Safety and efficacy of salvage endoscopic submucosal dissection for Barrett's neoplasia recurrence after radiofrequency ablation.

BACKGROUND: This study evaluated the safety and efficacy of salvage endoscopic submucosal dissection (ESD) for Barrett's neoplasia recurrence after radiofrequency ablation (RFA). METHODS: Data from patients at 16 centers were collected for a multicenter retrospective study. Patients who underwent at least one RFA treatment for Barrett's esophagus and thereafter underwent further esophageal ESD for neoplasia recurrence were included. RESULTS: Data from 56 patients who underwent salvage ESD between April 2014 and November 2022 were collected. Immediate complications included one muscular tear (1.8%) treated with stent (Agree classification: grade IIIa). Two transmural perforations (3.6%; treated with clips) and five muscular tears (8.9%; two treated with clips) had no clinical impact and were not considered as adverse events. Seven patients (12.5%) developed strictures (grade IIIa), which were treated with balloon dilation. Histological analysis showed 36 adenocarcinoma, 17 high grade dysplasia, and 3 low grade dysplasia. En bloc and R0 resection rates were 89.3% and 66.1%, respectively. Resections were curative in 33 patients (58.9%), and noncurative in 22 patients (39.3%), including 11 "local risk" (19.6%) and 11 "high risk" (19.6%) resections. At the end of follow-up with a median time of 14 (0-75) months after salvage ESD, and with further endoscopic treatment if necessary (RFA, argon plasma coagulation, endoscopic mucosal resection, ESD), neoplasia remission ratio was 37/53 (69.8%) and the median remission time was 13 (1-75) months. CONCLUSION: In expert hands, salvage ESD was a safe and effective treatment for recurrence of Barrett's neoplasia after RFA treatment.

Low risk of local recurrence after a successful en bloc endoscopic submucosal dissection for noninvasive colorectal lesions with positive horizontal resection margins (R-ESD study).

BACKGROUND : During endoscopic submucosal dissection (ESD), the normal mucosa is cut under constant optical control. We studied whether a positive horizontal resection margin after a complete en bloc ESD predicts local recurrence. METHODS: In this European multicenter cohort study, patients with a complete en bloc colorectal ESD were selected from prospective registries. Cases were defined by a horizontal resection margin that was positive or indeterminate for dysplasia (HM1), whereas controls had a free resection margin (HM0). Low risk lesions with submucosal invasion (T1) and margins free of carcinoma were analyzed separately. The main outcome was local recurrence. RESULTS: From 928 consecutive ESDs (2011-2020), 354 patients (40 % female; mean age 67 years, median follow-up 23.6 months), with 308 noninvasive lesions and 46 T1 lesions, were included. The recurrence rate for noninvasive lesions was 1/212 (0.5 %; 95 %CI 0.02 %-2.6 %) for HM0 vs. 2/96 (2.1 %; 95 %CI 0.57 %-7.3 %) for HM1. The recurrence rate for T1 lesions was 1/38 (2.6 %; 95 %CI 0.14 %-13.5 %) for HM0 vs. 2/8 (25 %; 95 %CI 7.2 %-59.1 %) for HM1. CONCLUSION: A positive horizontal resection margin after an en bloc ESD for noninvasive lesions is associated with a marginal nonsignificant increase in the local recurrence rate, equal to an ESD with clear horizontal margins. This could not be confirmed for T1 lesions.

A computer-assisted algorithm for narrow-band imaging-based tissue characterization in Barrett's esophagus.

