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Background and Aims: Whether eradication of Helicobacter pylori reduces the incidence of metachronous gastric cancer (MGC) is still debatable. We aimed to evaluate the long-term effect of H pylori eradication on the development of MGC after endoscopic gastric tumor resection., Methods: We undertook an open-label, prospective, randomized controlled trial at a tertiary hospital in Seoul, Korea. Participants were recruited during April 2005 to February 2011 and followed until December 2016. We assigned 898 patients with H pylori infection treated with endoscopic resection (ER) for gastric dysplasia or early gastric cancer to receive (n =442) or not receive (n =456) eradication therapy using a random-number chart. Eradication group patients received oral omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg twice daily for a week, whereas control group patients received no H pylori treatment. The primary outcome was the incidence of MGC (intention-to-treat analysis)., Results: The 877 patients who attended ≥1 follow-up examination (eradication group, 437; control group, 440) were analyzed. Median follow-up was 71.6 months (interquartile range, 42.1-90.0). MGC developed in 18 (4.1%) eradication and 36 (8.2%) control group patients (log-rank test, P = .01). In our yearly analysis, the effect of eradication showed a significant difference in 5 years after allocation (log-rank test, P = .02). The adjusted hazard ratio for the control group was 2.02 (95% CI, 1.14-3.56; P = .02), compared with the eradication group., Conclusions: H pylori eradication significantly reduces the incidence of MGC after ER of gastric tumors and should be considered for H pylori-positive gastric tumor patients treated with ER. (Clinical trial registration number: NCT01510730.)., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Gastroscopy and colonoscopy are widely used for the early diagnosis of stomach and colorectal cancer. The present revision integrates recent data regarding previous quality indicators and novel indicators suggested for gastroscopy and colonoscopy procedures for the National Cancer Screening Program in Korea. The new indicators, developed by the Quality Improvement Committee of the Korean Society for Gastrointestinal Endoscopy, vary in the level of supporting evidence, and most are based solely on expert opinion. Updated indicators validated by clinical research were prioritized, but were chosen by expert consensus when such studies were absent. The resultant quality indicators were graded according to the levels of consensus and recommendations. The updated indicators will provide a relevant guideline for high-quality endoscopy. The future direction of quality indicator development should include relevant outcome measures and an evidence-based approach to support proposed performance targets.

Background: Although gastric adenoma is widely accepted as a precursor of gastric cancer, pre-existing adenoma is not always detected in gastric cancer patients., Objective: To investigate the clinical characteristics of early gastric cancer (EGC) arising from adenoma, compared with those of EGC without pre-existing adenoma., Methods: Patients who underwent endoscopic resection for EGC at a single tertiary hospital were divided into two groups based on the presence (ex-adenoma group) or absence (de novo group) of pre-existing adenoma on pathologic specimens. Clinicopathologic characteristics, endoscopic features and long-term outcomes were analyzed., Results: Of 1,509 patients, 236 (15.6%) were included in the ex-adenoma group. Mean age (P = 0.003) and Helicobacter pylori infection rate (P = 0.040) were significantly higher in the ex-adenoma than in the de novo group. Mean endoscopic size was significantly larger, elevated lesions were more prevalent (both P < 0.001), and carcinomas were more differentiated in the ex-adenoma group than in the de novo group (P = 0.037). The degree of atrophy (P = 0.025) or intestinal metaplasia (P < 0.001) was more advanced in the ex-adenoma group. Synchronous gastric neoplasia was significantly more prevalent in the ex-adenoma group (P < 0.001), whereas metachronous cancer recurrence rate was not significantly different between the two groups., Conclusions: EGCs with pre-existing adenoma show a greater association with H. pylori-related chronic inflammation than those without, which could explain the differences in the characteristics between groups. Potential differences in carcinogenic mechanisms between the groups were explored.

