• Journal of Gastric Cancer
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• 제20권4호
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• pp.345-354
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• 2020

Early detection of gastric cancer is crucial because the survival rate can be improved through curative treatment. Although surgery and gastrectomy with lymph node dissection remain as the gold standard for curative treatment, early gastric cancer (EGC) with negligible risk of lymph node metastasis can be treated with endoscopic resection (ER), such as endoscopic submucosal dissection. Among gastric cancers, undifferentiated-type cancer is distinguished from differentiated-type cancer in various aspects in terms of clinical features and pathophysiology. The undifferentiated-type cancer is also known to be associated with an aggressive behavior and a poor prognosis. Therefore, the indication of ER for undifferentiated EGC is limited compared with differentiated-type. Recent studies have reported that ER for undifferentiated EGC is safe and shows favorable short- and long-term outcomes. However, it is necessary to understand the details of the research results and to selectively accept them. In this review, we aimed to evaluate the current practice guidelines and the short-term and long-term outcomes of ER for undifferentiated type EGC.

• Journal of Gastric Cancer
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• 제9권3호
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• pp.71-77
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• 2009

내시경 절제술은 림프절 전이의 위험도가 낮은 조기위암에 대한 근치적 국소 치료로 받아들여지고 있다. 최근 조기위암의 림프절 전이에 대한 연구결과들과 내시경 수기 및 부속기구의 발전에 기초하여 내시경 절제의 적용 범위는 확대되는 추세이다. 현재 조기위암의 내시경 절제의 확대 적응증으로는 궤양이 동반되지 않는 경우의 점막암이나, 궤양이 동반된 3 cm 이하의 점막암, 궤양이 없는 3 cm 이하의 미분화 점막암, 3 cm 이하의 궤양을 동반하지 않은 분화가 좋은 미세점막하암으로 림프혈관 침범이 없는 경우이다. 이 중 미분화암은 분화가 좋은 암과 비교하여 다른 생물학적 행태를 가진다는 관점에서 내시경 절제의 확대 적응증으로 포함하는 것에 있어 논란이 있는 상태이다. 따라서, 본 종설에서는 미분화 조기위암의 생물학적 행태와 내시경 절제술 결과에 기초하여 미분화 조기위암에서의 내시경 절제술 적용에 관하여 논해보고자 한다.

• Journal of Gastric Cancer
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• 제10권2호
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• pp.49-54
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• 2010

Endoscopic resection is now accepted as curative treatment modalities for early gastric cancer without lymph node metastasis. However, based on large-scaled data about the risk of lymph node metastasis in early gastric cancer and as a result of the technical development of endoscopic devices, it was suggested that the criteria for endoscopic resection should be extended. According to the treatment guidelines for gastric cancer in Japan, the extended indications include the following: differentiated-type mucosal cancer without ulceration and greater than 2 cm in diameter, differentiated-type mucosal cancer with ulceration and up to 3 cm in diameter, undifferentiated-type mucosal cancer without ulceration and up to 2 cm in diameter, and, in the absence of lymphovascular invasion, a tumor not deeper than submucosal level 1 (less than $500\;{\mu}m$). In this review, we discuss the evidence of the application of expanded endoscopic indication based on analysis of biologic behavior and data of endoscopic resection.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5371-5375
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• 2014

Background: An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of early gastric cancers. Therefore, this study analyzed predictive factors associated with lymph node metastasis and identified differences between mucosal and submucosal gastric cancers. Materials and Methods: A total of 518 early gastric cancer patients who underwent radical gastrectomy were reviewed in this study. Clinicopathological features were analyzed to identify predictive factors for lymph node metastasis. Results: The rate of lymph node metastasis in early gastric cancer was 15.3% overall, 3.3% for mucosal cancer, and 23.5% for submucosal cancer. Using univariate analysis, risk factors for lymph node metastasis were identified as tumor location, tumor size, depth of tumor invasion, histological type and lymphovascular invasion. Multivariate analysis revealed that tumor size >2 cm, submucosal invasion, undifferentiated tumors and lymphovascular invasion were independent risk factors for lymph node metastasis. When the carcinomas were confined to the mucosal layer, tumor size showed a significant correlation with lymph node metastasis. On the other hand, histological type and lymphovascular invasion were associated with lymph node metastasis in submucosal carcinomas. Conclusions: Tumor size >2 cm, submucosal tumor, undifferentiated tumor and lymphovascular invasion are predictive factors for lymph node metastasis in early gastric cancer. Risk factors are quite different depending on depth of tumor invasion. Endoscopic treatment might be possible in highly selective cases.

