Vol.10 No.1, June 01, 2022
최수인Journal of Digestive Cancer Research 2022; 10(1): 1-8 https://doi.org/10.52927/jdcr.2022.10.1.1
Abstract : The incidence of gastric neuroendocrine tumors (NET) has been increased with the improvement of endoscopy accessibility. The World Health Organization classified NET of low (G1), intermediate (G2), high (G3) grade and neuroendocrine carcinoma with poor differentiation by mitotic count and Ki-67 labeling index. Gastric NET are divided into three subtypes based on the pathophysiology, and treatment is determined according to the subtype and prognostic factors of tumor. For diagnosis, endoscopy with biopsy, endoscopic ultrasonography, abdominal pelvis computed tomography, and serum gastrin level measure are required. In general, type 3, size > 2 cm, deep submucosal infiltration, high histological grade, lymphovascular invasion and metastasis are poor prognostic factors. Type 1 or 2 without these factors are treated by endoscopic resection, and other tumors needs surgery. Endoscopic resection of early type 3 or type 1 and 2 tumors with poor prognostic factors still remains a challenge.
서승인Journal of Digestive Cancer Research 2022; 10(1): 9-15 https://doi.org/10.52927/jdcr.2022.10.1.9
Abstract : Proton pump inhibitors (PPIs), a potent gastric acid inhibitor, are widely used in gastric acid-related diseases such as gastroesophageal reflux disease and peptic ulcer, and are known as the most frequently used drugs worldwide. However, as the frequency of use increases, the number of cases of long-term PPI therapy without clear indications is increasing. Recently, there have been concerns about the risk of gastric cancer in patients with long-term PPI users. Potential mechanisms for the association between PPI and gastric cancer include enterochromaffin-like cell proliferation due to hypergastrinemia caused by gastric acid suppression, progression of atrophic gastritis, and corpus-predominant type through interaction with Helicobacter pylori (H. pylori) infection. Several epidemiologic studies showed controversial results on the issue, and it is difficult to prove a causal relationship between PPI and gastric cancer. Nevertheless, long-term PPI should be administered cautiously based on individual risk-benefit profile, specifically among those with history of H. pylori infection, in high-risk region of gastric cancer.
임현철Journal of Digestive Cancer Research 2022; 10(1): 16-21 https://doi.org/10.52927/jdcr.2022.10.1.16
Abstract : Diagnosis of gastric subepithelial tumors (SETs) is sometimes difficult with conventional endoscopy or tissue sampling with standard biopsy, so non-invasive imaging modalities such as endoscopic ultrasound (EUS) and computed tomography are used to evaluate the characteristics of SETs features (size, location, originating layer, echogenicity, shape). However imaging modalities alone is not able to distinguish among all types of SETs, so histology is the gold standard for obtaining the final diagnosis. For tissue sampling, mucosal cutting biopsy and mucosal incision-assisted biopsy and EUS-guided fine-needle aspiration or biopsy (EUS-FNA or EUS-FNB) is commonly recommended. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used for resection of SETs involving the mucosal and superficial submucosal layers, could not treat adequately and safely the SETs involving the deep mucosa and muscularis propria. Submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) is used as a therapeutic option for the treatment of SETs with the development of reliable endoscopic closure techniques and tools.
손병석Journal of Digestive Cancer Research 2022; 10(1): 22-30 https://doi.org/10.52927/jdcr.2022.10.1.22
Abstract : Immune checkpoint inhibition has been established as a new treatment option for various types of carcinoma, and many clinical trials are being actively conducted as a treatment for advanced or metastatic gastric cancer, either as a monotherapy with an immune checkpoint inhibitor or as a combination therapy with standard chemotherapy. In the CheckMate-649 clinical trial to confirm the efficacy of the combination of nivolumab and chemotherapy (FP) in advanced gastric cancer and gastroesophageal junction cancer, nivolumab group showed improvement in overall survival in programmed death ligand 1-positive cancer patients compared with placebo group. Also, the combination therapy of pembrolizumab, trastuzumab and chemotherapy (FP) in first-line treatment was tested through the KEYNOTE-811 trial. The pembrolizumab group showed 22.7% of improvement in objective response rate compared with placebo group. Accordingly, the combination of nivolumab/pembrolizumab with standard chemotherapy was approved for the first-line treatment. In KEYNOTE-059 trials for patients with progressive disease after at least two lines of chemotherapy, pembrolizumab monotherapy showed improvement in objective response rate and overall survival, and the use of pembrolizumab was approved for the third-line or more treatment. In this article, we review the result of clinical trials related to immune checkpoint inhibitors that have been recently introduced in the treatment of gastric cancer.
성미경Journal of Digestive Cancer Research 2022; 10(1): 31-38 https://doi.org/10.52927/jdcr.2022.10.1.31
Abstract : Ulcerative colitis (UC) exhibits chronic intestinal inflammatory conditions with cycles of relapse and remission. The incidence is rapidly growing in Asian countries including South Korea possibly due to changes in lifestyles. Although the etiology of inflammatory bowel disease is inconclusive, gut microbiota composition is considered a critical factor involved in the pathogenesis of UC. The overgrowth of pathogenic bacteria evokes hyper-immune responses in gut epithelium causing tissue inflammation and damage. Also, failure to regulate gut epithelium integrity due to chronic inflammation and mucus depletion accelerates bacterial translocation aggravating immune dysregulation. Gut microbiota composition responds to the diet in a very rapid manner. Epidemiological studies have indicated that the risk of UC is associated with low plant foods/high animal foods consumption. Several bacterial strains consistently found depleted in UC patients use plant food-originated dietary fiber producing short chain fatty acids to maintain epithelial integrity. These bacteria also use mucus layer mucin to keep gut microbiota diversity. These studies partly explain the association between dietary modification of gut microbiota in UC development. Further human intervention trials are required to allow the use of specific bacterial strains in the management of UC.
Abstract : Primary duodenal follicular lymphoma is rare and presents as multiple, small polyp-like lesions on endoscopy. If this lesion is suspected, an endoscopic biopsy is crucial for diagnosis. A watchful wait would be appropriate management as it has a fairly indolent clinical course. Herein, we present a rare case of primary duodenal follicular lymphoma.