Transcriptome analysis reveals the essential role of NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) in gastric adenocarcinoma of fundic-gland type.

BACKGROUND: Gastric adenocarcinoma of fundic-gland type (GA-FG) is a gastric malignancy with little relation to Helicobacter pylori. Clinical characteristics of GA-FG have been established, but molecular mechanisms leading to tumorigenesis have not yet been elucidated. METHODS: We subjected three GA-FG tumors-normal mucosa pairs to microarray analysis. Network analysis was performed for the top 30 up-regulated gene transcripts, followed by immunohistochemical staining to confirm the gene expression analysis results. AGS and NUGC4 cells were transfected with the gene-encoding NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) to evaluate transcriptional changes in its target genes. RESULTS: Comprehensive gene expression analysis identified 1410 up-regulated and 1395 down-regulated gene probes with ≥ two-fold difference in expression. Among the top 30 up-regulated genes in GA-FG, we identified transcription factor NKX2-1/TTF-1, a master regulator of lung/thyroid differentiation, together with surfactant protein B (SFTPB), SFTPC, and secretoglobin family 3A member 2(SCGB3A2), which are regulated by NKX2-1/TTF-1. Immunohistochemical analysis of 16 GA-FG specimens demonstrated significantly higher NKX2-1/TTF-1 and SFTPB levels, as compared to that in adjacent normal mucosa (P < 0.05), while SCGB3A2 levels did not differ (P = 0.341). Transduction of NKX2-1/TTF-1 into AGS and NUGC4 cells induced transactivation of SFTPB and SFTPC, indicating that NKX2-1/TTF-1 can function as normally in gastric cells as it can in the lung cells. CONCLUSIONS: Our first transcriptome analysis of GA-FG indicates significant expression of NKX2-1/TTF1 in GA-FG. Immunohistochemistry and cell biology show ectopic expression and normal transactivation ability of NKX2-1/TTF-1, suggesting that it plays an essential role in GA-FG development.

Analysis of Barrett's Esophagus and Its Risk Factors: A Cross-Sectional Study of 10,122 Subjects at a Japanese Health Examination Center.

INTRODUCTION: Helicobacter pylori eradication is expected to significantly change the prevalence of Barrett's esophagus (BE). However, few reports on this relationship exist. We analyzed the risk factors of BE using the current consensus on length of BE considering H. pylori infection status. METHODS: We analyzed 10,122 individuals (5,962 men; mean age = 52.9 ± 9.9 years) who had undergone esophagogastroduodenoscopy as part of a medical checkup. Correlations among factors including H. pylori infectious status, endoscopic findings, and BE ≥1 cm were analyzed. RESULTS: Prevalence of BE, long-segment BE, and esophageal adenocarcinoma was 22.5%, 0.014%, and 0%, respectively. Logistic regression analysis showed that the risk factors for BE were hiatal hernia (odds ratio [OR]: 2.89 [2.59-3.24]), female sex (OR: 0.52 [0.46-0.59]), social drinking (OR:0.77 [0.68-0.87]), H. pylori eradication therapy (OR: 1.34 [1.19-1.51]), proton pump inhibitor (PPI) use (OR: 1.52 [1.18-1.96]), bile reflux (OR: 1.18 [1.04-1.33]), age ≥50 years (OR: 1.13 [1.02-1.26]), and nonsteroidal anti-inflammatory drug (NSAID) use (OR: 1.29 [1.02-1.62]). Although reflux esophagitis (RE) was more common in H. pylori-negative patients (17.2%) than in those after H. pylori eradication therapy (11.8%, p < 0.00001), the latter was correlated with BE, disputing RE as a strong risk factor for BE. Therefore, we conducted a subgroup analysis; most of the risk factors except for PPI use (p = 0.75), H2-receptor antagonist use (p = 0.078), and atrophic gastritis absence (p = 0.72) were positively correlated with BE after H. pylori eradication therapy compared with H. pylori-negative status. CONCLUSIONS: H. pylori eradication, bile reflux, PPI use, and NSAID use were risk factors for BE along with hiatal hernia, male sex, and older age.