BACKGROUND AND AIMS: The endoscopic evaluation of narrow-band imaging (NBI) zoom imagery in Barrett's esophagus (BE) is associated with suboptimal diagnostic accuracy and poor interobserver agreement. Computer-aided diagnosis (CAD) systems may assist endoscopists in the characterization of Barrett's mucosa. Our aim was to demonstrate the feasibility of a deep-learning CAD system for tissue characterization of NBI zoom imagery in BE. METHODS: The CAD system was first trained using 494,364 endoscopic images of general endoscopic imagery. Next, 690 neoplastic BE and 557 nondysplastic BE (NDBE) white-light endoscopy overview images were used for refinement training. Subsequently, a third dataset of 112 neoplastic and 71 NDBE NBI zoom images with histologic correlation was used for training and internal validation. Finally, the CAD system was further trained and validated with a fourth, histologically confirmed dataset of 59 neoplastic and 98 NDBE NBI zoom videos. Performance was evaluated using fourfold cross-validation. The primary outcome was the diagnostic performance of the CAD system for classification of neoplasia in NBI zoom videos. RESULTS: The CAD system demonstrated accuracy, sensitivity, and specificity for detection of BE neoplasia using NBI zoom images of 84%, 88%, and 78%, respectively. In total, 30,021 individual video frames were analyzed by the CAD system. Accuracy, sensitivity, and specificity of the video-based CAD system were 83% (95% confidence interval [CI], 78%-89%), 85% (95% CI, 76%-94%), and 83% (95% CI, 76%-90%), respectively. The mean assessment speed was 38 frames per second. CONCLUSION: We have demonstrated promising diagnostic accuracy of predicting the presence/absence of Barrett's neoplasia on histologically confirmed unaltered NBI zoom videos with fast corresponding assessment time.

Development and validation of the international Blue Light Imaging for Barrett's Neoplasia Classification.

BACKGROUND AND AIMS: Detecting subtle Barrett's neoplasia during surveillance endoscopy can be challenging. Blue-light imaging (BLI) is a novel advanced endoscopic technology with high-intensity contrast imaging that may improve the identification of Barrett's neoplasia. The aim of this study was to develop and validate the first classification to enable characterization of neoplastic and non-neoplastic Barrett's esophagus using BLI. METHODS: In phase 1, descriptors pertaining to neoplastic and non-neoplastic Barrett's esophagus were identified to form the classification, named the Blue Light Imaging for Barrett's Neoplasia Classification (BLINC). Phase 2 involved validation of these component criteria by 10 expert endoscopists assessing 50 BLI images. In phase 3, a web-based training module was developed to enable 15 general (nonexpert) endoscopists to use BLINC. They then validated the classification with an image assessment exercise in phase 4, and their pre- and post-training results were compared. RESULTS: In phase 1 the descriptors were grouped into color, pit, and vessel pattern categories to form the classification. In phase 2 the sensitivity of neoplasia identification was 96.0% with a very good level of agreement among the experts (κ = .83). In phase 3, 15 general endoscopists completed the training module. In phase 4 their pretraining sensitivity (85.3%) improved significantly to 95.7% post-training with a good level of agreement (κ = .67). CONCLUSIONS: We developed and validated a new classification system (BLINC) for the optical diagnosis of Barrett's neoplasia using BLI. Despite the limitations of this image-based study with a high prevalence of neoplasia, we believe it has the potential to improve the optical diagnosis of Barrett's neoplasia given the high degree of sensitivity (96%) noted. It is also a promising tool for training in Barrett's esophagus optical diagnosis using BLI.

Efficacy of novel sedation using the combination of dexmedetomidine and midazolam during endoscopic submucosal dissection for esophageal squamous cell carcinoma.

BACKGROUND: Endoscopic submucosal dissection (ESD) is the preferred treatment for esophageal squamous cell carcinoma (ESCC). However, ESD can be difficult when patients move due to insufficient sedation. We conducted a prospective confirmatory single arm study to evaluate the efficacy of using dexmedetomidine (DEX) in combination with midazolam as a novel sedation for ESD. METHODS: Endoscopic submucosal dissection was performed without intubation in 65 patients. The primary outcome was the proportion of patients who did not move or require restraint during ESD, compared to historical control of ESD performed under midazolam sedation. Secondary outcomes included the frequency of complications and self-report questionnaires from patients and endoscopists. RESULTS: Restraint was not required in 97% of patients sedated using the combination of DEX and midazolam. Depressed respiration, low blood pressure, and bradycardia occurred in 23, 37, and 26% of patients, respectively. All patients recovered without severe complication. Occurrence of low blood pressure and bradycardia were higher, while respiratory depression was lower for the combination group than for the historical control group. The amount of midazolam used was significantly lower than in the control. Of note, 94% of patients had no painful sensations, with 3 reporting chest pain and 3 having a recollection of the procedure. Endoscopists were satisfied with the sedation in 94% of cases. All lesions were resected in en bloc fashion, without perforation. CONCLUSIONS: The combination of DEX and midazolam provided effective sedation for ESD for ESCC.

