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Background: Only a subset of gastric cancer (GC) patients with stage II–III benefits from chemotherapy after surgery. Tumour infiltrating lymphocytes per area (TIL density) has been suggested as a potential predictive biomarker of chemotherapy benefit. Methods: We quantified TIL density in digital images of haematoxylin-eosin (HE) stained tissue using deep learning in 307 GC patients of the Yonsei Cancer Center (YCC) (193 surgery+adjuvant chemotherapy [S + C], 114 surgery alone [S]) and 629 CLASSIC trial GC patients (325 S + C and 304 S). The relationship between TIL density, disease-free survival (DFS) and clinicopathological variables was analysed. Results: YCC S patients and CLASSIC S patients with high TIL density had longer DFS than S patients with low TIL density (P = 0.007 and P = 0.013, respectively). Furthermore, CLASSIC patients with low TIL density had longer DFS if treated with S + C compared to S (P = 0.003). No significant relationship of TIL density with other clinicopathological variables was found. Conclusion: This is the first study to suggest TIL density automatically quantified in routine HE stained tissue sections as a novel, clinically useful biomarker to identify stage II–III GC patients deriving benefit from adjuvant chemotherapy. Validation of our results in a prospective study is warranted.

Supplementary Figures

Supplementary Figure S1. Effect of H. pylori infection. Supplementary Figure S2. Suppression of CDX1 in gastric cancer cell lines. Supplementary Figure S3. Expression of CDX1 and stemness markers. Supplementary Figure S4. Effect of metformin on CDX1-expressing cells. Supplementary Figure S5. CDX1 suppression and the effect of chemotherapeutic agents.

Intestinal-type gastric cancer often results from Helicobacter pylori infection through intestinal metaplasia, a transdifferentiated premalignant phenotype. Because H. pylori virulence factor CagA has been associated with aberrant expression of the transcription factor CDX1, which regulates intestinal differentiation, we explored its relationship with H. pylori infection and function during gastric carcinogenesis in normal gastric epithelial cells and gastric cancer cell lines. Infection of HFE 145 cells with CagA+ H. pylori increased expression of CDX1, as well as the epithelial-to-mesenchymal transition (EMT) markers Snail and Slug, increased invasion and migration, but those effects were not found in HFE 145 cells infected with CagA-deficient H. pylori. CDX1 overexpression increased expression of the intestinal markers Villin, sucrose isomaltase (SI), and MUC2, induced spheroid formation, and enhanced expression of the stem cell markers CD44, SOX2, Oct4, and Nanog, while CDX1 knockdown inhibited proliferation and intestinal stemness. Treatment of CDX1-expressing cells with metformin, an antidiabetic drug known to decrease the risk of gastric cancer, decreased expression of EMT and stemness markers, and reduced spheroid formation. In a murine xenograft model, combining metformin or shCDX1 with cisplatin reduced tumor growth, increased caspase-3 cleavage, and reduced expression of CD44 and MMP-9 to a greater degree than cisplatin alone. Patients with more advanced intestinal metaplasia staging exhibited higher CDX1 expression than those with earlier intestinal metaplasia staging (P = 0.039), and those with H. pylori tended to have more CDX1 expression than noninfected patients (P = 0.061). Finally, human tissue samples with higher CDX1 levels showed prominent CD44/SOX2 expression. Our findings indicate CagA+ H. pylori–induced CDX1 expression may enhance gastric cancer tumorigenesis and progression, and support therapeutic targeting of CDX1 in gastric cancer.Implications:This study shows that CDX1 contributes to the tumorigenesis and progression of gastric cancer and suggests the potential of targeting CDX1 to treat this malignancy.

Supplementary Figure Legend

Supplementary Figures S1-S5

Purpose:Lauren diffuse-type gastric adenocarcinomas (DGAs) are generally genomically stable. We identified lysine (K)-specific methyltransferase 2C (KMT2C) as a frequently mutated gene and examined its role in DGA progression.Experimental Design:We performed whole exome sequencing on tumor samples of 27 patients with DGA who underwent gastrectomy. Lysine (K)-specific methyltransferase 2C (KMT2C) was analyzed in DGA cell lines and in patient tumors.Results:KMT2C was the most frequently mutated gene (11 of 27 tumors [41%]). KMT2C expression by immunohistochemistry in tumors from 135 patients with DGA undergoing gastrectomy inversely correlated with more advanced tumor stage (P = 0.023) and worse overall survival (P = 0.017). KMT2C shRNA knockdown in non-transformed HFE-145 gastric epithelial cells promoted epithelial-to-mesenchymal transition (EMT) as demonstrated by increased expression of EMT-related proteins N-cadherin and Slug. Migration and invasion in gastric epithelial cells following KMT2C knockdown increased by 47- to 88-fold. In the DGA cell lines MKN-45 and SNU-668, which have lost KMT2C expression, KMT2C re-expression decreased expression of EMT-related proteins, reduced cell migration by 52% to 60%, and reduced cell invasion by 50% to 74%. Flank xenografts derived from KMT2C-expressing DGA organoids, compared with wild-type organoids, grew more slowly and lost their infiltrative leading edge. EMT can lead to the acquisition of cancer stem cell (CSC) phenotypes. KMT2C re-expression in DGA cell lines reduced spheroid formation by 77% to 78% and reversed CSC resistance to chemotherapy via promotion of DNA damage and apoptosis.Conclusions:KMT2C is frequently mutated in certain populations with DGA. KMT2C loss in DGA promotes EMT and is associated with worse overall survival.

