• Journal of Gastric Cancer
• /
• v.20 no.4
• /
• pp.345-354
• /
• 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
• /
• v.11 no.3
• /
• pp.146-154
• /
• 2011

Endoscopic resection has been accepted as a curative modality for early gastric cancer (EGC). Since conventional endoscopic mucosal resection (EMR) has been introduced, many improvements in endoscopic accessories and techniques have been achieved. Recently, endoscopic submucosal dissection (ESD) using various electrosurgical knives has been performed for complete resection of EGC and enables complete resection of EGC, which is difficult to completely resect in the era of conventional EMR. Currently, ESD is accepted as the standard method for endoscopic resection of EGC in indicated cases. In this review, the history of endoscopic treatment for EGC, overall ESD procedures, and indications and clinical results of endoscopic treatment will be presented.

• Journal of Gastric Cancer
• /
• v.18 no.2
• /
• pp.152-160
• /
• 2018

Purpose: Totally laparoscopic gastrectomy (TLG) for advanced gastric cancer (AGC) is a technically and oncologically challenging procedure for surgeons. This study aimed to compare the oncologic feasibility and technical safety of TLG for AGC versus early gastric cancer (EGC). Materials and Methods: Between 2011 and 2016, 535 patients (EGC, 375; AGC, 160) underwent curative TLG for gastric cancer. Clinicopathologic characteristics and surgical outcomes of both patient groups were analyzed and compared. Results: Patients with AGC required a longer operation time and experienced more intraoperative blood loss than those with EGC did. However, patients from both the AGC and EGC groups demonstrated similar short-term surgical outcomes such as postoperative morbidity (14.4% vs. 13.3%, P=0.626), mortality (0% vs. 0.5%, P=0.879), time-to-first oral intake (2.7 days for both groups, P=0.830), and postoperative hospital stay (10.2 days vs. 10.1 days, P=0.886). D2 lymph node dissection could be achieved in the AGC group (95%), with an adequate number of lymph nodes being dissected ($36.0{\pm}14.9$). In the AGC group, the 3-year overall and disease-free survival rates were 80.5% and 73.7%, respectively. Conclusions: TLG is as safe and effective for AGC as it is for EGC.

• Journal of Gastric Cancer
• /
• v.23 no.1
• /
• pp.146-158
• /
• 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
• /
• v.10 no.3
• /
• pp.87-90
• /
• 2010

Early gastric cancer (EGC) is defined as tumor invasion confined to the mucosa or submucosa, regardless of the presence of regional lymph node metastasis. Lymph node metastasis is the most powerful and important prognostic factor for gastric cancer. Based on the risk of lymph node metastasis in EGC obtained from a large number of surgical cases in Japan, it was suggested that the criteria for endoscopic mucosal resection (EMR) and endoscopic submucosal resection (ESD) as local treatment for EGC might be extended. However, extending the indications for EMR and ESD remains controversial because the long-term outcomes of these procedures have not been fully documented, and there is a risk for lymph node metastasis. Furthermore, current diagnostic imaging techniques are unsatisfactory for accurately predicting metastasis to lymph nodes. Moreover, the long-term results of standard radical gastrectomy including minimally invasive procedures for stage IA have been increasing and have reached 99 to 100%. To determine the true efficacy of endoscopic resection of EGC, we need more evidence of long-term follow-up, standardization of techniques, and pathological interpretation.

• Journal of Gastric Cancer
• /
• v.17 no.4
• /
• pp.331-341
• /
• 2017

Purpose: This study aimed to evaluate the clinical significance of microscopic invasion to determine the adequate resection margin in early gastric cancer (EGC). Materials and Methods: A retrospective review was performed that included patients who underwent gastrectomy for clinical early gastric cancer (cEGC) at Seoul National University Hospital between January 2007 and December 2010. After subtracting the microscopic resection margin from the gross resection margin for each proximal or distal resection margin, microscopic invasion was represented by the larger value. Microscopic invasion and its risk factors were analyzed according to the clinicopathologic characteristics. Results: In total, 861 patients were enrolled in the study. Microscopic invasion of cEGC was $6.0{\pm}12.8mm$, and the proportion of patients with microscopic invasion ${\geq}0mm$ was 78.4%. In the risk group, tumor location, pT stage, and differentiation did not significantly discriminate the presence of microscopic invasion. The microscopic invasion of EGC-IIb was $13.9{\pm}16.8mm$, which was significantly greater than that of EGC-I. No linear correlation was observed between the overall tumor size and microscopic invasion (R=0.030). The independent risk factors for microscopic invasion ${\geq}20mm$ were EGC-IIb vs. EGC-I/IIa/IIc/III (odds ratio [OR], 3.103; 95% confidence interval [CI], 1.533-6.282; P=0.002) and male vs. female sex (OR, 1.655; 95% CI, 1.012-2.705; P=0.045). Conclusions: Male sex and EGC-IIb were independent risk factors for microscopic invasion ${\geq}20mm$. Examination of intraoperative frozen sections is highly recommended to avoid resection margin involvement, especially in cases of EGC-IIb.