Mixed poorly differentiated adenocarcinoma in undifferentiated-type early gastric cancer predicts endoscopic noncurative resection.

BACKGROUND: Comparisons between surgical cases of mixed poorly differentiated adenocarcinoma and pure signet ring cell carcinoma have revealed higher frequencies of lymph node metastasis and submucosal invasion in the former. However, this comparison has not been reported for endoscopically treated cases. Therefore, we compared cases of curative and noncurative resection in patients who underwent endoscopic submucosal dissection to determine what factors could influence the curative resection rate. METHODS: We analyzed 268 undifferentiated-type early gastric cancers in 264 patients treated with endoscopic submucosal dissection in our hospital between March 2005 and March 2017, involving 229 and 39 cases of curative and noncurative resection, respectively. Treatment results were compared between 129 lesions of pure signet ring cell carcinoma and 139 lesions of mixed poorly differentiated adenocarcinoma. RESULTS: The overall curative resection rate was 85.4% (229/268). On comparing noncurative and curative resection cases, after excluding factors that determine curative resection (e.g., tumor diameter), we found that the former was associated with older age and significantly more mixed poorly differentiated adenocarcinomas, with odds ratios of 1.052 [95% confidence interval (CI), 1.017-1.089] and 2.746 (95% CI, 1.162-6.485), respectively, on multivariate analysis. The curative resection rate was significantly higher in pure signet ring cell carcinoma than in mixed poorly differentiated adenocarcinoma (93.8% vs. 77.7%, respectively). CONCLUSION: Advanced age and mixed poorly differentiated adenocarcinoma predicted endoscopic noncurative resection.

Treatment Outcomes of Endoscopic Submucosal Dissection for Adenocarcinoma Originating from Long-Segment Barrett's Esophagus versus Short-Segment Barrett's Esophagus.

BACKGROUND: In recent years, effective outcomes of endoscopic submucosal dissection (ESD) for esophagogastric junction cancer including short-segment Barrett's esophagus (SSBE) cancer have been reported. However, the efficacy of ESD for long-segment Barrett's esophagus (LSBE) cancer is unknown. AIM: To clarify the treatment outcomes of ESD for LSBE cancer versus SSBE cancer. METHODS: A total of 86 patients with 91 superficial Barrett's esophageal adenocarcinomas who underwent ESD were enrolled; of these, 68 had underlying SSBE and 18 had LSBE. Procedure outcomes and prognosis were compared. RESULTS: There was no significant difference in age and tumor diameter among patients. The only complication observed was stricture, but it was not significant (2 vs. 9%). No significant difference was observed in the negative horizontal margin rates (94.1 vs. 95.7%), R0 resection rates (83.8 vs. 82.6%), curative resection rates (72.1 vs. 73.9%), and noncurative factors. Both LSBE and SSBE cancer showed favorable 3-year overall survival rates (95.0 vs. 94.4%) in the median observation period of 28.5 months. CONCLUSIONS: ESD for LSBE cancer achieved procedure outcomes and short-term prognosis comparable to SSBE. ESD has the potential to be an effective therapeutic option for esophageal neoplasms in patients with LSBE.

Diagnostic performance of routine esophagogastroduodenoscopy using magnifying endoscope with narrow-band imaging for gastric cancer.