Magnifying endoscopy with narrow-band imaging is useful in differentiating gastric cancer from matched adenoma in white light imaging.

This study assessed the effect of magnifying endoscopy with narrow-band imaging (M-NBI) on the endoscopic differential diagnosis between intramucosal gastric carcinomas and adenomas with matched characteristics. Associations between magnified endoscopic findings and pathological high-grade cellular and architectural atypia were also investigated. In total, the records of 50 adenomas and 50 intramucosal well-differentiated adenocarcinomas matched by tumor size (≥ 20 mm or < 20 mm), shape (depression or non-depression), and color (red or non-red) were extracted. Fourteen endoscopists diagnosed adenoma or cancer in the 100 cases with conventional white light imaging (C-WLI), then did the same with C-WLI + M-NBI.The cancer diagnostic sensitivity, specificity, and accuracy were assessed. The sensitivity of C-WLI + M-NBI for cancer diagnosis was 79.9% compared to 71.6% with C-WLI (p < 0.001). There were no significant differences in specificity (40.1% vs. 36.3%, p = 0.296) and accuracy (55.9% vs. 58.1%, p = 0.163). High-grade cytological or architectural atypia was diagnosed more often with irregular microvascular pattern (IMVP) or microsurface pattern (IMSP), respectively, than the low-grade forms. In conclusion, IMVP and IMSP correlate with high-grade cytological and architectural atypia. M-NBI is useful in differentiating intramucosal carcinoma from adenoma and can reduce underdiagnosis of cancer.

The impact of sarcopenia on adverse events associated with gastric endoscopic submucosal dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) is one of the main methods of treatments for early gastric cancer. Sarcopenia is a known risk factor for postoperative adverse events; however, the effect of sarcopenia on gastric ESD is unclear. We investigated the impact of sarcopenia on short-term prognosis after gastric ESD. METHODS: This was a retrospective cohort study. We reviewed 832 patients who underwent gastric ESD between January 2015 and December 2019 and classified them into two groups: sarcopenia and non-sarcopenia groups. The curative resection rate, adverse events, and lengths of hospital stay were evaluated. We also evaluated risk factors associated with adverse events. RESULTS: 700 patients were analyzed (239 in the sarcopenia group and 461 in the non-sarcopenia group). The curative resection rates were similar in both groups. Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 2 (17% vs. 10%) were significantly more common, and the length of hospital stay was longer (8 vs. 7 days) in the sarcopenia group. Univariate analysis identified age ≥ 75 years, antithrombotic medication, history of gastric surgery, submucosal (SM) invasion, and sarcopenia as risk factors for CTCAE grade ≥ 2. Multivariate analysis showed that sarcopenia [odds ratio (OR) 1.79, 95% confidence interval (CI) 1.11-2.89, p = 0.016], history of gastric surgery (OR 9.32, 95% CI 1.97-44.05, p = 0.005), and SM invasion (OR 2.14, 95% CI 1.24-3.70, p = 0.006) were significant independent risk factors. CONCLUSIONS: Sarcopenia significantly affected short-term prognosis and is a novel risk factor for gastric ESD.

Clinicopathological features and prognosis of developed gastric cancer based on the diagnosis of mucosal atrophy and enlarged folds of stomach by double-contrast upper gastrointestinal barium X-ray radiography.

BACKGROUND: Mucosal atrophy and enlarged folds of stomach by double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) are two major features of Helicobacter pylori-induced chronic gastritis. These were previously shown to be risk indicators of gastric cancer, but their predictability for clinicopathological characters of developed gastric cancer is unelucidated. In addition, evidence for decreasing the mortality of gastric cancer by appropriate follow-up of UGI screening is needed. METHODS: The 5134 generally healthy UGI-XR examinees, who underwent follow-up UGI-XR or upper gastrointestinal endoscopy (UGI-ES) more than once, were prospectively observed for 10 years. RESULTS: At the beginning of follow-up, 1515 (29.5%) had mucosal atrophy and 990 (19.5%) had enlarged folds. For the serum anti-H. pylori IgG, 1301 (25.3%) were positive, 177 (3.4%) were possibly positive, and 3656 (71.2%) were negative. During the 10-year observation period, gastric cancer developed in 15 subjects, among which 13 had mucosal atrophy and 10 had enlarged folds. These two features were expectedly useful indicators for gastric cancer incidence, but they showed no significant association with tumor stage or histological type of developed cancer. Only one of the 5134 subjects died of gastric cancer during 10 years, which was significantly lower than the predicted number of gastric cancer death (6.78 for 10 years) according to the mortality rate in Japan. CONCLUSIONS: Neither mucosal atrophy nor enlarged folds of stomach showed a significant association with clinicopathological features of developed gastric tumors. Appropriate follow-up of cancer screening by UGI-XR or UGI-ES can reduce the risk of gastric cancer-related death.

