved diagnostic procedure for early gastroesophageal epithelial neoplasms

Endoscopic mucosal resection (EMR), which is advocated for the treatment of early (superficial) gastroesophageal neoplasms, has also been alluded to represent a superior diagnostic and staging modality. We compared the diagnostic concordance of preceding biopsies with EMR specimens in 31 gastric and 10 esophageal EMRs consisting of 6 low-grade and 12 high-grade dysplasias, 21 intramucosal adenocarcinomas, and 2 submucosal invasive adenocarcinomas. Discrepancies were considered as either major or minor if the histologic grades differed by 2 or more, or by only 1, respectively. Discrepant and concordant cases were compared with regard to the size of lesion (maximum dimension and surface area), number of biopsy fragments, and extent of biopsy sampling (ratio between lesion size and number of biopsy fragments). These same variables were used to evaluate the differences seen between gastric and esophageal cases. Of the 41 cases, 16 (39%) had discrepant diagnoses, including 14 gastric and 2 esophageal neoplasms. A major discrepancy was seen in 2% of the cases (n = 1, gastric) and a minor discrepancy, in 15 cases. All but 2 of the discrepant cases were found to have a higher grade on EMR. The average number of biopsy fragments was 4.4 in both concordant and discrepant groups. The maximal dimension, surface area, and biopsy sampling ratios of the lesion were significantly greater in the discrepant cases than in the concordant cases. The esophageal cases trended toward having smaller size and a significantly extensive biopsy sampling. We conclude that EMR is superior to biopsy for diagnosing superficial gastroesophageal tumors. Discrepancies between the specimens occur in larger lesions (>10 mm) with less extensive biopsy sampling. EMR can substantially modify the diagnostic grade of a lesion and therefore facilitate optimal therapeutic decisions by avoiding undertreatment and overtreatment based on inaccurate grading and staging.

The endoscopic diagnosis and staging of oesophageal adenocarcinoma

The endoscopic evaluation of patients with oesophageal adenocarcinoma does not only serve the purpose of diagnosing the lesion and obtaining biopsies for histological evaluation: a systematic description of advanced lesions is also required to guide further therapeutic decisions. New endoscopic imaging modalities hold the promise of better endoscopic detection of early cancer and its precursor lesions in Barrett's oesophagus. Video-autofluorescence and narrow band imaging are the most promising techniques in this respect. The former may be used as a 'red flag' technique, identifying lesions that remain occult with white light endoscopy; the latter may be used as a targeted imaging technique, allowing for detailed inspection of the mucosal and vascular patterns that may help to distinguish early neoplasia from non-dysplastic tissue. Currently, prototypes are under investigation that combine high-resolution endoscopy, narrow band imaging and video-autofluorescence in one endoscopy system. Endoscopic ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumour infiltration of oesophageal adenocarcinoma and locoregional lymph nodes status. EUS allows for the identification of patients with advanced disease who are unlikely to benefit from attempts at curative surgery and in whom a conservative palliative treatment is indicated. EUS may also play a role in the selection of patients for local endoscopic treatment of early oesophageal cancer. EUS guided fine needle aspiration (EUS-FNA) of locoregional lymph nodes is safe with a high sensitivity and an impeccable specificity for assessment of malignant involvement. The indications for EUS-FNA of lymph nodes, however, depend on local treatment protocols: caeliac nodes (M1a) and lymph nodes located at or above the subcarinal area are the most widely used indications. In addition, it may be important if the choice for specific treatment protocols (e.g. neoadjuvant chemoradiotherapy) depends on lymph node status.

Uses of photodynamic therapy in premalignant and malignant lesions of the gastrointestinal tract beyond the esophagus

Much has recently been written regarding the use of photodynamic therapy for the treatment of esophageal carcinoma and dysplastic Barrett's esophagus. This review, however, describes the clinical experience using photodynamic therapy with various photosensitizer agents for the treatment of diseases in other areas of the gut, especially the pancreaticobiliary tract where European studies have established the role of porfimer sodium photodynamic therapy in the management of patients with cholangiocarcinoma.