BACKGROUND AND AIM: In Japan, an increase in the number of routine esophagogastroduodenoscopy procedures is expected because several studies have reported that endoscopy screening has reduced gastric cancer mortality. Magnifying narrow-band imaging has been reported to be effective for accurate diagnosis of gastric abnormalities such as cancers, adenomas, and intestinal metaplasia. However, the efficacy of this method in routine esophagogastroduodenoscopy has not been clarified. METHODS: We divided 3763 patients into two groups. The non-magnification group included 1842 patients who underwent endoscopy screening using GIF-H260/LUCERA-SPECTRUM between October 2014 and February 2015, whereas the magnification group included 1921 patients who underwent screening using GIF-H290Z/LUCERA-ELITE between March 2015 and May 2015. In the magnification group, diagnosis of cancer was conducted using the VS classification system. We did not carry out a biopsy when results were confirmed as non-cancer using magnifying narrow-band imaging. If cancer was diagnosed, or when a cancer or non-cancer diagnosis was difficult, we carried out a biopsy. We analyzed and compared the diagnostic performance between the two groups. RESULTS: Gastric biopsy rate was significantly lower in the magnification group (29%) than in the non-magnification group (41%) (P < 0.001). Positive predictive value (PPV) for gastric cancer was significantly higher in the magnification group (5.5%) than in the non-magnification group (2.5%) (P < 0.001). Furthermore, PPV for gastric epithelial neoplasia was significantly higher in the magnification group (7.9%) than in the non-magnification group (3.2%) (P < 0.001). CONCLUSION: Magnifying narrow-band imaging improves the diagnostic performance of routine esophagogastroduodenoscopy.

Undifferentiated-type component mixed with differentiated-type early gastric cancer is a significant risk factor for endoscopic non-curative resection.

BACKGROUND AND AIM: Previous studies of surgical specimens have found that the presence of mixed histological components in differentiated-type early gastric cancer (EGC) is a risk factor for lymph node metastasis and indicates greater malignancy. As there have been no reports on its endoscopic treatment, we examined endoscopic curative resection in relation to differentiated-type-predominant mixed-type (MT). METHODS: This was a single-center, retrospective study. Subjects were 2585 differentiated-type EGC in 2551 patients treated with endoscopic submucosal dissection (ESD) in our hospital between March 2005 and January 2016. These lesions comprised 2231 cases of curative resection and 354 cases of non-curative resection. Histologically, 2339 lesions were pure differentiated-type (PDT) and 246 lesions were MT. Rates of curative resection were compared, according to tumor size, between different histological types. RESULTS: When curative and non-curative cases were compared using multivariate analysis among lesions measuring ≤20 mm for factors other than those determining curative resection, significant differences were obtained for tumor diameter, ulcer, and MT. Among lesions measuring 21-30 mm, ulcer and MT were associated with significant differences. Among lesions measuring >30 mm, upper region and MT were associated with significant differences. Curative resection rates, in relation to histological type among lesions measuring ≤20 mm, were 93.4% for PDT and 63.4% for MT, whereas corresponding rates were 85.1% and 60.0%, respectively, among lesions measuring 21-30 mm, and 55.3% and 30.2%, respectively, among lesions measuring >30 mm. CONCLUSION: We found that MT was a risk factor for non-curative resection irrespective of lesion size.

Clinicopathological features of Siewert type II adenocarcinoma: comparison of gastric cardia adenocarcinoma and Barrett's esophageal adenocarcinoma following endoscopic submucosal dissection.

OBJECTIVES: Siewert type II esophagogastric junction adenocarcinoma encompasses both gastric cardia adenocarcinoma (GCA) and Barrett's esophageal adenocarcinoma (BEA) due to short-segment Barrett's esophagus. We compared these two types of Siewert type II esophagogastric junction adenocarcinoma in terms of background factors and clinical outcomes of endoscopic submucosal dissection (ESD). METHODS: We enrolled 139 patients (142 lesions) who underwent ESD from 2006 to 2014 at our institution. Background factors evaluated were age, sex, body mass index, hypertension, hyperlipidemia, hyperuricemia, diabetes mellitus, smoking, drinking, double cancer, and endoscopic findings. Clinical outcomes evaluated were procedure time, en bloc resection rate, curative resection rate, and adverse events. RESULTS: There were 87 GCA lesions (61.2%) and 55 BEA lesions. Features of BEA [55 lesions (38.8%)] included a younger age, small diameter, and a protruding type, along with a high frequency of esophageal hiatal hernia and less mucosal atrophy. There were no significant differences in lifestyle-related background factors between the GCA and BEA groups. Curative resection rate was greater for GCA (81%) than for BEA (66%) (P = 0.01). There were no serious adverse events in either group. Among the factors for noncurative resection, lymphovascular invasion and depth of invasion were greater for BEA (33.3 vs. 7 and 20.7 vs. 8.2%, respectively (P < 0.01). Of the noncured patients, 70% underwent additional surgery and none had postoperative lymph node metastasis. CONCLUSIONS: Siewert type II adenocarcinoma encompasses two types of cancers with different etiologies: GCA and BEA. Although there are no significant differences in lifestyle-related background factors between GCA and BEA, BEA is a risk factor for noncurative resection via ESD.