Background: For residual gastric tumors (RT) found at the treated sites after endoscopic resections (ER), additional treatment options are additional ER, surgery or argon plasma coagulation (APC). Long-term efficacy of APC as the curative modality for RT has not been fully elucidated. This study aimed to investigate the efficacy and long-term outcome of APC for RT with relevant tumor factors., Methods: Eighty-two patients who received ER for gastric adenocarcinoma or adenoma and were subsequently treated with APC for RT were reviewed retrospectively. Characteristics of the tumors curatively ablated with single-session of APC and the non-curatively ablated were compared by multiple logistic regression analysis. Overall rate of curative ablation and follow-up duration was calculated., Results: Initial tumor size <20 mm [odds ratio for second residual recurrence (OR) 0.16; 95 % confidence interval (CI) 0.039-0.63], en-bloc resection (OR 0.16; 95 % CI 0.039-0.72), histologic complete resection (OR 0.14; 95 % CI 0.028-0.66) and RT with flat or depressed type (OR 0.20; 95 % CI 0.051-0.77) were significantly associated with curative ablation of RT by single-session of APC. Anterior wall or lesser curvature location showed a tendency toward curative APC, but not reached statistical significance (OR 0.36; 95 % CI 0.11-1.16). A total of 60 patients (73.2 %) achieved curative ablation after single-session of APC. Eleven among the patients (n = 22) with second or more residual recurrence achieved curative ablation with one or two more additional sessions of APC. Overall rate of curative ablation was 86.6 % (71/82). From the last APC, the final curative ablation group (n = 71) has been followed up for 49.7 ± 37.4 months., Conclusions: En-bloc resection, histologic complete resection, RT with flat or depressed type and initial tumor size less than 2 cm can be predictors of favorable clinical outcome of APC as an additional treatment for RT. For selected patients with RT, APC and close monitoring could be a reasonable alternative to immediate resection.

Background and Aim: The role of screening endoscopy in primary gastric lymphoma (PGL) has not been investigated. This study aimed to evaluate the clinical characteristics and outcomes of PGLs detected by screening endoscopy in the high prevalence area of Helicobacter pylori (H. pylori) infection., Methods: This retrospective cohort study enrolled consecutive subjects who were diagnosed with PGL by endoscopic screening in Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea, between October 2003 and September 2013. The characteristics and outcome of screening-detected patients (screening group) were compared with consecutive subjects diagnosed with PGL in the outpatient clinic (outpatient group)., Results: Of the 105 194 recipients of screening upper endoscopy, 52 (0.049%) were found to have PGL. The median age was 54.2 years (range 23-79), and 65.4% were women. The proportion of PGL to gastric malignancy was 12.1% (52/429) overall, but >30% (25/73) in middle-aged (40-59) women. PGLs in the screening group were more likely to be mucosa-associated lymphoid tissue lymphoma (98.1% vs 60.0%, P < 0.001) and treated with H. pylori eradication alone (90.0% vs 48.1%, P < 0.001) than those in the outpatient group. Moreover, the screening group showed better 5-year overall survival (100.0% vs 89.3%, P = 0.016) and progression-free survival (94.9% vs 83.4%, P = 0.040) than the outpatient group., Conclusions: In Korea, a high prevalence area of H. pylori infection, PGL seems more prevalent than in Western countries. Endoscopic screening may help to detect early stage H. pylori-positive mucosa-associated lymphoid tissue lymphoma. A high index of suspicion is needed, especially in middle-aged women., (© 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background: No residual disease (NRD) can be found in the specimen after endoscopic resection (ER) of biopsy-proven gastric neoplasm. This study aimed to evaluate the endoscopic and pathologic characteristics of patients with NRD and identify the cause and long-term prognosis., Methods: Medical records of patients who underwent ER for biopsy-proven gastric neoplasms at a single tertiary hospital between January 2005 and November 2014 were retrospectively reviewed. Patients whose post-ER histology was revealed as NRD were included. Overall incidence, clinicopathologic characteristics, cause, and long-term prognosis were analyzed., Results: NRD was detected in 143 (3.2%) of 4401 cases of gastric neoplasms treated with ER. Mean endoscopic size of the initial lesion was 8.15 ± 6.64 mm; in 93 cases (65.0%), the lesion was located in the lower third of the stomach. Initial pathologic diagnosis was as follows: adenoma (n = 110), carcinoma (n = 29), and atypical gland (n = 4). The causes of NRD were minute lesions removed by biopsy in 140 patients, pathologic misdiagnoses in two, and localization error in one. Local recurrence was detected in five patients (3.6%) with minute lesions during follow-up and treated with argon plasma coagulation (n = 4) or re-ER (n = 1). Synchronous (n = 5, 3.6%) and metachronous gastric lesions (n = 6, 4.3%) were also detected during follow-up., Conclusions: The main cause of NRD was minute lesions which might be completely removed by initial diagnostic biopsy. These cases showed a minimal rate of local recurrence and synchronous or metachronous gastric neoplasms. Careful follow-up is also mandatory for detection of residual disease.