• Journal of Digestive Cancer Research
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• 제6권2호
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• pp.55-58
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• 2018

Gastric signet ring cell carcinoma (SRC) is a poorly differentiated or undifferentiated cancer of the stomach. However, early gastric SRC showed lower LN metastasis in many studies, thus some endoscopists now regard early gastric SRC as a candidate for endoscopic treatment. But there are unsolved problems of the validity of endoscopic resection in early gastric SRC. In this review, we will comprehensively review the previous clinical studies and discuss the limitation of current studies and the possibility of endoscopic resection of early gastric SRC.

• Journal of Gastric Cancer
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• 제16권1호
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• pp.34-42
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• 2016

Purpose: Early gastric cancer cases that are estimated to meet indications for treatment before endoscopic submucosal resection are often revealed to be out-of-indication after the treatment. We investigated the short-term treatment outcomes in patients with early gastric cancer according to the pretreatment clinical endoscopic submucosal resection indications. Materials and Methods: We retrospectively reviewed the medical records of patients with early gastric cancer that met the pretreatment endoscopic submucosal resection indications, from 2004 to 2011. Curative resection rate and proportion of out-of-indication cases were compared according to the pre-endoscopic submucosal resection indications. Pre-endoscopic submucosal resection factors associated with out-of-indication in the final pathological examination were analyzed. Results: Of 756 cases, 660 had absolute and 96 had expanded pre-endoscopic submucosal resection indications. The curative resection rate was significantly lower in the patients with expanded indications (64.6%) than in those with absolute indications (81.7%; P<0.001). The cases with expanded indications (30.2%) were revealed to be out-of-indication more frequently than the cases with absolute indications (13.8%; P<0.001). Age of >65 years, tumor size of >2 cm, tumor location in the upper-third segment of the stomach, and undifferentiated histological type in pre-endoscopic submucosal resection evaluations were significant risk factors for out-of-indication after endoscopic submucosal resection. Conclusions: Non-curative resection due to out-of-indication occurred in approximately one-third of the early gastric cancer cases that clinically met the expanded indications before endoscopic submucosal resection. The possibility of additional surgery should be empha-sized for patients with early gastric cancers that clinically meet the expanded indications.

• Journal of Gastric Cancer
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• 제18권4호
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• pp.400-408
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• 2018

Purpose: This study aimed to evaluate immediate outcomes and clinical courses of patients with early gastric carcinoma with lymphoid stroma (GCLS) who underwent endoscopic resection. Materials and Methods: We retrospectively reviewed the medical records of 40 patients (mean age, 56.9 years; 90.0% male) who underwent endoscopic resection and were pathologically diagnosed with GCLS confined to the mucosa or to the submucosa between March 1998 and December 2017. Results: Forty GCLS lesions in 40 patients were treated using endoscopic resection. Only 4 (10%) patients received diagnosis of GCLS before endoscopic resection. Fourteen (35.0%) lesions were intramucosal cancers and 26 (65.0%) exhibited submucosal invasion. En bloc resection (97.5%) was achieved for all lesions except one, with no significant complications. The complete resection rate was 85.0% (34 of 40 lesions). After endoscopic resection, 17 patients were referred for surgery and underwent gastrectomy with lymph node (LN) dissection because of deep submucosal invasion (n=16) and misclassification as undifferentiated cancer (n=1). No LN metastasis was determined in the specimens obtained during surgery. During a mean follow-up period of 49.7 months for 23 patients without surgical treatment, no regional LN enlargements, distant metastases, or gastric cancer-related deaths were found, although 1 metachronous lesion (undifferentiated adenocarcinoma, follow-up duration: 7 months) was observed. Conclusions: In patients with early GCLS, endoscopic resection is technically feasible and has favorable clinical outcomes. Therefore, endoscopic resection might represent an alternative treatment modality in patients with early GCLS with a low likelihood of LN metastasis.