The natural history of sporadic non-ampullary duodenal epithelial tumors: Can we wait and see?

Objectives: The natural history of sporadic non-ampullary duodenal epithelial tumors (SNADETs) is poorly documented. The aim of this study was to evaluate the history of SNADETs in patients where immediate resection could not be performed. Methods: This is a single-center retrospective study of 86 consecutive cases of SNADETs who did not undergo immediate resection and were followed-up with upper gastrointestinal endoscopy for more than 6 months. Results: During a follow-up period of 36.8 (6.0-613.0) months, macroscopic progression was admitted in eight (9.3%). Of these, the final histology in four was adenocarcinoma, and three cases demonstrated submucosal invasion. Rates of macroscopic progression at 150 months after detection were 11.1%, 16.7%, and 30.0% for SNADETs <5 mm, <10 mm, and ≥10 mm, respectively. Conclusion: The overall risk of SNADETs progressing to invasive cancer is low. However, changes in macroscopic size or shape of SNADETs signify a high risk of progression to invasive cancer.

Highly accurate artificial intelligence systems to predict the invasion depth of gastric cancer: efficacy of conventional white-light imaging, nonmagnifying narrow-band imaging, and indigo-carmine dye contrast imaging.

BACKGROUND AND AIMS: Diagnosing the invasion depth of gastric cancer (GC) is necessary to determine the optimal method of treatment. Although the efficacy of evaluating macroscopic features and EUS has been reported, there is a need for more accurate and objective methods. The primary aim of this study was to test the efficacy of novel artificial intelligence (AI) systems in predicting the invasion depth of GC. METHODS: A total of 16,557 images from 1084 cases of GC for which endoscopic resection or surgery was performed between January 2013 and June 2019 were extracted. Cases were randomly assigned to training and test datasets at a ratio of 4:1. Through transfer learning leveraging a convolutional neural network architecture, ResNet50, 3 independent AI systems were developed. Each system was trained to predict the invasion depth of GC using conventional white-light imaging (WLI), nonmagnifying narrow-band imaging (NBI), and indigo-carmine dye contrast imaging (Indigo). RESULTS: The area under the curve of the WLI AI system was .9590. The lesion-based sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the WLI AI system were 84.4%, 99.4%, 94.5%, 98.5%, and 92.9%, respectively. The lesion-based accuracies of the WLI, NBI, and Indigo AI systems were 94.5%, 94.3%, and 95.5%, respectively, with no significant difference. CONCLUSIONS: These new AI systems trained with multiple images from different angles and distances could predict the invasion depth of GC with high accuracy. The lesion-based accuracy of the WLI, NBI, and Indigo AI systems was not significantly different.

Steroid injection and polyglycolic acid shielding to prevent stricture after esophageal endoscopic submucosal dissection: a retrospective comparative analysis (with video).

