Endoscopic Resection Of Early Gastric Cancer Research Articles

Endoscopic resection of early gastric cancer

Endoscopic resection (ER) is an effective treatment for early gastric cancer (EGC) without metastases. Existing endoscopic mucosal resec-tion (EMR) is easy to perform, has few complications, and can be ap-plied when the lesion size is small. However, <i>en bloc</i> and complete re-section rates vary depending on the size and severity of the lesion. EMR using the cap-mounted panendoscopic method and EMR after circum-ferential preamputation of the lesion are useful in the treatment of EGC. However, completely oversized lesions (≥2 cm) and lesions associated with ulcers or submucosal fibrosis are more likely to fail resection. En-doscopic submucosal dissection has been widely used to resect tu-mors larger than 2 cm in diameter and has a higher acceptable compli-cation rate and <i>en bloc</i> and complete resection rates than EMR. ER for EGC is superior to surgical resection in terms of improving patient quali-ty of life. Additionally, compared to surgery, emergency rooms have a lower rate of treatment-related complications, shorter hospital stays, and lower costs. Accordingly, the indications for ER are expanding in the field of therapeutic endoscopy. Long-term outcomes regarding re-currence are excellent in both absolute and extended criteria for ER in EGC. Close surveillance should be performed after ER to detect early metachronous gastric cancer and precancerous lesions that can be treated with ER. Follow-up gastroscopy and abdominopelvic computed tomography scans every 6 to 12 months are recommended for patients who undergo curative ER for EGC on absolute or extended criteria.

Outcomes of endoscopic resection for early gastric cancer in very elderly patients: A nationwide population-based study.

403 Background: Few studies have investigated the long-term outcomes of endoscopic resection for early gastric cancer (EGC) in very elderly patients. The aim of this study was to determine the appropriate treatment strategy and identify the risk factors for mortality in these patients. Methods: Patients with EGC who underwent endoscopic resection from 2006 to 2017 were identified using National Health Insurance Data and divided into three age groups: very elderly (≥85 years), elderly (65–84 years), and non-elderly (≤64 years). Their long- and short-term outcomes were compared in the three age groups, and the survival in the groups was compared with that in the control group, matched by age and gender. We also evaluated the risk factors for long- and short-term outcomes. Results: A total of 8,426 patients were included in our study: 118 very elderly, 4,583 elderly, and 3,725 non-elderly. The overall survival (OS) and cancer-specific survival (CSS) rates were significantly lower in the very elderly group than in the elderly and the non-elderly groups. Congestive heart failure was negatively associated with CSS. A significantly decreased risk for mortality was observed in all groups (P-value < 0.001). The very elderly group had significantly higher readmission and mortality rates within 3 months of endoscopic resection than the non-elderly and elderly groups. Further, cerebrovascular disease was associated with mortality within 3 months after endoscopic resection. Conclusions: Endoscopic resection for EGC can be helpful for very elderly patients, and it may play a role in achieving OS comparable to that of the control group.[Table: see text]

Outcomes of Endoscopic Resection for Early Gastric Cancer in Very Elderly Patients: A Nationwide Population-Based Study.

Few studies have investigated the long-term outcomes of endoscopic resection for early gastric cancer (EGC) in very elderly patients. The aim of this study was to determine the appropriate treatment strategy and identify the risk factors for mortality in these patients. Patients with EGC who underwent endoscopic resection from 2006 to 2017 were identified using National Health Insurance Data and divided into three age groups: very elderly (≥85 years), elderly (65 to 84 years), and non-elderly (≤64 years). Their long- and short-term outcomes were compared in the three age groups, and the survival in the groups was compared with that in the control group, matched by age and sex. We also evaluated the risk factors for long- and short-term outcomes. A total of 8,426 patients were included in our study: 118 very elderly, 4,583 elderly, and 3,725 non-elderly. The overall survival and cancer-specific survival rates were significantly lower in the very elderly group than in the elderly and the non-elderly groups. Congestive heart failure was negatively associated with cancer-specific survival. A significantly decreased risk for mortality was observed in all groups (p<0.001). The very elderly group had significantly higher readmission and mortality rates within 3 months of endoscopic resection than the non-elderly and elderly groups. Furthermore, the cerebrovascular disease was associated with mortality within 3 months after endoscopic resection. Endoscopic resection for EGC can be helpful for very elderly patients, and it may play a role in achieving overall survival comparable to that of the control group.