Supplementary Tables 1-4

Lymphatic invasion (LI) is a potent risk factor for lymph node metastasis (LNM) in early gastric cancer (EGC) after endoscopic submucosal dissection (ESD). However, there are also other risk factors for LNM. Hence, to identify the need for additional surgery in some case of EGC without LI, the present study aimed to identify the risk factors for LNM in patients with EGC without LI.Data from 2284 patients diagnosed with EGC who underwent curative surgery at National Cancer Center in Korea from January 2012 to May 2019 were collected. The clinicopathological characteristics of patients with EGC without LI were compared on the basis of LNM status.There were 339 (17.1%) and 1648 (82.9%) patients with and without LI respectively. Among these patients with and without LI, 118 (34.8%) and 91 (5.5%) patients presented with LNM, respectively. In patients with EGC without LI, tumor size larger than 3 cm (OR = 2.12, 95% CI = 1.22-3.68; p = 0.007), submucosal invasion (OR = 4.14, 95% CI = 2.57-6.65; p 0.001), and undifferentiated histologic type (OR = 2.33, 95% CI = 1.45-3.76; p 0.001) were significant risk factors for LNM. Rates of LNM in patients meeting absolute, expanded, and beyond expanded criteria without LI were 0%, 1.5% (OR = 3.27, 95% CI = 0.18-59.41; p = 0.423), and 7.3% respectively. When the expanded criteria were divided into four subtypes patients with EGC, without LI within each subtype did not show significant risk of incidence of LNM compared to the absolute criteria.The current expanded criteria for endoscopic resection (ER) are tolerable in cases without LI, even though minimal risk LNM exists. Therefore, additional surgery may not be needed for patients meeting expanded criteria for ER.

PURPOSE Adjuvant chemotherapy after D2 gastrectomy is standard for resectable locally advanced gastric cancer (LAGC) in Asia. Based on positive findings for perioperative chemotherapy in European phase III studies, the phase III PRODIGY study (ClinicalTrials.gov identifier: NCT01515748 ) investigated whether neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) followed by surgery and adjuvant S-1 could improve outcomes versus standard treatment in Korean patients with resectable LAGC. PATIENTS AND METHODS Patients 20-75 years of age, with Eastern Cooperative Oncology Group performance status 0-1, and with histologically confirmed primary gastric or gastroesophageal junction adenocarcinoma (clinical TNM staging: T2-3N+ or T4Nany) were randomly assigned to D2 surgery followed by adjuvant S-1 (40-60 mg orally twice a day, days 1-28 every 6 weeks for eight cycles; SC group) or neoadjuvant DOS (docetaxel 50 mg/m2, oxaliplatin 100 mg/m2 intravenously day 1, S-1 40 mg/m2 orally twice a day, days 1-14 every 3 weeks for three cycles) before D2 surgery, followed by adjuvant S-1 (CSC group). The primary objective was progression-free survival (PFS) with CSC versus SC. Two sensitivity analyses were performed: intent-to-treat and landmark PFS analysis. RESULTS Between January 18, 2012, and January 2, 2017, 266 patients were randomly assigned to CSC and 264 to SC at 18 Korean study sites; 238 and 246 patients, respectively, were treated (full analysis set). Follow-up was ongoing in 176 patients at data cutoff (January 21, 2019; median follow-up 38.6 months [interquartile range, 23.5-62.1]). CSC improved PFS versus SC (adjusted hazard ratio, 0.70; 95% CI, 0.52 to 0.95; stratified log-rank P = .023). Sensitivity analyses confirmed these findings. Treatments were well tolerated. Two grade 5 adverse events (febrile neutropenia and dyspnea) occurred during neoadjuvant treatment. CONCLUSION PRODIGY showed that neoadjuvant DOS chemotherapy, as part of perioperative chemotherapy, is effective and tolerable in Korean patients with LAGC.

With the increase in the incidence of early gastric cancer (EGC), several endoscopic and laparoscopic approaches, such as endoscopic submucosal dissection and function-preserving gastrectomy, have been accepted as standard treatments. Sentinel node navigation surgery (SNNS) is an ideal surgical option for preservation of most parts of the stomach and consequent maintenance of normal gastric function to improve quality of life in patients with EGC. Although many previous studies and clinical trials have demonstrated the safety and feasibility of the sentinel node concept in gastric cancer, the clinical application of SNNS is debatable. Several issues regarding technical standardization and oncological safety need to be resolved. Recently several studies to resolve these problems are being actively performed, and SNNS might be an important surgical option in the treatment of gastric cancer in the future.