Endoscopic mucosal resection for gastric epithelial neoplasms: a study of 39 cases with emphasis on the evaluation of specimens and recommendations for optimal pathologic analysis

Endoscopic mucosal resection of gastric neoplasms is a curative technique that avoids surgery and its potential complications. Infrequently performed in the West, the limitations, pitfalls and challenges provided by this new therapeutic modality are not well known by general surgical pathologists. We evaluated a series of 39 endoscopic mucosal resections and assessed the correlation between original biopsies and final diagnoses, depth of excision, status of deep and lateral margins, artifactual changes and recurrence rate. The tumors consisted of 24 intramucosal carcinomas, six high-grade dysplasias, eight low-grade dysplasias and one submucosal invasive carcinoma. The preresection diagnoses corresponded to the final evaluation in 63% of the cases with previous biopsies. In 37% of the cases, the biopsies under-diagnosed the neoplasia. The rate of positive margins was 38%. Iatrogenic changes, that is, intramucosal hemorrhage and electrodiathermic burn, were noted in 44% of the cases but hindered the pathologic evaluation in only 10% of the cases. Persistence or recurrence was observed in only seven cases and there was no progression to advanced adenocarcinoma. Based on our experience, we offer some recommendations in order to provide optimal pathologic analysis of endoscopic mucosal resection specimens.

Curative treatment of gastric cancer: towards a multidisciplinary approach?

Despite marked decreases in incidence over the last century, particularly in developed countries, gastric cancer is still the second-most common tumor worldwide. Surgery remains the gold standard for the cure of locoregional disease. However, in most countries, the diagnosis is made at an advanced stage, and the 5-year survival for surgically resectable disease stays far below 50%. The efficacy of chemotherapy and/or radiation therapy in addition to surgery has been actively studied over the last 30 years. Unfortunately, with few exceptions, most studies of adjuvant therapy in gastric cancer have given deceiving results. The purpose of this review is to address the reasons for our failure to objectivate an improvement in the cure of gastric cancer with adjuvant treatment in most trials, and to consider potential solutions. The low efficacy of chemotherapy regimens available up to now may have hampered our progress. In addition, many previous studies suffered limitations of design or methodology (e.g. low accrual, inadequate disease stage selection, inadequate surgical treatment) that may have obscured a treatment effect. Furthermore, the reduced treatment tolerance of post-gastrectomy patients, perhaps due to their poor nutritional status, results in decreased or delayed adjuvant systemic therapy, with potential adverse consequences in its efficacy. Among potential solutions, the arrival of new drugs, taxanes and topoisomerase I inhibitors in particular, which have shown encouraging results in metastatic disease, may increase the impact of chemotherapy in a multidisciplinary treatment approach. Pre-treatment with chemotherapy and/or radiation therapy prior to surgery may also be advantageous, averting the problems associated with post-surgical treatment. Such an approach has been shown to be feasible in phase II studies, and is relatively well tolerated by patients. Several carefully designed randomized phase III trials are underway to answer this question.

Endoscopic ultrasonography in preoperative staging of gastric cancer: determination of tumor invasion depth, nodal involvement and surgical resectability

AIM: Current study was aimed to evaluate the usefulness of EUS in TNM staging of gastric cancer by comparing EUS preoperative staging with pathological findings, and the preliminary exploration of possible reasons for overstaging and understaging phenomenon was especially intended.

METHODS: A total of 35 patients with histologically confirmed gastric adenocarcinoma were referred to EUS and staged preoperatively by using the TNM system. The preoperative endosonographic results were compared with the histopathological staging.

RESULTS: The overall accuracy of EUS for determination of the T stage was 80.0%, and for T1, T2, T3, and T4 was 100%, 71.4%, 87.5% and 72.7%, respectively. For N stage, EUS had the accuracy of 68.6%, with sensitivity and specificity of 66.7% and 73.7%, respectively. Resectability was predicted with sensitivity and specificity of 87.5% and 100%, respectively.