• Journal of Gastric Cancer
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• 제23권1호
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• pp.146-158
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• 2023

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

• Journal of Gastric Cancer
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• 제7권1호
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• pp.23-30
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• 2007

목적: 위암 환자 수술 후 재발의 임상병리학적 특성에 대한 이해는 재발의 조기 발견과 이에 따른 보다 나은 치료 성적을 얻기 위하여 필수적인 정보이다. 즉 종양의 특성에 따른 재발의 유형, 재발시기, 재발 이후의 경과 등을 이해하고자 본 연구를 시행하였다. 대상 및 방법: 1992년 6월부터 2005년 12월까지 본원 외과에서 위암으로 근치적수술을 시행 받은 1,338명의 환자 가운데 재발 유형을 모르는 경우(n=60), 사고사 및 타 질환으로 사망한 경우(n=55)를 제외한 1,223명을 연구 대상자로 하였다. 재발예(n=241)와 비재발예(n=982) 사이의 임상병리학적 특성 및 재발예 가운데 재발의 유형에 따른 임상병리학적 특성을 비교 분석하였다. 결과: 재발예는 비재발예에 비하여 위전절제술, 진행된 병기, 림프관이나 혈관 침윤예, 위전벽암, 크기가 큰 암, 미분화암, 미만형, Borrmann 4형이 의미 있게 많았다. 복막파종은 여성, stage III, 위상부 및 위전벽암, 미분화암, 미만형, Borrmann 4형이 의미 있게 많았고, 혈행성전이는 조기위암, stage I, 국소전이는 Borrmann 1, 2, 3형이 의미 있게 많았다. 복막파종의 경우 혈행성전이나 국소전이에 비하여 재발 후 생존기간이 짧았다(7.0개월, 9.5개월, 12.5개월). 조기재발군은 병기3, 4기, N3, 림프관침윤율이 높았고, 후기재발군은 병기3기, N1이 조기재발군에 비해 의미 있게 많았다. 결론: 위암의 임상병리학적 특성에 대한 이해가 위암수술 후 재발을 조기에 발견하는 데 중요할 것으로 판단된다.

• Journal of Gastric Cancer
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• 제24권2호
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• pp.172-184
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• 2024

Purpose: The original eCura system was designed to stratify the risk of lymph node metastasis (LNM) after endoscopic resection (ER) in patients with early gastric cancer (EGC). We assessed the effectiveness of a modified eCura system for reflecting the characteristics of undifferentiated-type (UD)-EGC. Materials and Methods: Six hundred thirty-four patients who underwent non-curative ER for UD-EGC and received either additional surgery (radical surgery group; n=270) or no further treatment (no additional treatment group; n=364) from 18 institutions between 2005 and 2015 were retrospectively included in this study. The eCuraU system assigned 1 point each for tumors >20 mm in size, ulceration, positive vertical margin, and submucosal invasion <500 ㎛; 2 points for submucosal invasion ≥500 ㎛; and 3 points for lymphovascular invasion. Results: LNM rates in the radical surgery group were 1.1%, 5.4%, and 13.3% for the low-(0-1 point), intermediate- (2-3 points), and high-risk (4-8 points), respectively (P-fortrend<0.001). The eCuraU system showed a significantly higher probability of identifying patients with LNM as high-risk than the eCura system (66.7% vs. 22.2%; McNemar P<0.001). In the no additional treatment group, overall survival (93.4%, 87.2%, and 67.6% at 5 years) and cancer-specific survival (99.6%, 98.9%, and 92.9% at 5 years) differed significantly among the low-, intermediate-, and high-risk categories, respectively (both P<0.001). In the high-risk category, surgery outperformed no treatment in terms of overall mortality (hazard ratio, 3.26; P=0.015). Conclusions: The eCuraU system stratified the risk of LNM in patients with UD-EGC after ER. It is strongly recommended that high-risk patients undergo additional surgery.