Background: There is often a discrepancy between results from endoscopic forceps biopsy and resected specimen. We aimed to identify endoscopic predictors for undifferentiated histology in differentiated gastric neoplasms prior to endoscopic resection., Methods: Medical records of the patients who underwent endoscopic submucosal dissection (ESD) for biopsy-proven differentiated gastric neoplasms at Seoul National University Hospital between July 2005 and July 2014 were retrospectively reviewed. The lesions were divided into two groups based on the final histologic result of ESD: differentiated adenocarcinoma (DA group) and undifferentiated histology (UDH group). The discordant rate, clinicopathologic characteristics, and endoscopic factors were analyzed., Results: A total of 1641 early gastric cancers from 1615 patients were included. Of these, 1556 (94.8%) were diagnosed as DA and 85 (5.2%) as UDH. The mean age was significantly lower, and number of women was higher in the UDH group than in the DA group. On multivariate analysis, age <65 years [odds ratio (OR) 1.75, 95 % confidence interval (CI) 1.10-2.80], female sex (OR 3.19, 95% CI 2.00-5.08), endoscopic size >10 mm (OR 1.81, 95% CI 1.12-2.92), depressed type (OR 2.85, 95% CI 1.56-5.21), nodularity (OR 2.83, 95% CI 1.59-5.05), and whitish discoloration (OR 19.64, 95% CI 6.98-55.25) were independent predictors., Conclusions: Female sex, age <65 years, large endoscopic size, depressed morphology, surface nodularity, and whitish discoloration were predictors for UDH. Meticulous attention should be paid to the lesions with these endoscopic predictors for determining the risk of UDH prior to endoscopic resection.

Background: Although post-endoscopic submucosal dissection (ESD) iatrogenic ulcer is known to heal faster than peptic ulcer, some iatrogenic ulcers show delayed healing. The aim of this study was to clarify risk factors of delayed ulcer healing after gastric ESD., Methods: We retrospectively reviewed medical records of all patients who had ESD for gastric neoplasms (866 adenomas and 814 early gastric cancers) between January 2005 and February 2011., Results: Of 1680 subjects, 95 had delayed ulcer healing in 3-month follow-up. Multivariate analysis showed that diabetes (OR 1.743; 95% CI 1.017-2.989, p = 0.043), coagulation abnormality (OR 3.195; 95% CI 1.535-6.650, p = 0.002), specimen size greater than 4 cm (OR 2.999; 95% CI 1.603-5.611, p = 0.001), and electrocoagulation (OR 7.149; 95% CI 1.738-29.411, p = 0.006) were revealed to be independent risk factors of delayed ulcer healing. Meanwhile, persistent Helicobacter pylori infection was not related to the delayed ulcer healing., Conclusions: Large iatrogenic ulcer by ESD with massive hemostasis, especially in patients with diabetes mellitus or coagulation abnormalities, tends to take more than 3 months to heal. For such cases, initial dosage increment of PPI or addition of other anti-ulcer agents after ESD may be beneficial.