Sentinel node navigation surgery reduces the extent of gastric and lymph node dissection, and may improve quality of life. The benefit and harm of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer is unknown. The SENORITA (SEntinel Node ORIented Tailored Approach) trial investigated the pathological and surgical outcomes of LSNNS compared with laparoscopic standard gastrectomy (LSG) with lymph node dissection.The SENORITA trial was an investigator-initiated, open-label, parallel-assigned, non-inferiority, multicentre RCT conducted in Korea. The primary endpoint was 3-year disease-free survival. The secondary endpoints, morbidity and mortality within 30 days of surgery, are reported in the present study.A total of 580 patients were randomized to LSG (292) or LSNNS (288). Surgery was undertaken in 527 patients (LSG 269, LSNNS 258). LSNNS could be performed according to the protocol in 245 of 258 patients, and a sentinel node basin was detected in 237 (96·7 per cent) Stomach-preserving surgery was carried out in 210 of 258 patients (81·4 per cent). Postoperative complications occurred in 51 patients in the LSG group (19·0 per cent) and 40 (15·5 per cent) in the LSNNS group (P = 0·294). Complications with a Clavien-Dindo grade of III or higher occurred in 16 (5·9 per cent) and 13 (5·0 per cent) patients in the LSG and LSNNS groups respectively (P = 0·647).The rate and severity of complications following LSNNS for early gastric cancer are comparable to those after LSG with lymph node dissection. Registration number: NCT01804998 ( http://www.clinicaltrials.gov).La cirugía de navegación del ganglio centinela (sentinel node navigation surgery, SNNS) reduce la extensión de la resección gástrica y ganglionar, y puede mejorar la calidad de vida. Se desconoce el beneficio y el daño de la cirugía de navegación del ganglio centinela por vía laparoscópica (laparoscopic sentinel node navigation surgery, LSNNS) para el cáncer gástrico precoz. El ensayo clínico SENORITA investigó los resultados patológicos y quirúrgicos de LSNNS en comparación con la gastrectomía laparoscópica estándar (laparoscopic gastrectomy, LSG) con disección ganglionar (lymph node dissection, LND). MÉTODOS: El ensayo SENORITA fue un ensayo multicéntrico aleatorizado y controlado, iniciado por investigadores, abierto, con asignación a grupos paralelos y de no inferioridad llevado a cabo en Corea. El resultado primario fue la supervivencia libre de enfermedad a los 3 años. En el presente estudio, se describen los resultados secundarios correspondientes a morbilidad y mortalidad a los 30 días del postoperatorio.Un total de 580 pacientes fueron aleatorizados a LG (n = 292) o LSNNS (n = 288). La cirugía se realizó en 527 pacientes (LG 269, LSNNS 258). LSNNS pudo ser realizada de acuerdo con el protocolo en 245 de 258 pacientes y en 237 de 245 pacientes (96,7%) se detectó un ganglio centinela. La cirugía con preservación del estómago se realizó en 210 de 258 pacientes (81,4%). Las complicaciones postoperatorias se presentaron en 51 pacientes del grupo LSG (19,0%) y en 40 pacientes (15,5%) del grupo LSNNS (P = 0,294). Las complicaciones grado III o mayor de Clavien-Dindo se detectaron en 16 (5,9%) y 13 pacientes (5,0%) de los grupos LSG y LSNNS, respectivamente (P = 0,647). CONCLUSIÓN: El porcentaje y la gravedad de las complicaciones tras LSNNS para cancer gástrico precoz son comparables a la LSG con LND.

PURPOSE To compare postoperative complications, long-term survival, and quality of life (QOL) after laparoscopic sentinel node navigation surgery (LSNNS) and laparoscopic standard gastrectomy (LSG). METHODS Five hundred eighty patients with preoperatively diagnosed stage IA gastric adenocarcinoma (≤ 3 cm) were assigned to undergo either LSG or LSNNS. Observers were not blinded to patient grouping. The primary outcome was 3-year disease-free survival (3y-DFS). Secondary outcomes included postoperative complications, QOL, 3-year disease-specific survival (3y-DSS), and 3-year overall survival (3y-OS). RESULTS In total, 527 patients were included in the modified intention-to-treat analysis population for the primary outcome (LSG, 269; LSNNS, 258). Stomach-preserving surgery was performed in 210 patients (81%) in the LSNNS group. During the median follow-up duration, the 3y-DFS rates in the LSG and LSNNS groups were 95.5% and 91.8%, respectively (difference: 3.7%; 95% CI, –0.6 to 8.1). Three patients with recurrence and five with metachronous gastric cancer in the LSNNS group underwent standard surgery. Two patients with distant metastasis in both groups were treated with palliative chemotherapy. The 3y-DSS and 3y-OS rates in the LSG and LSNNS groups were 99.5% and 99.1% ( P = .59) and 99.2% and 97.6% ( P = .17), respectively. Postoperative complications occurred in 19.0% of the LSG group and 15.5% of the LSNNS group ( P = .294). The LSNNS group showed better physical function ( P = .015), less symptoms ( P < .001), and improved nutrition than the LSG group. CONCLUSION LSNNS did not show noninferiority to LSG for 3y-DFS, with a 5% margin. However, the 3y-DSS and 3y-OS were not different after rescue surgery in cases of recurrence/metachronous gastric cancer, and LSNNS had better long-term QOL and nutrition than LSG.