CONCLUSION: EUS is an accurate staging modality in most cases, with a few exceptions of overstaging and understaging. Patients with gastric cancers can benefit from preoperative EUS staging for establishing individualized therapy. However, EUS criteria to differentiate benign from malignant nodes still need to be further defined by future studies.

Interventional endoscopy in the diagnosis and staging of upper gastrointestinal malignancy

Increased population longevity as well as an emphasis on earlier diagnosis and more effective treatment of cancer have created an environment for new technologies and techniques to flourish. Some of the endoscopic entities discussed in this article have not been fully validated in clinical practice. Innovative spectroscopic modalities hold a great deal of promise, but are years away from general applicability. In contrast, many interventional endoscopic techniques are currently available and confer heightened levels of diagnostic and staging accuracy for gastric and esophageal malignancies. Earlier diagnosis can identify patients who may be eligible for less-invasive treatment options such as EMR. Minimally invasive treatment options and maximum staging accuracy are more important for patients who are marginal surgical candidates and for accurate comparison of clinical trials studying treatment options. Our challenge for the future is to properly integrate these technologic advances with the science of good medical practice.

Risk factors predictive of lymph node metastasis in depressed early gastric cancer

BACKGROUND

This study was conducted to identify risk factors predictive of regional lymph node metastasis in depressed early gastric cancer and further to establish an objective criterion useful to indicate additional surgical treatment in cases in which submucosal tumor extension becomes evident by endoscopic mucosal resection (EMR).

METHODS

Data from 276 patients surgically treated for depressed early gastric cancer were collected, and the relationship between the patient and tumor characteristics, and the lymph node metastasis was retrospectively evaluated by multivariate analysis.

RESULTS

In the multivariate logistic regression model, female sex, a larger tumor size (20 mm or more), submucosal invasion, and presence of lymphatic vessel involvement were found to be independent risk factors for lymph node metastasis. Among 145 patients with submucosally invasive carcinoma, no lymph node metastasis was observed in patients who showed none of the other three risk factors, whereas 14.3% and 23.3% of patients with one and two of these factors had lymph node metastasis, respectively. The lymph node metastasis rate was calculated to be 86.7% in patients who had all three factors.

CONCLUSIONS

Submucosal invasion, female sex, tumor size of 20 mm or more, and lymphatic vessel involvement were significantly and independently related to the presence of lymph node metastasis in depressed early gastric cancer. The positive number of the latter three risk factors is a simple criterion to indicate additional surgical treatment in cases with submucosal invasion revealed first by EMR.

High-resolution endoscopic imaging of the GI tract: a comparative study of optical coherence tomography versus high-frequency catheter probe EUS

BACKGROUND

Both optical coherence tomography (OCT) and catheter probe EUS (CPEUS) are candidates for high-resolution imaging of the GI wall, but their potential roles in this clinical context have not been investigated.

METHODS

OCT and CPEUS were used to image normal-appearing portions of the GI tract at the same sites. CPEUS was performed with a 20-MHz or a new 30-MHz catheter probe.

RESULTS

Forty-four histologically confirmed normal sites in 27 patients were evaluated. With OCT, mucosa and muscularis mucosa were clearly seen at all sites. Except for stomach, OCT demonstrated the submucosa in all sites. OCT penetration ranged from 0.7 to 0.9 mm. Microscopic structures such as esophageal glands, intestinal villi, colonic crypts, and blood vessels were easily identified. CPEUS penetration ranged from 10 mm to 20 mm, and 5 to 7 distinct layers were discernible. However, both mucosa and submucosa were seen as thin layers without microscopic detail.

CONCLUSION

OCT resolution is superior to high-frequency CPEUS, but depth of penetration is limited to mucosa and submucosa. OCT images the major structural components of the mucosa and submucosa whereas CPEUS does not. Potentially, OCT and high-frequency CPEUS may be complementary for clinical imaging.