Background: Despite many advantages, the development of synchronous or metachronous neoplasm is one of the main concerns with endoscopic resection. We aimed to clarify the independent risk factors for synchronous or metachronous gastric neoplasm., Methods: We retrospectively reviewed the medical records of all patients who had undergone endoscopic resection for gastric high-grade dysplasia or early gastric cancer between April 2001 and February 2011., Results: Among 971 subjects, 56 synchronous neoplasms and 42 metachronous neoplasms developed during 12-131 months of follow-up. In univariate analysis, age over 65 years, male gender, absence of Helicobacter pylori infection, lower third location, mucosal atrophy, and intestinal metaplasia were related to multiple gastric neoplasms. In multivariate analysis, absence of H. pylori infection [odds ratio (OR) 1.610, 95 % confidence interval (CI) 1.038-2.497)], lower third location (OR 1.704, 95 % CI 1.070-2.713), and intestinal metaplasia (OR 4.461, 95 % CI 1.382-14.401) were independent risk factors for multiple gastric neoplasms. For synchronous neoplasm, primary tumor size less than 1 cm was the only independent risk factor. For metachronous neoplasm, absence of H. pylori infection (OR 2.416, 95 % CI 1.214-4.810) was found to be the only independent risk factor. H. pylori eradication was found to be unrelated to the development of metachronous gastric neoplasms., Conclusions: For tumors located in the antrum and accompanied by intestinal metaplasia, meticulous endoscopic evaluation with close follow-up after endoscopic resection is recommended.

Background: We aimed to evaluate long-term clinical outcomes of endoscopic resection for early gastric cancer (EGC)., Patients and Methods: From 2005 through 2011, 961 patients with EGC were treated with endoscopic submucosal dissection (ESD). Patients were grouped as standard and expanded criteria, while those who did not meet the expanded criteria were regarded as the group beyond the expanded criteria. Complete resection rate and the long-term clinical outcomes were compared among the three groups., Results: Complete resection rate was significantly higher in the standard group than in expanded and beyond the expanded group; 96.1% for standard, 92.5% for expanded, 55.5% for beyond the expanded indication group. During a mean follow-up of 42 months, local tumor recurrence developed more frequently in beyond the expanded group (7.8%) than in the standard and expanded group (1.8%). Metachronous cancer incidence (6.5%) did not differ significantly between the three groups. Two-thirds of recurred or metachronous tumors were treated with additional ESD. Lymph node metastasis developed in 0.6%. Five-year overall survival rate was 94.8% (96.6% for standard, 94.2% for expanded, 84.4% for beyond expanded, P < 0.001) and disease-free survival rate was 99.1% (100, 99.3, 92.8%, respectively, P < 0.001)., Conclusions: Endoscopic resection for EGC showed favorable long-term clinical outcomes in the patients within the standard and expanded criteria, whereas less favorable clinical outcomes in the patients beyond the expanded criteria.

Background: Although surgery is recommend for non-curative endoscopic resection of early gastric cancer (EGC), only a part of patients are found to have lymph node (LN) metastasis. This study aimed to identify the predictors of LN metastasis in patients with non-curative endoscopic resection., Methods: Between April 2005 and July 2013, consecutive patients who received non-curative endoscopic resection and then underwent gastrectomy with lymphadenectomy or followed at least 1 year with abdominal computed tomography were retrospectively enrolled at a single tertiary hospital. Non-curative resection was defined as a resection beyond the expanded criteria in pathologic mapping. The predictors for LN metastasis were identified by fitting a multivariate logistic regression model., Results: Among the 1783 consecutive patients who received endoscopic resection of EGC, non-curative resection was performed in 323 (18.1%) patients. Of these patients, a total of 267 patients were enrolled, and the rate of LN metastasis was 6.7% (18/267). In multivariate analysis, venous invasion [odds ratio (OR), 7.83; 95% confidence interval (CI) 2.20-27.86; p = 0.001], sm2 invasion (tumor invasion ≥500 µm into submucosa; OR 4.98; 95% CI 1.34-18.47; p = 0.016), or antral tumor location (OR 12.65; 95% CI 1.57-102.00; p = 0.017) were independent predictors for LN metastasis. The rates of LN metastasis were 1.1% (95% CI 0-2.7) for patients with one or no predictor and 17.8% (95% CI 9.7-25.8) for those with two or more predictors., Conclusions: Additional gastrectomy with lymphadenectomy after non-curative endoscopic resection of EGC is recommended for the patients with two or more identified predictors. However, close follow-up without immediate surgery might be considered cautiously for those with only one or no predictor.