Study on Clinical Factors Involved in Helicobacter pylori-Uninfected, Undifferentiated-Type Early Gastric Cancer.

BACKGROUND: The factors associated with the pathogenesis of Helicobacter pylori-uninfected undifferentiated-type early gastric cancer (HPUGC) remain unclear. This study compared patient characteristics, including medical history and alcohol/tobacco use, of HPUGC patients with characteristics of patients with H. pylori-positive undifferentiated-type early gastric cancer (HPPGC) to clarify and gain understanding on those differences that could play a role in the pathogenesis. METHODS: This retrospective study included 282 patients who were treated endoscopically from March 2005 to March 2014. This cohort consisted of 232 patients with HPPGC (82.3%) and 50 patients with HPUGC (17.7%). Patient characteristics were analyzed by subgroups of HPUGC vs. HPPGC, with comparisons for age, gender, cancer history, comorbidity of lifestyle diseases requiring medication (hypertension, type 2 diabetes, and dyslipidemia), cumulative amount of alcohol consumption, and smoking history (Brinkman index [BI]). RESULTS: HPUGC patients were typically younger, had less frequent hypertension, and had higher BI values (p < 0.05 for all parameters). In a younger non-hypertensive subgroup, the OR for high BI (BI ≥340) in the HPUGC group vs. HPPGC group was 5.049 (95% CI 2.458-10.373, p < 0.0001). CONCLUSIONS: The investigation of clinical factors identified smoking history as being possibly contributing to the pathogenesis of HPUGC. Future research is necessary at the cellular and genetic levels.

Accuracy of diagnostic demarcation of undifferentiated-type early gastric cancer for magnifying endoscopy with narrow-band imaging: surgical cases.

BACKGROUND AND AIM: The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) in undifferentiated-type early gastric cancers (UD-type EGCs) is unclear. This study investigated the accuracy of ME-NBI in the diagnostic demarcation. METHODS: Among UD-type EGCs that were initially surgically resected between June 2011 and August 2014 in this hospital, 74 lesions were studied that were preoperatively diagnosed with white-light imaging (WLI) or endoscopic ultrasonography as lesions for which endoscopic treatment was not indicated and found to be early gastric cancers by postoperative pathology. The demarcation line was marked on the most oral and anal sides with argon plasma coagulation using WLI and ME-NBI, and the diagnostic demarcation of cancer was defined as correct, if consistent with the results of postoperative pathology. The length of extension into the proliferative zone, distance between crypts and inflammatory cell infiltration (updated Sydney classification: USC) were compared between the correctly diagnosed and the misdiagnosed cases. RESULTS: The diagnosis was correct in 62 cases (83.8 %). The average distance between crypts in correctly diagnosed and misdiagnosed cases was approximately 1.9 and 1.3 times, respectively, that in normal mucosa (p < 0.0001). The accuracy of diagnosis was higher when atrophy and neutrophil and monocyte infiltration were mild according to the USC (p < 0.05). The additional use of ME-NBI improved the accuracy of diagnosis by 36.5 % compared with the use of WLI alone. CONCLUSION: The use of ME-NBI in the preoperative diagnosis of the demarcation of cancer is useful to prevent postoperative positive surgical margins.

Efficacy of double-scope endoscopic submucosal dissection and long-term outcomes of endoscopic resection for superficial pharyngeal cancer.