Management of Barrett's oesophagus, dysplasia and early adenocarcinoma

There has been a dramatic increase in recent years in the incidence of Barrett's oesophagus and the oesophageal adenocarcinoma associated with it. Adequate monitoring strategies and improved diagnostic procedures are therefore essential. Alongside conventional video-endoscopy with four-quadrant biopsies, many additional diagnostic procedures are now available to improve monitoring. These allow the early diagnosis of dysplastic areas and early carcinomas. Both thermal procedures (argon plasma coagulation, multipolar electrocoagulation and KTP laser and Nd&ratio;YAG laser treatment) and non-thermal ablation procedures (photodynamic therapy) are used for the endoscopic ablation of Barrett's mucosa without dysplasia, being employed in addition to acid suppression treatment. On the basis of the data currently available, it is, however, not yet possible to offer a general recommendation in favour of endoscopic ablation. Alongside surgical treatment for high-grade dysplasia and early carcinoma, endoscopic treatment procedures, which have a much lower complication and mortality rate, will probably play an important role in the future. Endoscopic mucosal resection and photodynamic therapy are particularly promising. Long-term results with these procedures are, however, still awaited.

Role of endoscopy in the staging of esophageal and gastric cancer

Progress in instrumentation and clinical research continues to expand the potential utility of endoscopic ultrasound (EUS) in the treatment of esophageal and gastric cancer. This review focuses on the role of EUS in the staging and treatment planning of patients with esophageal and gastric cancer.

Comparison of a linear miniature ultrasound probe and a radial-scanning echoendoscope in TN staging of esophageal cancer

BACKGROUND

Endoscopic ultrasonography is a precise method for TN staging of esophageal cancer. We explored the staging properties of a linear miniprobe as compared with a radial-scanning echoendoscope.

METHODS

Sixty-eight patients with esophageal cancer underwent preoperative TN staging using a 20-MHz linear miniprobe and a 7.5/12-MHz radial-scanning echoendoscope. Tumor stage was verified by surgery and/or histology.

RESULTS

T and N stages were verified in 53 and 54 patients, respectively. T-staging accuracy using the echoendoscope was 70%. The high-frequency miniprobe could not differentiate between T3 and T4 tumors, but both systems had an accuracy of 87% in discriminating between T1, T2, and T3/4 stages. With traversable tumors, the accuracy of N staging was significantly better with the echoendoscope than with the miniprobe (90% vs. 48%, P = 0.008).

CONCLUSIONS

The two endosonographic systems had similar accuracy for assessing transmural tumor growth, but the echoendoscope was superior in staging advanced transmural tumors and in predicting lymph node metastasis with traversable tumors.