Long-term outcome of the endoscopic submucosal dissection of early gastric cancer: A comparison between patients with and without liver cirrhosis.

Gastric cancer (GC) and liver cirrhosis (LC) have high incidence rates, particularly in Eastern Asia; however, the long-term clinical outcomes or recurrence of GC following endoscopic submucosal dissection (ESD) in patients with comorbid LC remain unclear. The present study aimed to compare the long-term efficacy and safety of ESD in patients with GC, with and without LC. Patients with early GC (EGC) who had underlying LC and underwent endoscopic treatment (LC-EGC group) were enrolled in the present study. In addition, patients with EGC without LC (non-LC-EGC group) were matched at a ratio of 1:3 via propensity score matching. The clinical outcomes and histopathological data of both groups were analyzed. No significant differences were observed in procedure type, complications [intraprocedural bleeding (11.8%) and perforation (0.0%)], en bloc resection rate (94.1%) and complete resection rate (100%) between the two groups. Multivariate Cox regression analysis demonstrated that procedure time was significantly associated with procedure-associated bleeding [adjusted hazard ratio (HR), 1.017; 95% confidence interval (CI), 1.001-1.032; P=0.033]. Furthermore, LC was significantly associated with cancer recurrence (adjusted HR, 5.482; 95% CI, 1.102-27.279; P=0.038). Taken together, the results of the present study suggest that endoscopic resection of EGC in patients with LC is an effective and safe treatment method. However, further studies are required to assess recurrence.

Machine Learning Model to Stratify the Risk of Lymph Node Metastasis for Early Gastric Cancer: A Single-Center Cohort Study.

Simple SummaryEndoscopic resection (ER) is a treatment option for clinically T1a early gastric cancer (EGC) without suspicion of lymph node metastasis (LNM). In patients with non-curative resection after ER, additional surgery is recommended owing to the LNM risk. However, of those patients treated with additional surgery after ER, the actual rate of LNM was about 5–10%; that is, the other patients underwent unnecessary surgeries. Therefore, it is crucial to estimate LNM risk in EGC patients to determine additional management after ER. We derived a machine learning (ML) model to stratify the LNM risk in EGC patients and validate its performance. The constructed ML model, which showed good performance with an area under the receiver operating characteristic of 0.85 or higher, could stratify LNM risk into very low (<1%), low (<3%), intermediate (<7%), and high (≥7%) risk categories. These findings suggest that the ML model can stratify the LNM risk in EGC patients.Stratification of the risk of lymph node metastasis (LNM) in patients with non-curative resection after endoscopic resection (ER) for early gastric cancer (EGC) is crucial in determining additional treatment strategies and preventing unnecessary surgery. Hence, we developed a machine learning (ML) model and validated its performance for the stratification of LNM risk in patients with EGC. We enrolled patients who underwent primary surgery or additional surgery after ER for EGC between May 2005 and March 2021. Additionally, patients who underwent ER alone for EGC between May 2005 and March 2016 and were followed up for at least 5 years were included. The ML model was built based on a development set (70%) using logistic regression, random forest (RF), and support vector machine (SVM) analyses and assessed in a validation set (30%). In the validation set, LNM was found in 337 of 4428 patients (7.6%). Among the total patients, the area under the receiver operating characteristic (AUROC) for predicting LNM risk was 0.86 in the logistic regression, 0.85 in RF, and 0.86 in SVM analyses; in patients with initial ER, AUROC for predicting LNM risk was 0.90 in the logistic regression, 0.88 in RF, and 0.89 in SVM analyses. The ML model could stratify the LNM risk into very low (<1%), low (<3%), intermediate (<7%), and high (≥7%) risk categories, which was comparable with actual LNM rates. We demonstrate that the ML model can be used to identify LNM risk. However, this tool requires further validation in EGC patients with non-curative resection after ER for actual application.