Countries differ in their treatment expertise and research results regarding gastric cancer; hence, treatment guidelines are diverse based on evidence and medical situations. A comprehensive and comparative review of each country's guidelines is imperative to understand the similarities and differences among countries. We reviewed and compared five gastric cancer treatment guidelines in terms of endoscopic, surgical, perioperative, and palliative systemic treatment based on evidence levels and recommendation grades, as well as the postoperative follow-up strategies for each guideline. The Korean, Chinese, and European guidelines provided evidence and grading of the recommendations. The United States guidelines suggested categories for evidence and consensus. The Japanese guidelines suggested evidence and recommendations only for systemic treatment. The Korean and Japanese guidelines described endoscopic treatment, surgery, and lymphadenectomy in detail. The Chinese, United States, and European guidelines more intensively considered perioperative chemotherapy. In particular, the indications for chemotherapy and the regimens recommended by each guideline differed slightly. Considering their medical situations, each guideline had some diversity in terms of adopting evidence, which resulted in heterogeneous recommendations. This review will help medical personnel to comprehensively understand the diversity in gastric cancer treatment guidelines for each country in terms of evidence and recommendations.

Smad4 and p53 mutations are the most common mutations in human colorectal cancers (CRCs). We evaluated whether and how they are synergistic in intestinal carcinogenesis using novel autochthonous mouse models.To recapitulate human CRCs, we generated Villin-Cre;Smad4Twenty-week-old Villin-Cre;Smad4Smad4 loss and p53 loss are synergistic in autochthonous intestinal carcinogenesis, by downregulating p21 and activating Wnt/β-catenin pathway.

Background Helicobacter pylori infection and a family history of gastric cancer are the main risk factors for gastric cancer. Whether treatment to eradicate H. pylori can reduce the risk o...

Objective There has been a demand for a tumor-specific marker for metastatic lymph nodes in sentinel navigation surgery for gastric cancer. The aim of this study is to analyze protein expression in both primary tumors and metastatic lymph nodes in early gastric cancer patients. Methods We collected primary tumors and metastatic lymph nodes from 71 patients who underwent curative gastrectomy and pathologically diagnosed with T1N1 or T1N2 (8th Union for International Cancer Control 8th edition/American Joint Committee on Cancer staging system) gastric cancer. Immunohistochemistry was used to determine the expression of six cell membrane proteins, including carcinoembryonic antigen (CEA), E-cadherin, epithelial cell adhesion molecule (EpCAM), P-cadherin, CD44v6, and c-erbB2 in the patient samples. Results The expression of CEA, E-cadherin, EpCAM, P-cadherin, CD44v6 and c-erbB2 in the evaluable primary tumor samples was 75.4%, 97.1%, 100%, 89.9%, 11.1% and 7.2%, respectively. Among cases wherein both the primary tumor and metastatic lymph nodes were evaluable, double positivity (expression in both primary tumor and metastatic lymph nodes) was observed for CEA, E-cadherin, EpCAM, P-cadherin, CD44v6 and c-erbB2 in 53.2%, 97.9%, 98.1%, 76.6%, 0 and 6.8% of the cases, respectively. The proportion of metastatic lymph nodes positive for CEA, E-cadherin, EpCAM, P-cadherin, CD44v6 and c-erbB2 was 71.4%, 100%, 98.1%, 83.7%, 0, and 75%, respectively in primary tumors positive for the same markers. Conclusions E-cadherin and EpCAM had an overlap of 100% and 98.1% between the primary tumor and metastatic lymph nodes, respectively. Thus, E-cadherin and EpCAM are potential molecular markers to detect metastatic lymph nodes in patients with early gastric cancer.

Early gastric cancer that meets the expanded criteria for endoscopic resection (ER) is expected to be associated with a negligible risk for lymph node metastasis (LNM); however, recent studies have reported LNM in submucosal gastric cancer patients who met the existing criteria. In this study, we develop the revised criteria for ER of submucosal gastric cancer with the aim of minimizing LNM. We analyzed the clinicopathological data of 2461 patients diagnosed with differentiated, submucosal gastric cancer who underwent surgery at three tertiary hospitals between March 2001 and December 2012, and re-analyzed the pathological slides of all patients. The depth of submucosal invasion was measured histopathologically in two different ways (the classic and alternative methods) to obtain accurate data. Of the enrolled subjects, 306 (17.0%) had LNM. The width of submucosal invasion correlated well with the LNM. We defined the depth and width of submucosal infiltration associated with the lowest incidence of LNM. None of the 254 subjects developed LNM when the following criteria were met: tumor diameter ≤ 3 cm, submucosal invasion depth