Current status and future perspectives in gastric cancer management

Gastric cancer is still a major health problem and a leading cause of cancer mortality despite a worldwide decline in incidence. Environmental and Helicobacter pylori (Hp) acting early in life in a multistep and multifactorial process may cause intestinal type carcinomas, whereas genetic abnormalities are related more to the diffuse type of disease. Primarily due to early detection of the disease, the results of treatment for gastric cancer have improved in Japan, Korea and several specialized Western centres. Surgery offers excellent long-term survival results for early gastric cancer (EGC). Advances in diagnostic and treatment technology have contributed to a trend towards minimal invasive surgery such as endoscopic mucosal resection (EMR) and laparoscopic surgery for selected mucosal cancers. In the Western world, however, more than 80% of patients at diagnosis have an advanced gastric cancer with a poor prognosis. The aim of surgery is complete removal of the tumour (UICC R0-resection), which is known to be the only proven, effective treatment modality and the most important treatment-related prognostic factor. Gastrectomy with preservation of the spleen and pancreas in most cases is the standard procedure. However, at present there is no consensus about the optimal extent of lymph-node dissection. The hypothesis that extended (D2) lymph-node dissection leads to improved survival has not been confirmed in randomized trials. Results from specialized centres and ongoing multi-institutional randomized trials, however, indicate that D2 dissection, with preservation of the spleen and pancreas, can be performed with the same safety as a D1 dissection. Furthermore, in 50% of patients with node-positive disease, the extraperigastric N2 nodes are involved (N2 disease) and thus an R0-resection is achievable only by a D2 node dissection resulting in a 5-year survival of about 30% for such patients. However, even after a D2 node dissection with curative potential, disease recurs in two-thirds of patients with locally advanced gastric cancer (LAGC) and is rapidly fatal. The need for an adjuvant treatment is obvious, but at present there is no such treatment of proven effectiveness. Promising results with preoperative chemotherapy, which increases the R0-resection rate, and intra-or early postoperative intraperitoneal chemohyperthermia to prevent peritoneal dissemination have been reported. However, randomized trials are necessary before these combined treatments become widely accepted. Present data indicate that the treatment of gastric cancer has become more and more sophisticated with a tailored therapy for individual cases. Treatment includes a broad spectrum of therapeutic options from EMR for selected mucosal cancers to aggressive combined treatment for LAGC. Precise knowledge of patterns of recurrence and metastases, critical evaluation of clinicopathologic variables, integration of high technology into diagnosis to predict accurately pre-treatment staging, and the surgeon's ability to perform minimally invasive surgery and D2 node dissection technique are necessary for an appropriate treatment option. All these prerequisites are best ensured by management in experienced surgical oncology units.

Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy

Optical coherence tomography (OCT) is an emerging technology for performing high-resolution cross-sectional imaging. OCT is analogous to ultrasound imaging, except that it uses light instead of sound. OCT can provide cross-sectional images of tissue structure on the micron scale in situ and in real time. Using OCT in combination with catheters and endoscopes enables high-resolution intraluminal imaging of organ systems. OCT can function as a type of optical biopsy and is a powerful imaging technology for medical diagnostics because unlike conventional histopathology which requires removal of a tissue specimen and processing for microscopic examination, OCT can provide images of tissue in situ and in real time. OCT can be used where standard excisional biopsy is hazardous or impossible, to reduce sampling errors associated with excisional biopsy, and to guide interventional procedures. In this paper, we review OCT technology and describe its potential biomedical and clinical applications.

Three-dimensional endoscopic ultrasonography of lesions of the upper gastrointestinal tract using a radial-linear switchable thin ultrasound probe

BACKGROUND

The objective of three-dimensional (3-D) endoscopic ultrasonography (EUS) is to recognize lesions stereoscopically.

METHODS AND RESULTS

We investigated a total of 43 lesions in the upper gastrointestinal (GI) tract by regenerating 3-D images in eight cases of oesophageal cancer, two cases of oesophageal submucosal tumour, two oesophageal varices, two cases of achalasia, 27 gastric cancers, one gastric carcinoid, and one duodenal submucosal tumour. Using a prototype system (Fujinon, Omiya, Japan), we reconstructed 3-D images from conventional EUS images taken by a thin ultrasound probe (Sonoprobe, SP-701, Fujinon) having a radial-linear scanning mode. The basic 3-D images could be obtained in a short period during EUS performed using the conventional thin-ultrasound probe. The acceptable quality level of the reconstructed 3-D images was 37% (57% in the oesophagus, 25% in the stomach and 100% in the duodenum). Deterioration of 3-D images was due to a wobbling of linear scanning mainly caused by peristalsis of the GI tract, cardiac impulses, and respiration.

CONCLUSIONS

Our study has proved that the simple and speedy 3-D display system built using the existing linear-radial switchable probe is easily applicable to clinical cases.