BACKGROUND AND AIM: Owing to increased awareness and use of narrow-band imaging, there are more opportunities to treat superficial pharyngeal cancer (SPC). The present study aimed to describe the short- and long-term outcomes of endoscopic resection (ER) for SPC. METHODS: This study included 166 consecutive SPC in 113 patients treated during 2006 to 2013 at one referral cancer center. In the first period, we treated patients using endoscopic mucosal resection (EMR), in the second period using conventional ESD (cESD) and in the recent period using double-scope ESD (dsESD), which involves a second thin endoscope for assistance to produce traction. Median follow-up period was 30 months. RESULTS: All lesions were diagnosed as squamous cell carcinoma. Complete resection rate of cESD and dsESD procedures was 56.4% and 82.3% (P < 0.01), and local recurrence rate was 2.6% and 0.0%, respectively. Procedure duration was significantly shorter for dsESD than for cESD (P < 0.05). Four cases of recurrent lymph node (LN) metastasis were observed; however, all patients with LN metastases survived to a 48-month median interval after neck dissection. Risk factors for LN metastasis included subepithelium invasion, tumor thickness >1000 µm, droplet infiltration, and lymphovascular invasion. Overall survival rate after 5 years was 79.5%; no patients died of SPC. Cumulative rate of metachronous SPC after 5 years was 46.5%. CONCLUSION: ER for SPC is a feasible and effective treatment, although metachronous SPC occurred frequently. For the technique of ER, dsESD was effective.

Effect of direct oral anticoagulants on the risk of delayed bleeding after gastric endoscopic submucosal dissection.

BACKGROUND AND AIM: Anticoagulants are used to prevent thromboembolic events. Direct oral anticoagulants (DOAC) are our new choice; however, their effect on bleeding risk for endoscopic treatment has not been reported. We aimed to assess the clinical effect of DOAC compared to warfarin for gastric endoscopic submucosal dissection (ESD). METHODS: We retrospectively studied 97 patients on anticoagulants and treated 108 gastric neoplasms with ESD in three referral institutes. Twenty-four patients were taking DOAC, including dabigatran (12), rivaroxaban (11), and apixaban (one) and 73 were taking warfarin. RESULTS: In the DOAC group, delayed bleeding rate was significantly higher in patients on rivaroxaban than in patients on dabigatran (45% vs 0%, P < 0.05) without relation to heparin bridge therapy (HBT). In the warfarin group, 78% of patients underwent HBT, and delayed bleeding rate was significantly higher in patients with HBT than in those without (36% vs 0%, P < 0.05). Delayed bleeding rate increased as intake of antithrombotic agents increased (P < 0.05). HBT period was shorter (P < 0.05) in DOAC because DOAC achieve the maximum effect quicker, and hospitalization period was shorter (P < 0.05), compared with warfarin. Multivariate analysis showed that HBT (OR, 10.7), rivaroxaban (OR, 6.00) and multiple antithrombotic agents (OR, 4.35) were independent delayed bleeding risk factors. CONCLUSIONS: The DOAC effect differs in each agent. Dabigatran is a feasible alternative to warfarin for shortening the hospitalization period and decreasing delayed bleeding rate, although rivaroxaban has a significantly higher delayed bleeding risk.

Biological behavior of the intramucosal Helicobacter pylori-negative undifferentiated-type early gastric cancer: comparison with Helicobacter pylori-positive early gastric cancer.

BACKGROUND: The differences in the growth morphology, proliferative ability, and background mucosa of the cancer between Helicobacter pylori (HP)-positive (HP+) gastric cancer (GC) and HP-negative (HP-) GC are still unclear. To clarify the differences, we compared the characteristics of the two types of cancer. METHODS: Of the 91 patients with undifferentiated-type early GC who underwent endoscopic treatment at our hospital between August 2005 and April 2011, 23 HP- GC patients (all of whom had signet ring cell carcinoma measuring 20 mm or less in diameter) and 46 HP+ GC patients with signet ring cell carcinoma measuring 20 mm or less in diameter (out of a total of 68 HP+ GC patients) were enrolled in this study. Endoscopic atrophy and background mucosa were classified according to the updated Sydney system. The proliferative capacity of the cancer was assessed by examining the MIB-1 labeling index. RESULTS: With regard to the growth in the mucosal layer, the proportion of patients with cancer confined to the proliferative zone was significantly higher in the HP- GC group. Moderate or severer atrophy, intestinal metaplasia, mononuclear cell infiltration, and neutrophil infiltration according to the updated Sydney system were significantly commoner in the HP+ GC patients. Also, the MIB-1 labeling index was significantly higher in the HP+ GC group. CONCLUSION: HP+ GC appeared to show a higher proliferative capacity, more extensive spread, and more rapid progression, and inflammation associated with HP infection was suggested to be involved in the proliferation of this type of GC.