BACKGROUND AND AIMS: Postoperative stricture after expansive esophageal endoscopic submucosal dissection (ESD) is a severe adverse event. Previous single-arm reports have suggested that polyglycolic acid (PGA) shielding may prevent stricture. This study was performed to assess the efficacy of this method through a comparative analysis. METHODS: This is a retrospective analysis of 500 consecutive cases of esophageal ESD performed between 2002 and 2018 at the University of Tokyo Hospital. After 2013, patients with a diagnosis of superficial esophageal carcinoma covering more than half of the esophageal circumference underwent preventive treatment with either PGA shielding or steroid injection + PGA shielding after ESD. The efficacy of these methods for preventing post-ESD stricture was assessed through multivariable logistic regression analysis. RESULTS: The risk of postoperative stricture was especially high in the cervical esophagus (odds ratio [OR], 4.60; 95% confidence interval [CI], 0.65-61.09) and after total circumferential resection (OR, 3.58×103; lower bound of 95% CI, >185). Steroid injection + PGA shielding was the only method significantly effective in preventing stricture (OR, 0.30; 95% CI, 0.10-0.78; P = .009). In the relatively low-risk subgroup (excluding cervical esophageal cancer and complete circumferential resection), the postoperative stricture rates for steroid injection + PGA shielding versus PGA shielding versus control were 18.9% versus 41.4% versus 51.7%, respectively (P = .015). However, the efficacy of this was limited in extremely high-risk cases. CONCLUSION: The combination of steroid injection and PGA shielding is effective for preventing post-ESD stricture. There is a need for even more effective methods for cervical esophageal cancer and complete circumferential resection.

Gastroesophageal Reflux Disease-Related Disorders of Systemic Sclerosis Based on the Analysis of 66 Patients.

BACKGROUND/AIMS: Gastroesophageal reflux disease (GERD)-related disorders of systemic sclerosis (SSc) patients have not been adequately investigated. METHODS: Sixty-six SSc patients (5 males and 61 females; 56.6 ± 14.6 years old) who underwent esophagogastroduodenoscopy were analyzed on the basis of 16 background factors. They were additionally compared with 116 matched non-SSc subjects controlling age, sex, and use of proton pump inhibitors (PPIs). RESULTS: The mean disease duration of 66 patients was 5.1 ± 8.1 years, and their breakdown was as follows: 53 (80.3%) with GERD, 38 (57.6%) with GERD-related symptoms, and 20 (30.3%) with reflux esophagitis (RE; LA-A: 10, LA-B: 5, LA-C: 4, LA-D: 1). Use of PPI (p = 0.0455), complication of interstitial lung disease (p = 0.0242), and history of cyclophosphamide therapy (p = 0.0184) denoted significant association with GERD-related symptoms. Older age (p = 0.0211) was significantly associated with RE. None of GERD-related disorders showed any difference between 37 diffuse cutaneous SSc and 29 limited cutaneous SSc patients. The matched analysis indicated that SSc patients had higher prevalence of GERD (p < 0.0001), GERD-related symptoms (p = 0.0034), and RE (p = 0.0002). CONCLUSION: SSc patients tend to have worse GERD symptoms and severer RE. However, most SSc-associated factors did not show significant association with GERD-related disorders, indicating the difficulty in predicting GERD-related disorders among SSc patients.

Expression of Gastric Markers Is Associated with Malignant Potential of Nonampullary Duodenal Adenocarcinoma.

BACKGROUND: Sporadic nonampullary duodenal epithelial tumors (NADETs) are uncommon, and thus their clinicopathological features have not been fully assessed. AIMS: In this study, we have analyzed a series of early sporadic NADETs, focusing on various immunohistological features. METHODS: We conducted a multicenter retrospective analysis of 68 patients with endoscopically resected sporadic NADETs. Associations between immunohistological features and clinicopathological features were statistically analyzed. RESULTS: The 68 patients consisted of 46 men (68%) and 22 women (32%) with a mean age of 60.7 ± 12.2 years (range 37-85 years). The 68 tumors were composed of 39 adenomas (57%) and 29 early-stage adenocarcinomas (43%). Duodenal adenocarcinomas were larger in size than adenomas and had papillary architecture in their pathological diagnosis with statistical significance. Duodenal adenocarcinomas also demonstrated a significantly higher expression of gastric markers (MUC5AC and MUC6) and a higher MIB-1 index. Duodenal adenomas were contrastively apt to express intestinal markers (MUC2, CDX1 and CDX2). Of the 68 cases analyzed, there were only 3 tumors positive for p53 staining, all of which were adenocarcinoma. When 7 submucosal invasive cancers and 21 intramucosal cancers were compared, submucosal invasion was positively associated with expression of MUC5AC. Also, submucosal invasion showed strong association with double-positivity of MUC5AC and MUC6. CONCLUSIONS: Our results indicate that immunohistochemical evaluation is useful for predicting malignant potential of NADETs, especially focusing on the expression of gastrointestinal markers.