Intestinal-type gastric cancer often results from Helicobacter pylori infection through intestinal metaplasia, a transdifferentiated premalignant phenotype. Because H. pylori virulence factor CagA has been associated with aberrant expression of the transcription factor CDX1, which regulates intestinal differentiation, we explored its relationship with H. pylori infection and function during gastric carcinogenesis in normal gastric epithelial cells and gastric cancer cell lines. Infection of HFE 145 cells with CagA+ H. pylori increased expression of CDX1, as well as the epithelial-to-mesenchymal transition (EMT) markers Snail and Slug, increased invasion and migration, but those effects were not found in HFE 145 cells infected with CagA-deficient H. pylori. CDX1 overexpression increased expression of the intestinal markers Villin, sucrose isomaltase (SI), and MUC2, induced spheroid formation, and enhanced expression of the stem cell markers CD44, SOX2, Oct4, and Nanog, while CDX1 knockdown inhibited proliferation and intestinal stemness. Treatment of CDX1-expressing cells with metformin, an antidiabetic drug known to decrease the risk of gastric cancer, decreased expression of EMT and stemness markers, and reduced spheroid formation. In a murine xenograft model, combining metformin or shCDX1 with cisplatin reduced tumor growth, increased caspase-3 cleavage, and reduced expression of CD44 and MMP-9 to a greater degree than cisplatin alone. Patients with more advanced intestinal metaplasia staging exhibited higher CDX1 expression than those with earlier intestinal metaplasia staging (P = 0.039), and those with H. pylori tended to have more CDX1 expression than noninfected patients (P = 0.061). Finally, human tissue samples with higher CDX1 levels showed prominent CD44/SOX2 expression. Our findings indicate CagA+ H. pylori–induced CDX1 expression may enhance gastric cancer tumorigenesis and progression, and support therapeutic targeting of CDX1 in gastric cancer. Implications: This study shows that CDX1 contributes to the tumorigenesis and progression of gastric cancer and suggests the potential of targeting CDX1 to treat this malignancy.

Objective:We investigated microsatellite instability (MSI) status and programed cell death ligand 1 (PD-L1) expression as predictors of prognosis and responsiveness to chemotherapy for stage II/III gastric cancer.Background:The clinical implications of MSI status and PD-L1 expression in gastric canc

Circulating tumor DNA (ctDNA) has emerged as a candidate biomarker for cancer screening. However, studies on the usefulness of ctDNA for postoperative recurrence monitoring are limited. The present study monitored ctDNA in postoperative blood by employing cancer-specific rearrangements. Personalized cancer-specific rearrangements in 25 gastric cancers were analyzed by whole-genome sequencing (WGS) and were employed for ctDNA monitoring with blood up to 12 months after surgery. Personalized cancer-specific rearrangements were identified in 19 samples. The median lead time, which is the median duration between a positive ctDNA detection and recurrence, was 4.05 months. The presence of postoperative ctDNA prior to clinical recurrence was significantly correlated with cancer recurrence within 12 months of surgery (P = 0.029); in contrast, no correlation was found between cancer recurrence and the presence of preoperative ctDNA, suggesting the clinical usefulness of postoperative ctDNA monitoring for cancer recurrence in gastric cancer patients. However, the clinical application of ctDNA can be limited by the presence of ctDNA non-shedders (42.1%, 8/19) and by inconsistent postoperative ctDNA positivity., Cancer: Tell-tale signs of recurrence Fragments of tumor DNA, or circulating tumor DNA (ctDNA), in blood can help predict stomach cancer recurrence within 12 months of surgery. Kyeong-Man Hong at the National Cancer Center, in Goyang-si, South Korea, and colleagues, carried out whole genome sequencing of stomach tumor samples from 25 patients to identify personalized cancer-specific rearranged DNA sequences. When they used this information to monitor ctDNA in blood samples obtained after surgical removal of the tumor, they found a significant correlation between the presence of ctDNA and cancer recurrence. In most cases, ctDNA was detected around four months prior to clinical recurrence, highlighting the potential usefulness of ctDNA monitoring. The lack of correlation between ctDNA levels and tumor size suggests that further research into the factors determining ctDNA levels is needed.

Recently, nonexposure simple suturing endoscopic full-thickness resection (NESS-EFTR) method was developed to avoid tumor exposure to the peritoneal cavity. The aim of this study is to compare the short-term outcomes of the NESS-EFTR method with those of laparoscopic and endoscopic cooperative surgery (LECS) for gastric subepithelial tumors (SETs). A prospective single-center trial of LECS for gastric SETs was performed from March 2012 to October 2013 with a separate prospective trial of NESS-EFTR performed from August 2015 to June 2017, enrolling 15 patients each. Among the 30 enrolled patients, 14 who underwent LECS and 11 who underwent NESS-EFTR were finally included in the analysis. The rate of complete resection and successful closure was 100% in both groups. The operating time was longer for NESS-EFTR group than for LECS (110 vs. 189 min, p &lt, 0.0001). There were no postoperative complications except one case of transient fever in the NESS-EFTR group. One patient in the LECS group had peritoneal seeding of gastrointestinal stromal tumor at 17 months postoperatively, and there was no other recurrence. Although NESS-EFTR had long operating and procedure times, it was feasible for patients with gastric SETs requiring a nonexposure technique.