Background & Aims: It is not clear whether eradication of Helicobacter pylori infection reduces the risk for metachronous gastric carcinoma. We performed a prospective, randomized, open-label trial of the effects of H pylori eradication on the incidence of metachronous carcinoma after endoscopic resection of gastric tumors., Methods: From April 2005 through February 2011 there were 901 consecutive patients with H pylori infection who had been treated with endoscopic resection for gastric dysplasia or cancer and who were assigned randomly to groups given therapy to eradicate the infection (n = 444) or no therapy (controls, n = 457). The eradication group received 20 mg omeprazole, 1 g amoxicillin, and 500 mg clarithromycin twice daily for 1 week. Patients underwent endoscopic examination 3, 6, and 12 months after treatment, and then yearly thereafter. The primary outcome was development of metachronous gastric carcinoma., Results: During a median follow-up period of 3 years, 10 patients who received H pylori eradication and 17 controls developed metachronous carcinoma; this difference was not significant (P = .15). The incidence of metachronous carcinoma between the 2 groups did not differ significantly at 1, 2, 3, and 4 years after administration of the therapy. There were no significant differences in the development of metachronous carcinoma among patients who were positive (n = 16) or negative (n = 11) for H pylori infection (P = .32)., Conclusions: In this prospective trial, eradication of H pylori after endoscopic resection of gastric tumors did not significantly reduce the incidence of metachronous gastric carcinoma. ClinicalTrials.gov Number: NCT01510730., (Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background/aims: The accurate preoperative prediction of the risk of malignancy of gastrointestinal stromal tumors (GISTs) is difficult. The aim of this study was to determine whether tumor size and endoscopic ultrasonography (EUS) features can preoperatively predict the risk of malignancy of medium-sized gastric GISTs., Methods: Surgically resected, 2 to 5 cm gastric GIST patients were enrolled and retrospectively reviewed. EUS features, such as heterogeneity, hyperechoic foci, calcification, cystic change, hypoechoic foci, lobulation, and ulceration, were evaluated. Tumors were grouped in 1 cm intervals. The correlations of tumor size or EUS features with the risk of malignancy were evaluated., Results: A total of 75 patients were enrolled. The mean tumor size was 3.43±0.92 cm. Regarding the risk of malignancy, 51 tumors (68%) had a very low risk, and 24 tumors (32%) had a moderate risk. When the tumors were divided into three groups in 1 cm intervals, the proportions of tumors with a moderate risk were not different between the groups. The preoperative EUS features also did not differ between the very low risk and the moderate risk groups., Conclusions: Tumor size and EUS features cannot be used to preoperatively predict the risk of malignancy of medium-sized gastric GISTs. A preoperative diagnostic modality for predicting risk of malignancy is necessary to prevent the overtreatment of GISTs with a low risk of malignancy.

Background: Although the accurate estimation of tumor size is essential for proper patient selection for endoscopic resection in early gastric cancer (EGC), no study has been conducted to date on tumor size estimation. We aimed to evaluate the accuracy of endoscopic visual estimation of tumor size of EGC., Methods: In 508 EGC patients that underwent endoscopic resection, endoscopic visual estimations were performed retrospectively by independent two endoscopists using still images. Data were compared with pathologic measurements as gold standard. Inter-observer agreement was determined using the Bland-Altman method and intra-class correlation coefficients (ICC). Measurement discrepancies were presented as differences between measurements., Results: The ICC between the two endoscopists was 0.915 (95 % CI 0.900-0.928). Mean endoscopic estimates for both endoscopists were significantly lower than mean pathologic measurements (1.50 and 1.67 vs. 1.80 cm, P < 0.001). Absolute differences between average endoscopic estimates and pathologic measurements were found to be acceptable in most cases: an absolute difference of <0.4 cm was found for 80 % (404/508) of cases. Bland-Altman plot showed that 94 % of cases lay within the 95 % limits of agreement. Measurement discrepancy was proportional to tumor size and increased for an undifferentiated histology., Conclusions: Endoscopic visual estimations were found to show reliable agreement with pathologic measurement in EGC patients undergoing endoscopic resection, together with good inter-observer agreement. Further prospective study is needed to confirm the validity of this method.