Sessile serrated adenoma detection rate is correlated with adenoma detection rate.

AIM: To investigated the association between adenoma detection rate (ADR) and sessile serrated ADR (SSADR) and significant predictors for sessile serrated adenomas (SSA) detection. METHODS: This study is a retrospective, single-center analysis. Total colonoscopies performed by the gastroenterologists at the University of Tokyo Hospital between January and December 2014 were retrospectively identified. Polyps were classified as low-grade or high-grade adenoma, cancer, SSA, or SSA with cytological dysplasia, and the prevalence of each type of polyp was investigated. Predictors of adenoma and SSA detection were examined using logistic generalized estimating equation models. The association between ADR and SSADR for each gastroenterologist was investigated by calculating a correlation coefficient weighted by the number of each gastroenterologist's examination. RESULTS: A total of 3691 colonoscopies performed by 35 gastroenterologists were assessed. Overall, 978 (26.5%) low- and 84 (2.2%) high-grade adenomas, 81 (2.2%) cancers, 66 (1.8%) SSAs, and 2 (0.1%) SSAs with cytological dysplasia were detected. Overall ADR was 29.5% (men 33.2%, women 23.8%) and overall SSADR was 1.8% (men 1.7%, women 2.1%). In addition, 672 low-grade adenomas (68.8% of all the detected low-grade adenomas), 58 (69.9%) high-grade adenomas, 29 (34.5%) cancers, 52 (78.8%) SSAs, and 2 (100%) SSAs with cytological dysplasia were found in the proximal colon. Adenoma detection was the only significant predictor of SSA detection (adjusted OR: 2.53, 95%CI: 1.53-4.20; P < 0.001). The correlation coefficient between ADR and SSADR weighted by the number of each gastroenterologist's examinations was 0.606 (P < 0.001). CONCLUSION: Our results demonstrated that ADR is correlated to SSADR. In addition, patients with adenomas had a higher prevalence of SSAs than those without adenomas.

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection.

Colorectal endoscopic submucosal dissection (ESD) is now a well-established endoscopic treatment for early-stage colorectal neoplasms, especially in Asian countries, including Japan. Despite the spread of colorectal ESD, there are still situations in which achieving successful submucosal dissection is difficult. Various novel techniques and devices have been developed to overcome these difficulties, and past reports have shown that some of these strategies can be applied to colorectal ESD. We review several recent developments in the field. The techniques reviewed include the pocket creation method and traction methods and the devices reviewed include the overtube with balloon and electrosurgical knives with water-jet function. These improved techniques and devices can facilitate safer, more reliable ESDs and expand its applicability and acceptability all over the world.

Evaluation of image-enhanced endoscopic technology using advanced diagnostic endoscopy for the detection of early gastric cancer: a pilot study.

BACKGROUND AND STUDY AIMS: Image-enhanced endoscopy (IEE) plays an important role in early detection and detailed examination of early gastric cancer (EGC). The current study aimed to clarify the efficacy of IEE using advanced diagnostic endoscopy for EGC detection without magnification. PATIENTS AND METHODS: We performed endoscopic examinations without magnification in patients referred to our hospital with a diagnosis of upper gastrointestinal tumor detected through routine screening endoscopy. In this study, we used three IEE technologies: narrow-band imaging; blue laser imaging; and i-scan optical enhancement. The detection rates for EGC between IEE and white-light imaging (WLI) were compared. RESULTS: Between July 2013 and June 2014, 156 patients were enrolled. Among upper gastrointestinal tumors, we analyzed endoscopic examination results of 119 lesions that were histologically diagnosed as EGC in 109 patients. The EGC detection rate in the IEE plus WLI groups was 77.3 %. Although the EGC detection rate in the IEE group was higher than that in the WLI group (80.0 % vs. 70.3 %), there was no significant difference between these two modalities. An important detection factor using IEE was tumor circumference, where the rate of detection in the anterior wall and lesser curvature was significantly higher than that in the posterior wall and greater curvature ( P  = 0.046). An important detection factor using WLI was color variation, where the rate of occurrence of a reddened or pale tumor was significantly higher than that of normal colored tumors ( P  = 0.030). CONCLUSIONS: The detection rate of EGC without magnification was similar between the IEE group and the WLI group. Important detection factors differed between IEE and WLI; therefore, the IEE and WLI modalities have different characteristics regarding EGC detection. Consequently, we propose to use both IEE and WLI in the evaluation of EGC.