Aspirin Use Is Not Associated with the Risk of Metachronous Gastric Cancer in Patients without Helicobacter pylori Infection.

Introduction: Helicobacter pylori (H. pylori) eradication can prevent metachronous gastric cancer (MGC) after the performance of an endoscopic resection for early gastric cancer (EGC). However, 50% of infections persist after eradication, and the identification of MGC protective factors is important. The anti-tumor activity of aspirin has been demonstrated, but its efficacy in preventing MGC remains controversial. We evaluated the effect of aspirin on metachronous recurrence in H. pylori-negative patients. Methods: A total of 4351 patients were evaluated between January 2007 and December 2016, and 2151 patients who met the inclusion criteria were analyzed. The primary outcome was the cumulative incidence of MGC after an endoscopic resection for EGC. Results: During a 5-year median follow-up (interquartile range, 3.5–6.2), MGC developed in 176 (7.7%) patients, with a cumulative incidence of 89.4% in aspirin users and 92.7% in non-users; this difference was not statistically significant (p = 0.64). The duration of aspirin uses and the occurrence of MGC in both groups were not significantly different. There was no significant difference between groups when the duration of aspirin use was categorized into ≤1 year (hazard ratio (HR), 0.64; 0.20–2.01, p = 0.45), 1–4 years (HR, 1.35; 0.66–2.76, p = 0.41), and >4 years (HR, 1.17; 0.67–2.03, p = 0.58). Conclusions: Aspirin use was not associated with a lower risk of MGC in H. pylori-negative patients. Further prospective studies are needed.

ID: 3521872 LONG-TERM OUTCOMES OF JAPANESE MULTICENTER PROSPECTIVE COHORT STUDY OF ENDOSCOPIC RESECTION FOR EARLY GASTRIC CANCER USING WEB REGISTRY (J-WEB/EGC)

Background and Aims: Limited data from multicenter prospective studies is available regarding the long-term outcomes of endoscopic resection (ER) for gastric cancer, particularly for EGC lesions fulfilling differentiated-type, pT1b (SM1), ≤3 cm. A Japanese multicenter prospective cohort study of ER for early gastric cancer (EGC) using a Web registry system (J-WEB/EGC) has been conducted to determine the long-term outcomes (Clinical Trial Registration: UMIN000005871). We aimed to clarify the long-term outcomes of ER for EGCs based on pathological curability of gastric ER to determine the effectiveness of ER for EGC.

Comparison of biannual and annual endoscopic gastric cancer surveillance after endoscopic resection.

Patients who received endoscopic resection (ER) for early gastric cancer (EGC) or high-grade dysplasia (HGD) are at high risk for the subsequent development of metachronous gastric cancer (MGC). This study aims to compare the detection rate and stage of MGC between biannual and annual endoscopic surveillance after ER of EGC or HGD. From September 2009 to August 2019, 859 patients who underwent ER for the treatment of EGC or HGD were analyzed, retrospectively. Patients received endoscopic surveillance twice a year (high-intensity group) or annually (low-intensity group) for 3years. A total of 521 patients were enrolled in this study (267 patients in the high-intensity group and 254 patients in the low-intensity group). During a mean follow-up of 5.3 ± 1.6years, MGCs were found in 27 patients (16.9%) in the high-intensity group and 18 patients (7.1%) in the low-intensity group (P = 0.219). In patients with moderate to severe atrophy (Kimura-Takemoto grade C3 ~ O3), detection rates of MGC during 3years from were 8.4% (16/191) and 2.2% (4/186), respectively (P = 0.007). Forty-four patients who received treatment for MGC, including endoscopic or surgical resection, were stage IA. Only one patient in the low-intensity group was diagnosed as stage IIIA advanced gastric cancer. There was no significant difference in the detection rate of MGC between biannual and annual endoscopic surveillance after ER of EGC or HGD. However, biannual surveillance showed a higher detection rate during the first 3years, especially for patients with moderate to severe gastric atrophy.