Endoscopic ultrasonography in patients with gastro-esophageal cancer

For patients with gastro-esophageal cancer ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumor infiltration and local lymph nodes status. EUS is especially important in the preoperative staging of patients with esophageal cancer and patients with proximal gastric cancer. Here it allows for the identification of those patients with advanced disease who are unlikely to benefit from surgery and in whom a conservative palliative treatment is indicated. In advanced gastric cancer the clinical implications of EUS less clear. Still preoperative EUS is indicated in every patient with cancer of the proximal stomach to assess tumor infiltration in the esophagus. Relatively new is the use of EUS in staging early cancers in order to select patients for local endoscopic treatment. High-frequency miniprobes are the instruments of choice for imaging these lesions. Strict criteria should be applied in the selection of patients for local endoscopic treatment of early gastro-esophageal cancers. EUS guided fine needle aspiration (EUS-FNA) is currently only indicated in patients with esophageal cancer and suspicious celiac lymph nodes. It may become more important if new treatment protocols demand more objective and reliable assessment of lymph node status.

Hydrogastric sonography in the preoperative staging of gastric cancer

PURPOSE

Depth of wall invasion is the main prognostic factor in gastric cancer. We studied the utility of hydrogastric sonography in the evaluation of transmural infiltration by gastric cancer.

METHODS

Thirty-seven patients with gastric adenocarcinoma were examined before surgery with a 5-MHz probe after the ingestion of 100-400 ml of water (mean, 330 ml). Sonographic results were compared with pathologic classifications obtained after surgery.

RESULTS

Of the 37 tumors, 15 were found at surgery to be in the antrum, 10 were in the gastric body, 5 were proximal, and 7 were diffuse. After surgery, tumors were classified as follows: 2 (5%) T1, 4 (11%) T2, 15 (41%) T3, and 16 (43%) T4. Hydrogastric sonography correctly classified 30 (81%) of the 37 tumors. Sonography was correct for 2 (100%) of the 2 T1 tumors, 2 (50%) of the 4 T2 tumors, 13 (87%) of the 15 T3 tumors, and 13 (81%) of the 16 T4 tumors. Five sonographic errors were due to understaging and 4 to overstaging. With regard to tumor site, sonographic results were correct for 4 (57%) of the 7 diffuse tumors, 3 (60%) of the 5 proximal tumors, 9 (90%) of the 10 gastric body tumors, and 14 (93%) of the 15 antral tumors.

CONCLUSIONS

Hydrogastric sonography is useful for preoperative evaluation of transmural infiltration by gastric cancers, particularly tumors in the antrum or gastric body.

Current advances and changes in treatment strategy may improve survival and quality of life in patients with potentially curable gastric cancer

BACKGROUND

The treatment strategy for gastric cancer is determined by the stage of disease. Advances in diagnostic techniques such as endoscopic ultrasound (EUS) and in staging have increased the accuracy of pretreatment staging. Correct staging is a prerequisite for the optimal treatment of gastric cancer patients. Long-term expected survival and quality of life (QOL) are the major criteria determining the therapeutic strategy.

RESULTS

Surgical resection offers excellent survival rates for early gastric cancer (EGC) patients. D1 resection is sufficient for mucosal cancers (T1m) and for most submucosal cancers (Tlsm); however, for the rest (about 5%) of these patients with N2 disease a D2 resection is required for complete tumor resection (R0). Considering QOL, endoscopic mucosal resection (EMR) or laparoscopic wedge resection is the best front-line therapy for several mucosal cancers. Prediction and selection of node-negative patients with the help of certain macroscopic and histologic criteria can eliminate the possibility for residual disease in perigastric lymph nodes. However, long-term survival data are needed before these new techniques become more generally accepted. In contrast, an aggressive approach is necessary for the treatment of advanced gastric cancer. Total gastrectomy, with the exception of distal tumors that can be treated by subtotal gastrectomy, is the procedure of choice. Splenectomy is indicated for proximal advanced tumors. Distal pancreatectomy should be avoided, however, because its adverse effect has been documented in all randomized trials. Although the survival benefit of extended (D2) lymphadenectomy is unproven in randomized trials, D2 resection increases the R0 resection rate and may improve survival in some selected node-positive patients. D2 resection has little effect on preventing peritoneal tumor spread and liver metastasis, and the traditional late administration of chemotherapeutic drugs has been proven ineffective. Current data suggest a possible beneficial effect of combined treatment for patients with local advanced gastric cancer (LAGC). Ongoing phase-III randomized trials will prove whether patients with LAGC treated by neoadjuvant chemotherapy plus D2 resection versus surgery alone or surgery plus intraoperative intraperitoneal chemotherapy derive any benefit from these combined treatment modalities.