Erratum: Evaluation of image-enhanced endoscopic technology using advanced diagnostic endoscopy for the detection of early gastric cancer: a pilot study.

[This corrects the article DOI: 10.1055/s-0043-113632.].

Evaluation of endoscopic submucosal dissection using a new endosurgical knife DN-D2718B: a first clinical feasibility study.

BACKGROUND AND STUDY AIMS: Endosurgical devices with injection function have been reported to decrease endoscopic submucosal dissection (ESD) operation times for experts, but the efficacy of these devices for inexperienced endoscopists is unclear. The aim of this study was to evaluate the feasibility of ESD using a novel ESD knife (DN-D2718B). PATIENTS AND METHODS: This is a single-center prospective pilot clinical feasibility study. Patients diagnosed with superficial gastrointestinal neoplasms were enrolled. A pre-specified group of ESD trainees with ESD experience on a porcine gastric model and fewer than 30 cases of ESD in their selected fields performed ESD under expert supervision, using the DN-D2718B. En bloc resection rates, R0 resection rates, procedure times, and incidence of intra-operational/post-operational adverse events were assessed. RESULTS: Between June 2015 and January 2016, 13 esophageal, 27 gastric, and 14 colorectal ESD cases were performed per-protocol with mean resection speeds of 10.2, 12.0, and 15.5 mm 2 /min, respectively. There were no intra-operational complications. CONCLUSION: ESD with this novel knife is feasible even when performed by non-experts.

Magnifying endoscopy with narrow-band imaging is more accurate for determination of horizontal extent of early gastric cancers than chromoendoscopy.

BACKGROUND AND STUDY AIMS: Although magnifying endoscopy with narrow-band imaging (ME-NBI) is reported to be useful for delineating the horizontal extent of early gastric cancers (EGCs), there are few reports which have objectively demonstrated the superiority of ME-NBI over chromoendoscopy with indigo carmine for this purpose. We conducted an exploratory comparison of the diagnostic accuracy of both modalities for the delineation of EGCs using prospectively collected data, and clarified the clinicopathological features related to inaccurate evaluation of the horizontal extent of EGCs. PATIENTS AND METHODS: EGCs were assigned to the oral narrow-band imaging (O-NBI) group or the oral chromoendoscopy (O-CE) group before endoscopic submucosal dissection (ESD). The oral border was observed according to assignment, and the anal border with the other modality. The horizontal extent of the tumor was evaluated by each modality and a marking dot was placed on the visible delineation line. After ESD, the marking dots were identified pathologically and defined as "accurate evaluation" if they were located within 1 mm of the pathological tumor border. We compared the rate of accurate evaluation of ME-NBI and chromoendoscopy, and analyzed the clinicopathological features related to inaccurate evaluation. RESULTS: A total of 113 marking dots evaluated by ME-NBI and 116 evaluated by chromoendoscopy were analyzed. The rate of accurate evaluation by ME-NBI was significantly higher than that by chromoendoscopy (89.4 % vs 75.9 %, P = 0.0071). The EGCs with flat borders and large EGCs were significantly related to inaccurate evaluation using ME-NBI. There were no significant factors related to inaccurate evaluation with chromoendoscopy. CONCLUSIONS: The accurate evaluation rate of the horizontal extent of EGCs by ME-NBI is significantly higher than that by chromoendoscopy. STUDY REGISTRATION: UMIN000007641.

Endoscopic ultrasound-guided fine-needle aspiration skill acquisition of gastrointestinal submucosal tumor by trainee endoscopists: A pilot study.