Metachronous Gastric Cancer Occurring after Endoscopic Resection of Early Gastric Cancer

Endoscopic resection (ER) has been widely used as a curative treatment for early gastric cancers (EGCs). Especially endoscopic submucosal dissection has several merits such as high en bloc and curative resection rates for EGCs and preservation of the entire stomach. However, ER has the inevitable limitation that the possibility of newly developing gastric cancers in the preserved stomach is still present. Metachronous gastric cancer (MGC) is defined as a newly developed gastric cancer occurring at a previously uninvolved site ≥1 year after the index ER of EGCs. The incidence of MGC is 3.3~15.6% and increases over time after ER. Old age, male sex, current smoking, severe atrophy and intestinal metaplasia, persistent Helicobacter pylori (H. pylori) infection, differentiated-type histology, and multiple initial gastric cancers are risk factors of MGC. As H. pylori eradication could reduce the risk of MGC after ER of EGCs, H. pylori eradication is strongly recommended for the prevention of MGC after ER of EGCs. Most MGCs are found at an early stage on regular surveillance endoscopy after ER and successfully treated with ER, with excellent long-term outcomes.

Risk of metachronous gastric neoplasm occurrence during intermediate-term follow-up period after endoscopic submucosal dissection for gastric dysplasia

After endoscopic resection (ER) of gastric dysplasia, metachronous gastric neoplasm (MGN) appears to have an incidence rate similar to that detected after ER of early gastric cancer (EGC). We investigated whether the risk of MGN after ER for gastric dysplasia is different between patients with low-grade dysplasia (LGD) and high-grade dysplasia (HGD). Between March 2011 and December 2016, 198 patients with LGD (LGD group) and 46 patients with HGD (HGD group) who underwent ER were included in the study. During a median follow-up of 2.5 years, MGNs developed in 21 patients (10.6%) in the LGD group and in 6 patients (13.0%) in the HGD group. Hazard ratios (HRs) for MGNs (HR, 1.45; P = 0.425) and for metachronous HGD or gastric cancer (HR, 2.41; P = 0.214) in the HGD group were not different than those of the LGD group. However, considering patients without Helicobacter pylori infection, those in the HGD group had a significantly increased risk of metachronous HGD or gastric cancer compared to those in the LGD group (HR in HGD-group, 5.23; P = 0.044). These results indicate that meticulous surveillance endoscopy is needed to detect MGNs after ER of gastric dysplasia, especially in patients with HGD, including those without H. pylori infection.

Statins and metachronous recurrence after endoscopic resection of early gastric cancer: a nationwide Korean cohort study.

Statins have shown to reduce the risk of various cancers. However, their effects on metachronous recurrence (MR) after endoscopic resection (ER) for early gastric cancer (EGC) are unknown. We evaluate their effects on MR development after ER for EGC. We selected 11,568 patients who received ER for EGC from 2002 to 2011 from the Korean National Health Insurance database and classified into 2 groups: control and statins using propensity score matching. Metachronous recurrence was defined as the second ER or gastrectomy performed 6months after the first ER. Mean follow-up period was 8.8 ± 3.1years. Statins showed a significantly lower incidence of MR than the control group (12.5% vs 2.2%, respectively, P < 0.01). After conducting competing risk analyses and time-dependent cox regression analysis considering immortal time bias, statins still showed a lower incidence rate of MR compared to that observed in the control group. For the multivariate analysis, statins remained significant (HR 0.17; 95% CI 0.13-0.24, P < 0.01). In the dose-response analysis, an inverse dose-response relationship was identified between MR and statins (P < 0.01). Statins was significantly associated with a reduced risk of MR after ER for EGC with an inverse dose-response relationship.

Helicobacter pylori Infection following Endoscopic Resection of Early Gastric Cancer.