4050 Background: A phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial) has been performed to confirm the oncologic safety of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer (EGC). The results did not show the non-inferiority of LSNNS relative to laparoscopic standard gastrectomy (LSG) in terms of 3-year disease-free survival (DFS), the primary endpoint of the SENORITA trial even though the improved quality of life (QOL) in the LSNNS group. However, the long-term oncologic outcomes of LSNNS have not been compared with conventional surgery. This study was planned to investigate the comparison of LSG and LSNNS for EGC in terms of 5 years survival. Methods: We collected 5-year follow-up data of 527 patients recruited in the SENORITA trial. The overall survival (OS), disease-free survival (DFS), and recurrence pattern were evaluated in full analysis sets of both LSG (n = 269) and LSNNS (n = 258). Results: The mean follow-up period was 58.5 and 57.7 months in LSNNS and LSG groups. There was no statistically significant difference in 5-year OS (p = 0.7403) and DFS (p = 0.0561) between LSG and LSNNS. In terms of DFS, additional five events in the LSG group and 7 in LSNNS occurred after a 3-year follow-up until 5-years. Primary site recurrence in 1 LSNNS, and metachronous gastric cancer occurred in one LSG and two in LSNNS were diagnosed from 3 to 5-year follow-up period. Other organ cancer developed in two vs. three and other deaths occurred in two v s. one in each group, respectively, from 3 to 5-year follow-up. Overall survival events were 6 in LSG and 7 in LSNNS, and disease-specific death events were two patients in both groups until five years. Conclusions: Although the SENORITA trial did not show non-inferiority of LSNNS in the primary endpoint, 3-year DFS relative to LSG, the 5-year DFS and OS did not reveal the statistical difference between the two groups. Considering the benefit of LSNNS regarding the postoperative QOL, LSNNS could be recommended as an alternative treatment option of LSG for EGC. Clinical trial information: NCT01804998.

The lancet / Digital health 3(10), e654-e664 (2021). doi:10.1016/S2589-7500(21)00133-3, Published by The Lancet, London

With the development of advanced and minimally invasive surgical techniques, and in view of the functional and cosmetic aspects, the need for rapid and accurate diagnosis during surgery is increasing. This study was conducted to develop a tissue diagnosis method using confocal microscopy after simple tissue staining that does not require freezing and slicing. At present, fluorescence staining with confocal microscopy is not generalized for real-time diagnosis during surgery. In this paper, we propose a fluorescence staining method using Hoechst 33342 and Eosin that does not require tissue freezing and slicing. The proposed method can be used as part of a rapid tissue diagnosis method that is suitable for use in the operating room, although further research is required before it can be applied in clinical practice.

Purpose: Lauren diffuse-type gastric adenocarcinomas (DGAs) are generally genomically stable. We identified lysine (K)-specific methyltransferase 2C (KMT2C) as a frequently mutated gene and examined its role in DGA progression. Experimental Design: We performed whole exome sequencing on tumor samples of 27 patients with DGA who underwent gastrectomy. Lysine (K)-specific methyltransferase 2C (KMT2C) was analyzed in DGA cell lines and in patient tumors. Results: KMT2C was the most frequently mutated gene (11 of 27 tumors [41%]). KMT2C expression by immunohistochemistry in tumors from 135 patients with DGA undergoing gastrectomy inversely correlated with more advanced tumor stage (P = 0.023) and worse overall survival (P = 0.017). KMT2C shRNA knockdown in non-transformed HFE-145 gastric epithelial cells promoted epithelial-to-mesenchymal transition (EMT) as demonstrated by increased expression of EMT-related proteins N-cadherin and Slug. Migration and invasion in gastric epithelial cells following KMT2C knockdown increased by 47- to 88-fold. In the DGA cell lines MKN-45 and SNU-668, which have lost KMT2C expression, KMT2C re-expression decreased expression of EMT-related proteins, reduced cell migration by 52% to 60%, and reduced cell invasion by 50% to 74%. Flank xenografts derived from KMT2C-expressing DGA organoids, compared with wild-type organoids, grew more slowly and lost their infiltrative leading edge. EMT can lead to the acquisition of cancer stem cell (CSC) phenotypes. KMT2C re-expression in DGA cell lines reduced spheroid formation by 77% to 78% and reversed CSC resistance to chemotherapy via promotion of DNA damage and apoptosis. Conclusions: KMT2C is frequently mutated in certain populations with DGA. KMT2C loss in DGA promotes EMT and is associated with worse overall survival.

We conducted an RNA sequencing study to identify novel gene fusions in 80 discovery dataset tumors collected from young patients with diffuse gastric cancer (DGC). Twenty-five in-frame fusions are associated with DGC, three of which (CLDN18-ARHGAP26, CTNND1-ARHGAP26, and ANXA2-MYO9A) are recurrent in 384 DGCs based on RT-PCR. All three fusions contain a RhoGAP domain in their 3’ partner genes. Patients with one of these three fusions have a significantly worse prognosis than those without. Ectopic expression of CLDN18-ARHGAP26 promotes the migration and invasion capacities of DGC cells. Parallel targeted RNA sequencing analysis additionally identifies TACC2-PPAPDC1A as a recurrent and poor prognostic in-frame fusion. Overall, PPAPDC1A fusions and in-frame fusions containing a RhoGAP domain clearly define the aggressive subset (7.5%) of DGCs, and their prognostic impact is greater than, and independent of, chromosomal instability and CDH1 mutations. Our study may provide novel genomic insights guiding future strategies for managing DGCs., Diffuse Gastric Cancer (DGC) is increasingly being considered separate to intestinal type gastric cancer; several fusions events have been reported as drivers of the disease but few of those have been subsequently validated. Here the authors perform RNA-seq on early-onset DGC patients who had not been treated with chemotherapy or radiation and identify a previously unknown fusion.