BACKGROUND AND OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an effective method for tissue diagnosis of gastrointestinal submucosal tumors (SMTs) that are difficult to diagnose by standard endoscopic biopsy. However, the learning curve, especially for gastrointestinal SMT, has not been sufficiently established. The aim of our study was to assess the skill acquisition and diagnostic accuracy of EUS-FNA for gastrointestinal SMT in trainee endoscopists in order to elucidate the optimal starting standards of EUS-FNA. MATERIALS AND METHODS: We prospectively evaluated 51 EUS-FNA procedures for gastrointestinal SMT between May 2010 and March 2014. The procedure was performed by two trainee endoscopists and two expert endoscopists. We investigated the diagnostic yield of EUS-FNA and the factors associated with the accuracy between the trainee endoscopists and expert endoscopists. RESULTS: The rate of adequate EUS-FNA materials for histological examination was 86.3%. Although infections occurred in two cases (3.9%), which were managed conservatively, no severe complications were identified. Comparing the trainee endoscopists with expert endoscopists, there was no significant difference in the rate of gaining adequate specimen (76.5% vs. 82.3%, P = 0.4626). However, the mean number of passes of the trainees tended to be more than that of the expert endoscopists (2.1 pass vs. 1.7 pass, P = 0.0511), and lesions located in the middle third of the stomach were the predictive factors for nondiagnostic tumors by the trainee endoscopists (P = 0.0075). CONCLUSION: EUS-FNA for gastrointestinal SMT by trainee endoscopists can be safely performed under the supervision of EUS-FNA expert endoscopists.

Bleeding after endoscopic submucosal dissection: Risk factors and preventive methods.

Endoscopic submucosal dissection (ESD) has become widely accepted as a standard method of treatment for superficial gastrointestinal neoplasms because it enables en block resection even for large lesions or fibrotic lesions with minimal invasiveness, and decreases the local recurrence rate. Moreover, specimens resected in an en block fashion enable accurate histological assessment. Taking these factors into consideration, ESD seems to be more advantageous than conventional endoscopic mucosal resection (EMR), but the associated risks of perioperative adverse events are higher than in EMR. Bleeding after ESD is the most frequent among these adverse events. Although post-ESD bleeding can be controlled by endoscopic hemostasis in most cases, it may lead to serious conditions including hemorrhagic shock. Even with preventive methods including administration of acid secretion inhibitors and preventive hemostasis, post-ESD bleeding cannot be completely prevented. In addition high-risk cases for post-ESD bleeding, which include cases with the use of antithrombotic agents or which require large resection, are increasing. Although there have been many reports about associated risk factors and methods of preventing post-ESD bleeding, many issues remain unsolved. Therefore, in this review, we have overviewed risk factors and methods of preventing post-ESD bleeding from previous studies. Endoscopists should have sufficient knowledge of these risk factors and preventive methods when performing ESD.

Atrophic gastritis and enlarged gastric folds diagnosed by double-contrast upper gastrointestinal barium X-ray radiography are useful to predict future gastric cancer development based on the 3-year prospective observation.

BACKGROUND: Double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) is the standard gastric cancer screening method in Japan. Atrophic gastritis and enlarged gastric folds are considered the two major features of Helicobacter pylori-induced chronic gastritis, but the clinical meaning of evaluating them by UGI-XR has not been elucidated. METHODS: We analyzed healthy UGI-XR examinees without a history of gastrectomy, previous Helicobacter pylori eradication and usage of gastric acid suppressants. RESULTS AND CONCLUSIONS: Of the 6433 subjects, 1936 (30.1 %) had atrophic gastritis and 1253 (19.5 %) had enlarged gastric folds. During the 3-year prospective observational follow-up, gastric cancer developed in seven subjects, six of whom (85.7 %) had atrophic gastritis with H. pylori infection and five of whom (71.4 %) had enlarged gastric folds with H. pylori infection. The Kaplan-Meier method with log-rank testing revealed that both UGI-XR-based atrophic gastritis (p = 0.0011) and enlarged gastric folds (p = 0.0003) are significant predictors for future gastric cancer incidence.