Accuracy of diagnostic demarcation of undifferentiated-type early gastric cancers for magnifying endoscopy with narrow-band imaging: endoscopic submucosal dissection cases.

BACKGROUND: The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) for undifferentiated-type early gastric cancers (UD-type EGCs) is unclear. The present study examined the accuracy of the diagnostic demarcation of lesions using ME-NBI. METHODS: The study population consisted of 76 patients with UD-type EGC lesions measuring ≤20 mm in diameter using white-light imaging (WLI) and endoscopic ultrasonography and diagnosed as intramucosa and UL(-); all the lesions were confirmed as early gastric cancer based on postoperative pathological examination. All the patients had undergone an initial endoscopic submucosal dissection (ESD) at this hospital between January 2010 and January 2014. After marking with demarcation lines at the utmost oral and anal sites of the lesion using argon plasma coagulation under ME-NBI for intervention, the cases with demarcations that were consistent with the postoperative pathological findings were defined as having been accurately diagnosed. The inflammatory cell infiltration (Updated Sydney System, USS) were also assessed. RESULTS: The diagnostic demarcations of the lesion were consistent in 62 cases (81.6 %). The accurate diagnosis rate was higher for the USS cases with mild neutrophil and monocyte infiltration (P < 0.05). The addition of ME-NBI to WLI improved the accurate diagnosis rate by 27.6 %. CONCLUSION: The use of ME-NBI in diagnostic demarcation of UD-type EGCs is recommended.

Helicobacter pylori-negative gastric cancer: characteristics and endoscopic findings.

Helicobacter pylori (H. pylori) leads to chronic gastritis and eventually causes gastric cancer. The prevalence of H. pylori infection is gradually decreasing with improvement of living conditions and eradication therapy. However, some reports have described cases of H. pylori-negative gastric cancers (HpNGC), and the prevalence was 0.42-5.4% of all gastric cancers. Diagnostic criteria of HpNGC vary among the different reports; thus, they have not yet been definitively established. We recommend negative findings in two or more methods that include endoscopic or pathological findings or serum pepsinogen test, and negative urease breath test or serum immunoglobulin G test and no eradication history the minimum criteria for diagnosis of HpNGC. The etiology of gastric cancers, excluding H. pylori infection, is known to be associated with several factors including lifestyle, viral infection, autoimmune disorder and germline mutations, but the main causal factor of HpNGC is still unclear. Regarding the characteristics of HpNGC, the undifferentiated type (UD-type) is more frequent than the differentiated type (D-type). The UD-type is mainly signet ring-cell carcinoma that presents as a discolored lesion in the lower or middle part of the stomach in relatively young patients. The gross type is flat or depressed. The D-type is mainly gastric adenocarcinoma of the fundic gland type that presents as a submucosal tumor-like or flat or depressed lesion in the middle and upper part of the stomach in relatively older patients. Early detection of HpNGC enables minimally invasive treatment which preserves the patient's quality of life. Endoscopists should fully understand the characteristics and endoscopic findings of HpNGC.

[Endoscopic therapy for cancer of the esophagogastric junction].

In Japan, the criteria for cancer of the esophagogastric junction (EGJ) are that the center of the lesions are located within 2cm from the EGJ orally and anally. The main histology of these lesions are squamous cell carcinoma and adenocarcinoma. Squamous cell carcinoma of the esophagus is treated following the guidelines published by the Japan Esophageal Society. This paper focuses on EGJ adenocarcinomas, which include cardiac gastric cancer and Barrett's cancer originating from the short-segment Barrett's esophagus. EGJ cancer is resected endoscopically at the termination of the palisade vessels or upper end of the gastric fold. The various types of cancer involving the EGJ are treated following the guidelines published by each medical specialist society in Japan. The main endoscopic treatment is endoscopic submucosal dissection. The EGJ is a narrow space, and therefore lesions are approached from the oral approach or anal approach using a reverse endoscope. Bleeding, perforation, and stenosis are major complications. When two-thirds or more of the wall is resected, stenosis occurs. Endoscopic therapy for cancer originating in the EGJ has not yet been fully established.