The role of Helicobacter pylori (H. pylori) infection in patients following endoscopic resection of early gastric cancer (EGC) remains unclear. This article presents a review of literature published in the past 15 years. H. pylori‐mediated persistent methylation levels are associated with the development of metachronous gastric cancer. The methylation of certain specific genes can be used to identify patients with a high risk of metachronous gastric cancer even after H. pylori eradication. H. pylori eradication after endoscopic resection should be performed as early as possible for eradication success and prevention of metachronous precancerous lesions. Although whether the eradication of H. pylori could prevent the development of metachronous cancer after endoscopic resection is controversial, several meta‐analyses concluded that H. pylori eradication could reduce the incidence of metachronous gastric cancer significantly. In addition, H. pylori eradication in gastric cancer survivors after endoscopic resection could reduce healthcare cost and save lives in a cost‐effective way. Taken together, H. pylori eradication after endoscopic resection of EGC is recommended as prevention for metachronous precancerous lesions and metachronous gastric cancer.

More Frequent Follow-up CT Scans in Postsurgical Resection Patients Than in Postendoscopic Resection Patients of Early Gastric Cancers: Impracticality of CTs for Mucosal Cancer

The aim of this study was to compare the utility and timing of computed tomography (CT) in the detection of recurrent tumors between patients after surgical and endoscopic resections for early gastric cancer (EGC). A total of 670 patients after surgical (n = 535) and endoscopic (n = 135) resections for EGC between 2007 and 2009 were enrolled. The mean numbers of CT and endoscopy between both treatment groups were compared. The mean and cumulative dose length products of CT examinations were calculated. The modality that detected recurrence was compared between the two groups using the Pearson chi-square test. The mean interval of CT was significantly shorter and the mean number of CTs was significantly larger in the surgical resection group than in the endoscopic resection group. All 34 gastric recurrences were diagnosed by endoscopy. All seven extragastric recurrences occurred in patients treated for EGC with submucosal invasion. Six extragastric recurrences were detected by CT out of a total of 5417 CT scans. The average cumulative dose length product was significantly higher in the surgical group than in the endoscopic resection group (P = 0.004). Follow-up CTs were performed more frequently in patients after surgical resection than in patients after endoscopic resection of EGCs. However, CT scans were not effective in detecting recurrent tumors after either treatment methods, especially for patients treated for mucosal gastric cancer.

Blue laser imaging-bright improves the real-time detection rate of early gastric cancer: a randomized controlled study

Blue laser imaging-bright (BLI-bright) has shown promise as a more useful tool for detection of early gastric cancer (EGC) than white-light imaging (WLI). However, the diagnostic performance of BLI-bright in the detection of EGC has not been investigated. We aimed to compare real-time detection rates of WLI with that of BLI-bright for EGC. This was a prospective, randomized, controlled study in 2 Japanese academic centers. We investigated 629 patients undergoing follow-up endoscopy for atrophic gastritis with intestinal metaplasia or surveillance after endoscopic resection of EGC. Patients were randomly assigned to receive primary WLI followed by BLI-bright or primary BLI-bright followed by WLI. The real-time detection rates of EGC were compared between primary WLI and primary BLI-bright. There were 298 patients in each group. The real-time detection rate of EGC with primary BLI-bright was significantly greater than that with primary WLI (93.1% vs 50.0%; P= .001). Primary BLI-bright had a significantly greater ability to detect EGCs in patients with a history of endoscopic resection for EGC, no Helicobacter pylori infection in the stomach after eradication therapy, lesions with an open-type atrophic border, lesions in the lower third of the stomach, depressed-type lesions, small lesions measuring<10mm and 10 to 20mm in diameter, reddish lesions, well-differentiated adenocarcinomas, and lesions with a depth of invasion of T1a. BLI-bright has a higher real-time detection rate for EGC than WLI. BLI-bright should be performed during surveillance endoscopy in patients at high risk for EGC. (Clinical trial registration number: UMIN000011324.).

Gastric cancer: epidemiology, prevention, and therapy.