CONCLUSION

Evaluation of all information concerning tumor stage, location, histologic type, expected survival, and QOL after resection is of paramount importance for the surgeon planning the extent of surgery. The therapeutic approach should be stratified according to the stage of disease.

Clinical implications of endoluminal ultrasonography using through-the-scope catheter probes

BACKGROUND

Ultrasound catheter probe-assisted endosonography is a relatively new technique. The aim of this prospective multicenter study was to determine its potential clinical impact by assessing changes in diagnostic and therapeutic management affected by catheter probes compared with ultrasound endoscopes.

METHODS

Endosonographers at three centers selected theoretic diagnostic and therapeutic plans that would be followed if neither catheter probes nor ultrasound endoscopes were available. Patients with suitable lesions underwent endosonography with catheter probes followed by an ultrasound endoscope. Diagnostic and therapeutic plans were noted after each examination.

RESULTS

Sixty-six patients, of whom 15 had a stenotic esophageal cancer, 39 had a mucosal or submucosal lesion, and 12 had a stricture of the pancreaticobiliary system or the gastrointestinal tract, were enrolled. If neither form of endosonography were available, invasive or surgical diagnostic procedures would have been performed on 23 (35%) patients and surgical therapy would have been planned in 31 (47%) patients. Catheter probe-assisted ultrasonography and endoscopic ultrasonography led to a less invasive diagnostic plan in 11 (16%) and 12 (18%) patients and a less invasive therapeutic plan in 10 (15%) and 14 (21%) patients, respectively (p > 0.1 for differences).

CONCLUSIONS

Catheter probe-assisted endosonography has a modest effect on diagnostic and therapeutic management, comparable with endoscopic ultrasonography in the same patients. The vast majority of effected changes are toward less invasive management.

Pretreatment staging of endoscopically early gastric cancer with a 15 MHz ultrasound catheter probe

BACKGROUND

The usefulness of and problems associated with an ultrasound catheter probe in the pretreatment staging of endoscopically early gastric cancer remain unexplored.

METHODS

Endoscopic ultrasonography using a 15 MHz catheter probe of 2.6 mm diameter was performed in a prospective study to determine the pretherapy staging of endoscopically early gastric cancer in 78 patients. The results of the ultrasound images were compared with the histologic findings of the specimens obtained by endoscopic mucosal resection or surgical resection.

RESULTS

The accuracy of the catheter probe for depth of invasion of endoscopically early gastric cancers was 67% (52 of 78 patients). The accuracy in determining depth of invasion in relation to endoscopic type was significantly higher for the elevated type (91%) than for the depressed type of early cancer (56%) (p < 0.01). The staging accuracy classified by histologic type was significantly higher for differentiated (86%) than for undifferentiated (18%) cancer (p < 0.01). Staging accuracy decreased as tumor size increased. The accuracy, sensitivity, and specificity for nodal staging were 80%, 17%, and 90%, respectively.

CONCLUSIONS

A 15 MHz ultrasound catheter probe is most useful for determining depth of invasion when the tumor is histologically differentiated and endoscopically of the small elevated type early gastric cancer, but it is unreliable in the diagnosis of metastatic lymph nodes.

