Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.ope

Treatment pattern and overall survival in esophageal cancer during a 13-year period: A nationwide cohort study of 6,354 Korean patients

Using data from the real world to solve clinical questions that cannot be answered using data from clinical trials is attracting more attention. Clinical outcomes for patients with esophageal cancer in a real-world setting might be different from data in randomized controlled trials. This study aimed to provide real world data on treatment and prognosis in Korean patients with esophageal cancer. This retrospective cancer cohort included newly diagnosed cases of esophageal cancer at 19 tertiary hospitals between January 1, 2005 and December 31, 2017. Cancer staging was defined according to the 7th edition of the American Joint Committee on Cancer criteria. We identified 6,354 patients with newly diagnosed esophageal cancer (mean age: 64.9 +/- 9.0 years, 96.9% squamous cell carcinoma). The proportion of early esophageal cancer increased from 24.7% in 2005 to 37.2% in 2015 (p<0.001). Among all cases, surgery alone was 31.3%, followed by definitive concurrent chemoradiotherapy (CCRT) (27.0%), neoadjuvant therapy (12.4%), adjuvant therapy (11.1%), and endoscopic resection (5.8%). The 5-year overall survival rate was 45.7 +/- 0.7%. Endoscopic resection provided similar median survival relative to surgery for stage Ia cases. Among stage II-III cases, definitive CCRT was associated with poorer survival than neoadjuvant or adjuvant therapy, although there was no survival difference between neoadjuvant and adjuvant therapy. Early esophageal cancer is gradually becoming more common and endoscopic resection provided similar long-term survival relative to surgery. Surgery with combined therapy provided better survival in locally advanced esophageal cancer, relative to definitive CCRT.ope

Application of A Convolutional Neural Network in The Diagnosis of Gastric Mesenchymal Tumors on Endoscopic Ultrasonography Images

Background and aims: Endoscopic ultrasonography (EUS) is a useful diagnostic modality for evaluating gastric mesenchymal tumors; however, differentiating gastrointestinal stromal tumors (GISTs) from benign mesenchymal tumors such as leiomyomas and schwannomas remains challenging. For this reason, we developed a convolutional neural network computer-aided diagnosis (CNN-CAD) system that can analyze gastric mesenchymal tumors on EUS images. Methods: A total of 905 EUS images of gastric mesenchymal tumors (pathologically confirmed GIST, leiomyoma, and schwannoma) were used as a training dataset. Validation was performed using 212 EUS images of gastric mesenchymal tumors. This test dataset was interpreted by three experienced and three junior endoscopists. Results: The sensitivity, specificity, and accuracy of the CNN-CAD system for differentiating GISTs from non-GIST tumors were 83.0%, 75.5%, and 79.2%, respectively. Its diagnostic specificity and accuracy were significantly higher than those of two experienced and one junior endoscopists. In the further sequential analysis to differentiate leiomyoma from schwannoma in non-GIST tumors, the final diagnostic accuracy of the CNN-CAD system was 72.5%, which was significantly higher than that of two experienced and one junior endoscopists. Conclusions: Our CNN-CAD system showed high accuracy in diagnosing gastric mesenchymal tumors on EUS images. It may complement the current clinical practices in the EUS diagnosis of gastric mesenchymal tumors.ope

Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea

Background: Treatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage. Methods: Patients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected. Results: A total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival. Conclusion: The majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.ope

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.ope

Current status and trend in training for endoscopic submucosal dissection: A nationwide survey in Korea

Background: Although endoscopic submucosal dissection (ESD) is widely used, the current status and trend in its training have yet to be fully evaluated. We aimed to investigate how ESD endoscopists have been trained in actual clinical practice. Methods: Endoscopists aged <45 years who have completed a gastroenterology fellowship or were currently in a fellowship for ≥2 years were included. We conducted a nationwide survey on the ESD training experiences of these endoscopists. Results: Among 79 young Korean endoscopists invited to participate in the survey, 68 (86.1%) trained in 24 major hospitals responded to the questionnaire. Twenty, 25, and 23 participants belonged to the second-year fellow, <5 years after training, and ≥5 years after training groups, respectively. Sixty-nine percent of the participants observed ≥50 ESD cases before starting ESD under supervision by an expert endoscopist. Additionally, 22% experienced ≥20 supervised ESDs during the training period. The proportion of the participants who underwent a hands-on course differed among the groups (≥5 years after training, 13.0%; <5 years after training, 40.0%; and second-year fellow, 50.0%; P = 0.027). ESD under supervision, observation, and hands-on course were the preferred methods for learning ESD (91.1%, 80.9%, and 35.3%, respectively). Overall, 42.6% of the participants were satisfied with their training program. More experience in supervised ESD (≥20 cases) was associated with an increased satisfaction (odds ratio, 6.65; 95% confidence interval, 1.62-36.31). Conclusions: Observation and performance of ESD under the supervision of an expert endoscopist are the primary methods for learning ESD. Hands-on course program has been used more frequently in recent years.ope