• Journal of Gastric Cancer
• /
• v.1 no.2
• /
• pp.106-112
• /
• 2001

Purpose: Even with excellent surgical outcome, recurrence of early gastric cancer (EGC) after a curative resection is not declining because the incidence of EGC is increasing. The aim of this study was to propose an appropriate treatment strategy by assessing the risk factors for recurrence of curatively resected early gastric cancer. Materials and Methods: Of 3662 patients who had undergone gastric resections for gastric cancer from 1987 to 1996, the cases of 1050 curatively resected EGC patients were reviewed retrospectively. Among those 1050 patients, 50 patients ($4.8\%$) were diagnosed as having recurrent cancer, which was confirmed by clinico-radiological examination or re-operation. The risk factors that determined the recurrence patterns were investigated by using univariate and multivariate analyses. Results: The mean time to recurrence was 30.9 months, and hematogenous recurrence was the most frequent type ($32.0\%$). Among the 50 recurred patients, peritoneal recurrence showed the shortest mean time to recurrence ($18.5\pm17.7$months). Between the recurred and the non-recurred patients, there was no statistically significant difference with respect to age, sex, operation type, tumor size, tumor location, gross appearance, or histological differentiation. However, depth of invasion (submucosal invasion) and nodal involvement were significantly different (P<0.001) between the two groups. Using logistic regression analyses, nodal involvement was the only significant risk factor for recurrence in early gastric cancer (P<0.001). The median survival after the recurrence had been diagnosed was 4 months. Conclusion: Although the prognosis for EGC patients is excellent and recurrence of EGC after a curative resection is rare, the time to recurrence and the patterns of recurrence in EGC patients were diverse and unpredictable, and the result after recurrence is dismal. Considering the impact of lymph node metastasis on recurrence of EGC, a systematic lymphadenectomy, rather than limited surgery, should be performed if lymph node involvement is confirmed pre- or intraoperatively. Also if the postoperative pathologic findings reveal lymph node involvement, adjuvant chemotherapy is recommended.

• Journal of Digestive Cancer Research
• /
• v.10 no.2
• /
• pp.56-64
• /
• 2022

Narrow-band imaging (NBI) is the most widely used image-enhanced endoscopic technique. The superficial microanatomy of gastric mucosa can be visualized when used with a magnifying endoscopy with narrow-band imaging (ME-NBI). The diagnostic criteria for early gastric cancer (EGC), using the classification system for microvascular and microsurface pattern of ME-NBI, have been developed, and their usefulness has been proven in the differential diagnosis of small depressed cancer from focal gastritis and in lateral extent delineation of EGC. Some studies reported on the prediction of histologic differentiation and invasion depth of gastric cancer using ME-NBI; however, its application is limited in clinical practice, and further well-designed studies are necessary. Clinicians should understand the ME-NBI classification system and acquire appropriate diagnostic skills through various experiences and training to improve the quality of endoscopy for EGC diagnosis.

• Journal of Gastric Cancer
• /
• v.21 no.3
• /
• pp.246-257
• /
• 2021

Purpose: It is unclear whether high-definition (HD) imaging improves visibility and diagnostic ability in early gastric cancer (EGC) compared with standard-definition (SD) imaging. We aimed to compare the diagnostic performance and visibility scores of HD and SD ultraslim endoscopes in EGC. Materials and Methods: We used HD and SD ultraslim endoscopes to obtain 60 images with similar compositions of gastric environments. Of the 60 images, 30 showed EGC (15 images for each modality) and 30 showed no EGC (15 images for each modality). Seventeen endoscopists evaluated the presence and location of the lesions in each image. Diagnostic ability was compared between modalities. The color difference between a lesion and the surrounding mucosa (ΔE) was measured and compared between the modalities. Results: The ability of HD to detect EGC was significantly higher than that of SD (accuracy: 80.8% vs. 71.6%, P=0.017; sensitivity: 94.9% vs. 76.5%, P<0.001; positive predictive value, 76.2% vs. 55.3%, P<0.001; and negative predictive value (NPV), 94.1% vs. 73.5%, P<0.001). The ability of HD to determine the horizontal extent of EGC was significantly higher than that of SD (accuracy: 71.0% vs. 57.8%, P=0.004; sensitivity: 75.3% vs. 49.0%, P<0.001; NPV, 72.9% vs. 55.9%, P<0.001; and area under the curve: 0.891 vs. 0.631, P=0.038). The mean ΔE was significantly higher for HD than for SD (10.3 vs. 5.9, P=0.011). Conclusions: The HD ultraslim endoscope showed a higher diagnostic performance in EGC than the SD endoscope because it provided good color contrast.

• Journal of Gastric Cancer
• /
• v.20 no.3
• /
• pp.245-255
• /
• 2020

Purpose: Recently, non-exposure simple suturing endoscopic full-thickness resection (NESS-EFTR) was developed to prevent tumor exposure to the peritoneal cavity. This study aimed to evaluate the feasibility of NESS-EFTR with sentinel basin dissection for early gastric cancer (EGC). Materials and Methods: This was the prospective SENORITA 3 pilot. From July 2017 to January 2018, 20 patients with EGC smaller than 3 cm without an absolute indication for endoscopic submucosal dissection were enrolled. The sentinel basin was detected using Tc^99m-phytate and indocyanine green, and the NESS-EFTR procedure was performed when all sentinel basin nodes were tumor-free on frozen pathologic examination. We evaluated the complete resection and intraoperative perforation rates as well as the incidence of postoperative complications. Results: Among the 20 enrolled patients, one dropped out due to large tumor size, while another underwent conventional laparoscopic gastrectomy due to metastatic sentinel lymph nodes. All NESS-EFTR procedures were performed in 17 of the 18 other patients (94.4%) without conversion, and the complete resection rate was 83.3% (15/18). The intraoperative perforation rate was 27.8% (5/18), and endoscopic clipping or laparoscopic suturing or stapling was performed at the perforation site. There was one case of postoperative complications treated with endoscopic clipping; the others were discharged without any event. Conclusions: NESS-EFTR with sentinel basin dissection is a technically challenging procedure that obtains safe margins, prevents intraoperative perforation, and may be a treatment option for EGC after additional experience.