Background: In cases with a tumor-positive resection margin after endoscopic resection of early gastric cancer (EGC), not all patients are found to have residual or recurrent tumor. The aim of this study was to identify risk factors associated with residual/recurrent tumor in patients with incomplete endoscopic resection of EGC., Methods: A retrospective analysis was performed on consecutive patients who underwent endoscopic resection of EGC at a single institution in South Korea. Patients with a tumor-positive resection margin in the specimen were divided into two groups, with and without residual/recurrent tumor, and the clinicopathologic characteristics were compared., Results: A total of 102 patients with a tumor-positive lateral or vertical resection margin after endoscopic mucosal resection (n = 10) or submucosal dissection (n = 92) were enrolled. Overall, the rate of residual/recurrent tumor was 33.3 % (34/102): 17 residual tumors in 46 patients who immediately underwent additional endoscopic or surgical resection, and 17 recurrent tumors in 56 patients who were initially followed up with regular endoscopy during a median period of 17 (range = 2-70) months. Univariate analysis showed that the presence of ulcer, the direction of the tumor-positive resection margin, and length of lateral resection margin involvement by the tumor were associated with the incidence of residual/recurrent tumor. In multivariate analysis, total length (cm) of lateral resection margin involvement was the only independent risk factor for residual/recurrent tumor (OR 2.05; 95 % CI 1.22-3.44, p = 0.006)., Conclusions: Patients with extensive tumor involvement of a lateral resection margin after endoscopic resection of EGC should consider additional endoscopic or surgical resection due to a high risk of residual/recurrent tumor.

Background: It is rarely known whether antiplatelets increase the risk of bleeding after endoscopic submucosal dissection (ESD)., Objective: To evaluate the effect of antiplatelets on post-ESD bleeding., Design: Retrospective study., Setting: Single, tertiary-care referral center., Patients: This study involved 1591 gastric neoplasms (815 adenomas and 776 early gastric cancers) in 1503 patients who had ESD between April 2005 and April 2010., Intervention: ESD., Main Outcome Measurements: Overt hematemesis/hematochezia, a drop of hemoglobin >2 g/dL from baseline, or requirement of endoscopic hemostasis, angiographic embolization, and/or transfusion., Results: Of 1591 subjects, 274 took antiplatelets, among whom 102 discontinued them for 7 days or more before ESD. Post-ESD bleeding occurred in 94 subjects including 20 from the continuation group, 6 from the withdrawal group, and 68 from the no-antiplatelet group. In univariate analysis, antiplatelets, early gastric cancer (EGC), comorbidity, and specimen diameter were related to post-ESD bleeding. In multivariate analysis, EGC (odds ratio [OR] 1.839; 95% confidence interval [CI], 1.168-2.896; P = .009), comorbidity (OR 2.246; 95% CI, 1.280-3.939; P = .005), and specimen diameter (OR 2.315; 95% CI, 1.282-4.180; P = .005) were independent risk factors of post-ESD bleeding, whereas antiplatelet usage was not (OR 1.596; 95% CI, 0.877-2.903; P = .126). In subgroup analysis, continuous antiplatelet usage was not found to be an independent risk factor of post-ESD bleeding in multivariate analysis (OR 2.027; P = .146). Among 102 subjects who discontinued antiplatelets, 1 developed an acute cerebral infarction (1.0%)., Limitation: A retrospective, single-center analysis., Conclusion: In ESD for antiplatelet users, continuous administration was not found to have an independent significant association with bleeding., (Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: Although endoscopic resection for early gastric cancer (EGC) is increasingly available, it has not been determined whether indications for endoscopic resection are equally acceptable for multiple EGCs., Objective: To compare the various clinicopathologic factors and risk of lymph node (LN) metastasis between multiple and solitary EGCs., Design: Case-control study., Setting: University hospital., Patients: This study involved 1717 patients with 156 multiple and 1561 solitary EGCs., Intervention: Gastrectomy with LN dissection., Main Outcome Measurements: Incidence of LN metastasis., Results: In multiple EGCs, main lesions had larger tumor size and deeper invasion depth than the accessory lesions (P < .001). The clinicopathologic features of multiple EGCs were similar to those of solitary EGCs with respect to tumor size, depth of invasion, lymphovascular invasion, and incidence of LN metastasis. Importantly, the risk of LN metastasis in multiple EGCs that met the indication criteria for endoscopic resection was not significantly different from that in solitary EGCs. Tumors meeting conventional indications for endoscopic resection had no risk of LN metastasis, whereas tumors meeting expanded indications showed a similar risk of LN metastasis in the two groups. In multiple EGCs, tumor size ≥3 cm and lymphovascular invasion were independent risk factors of LN metastasis., Limitations: Small number of patients with multiple EGCs studied., Conclusion: Multiple EGCs had clinicopathologic characteristics and risk of LN metastasis similar to those of solitary EGCs. Endoscopic resection may be adopted as curative treatment for multiple EGCs that meet indications for endoscopic resection. Further studies are needed to verify the present study results., (Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: Although conventional endoscopy is a good diagnostic tool to evaluate tumor depth (T staging) in early gastric cancer (EGC), its accuracy has not been determined and no consensus has been reached regarding standard endoscopic criteria., Objective: To evaluate the diagnostic accuracy of endoscopic T staging and to identify the characteristic endoscopic features for mucosal (T1m) and submucosal (T1sm) tumors., Design: Retrospective study., Patients: A consecutive 2105 patients with EGC who underwent either surgical (n=1624) or endoscopic (n=481) resection., Intervention: Endoscopic staging was performed by consensus of 2 endoscopists based on the characteristic endoscopic criteria of T1m (smooth surface protrusion or depression, slight marginal elevation, and the smooth tapering of converging folds) and T1sm (irregular surface, marked marginal elevation, and clubbing/abrupt cutting/fusion of converging folds). The endoscopic staging was compared with the pathologic staging of the resected specimen., Results: The overall accuracy of endoscopic staging was 78.0% (1642/2105). The sensitivity, specificity, and positive and negative predictive values of T1m endoscopic staging were 85.5%, 73.9%, 82.0%, and 78.5%, whereas those for T1sm were 72.6%, 81.9%, 71.9%, and 82.4%, respectively., Limitations: Retrospective study. Endoscopic predictions for T1sm tumors were correct in only 72% of cases., Conclusions: Conventional endoscopy was found to provide reliable accuracy for T staging in EGC and may be an effective method for assessing penetration depth. A detailed endoscopic evaluation regarding tumor base, margin, and converging folds may provide useful information to determine tumor depth and to select the optimal therapeutic strategy, particularly for endoscopic resection., (Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