Endoscopic screening has been adopted in South Korea for the national screening of gastric cancer (GC). This study aimed to assess the effect on overall survival of GC patients and determine the optimal endoscopic screening interval. The baseline characteristics and overall survival of GC patients treated at the National Cancer Center, Korea, between 2010 and 2016 were compared between those without a history of endoscopic evaluation (group N) and those in whom the interval between the last endoscopic evaluations and diagnosis of GC was ≤ 1, 1–2, 2–3, 3–4, or > 4 years (groups 1–5, respectively). A total of 2362 patients met the criteria for the study (1060 in group N and 1302 in groups 1–5). More patients in groups 1–5 were diagnosed with stage I GC (83.7, 83.7, 71.8, 78.2, and 71.6%, respectively) than in group N (62.4%, P

Summary Background Adjuvant chemotherapy after surgery improves survival of patients with stage II–III, resectable gastric cancer. However, the overall survival benefit observed after adjuvant chemotherapy is moderate, suggesting that not all patients with resectable gastric cancer treated with adjuvant chemotherapy benefit from it. We aimed to develop and validate a predictive test for adjuvant chemotherapy response in patients with resectable, stage II–III gastric cancer. Methods In this multi-cohort, retrospective study, we developed through a multi-step strategy a predictive test consisting of two rule-based classifier algorithms with predictive value for adjuvant chemotherapy response and prognosis. Exploratory bioinformatics analyses identified biologically relevant candidate genes in gastric cancer transcriptome datasets. In the discovery analysis, a four-gene, real-time RT-PCR assay was developed and analytically validated in formalin-fixed, paraffin-embedded (FFPE) tumour tissues from an internal cohort of 307 patients with stage II–III gastric cancer treated at the Yonsei Cancer Center with D2 gastrectomy plus adjuvant fluorouracil-based chemotherapy (n=193) or surgery alone (n=114). The same internal cohort was used to evaluate the prognostic and chemotherapy response predictive value of the single patient classifier genes using associations with 5-year overall survival. The results were validated with a subset (n=625) of FFPE tumour samples from an independent cohort of patients treated in the CLASSIC trial (NCT00411229), who received D2 gastrectomy plus capecitabine and oxaliplatin chemotherapy (n=323) or surgery alone (n=302). The primary endpoint was 5-year overall survival. Findings We identified four classifier genes related to relevant gastric cancer features ( GZMB, WARS, SFRP4 , and CDX1 ) that formed the single patient classifier assay. In the validation cohort, the prognostic single patient classifier (based on the expression of GZMB, WARS , and SFRP4 ) identified 79 (13%) of 625 patients as low risk, 296 (47%) as intermediate risk, and 250 (40%) as high risk, and 5-year overall survival for these groups was 83·2% (95% CI 75·2–92·0), 74·8% (69·9–80·1), and 66·0% (60·1–72·4), respectively (p=0·012). The predictive single patient classifier (based on the expression of GZMB, WARS , and CDX1 ) assigned 281 (45%) of 625 patients in the validation cohort to the chemotherapy-benefit group and 344 (55%) to the no-benefit group. In the predicted chemotherapy-benefit group, 5-year overall survival was significantly improved in those patients who had received adjuvant chemotherapy after surgery compared with those who received surgery only (80% [95% CI 73·5–87·1] vs 64·5% [56·8–73·3]; univariate hazard ratio 0·47 [95% CI 0·30–0·75], p=0·0015), whereas no such improvement in 5-year overall survival was observed in the no-benefit group (72·9% [66·5–79·9] in patients who received chemotherapy plus surgery vs 72·5% [65·8–79·9] in patients who only had surgery; 0·93 [0·62–1·38], p=0·71). The predictive single patient classifier groups (chemotherapy benefit vs no-benefit) could predict adjuvant chemotherapy benefit in terms of 5-year overall survival in the validation cohort (p interaction =0·036 in univariate analysis). Similar results were obtained in the internal evaluation cohort. Interpretation The single patient classifiers validated in this study provide clinically important prognostic information independent of standard risk-stratification methods and predicted chemotherapy response after surgery in two independent cohorts of patients with resectable, stage II–III gastric cancer. The single patient classifiers could complement TNM staging to optimise decision making in patients with resectable gastric cancer who are eligible for adjuvant chemotherapy after surgery. Further validation of these results in prospective studies is warranted. Funding Ministry of ICT and Future Planning; Ministry of Trade, Industry, and Energy; and Ministry of Health and Welfare.

Background Patients with early gastric cancers that are limited to gastric mucosa or submucosa usually have an advanced loss of mucosal glandular tissue (glandular atrophy) and are at high risk for subsequent (metachronous) development of new gastric cancer. The long-term effects of treatment to eradicate Helicobacter pylori on histologic improvement and the prevention of metachronous gastric cancer remain unclear. Methods In this prospective, double-blind, placebo-controlled, randomized trial, we assigned 470 patients who had undergone endoscopic resection of early gastric cancer or high-grade adenoma to receive either H. pylori eradication therapy with antibiotics or placebo. Two primary outcomes were the incidence of metachronous gastric cancer detected on endoscopy performed at the 1-year follow-up or later and improvement from baseline in the grade of glandular atrophy in the gastric corpus lesser curvature at the 3-year follow-up. Results A total of 396 patients were included in the modifie...