Gastric cancer (GC) is still the third leading cause of cancer death in both sexes worldwide. Helicobacter pylori infection is the most important risk factor for GC and, in spite of the consistent trend of a decreasing incidence, in 2015 approximately 4.4billion individuals-more than half the world's population-were infected with H.pylori. The birth cohort pattern of decreased H.pylori infection reported in a systematic review contributes to explain the declining GC mortality in Japan. Current trends in estimated annual percentage change of GC incidence foreshadow expected reversals in both falling incidence and male predominance among US non-Hispanic whites. Combining serum pepsinogen 1 and H.pylori serology was shown to be useful for GC risk stratification in a Finnish population. Gastritis staging by operative link on gastritis assessment was confirmed to be reliable in predicting GC risk in a large prospective study. In a randomized trial from South Korea, H.pylori eradication therapy significantly reduced the rates of metachronous GC in patients who received curative endoscopic resection for early GC. A study based on a territory-wide health care database of the Hong Kong Hospital Authority showed that aspirin use is associated with a reduced GC risk. Another study based on the same database showed that proton pump inhibitors increase GC risk, but methodological biases have most likely acted as confounders. Confirmatory data on the role of endoscopic submucosal dissection in patients with early GC have been published. The phase III FLOT4 trial has shown that the FLOT triplet regimen (docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil) improves the outcome of patients with GC and locoregional disease as compared to the ECF triplet (epirubicin, cisplatin, and 5-fluorouracil). In the phase III ATTRACTION-2 trial, nivolumab was shown to be an effective treatment option with a relative safe profile for heavily pretreated patients with advanced GC.

Preoperative predictors of beyond endoscopic submucosal dissection indication or lymphovascular invasion in endoscopic resection for early gastric cancer.

To successfully resect early gastric cancer (EGC), prediction of lymph node metastasis is essential. Beyond endoscopic submucosal dissection (ESD) indication or lymphovascular invasion (LVI) are known risk factors associated with lymph node metastasis. However, accurate prediction of tumor invasion depth or LVI is impossible before endoscopic resection even when endoscopic ultrasound is used. The aim of this study was to identify the predictive factors associated with beyond ESD indication or LVI after ESD for EGC. Between Jan 2011 and Feb 2015, 532 lesions from 506 patients who received ESD for EGCs were included. We reviewed the data of patients diagnosed as EGCs without ulceration or those smaller than 3cm with ulceration. The incidence of EGCs found to be beyond expanded ESD indications or present of LVI after ESD was 11.1% (59/532). On multivariable analysis, endoscopic features of SM invasion, surface color changes, and elevated lesions were associated with beyond ESD indication or LVI. In particular, submucosal (SM) invasive features such as SM tumor-like marginal elevation [odds ratio (OR) 17.2; 95% confidence interval (CI) 2.0-146.7], fusion of convergent folds (OR 12.9; 95% CI 3.9-42.1), irregular surface (OR 17.8; 95% CI 5.6-56.8), and discoloration of the tumor surface (OR 16.1; 95% CI 2.4-105.9) were significant risk factors for beyond ESD indication or LVI. The decision to proceed with endoscopic resection for EGCs with endoscopic features of SM invasion, surface color changes, or elevated forms must be made cautiously.

Long-Term Effects of Helicobacter pylori Eradication on Metachronous Gastric Cancer Development.

Background/AimsGastric mucosal atrophy and intestinal metaplasia due to Helicobacter pylori infection are the main precursor lesions of gastric cancer. The aim of this study was to evaluate the long-term effects of H. pylori eradication on the progression of precancerous lesions to metachronous cancer after endoscopic resection of early gastric cancer (EGC).MethodsPatients who underwent endoscopic resection of EGC were retrospectively reviewed. Changes in precancerous lesions and development of metachronous cancer were compared according to H. pylori eradication and final infection status.ResultsIn total, 565 patients were followed for over 5 years after endoscopic resection of EGC. The grade of atrophy on corpus was significantly lower in the H. pylori-eradicated group than in the persistent group during follow-up (p=0.029). In patients <70 years of age, the cumulative incidence rate of metachronous cancer was significantly lower in the H. pylori-eradicated group than in the persistent group (p=0.018). Age was an independent risk factor for metachronous cancer development.ConclusionsH. pylori eradication might prevent the development of metachronous cancer in patients <70 years of age by delaying the progression of precancerous lesions after endoscopic resection of EGC.

Metachronous Gastric Cancer Following Curative Endoscopic Resection of Early Gastric Cancer.