Strategies that Reduce Post-endoscopic Submucosal Dissection Bleeding

Bleeding after endoscopic submucosal dissection (ESD), one of the most common postprocedural adverse events, is the main cause of increased readmission rates and hospital costs. Generally, the incidence of post-ESD bleeding is estimated to be about 5%. However, the incidence of bleeding is particularly increased in high-risk patients. In particular, it has an incidence of over 50% in patients that use antithrombotic agents. The well-known risk factors for post-ESD bleeding include antithrombotic therapy, lesions in the proximal stomach, specimen size >4 cm, and concomitant renal disease. Currently, the number of patients at a high risk of post-ESD bleeding has been increasing. This may be due to the aging society and the increase in the usage of antithrombotic agents. Therefore, several strategies have been employed to prevent post-ESD bleeding. These strategies include acid inhibition therapy, preventive hemostasis using Doppler endoscopic ultrasound and artery-selective clipping, second look endoscopy, the closings method, and the shield methods. However, these methods are technically demanding, which hinders their wide usage in clinical practice. Recently, several hemostatic powders have been developed and clinically used in the treatment of gastrointestinal bleeding. In this article, we review the risk factors for post-ESD bleeding and the recently introduced prevention methods. Moreover, we aimed to explore realistic and appropriate strategies for the prevention of post-ESD bleeding.ope

Adverse Events Associated With Peroral Endoscopic Myotomy Affecting Extended Hospital Stay: A Multi-center Retrospective Study in South Korea

Background/aims: To analyze various adverse events (AEs) related to the peroral endoscopic myotomy (POEM) procedure and to analyze whether these AEs are related to an extended hospital stay. Methods: Patients admitted for POEM for esophageal motility disorders from August 2012 to February 2020 at 5 centers were retrospectively collected. Length of hospital stay, AEs during or after the POEM procedure were analyzed. Results: Of the 328 patients, 63.1% did not have any AEs, but 2.4% had major AEs, and 33.4% had minor AEs. Major AEs included mucosal injury, bleeding, and hemothorax, accounting for 1.5%, 0.6%, and 0.3%, respectively. Among the minor AEs, pneumoperitoneum was the most common gas-related AEs. Among non-gas-related minor AEs, pneumonia was the most common at 4.6%, followed by pain, fever, and pleural effusion. All major AEs had meaningful delayed discharge and significantly extended hospital stay compared to the no AEs group (median differences range 4.5-9.0 days). Among gas-related minor AEs, except for 4 cases of emphysema, the extended hospital stay was meaningless. All non-gas-related minor AEs was associated with a significant prolongation of hospital stay compared to that in the no AEs group (median differences range 2.0-4.0 days). Conclusions: In conclusion, most gas-related minor AEs do not significantly affect the patient's clinical course. However, subcutaneous emphysema and minor non-gas related AEs such as pneumonia, pain, fever, and pleural effusion can prolong the hospital stay, therefore careful observation is required. Efforts will be made to reduce major AEs that significantly prolong hospitalization.ope

High level of preoperative carbohydrate antigen 19-9 is a poor survival predictor in gastric cancer

AIM: To assess the clinical significance and the prognostic value of preoperative serum carbohydrate antigen 19-9 (CA 19-9) level in gastric cancer. METHODS: Between January 2005 and December 2006, 1960 patients underwent surgery for histologically confirmed gastric cancer. Of these, 163 patients had elevated serum levels of CA 19-9 preoperatively, and 1628 patients had normal serum levels of CA 19-9 preoperatively. For this study, 325 patients were selected from the group of 1628 patients by age, sex, and cancer stage to serve as controls. Statistically significant differences in survival rates were calculated using the log-rank test. A P value less than 0.05 was considered statistically significant and was determined using SAS software. RESULTS: The baseline characteristics showed some differences between the two groups with regard to histology. Overall survival (OS) in the elevated and non-elevated group was 37.90 and 68.67 mo, respectively (P < 0.001). N stage (P = 0.001) was a significant predictor of disease-free survival by multivariate analysis. Also, N stage (P < 0.001), and the presence of peritoneal metastasis (P < 0.001) remained independent factors in predicting OS by multivariate analysis. Additionally, preoperative serum CA 19-9 levels were significantly associated with OS in univariate (P = 0.009) and multivariate (P = 0.021) analyses. CONCLUSION: Serum CA 19-9 can be considered an independent prognostic factor in predicting OS in patients anticipating surgery for gastric cancer.ope

Efficacy of Endoscopic Vacuum-Assisted Closure Treatment for Postoperative Anastomotic Leak in Gastric Cancer

Background/aims: Endoscopic vacuum-assisted closure (EVAC) has been attempted as new nonsurgical treatment for anastomotic leakage. We aimed to evaluate the clinical outcomes of EVAC and compare its efficacy with the self-expandable metallic stent (SEMS) for postgastrectomy leakage. Methods: Between January 2007 and February 2018, 39 patients underwent endoscopic treatment for anastomotic leakage after gastric cancer surgery. Of them, 28 patients were treated with SEMS, seven with EVAC after SEMS failure, and four with EVAC. We retrospectively compared the clinical characteristics and therapeutic outcomes between EVAC (n=11) and SEMS (n=28). Results: The median followup duration was 17 months (interquartile range, 9 to 26 months) in both groups. In comparison of clinical characteristics between two groups, only the median size of the leak was larger in the EVAC group than in the SEMS group (2.1 cm vs 1.0 cm; p<0.001). All EVAC cases healed successfully; however, two cases (7.1%) failed to heal in the SEMS group. Anastomotic stricture occurred one case (9.1%) in EVAC and four cases (14.3%) in SEMS within 1 year after endoscopic treatment. The median treatment duration of EVAC was shorter than that of SEMS (15 days vs 36 days; p<0.001). Median weight loss after therapy was similar in both groups (8.0 kg in EVAC vs 9.0 kg in SEMS; p=0.356). Conclusions: EVAC can be effective endoscopic treatment for postgastrectomy anastomotic leakage. Substantial leakage could be an important clinical factor for considering EVAC as a treatment option. Large randomized controlled trials are needed to confirm the efficacy of EVAC.ope