• Journal of Digestive Cancer Research
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• v.8 no.1
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• pp.1-50
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• 2020

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.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.427-437
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• 2019

Purpose: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer. Materials and Methods: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS). Results: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423-2.054; P=0.861). Conclusions: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.665-671
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• 2004

Background: Lymph node metastasis is commonly reported in thoracic esophageal cancer, even in the early esophageal cancer which may be localized only in the mucosa or within the submucosal layer. Although lymph node metastasis greatly influence long-term outcome and cure of the disease, endoscopic mucosal resection or photodynamic therapy without lymph node dissection is widely attempted. The investigation of the pattern of lymph node metastasis and results of surgical resection of superficial esophageal cancer is needed. Material and Method: Pattern of lymph node metastsis and depth of tumor invasion were studied retrospectively from 44 patients with early esophageal cancer who underwent radical resection of the tumor from December, 1995 to August, 2001. Result: Lymph node metastasis was found in 10 patients (22.7%) out of total of 44 patients. Lymph node metastasis was found in 0% (0 of 3), 0% (0 of 4), 50% (2 of 4), and 24.24% (8 of 33) of tumors that invaded the intraepitherium, lamina propria, muscularis mucosa, and submucosa respectively. Anatomically distant lymph node metastases were found more frequently in recurrent laryngeal nerve node(5 cases of 10 patients) and in intraperitoneal node (8 cases of 10). than intrathoracic node (3 cases of 10). There was no operative mortality, however, there were 1 hospital death in patient with lamina propria cancer, 1 late death in patient with submucosal cancer. Three-year survival rates (except hospital death) were 100% in mucosal cancer and 97.0% in submucosal cancer (p>0.05), and 100% in the node negative group and 90.0% in the node positive group (p>0.05). Conclusion: The survival rate of superficial esophageal cancer patient who was recieved operative resection was excellent. But, lymph node metastasis were found in superficial esophageal cancer, even in esophageal cancer limited to the muscularis mucosa. Systemic lymph node dissection which includes recurrent laryngeal nerve nodes and intraperitoneal nodes was recommended for favorable outcome in superficial esophageal cancer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.9
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• pp.807-814
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• 2013

A fundamental study on laser-tissue interaction was conducted with the aim of developing a therapeutic medical device that can remove lesions on the intestinal wall by irradiating a high-power 808-nm infrared laser light incorporated in an endoscopic system. The perforation depth was linearly increased in the range of 1~4 mm in proportional to laser output (3~12 W) and irradiation time (5~20 s). We demonstrated that the perforation depth during laser irradiation was varied according to the tissue property of each extracted porcine organ. The measurement of the temperature distribution suggests that the energy is localized in the irradiation spot and transferred to deep tissue, which protects the surrounding tissue from thermal injury. These results can be used to set the driving parameters for a laser incision technique as an alternative to conventional surgical interventions.

• Journal of Gastric Cancer
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• v.23 no.2
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• pp.355-364
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• 2023

Background: There are no clear guidelines to determine whether to perform D1 or D1+ lymph node dissection in early gastric cancer (EGC). This study aimed to develop a nomogram for estimating the risk of extraperigastric lymph node metastasis (LNM). Materials and Methods: Between 2009 and 2019, a total of 4,482 patients with pathologically confirmed T1 disease at 6 affiliated hospitals were included in this study. The basic clinicopathological characteristics of the positive and negative extraperigastric LNM groups were compared. The possible risk factors were evaluated using univariate and multivariate analyses. Based on these results, a risk prediction model was developed. A nomogram predicting extraperigastric LNM was used for internal validation. Results: Multivariate analyses showed that tumor size (cut-off value 3.0 cm, odds ratio [OR]=1.886, P=0.030), tumor depth (OR=1.853 for tumors with sm2 and sm3 invasion, P=0.010), cross-sectional location (OR=0.490 for tumors located on the greater curvature, P=0.0303), differentiation (OR=0.584 for differentiated tumors, P=0.0070), and lymphovascular invasion (OR=11.125, P<0.001) are possible risk factors for extraperigastric LNM. An equation for estimating the risk of extraperigastric LNM was derived from these risk factors. The equation was internally validated by comparing the actual metastatic rate with the predicted rate, which showed good agreement. Conclusions: A nomogram for estimating the risk of extraperigastric LNM in EGC was successfully developed. Although there are some limitations to applying this model because it was developed based on pathological data, it can be optimally adapted for patients who require curative gastrectomy after endoscopic submucosal dissection.

• Journal of Gastric Cancer
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• v.14 no.2
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• pp.129-134
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• 2014

Purpose: This study aimed to analyze the effect of screening by using endoscopy on the diagnosis and treatment of gastric cancer. Materials and Methods: The clinicopathologic characteristics of gastric cancer were compared in individuals who underwent an endoscopy because of symptoms (non-screening group) or for screening purposes (screening group). The distributions of gastric cancer stages and treatment modalities in 2006 and 2011 were compared. Results: The proportion of patients in the screening group increased from 45.1% in 2006 to 65.4% in 2011 (P<0.001). The proportion of stage I cancers in the entire patient sample also increased (from 60.5% in 2006 to 70.6% in 2011; P=0.029). In 2011, the percentages of patients with cancer stages I, II, III, and IV were 79.9%, 8.2%, 10.9%, and 1.1%, respectively, in the screening group, and 47.9%, 10.8%, 29.8%, and 11.5%, respectively, in the non-screening group. The proportion of laparoscopic and robotic surgeries increased from 9.6% in 2006 to 48.3% in 2011 (P<0.001), and endoscopic submucosal dissection increased from 9.8% in 2006 to 19.1% 2011 (P<0.001). Conclusions: The proportion of patients diagnosed with gastric cancer by using the screening program increased between 2006 and 2011. This increase was associated with a high proportion of early-stage cancer diagnoses and increased use of minimally invasive treatments.