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.

Background and Study Aims: This study aimed to compare the diagnostic accuracy of endoscopic ultrasonography (EUS) with that of conventional endoscopy for staging depth of invasion (T staging) in early gastric cancer., Patients and Methods: A total of 955 patients with suspected early gastric cancer were prospectively registered. EUS staging was carried out prospectively by a single endoscopist using either miniprobe or radial EUS depending on the endoscopic appearance of the tumor. Conventional endoscopy staging was performed retrospectively by consensus between two endoscopists who were blinded to the EUS staging. Conventional endoscopy staging was conducted on the basis of endoscopic features such as surface nodularity and fold convergence. Patients underwent either surgical (n = 586) or endoscopic resection (n = 369) with curative intent. The staging accuracy of each test was compared with the pathological staging of the resected specimen., Results: The presence of a T1m tumor was histologically confirmed in 644 cases (67.4 %) and that of a T1sm tumor in 311 cases (32.6 %). The overall accuracy of EUS staging was 67.4 % (644 / 955) and that of conventional endoscopy staging was 73.7 % (704 / 955) ( P < 0.001). The accuracy of miniprobe EUS was significantly higher than that of radial EUS (79.5 % vs. 59.6 %, P < 0.001), but did not differ significantly from that of conventional endoscopy (79.0 %)., Conclusions: EUS does not substantially impact on pretreatment T staging of patients with early gastric cancer compared with conventional endoscopy. Therefore, EUS may not be necessary routinely, and conventional endoscopy may be sufficient for determining the optimal therapeutic strategy, especially in relation to endoscopic resection for early gastric cancer., (Copyright Georg Thieme Verlag KG Stuttgart . New York.)