Case report: hypoechoic submucosal nodules: a sign of Epstein-Barr virus-associated early gastric cancer

The Epstein-Barr virus (EBV) has been reported to be detectable in about 10% of gastric carcinomas. We performed a comparative study of endosonographic findings of EBV-positive and -negative early gastric carcinomas. Epstein-Barr virus was detected in 11.8% (four of 34) of endosonographically observed early gastric carcinoma lesions. Endoscopic ultrasonography (EUS) revealed a hypoechoic mass in the third layer, which reflected submucosal nodules, in 75% (three of four) of EBV-associated lesions. Endoscopically, in 66.7% (two of three) of EBV-associated carcinomas, the depressed lesion was surrounded by a raised margin covered with normal mucosa and was similar to a submucosal tumour (P < 0.05). Histologically, all three cases of EBV-associated lesions with submucosal tumour invasion had submucosal nodules of carcinoma with lymphoid stroma and 75% (three of four) were located in the gastric body. The ratio of maximal thickness to width of EBV-associated lesions was significantly larger than that of EBV-negative lesions, and this tendency was marked in lesions with submucosal tumour invasion (P < 0.05). This study indicated that EUS and endoscopy are of great use for the determination of EBV association with early gastric carcinoma.

[Superficial stomach cancers: surgical experience and study of prognostic factors in 102 patients]

STUDY AIM

The aim of this retrospective study was to analyze the characteristics, treatment and prognosis of early gastric carcinoma in a series of 102 patients.

METHODS

Between 1973 and 1994, 102 patients (68 males, 34 females) with a mean age of 65 years, were operated on for an early gastric carcinoma. Mean follow-up was 7 years. Survival was calculated using the Kaplan-Meier method. Prognosis was determined with univariate and multivariate analysis according to Cox model.

RESULTS

The carcinoma was limited to the mucosa in 57 patients (56%) and extended to the submucosa in 45 (44%). There was a lymph node invasion in 17 patients (16.5%). The postoperative mortality rate was 5.8% (n = 6). Secondary deaths occurred in relation with the gastric cancer in 10.4% (n = 10). The 5- and 10-year actuarial crude survival rates were 84% and 68.6%, respectively. Univariate analysis of prognosis factors showed a significant survival difference according to the age (P = 0.001), submucosal extension (P = 0.03), lymph node invasion (P = 0.0005) and type of gastric resection performed (P = 0.03). With multivariate analysis of prognostic factors, advanced patient age and lymph node metastases were the only statistically significant independent prognostic factors, advanced patient age and lymph node metastases were the only statistically significant independent prognostic factors (P = 0.0002 and P = 0.002, respectively).

CONCLUSIONS

Prognosis of early gastric cancer is usually excellent. Patients with high risk of recurrence may be identified in relation with prognostic factors and mainly with lymph node invasion.

Endoscopic ultrasonography and endoscopy for staging depth of invasion in early gastric cancer: a pilot study

BACKGROUND

We compared the accuracy of endoscopic ultrasonography (EUS) for staging depth of invasion of early gastric cancer with that of conventional endoscopy.

PATIENTS AND METHODS

We assessed the depth of invasion of 108 lesions (104 patients) using EUS with a thin 20 MHz probe and compared the results with those of conventional endoscopy and of histologic examination of endoscopically or surgically resected specimens.

RESULTS

The overall accuracy rates for staging depth of invasion for conventional endoscopy and EUS were 72.2% and 64.8%, respectively. Lesions that were classified as limited to the mucosa on both conventional endoscopy and EUS were very likely (92.2%) to be limited to the mucosa on histologic examination. The rates for understaging and overstaging were 16.7% and 11.1%, respectively, for conventional endoscopy; and 7.4% and 24.1%, respectively, for EUS. The highest rate for understaging based on conventional endoscopy occurred for lesions in the gastric body (including cardia, 23.9%).

CONCLUSIONS

EUS appears to be useful in combination with conventional endoscopy for staging depth of invasion of early gastric cancer. In particular, the two techniques in tandem may accurately predict that a lesion is limited to the mucosa, and EUS may be useful to overcome the potential for understaging by conventional endoscopy, particularly in the gastric body.