This review article summarizes knowledge about metachronous gastric cancer (MGC) occurring after curative endoscopic resection (ER) of early gastric cancer (EGC), treatment outcomes of patients who developed MGC, and efficacy of Helicobacter pylori eradication to prevent MGC. The incidence of MGC following curative ER increases over time and is higher than in patients undergoing gastrectomy. Increasing age and multifocal EGC are independent risk factors for developing MGC. An MGC following curative ER is usually a small (<20 mm) and differentiated intramucosal cancer. Most MGC lesions are found at an early stage on semiannual or annual surveillance endoscopy and are successfully treated by further ER, with excellent long-term outcomes. Eradication of H. pylori may reduce the risk of MGC following ER of EGC, but further prospective studies with long-term outcomes are required. Surveillance endoscopy following gastric ER should be continued indefinitely, due to the risk of MGC even after successful H. pylori eradication. Risk stratification and tailored endoscopic surveillance schedules need to be developed.

Additive endoscopic resection may be sufficient for patients with a positive lateral margin after endoscopic resection of early gastric cancer

No well-established treatment strategies exist for lateral margin positivity (LM+) alone after endoscopic resection (ER) of early gastric cancer (EGC). Thus, we aimed to clarify a treatment strategy for non-curative resection (non-CR) with LM+ alone after ER in EGC. Among 2065 patients with EGC treated by ER, 76 (3.6%) with only LM+ after non-CR of EGC were reviewed retrospectively. Of these, 28 underwent gastrectomy, 25 underwent argon plasma coagulation (APC), and 23 underwent repeat ER (re-ER). We analyzed the clinicopathologic characteristics of all patients and compared those who underwent additive surgery, APC, or re-ER. Of the 76 patients, 28 (36.8%) fulfilled the absolute criteria and 48 (63.2%) the expanded criteria for ER. Among the latter patients, the proportion undergoing additive surgery was 75.0%, higher than that of patients in the former group (P= .014). Residual cancer cells were observed in 70.6% of patients after additive surgery or re-ER. Residual cancer cells were observed significantly more often in patients with undifferentiated-type than in those with differentiated-type EGC (P= .02). However, no lymph node metastasis was observed in any patient after additive surgery. Our results suggest that endoscopic treatment may be a sufficient additive therapy for patients with LM+ alone after ER, irrespective of whether the absolute or expanded ER criteria are used. However, as complete ablation of remnant cells cannot be guaranteed, re-ER is a better additive treatment than APC.

The incidence and locational predilection of metachronous tumors after endoscopic resection of high-grade dysplasia and early gastric cancer.

The incidence of metachronous lesions after endoscopic resection (ER) of high-grade dysplasia (HGD) has not been evaluated, and optimal surveillance strategy remains vague. This study aimed to evaluate the incidence and characteristics of metachronous tumors including HGD and early gastric cancer (EGC) arising after ER. The medical records of 2779 patients with 2981 lesions (445 patients with HGD and 2334 patients with EGC) who underwent ER and surveillance endoscopy at Asan Medical Center between April 1999 and December 2011 were retrospectively reviewed, and clinicopathological features of metachronous tumors were analyzed. Ninety-six metachronous lesions (17 HGD and 79 EGC) occurred in 92 patients during median 42months of follow-up period (range 26-58months). The 5-year and 10-year overall cumulative incidences of metachronous tumors were 4.6 and 10.5%, respectively, and were on steady rise up to 10years. The 5- and 10-year cumulative incidences of metachronous lesions were 4.1 and 8.4% in HGD group and 4.7 and 11.3% in EGC group (P=0.578), respectively. The size of metachronous tumors was significantly smaller than initial lesion (2.3 vs. 1.9cm, P=0.039). Lower third of the stomach was most frequent site for both initial and metachronous lesions (77.1 and 70.8%, respectively) and age was the significant predicting factor for metachronous tumors. Cumulative incidence of metachronous tumors after ER of HGD was comparable to the incidence after ER of EGC. Surveillance endoscopy can be considered at least for 10years, with special attention on the lower third of the stomach.