Background: Depressed-type early gastric cancer (EGC) is known to repeat improvement and exacerbation of ulceration during its natural course, forming a "malignant cycle." However, it is difficult to observe the malignant cycle of EGC in clinical practice, and little is known about the clinicopathologic factors associated with this cycle. This study aimed to evaluate the malignant cycle of EGC and to determine the clinicopathologic factors associated with the time-dependent morphologic change of EGC., Methods: The medical records of EGC patients treated at the Seoul National University Hospital were retrospectively reviewed with two or more comparable endoscopic photos taken between March 1999 and December 2005. The ulcer stages in EGC were classified by the gastric ulcer stage system and evaluated for time-dependent morphologic changes according to the relevant factors., Results: In this study, 231 cases of depressed-type EGC were evaluated. At the follow-up endoscopy after a median interval of 23 days, a change in ulcer stage was observed in 66 patients (29%), with improvement in 45 patients (20%) and exacerbation in 21 patients (9%). Of the 177 patients who demonstrated an active or healing stage, 45 (25%) showed improvement and 10 (6%) exhibited exacerbation. The multivariate analysis showed that the usage of antisecretory medications, mucosal cancer, and a longer interval between the two endoscopic examinations were the factors that had a significant association with improvement of the ulcer stage., Conclusions: The malignant cycle was frequently observed in depressed-type EGC. The improvement of ulceration in EGC was time dependent and associated with the usage of antisecretory medication and the depth of invasion.

Background: Preoperative accurate diagnosis of the T and N stages in early gastric cancer (EGC) is important in determining the application of various limited treatments. The aim of this study is to analyze the accuracy of T and N staging of EGC with esophagogastroduodenoscopy (EGD), Stomach protocol CT (S-CT), and endoscopic ultrasonography (EUS), and the factors influencing the accuracy., Methods: Four hundred and thirty-four patients preoperatively diagnosed as EGC using EGD or S-CT and undergoing curative gastrectomy at Seoul National University Hospital in 2005 were included. The T and N stage reviewed by experienced personnel were compared with the surgical pathology., Results: The predictive values for EGC of EGD, S-CT, and EUS were 87.4%, 92.2%, and 94.1%, respectively. The predictive values for node negativity of S-CT, and EUS were 90.1% and 92.6%, respectively. The factors leading to underestimation of T stage with EGD were the upper third location, the size greater than 2 cm, and diffuse type of tumor. Those with S-CT were female sex, the upper third location and lesion size greater than 2 cm., Conclusions: Before applying limited treatment for EGC, a surgeon should consider the risk factors of underestimation of T stage with EGD or S-CT.

Backgrounds and Aims: Self-expanding metal stents (SEMS) have been used as a palliative treatment for malignant colorectal obstruction. However, the reports about primary stent patency rate and associated factors have been limited. This study was performed to evaluate clinical outcomes and factors associated with long-term complications and patency of SEMS in patients with malignant colorectal obstruction., Materials and Methods: Patients who underwent palliative endoscopic placement with uncovered SEMS for a malignant colorectal obstruction were prospectively enrolled at Seoul National University Hospital between April 2005 and August 2007., Results: Forty-nine patients underwent 51 SEMS placements. Obstruction sites were rectum in 15 patients (30.6%), descending or sigmoid colon in 25 (51.0%), and transverse colon in nine (18.4%), respectively. The causes of obstruction were colorectal cancer in 36 patients (73.5%), direct invasion of gastric cancer in seven (14.3%) and others in six (12.2%). Technical success was achieved in 100% and clinical success in 86%, and there was one procedure-related perforation. Re-obstruction and migration occurred in 16% and 6%, respectively, during mean follow-up period of 331 days. Median stent patency duration was 204 days, and patency rates at 30, 90, and 180 days were 91.2%, 81.0%, and 53.3%, respectively, which was not associated with patient demographics, site of obstruction, or palliative chemotherapy., Conclusion: Endoscopic SEMS placement is a safe and effective palliative treatment for malignant colorectal obstruction, and overall long-term complication and patency were favorable irrespective of the palliative chemotherapy.