In this single-center, double-blind, placebo-controlled trial, we screened 3100 first-degree relatives of patients with gastric cancer. We randomly assigned 1838 participants withA total of 1676 participants were included in the modified intention-to-treat population for the analysis of the primary outcome (832 in the treatment group and 844 in the placebo group). During a median follow-up of 9.2 years, gastric cancer developed in 10 participants (1.2%) in the treatment group and in 23 (2.7%) in the placebo group (hazard ratio, 0.45; 95% confidence interval [CI], 0.21 to 0.94; P = 0.03 by log-rank test). Among the 10 participants in the treatment group in whom gastric cancer developed, 5 (50.0%) had persistentAmong persons with

Purpose The guidelines for pathological evaluation of early gastric cancer (EGC) recommend wider section intervals for surgical specimens (5-7 mm) than those for endoscopically resected specimens (2-3 mm). Studies in surgically resected EGC specimens showed not negligible lymph node metastasis risks in EGCs meeting the expanded criteria for endoscopic submucosal dissection (ESD). Materials and Methods This retrospective study included 401 EGC lesions with an endoscopic size of ≤ 30 mm detected in 386 patients. Pathological specimens obtained by ESD or surgery were cut into 2-mm section intervals for reference. Submucosal or lymphovascular invasion (LVI) was evaluated arbitrarily in 4- or 6-mm section intervals. McNemar's tests compared the differences between submucosal and LVI. Results Submucosal invasion was detected in 29.2% (117/401) and LVI in 9.5% (38/401) at 2-mm interval. The submucosal invasion detection rates in 4-mm intervals decreased to 88.0% or 90.6% (both P

PURPOSE In the CLASSIC and MAGIC trials, microsatellite instability (MSI)–high status was a favorable prognostic and potential negative predictive factor for neoadjuvant/adjuvant chemotherapy in resectable gastric cancer (GC). Given the low prevalence of MSI-high status in GC and its association with other positive prognostic variables, large data sets are needed to draw robust evidence of its prognostic/predictive value. PATIENTS AND METHODS We performed a multinational, individual-patient-data meta-analysis of the prognostic/predictive role of MSI in patients with resectable GC enrolled in the MAGIC, CLASSIC, ARTIST, and ITACA-S trials. Prognostic analyses used multivariable Cox models (MVM). The predictive role of MSI was assessed both in an all-comer population and in MAGIC and CLASSIC trials by MVM testing of the interaction of treatment (chemotherapy plus surgery v surgery) with MSI. RESULTS MSI status was available for 1,556 patients: 121 (7.8%) had MSI-high status; 576 were European, and 980 were Asian. In MSI-high versus MSI-low/microsatellite stable (MSS) comparisons, the 5-year disease-free survival (DFS) was 71.8% (95% CI, 63.8% to 80.7%) versus 52.3% (95% CI, 49.7% to 55.1%); the 5-year overall survival (OS) was 77.5% (95% CI, 70.0% to 85.8%) versus 59.3% (95% CI, 56.6% to 62.1%). In MVM, MSI was associated with longer DFS (hazard ratio [HR], 1.88; 95% CI, 1.28 to 2.76; P < .001) and OS (HR, 1.78; 95% CI, 1.17 to 2.73; P = .008), as were pT, pN, ethnicity, and treatment. Patients with MSI-low/MSS GC benefitted from chemotherapy plus surgery: the 5-year DFS compared with surgery only was 57% versus 41% (HR, 0.65; 95% CI, 0.53 to 0.79), and the 5-year OS was 62% versus 53% (HR, 0.75; 95% CI, 0.60 to 0.94). Conversely, those with MSI-high GC did not: the 5-year DFS was 70% versus 77% (HR, 1.27; 95% CI, 0.53 to 3.04), and the 5-year OS was 75% versus 83% (HR, 1.50; 95% CI, 0.55 to 4.12). CONCLUSION In patients with resectable primary GC, MSI is a robust prognostic marker that should be adopted as a stratification factor by clinical trials. Chemotherapy omission and/or immune checkpoint blockade should be investigated prospectively in MSI-high GCs according to clinically and pathologically defined risk of relapse.

4054 Background: Laparoscopic sentinel node navigation surgery (LSNNS) has been suggested as an alternative to laparoscopic standard gastrectomy (LSG) in early gastric cancer patients to improve long-term quality of life (QOL) and nutritional outcomes. Here, we present 3-year results of patient-reported quality of life (QOL) and nutrition, secondary endpoints of SENORITA trial. Methods: SENORITA is a prospective multicenter randomized phase 3 trial. Patients diagnosed with early gastric cancer of 3 cm or less were randomly allocated (1:1) to LSNNS for stomach preservation or LSG. The primary endpoint was 3-year disease-free survival. In this study, we analyzed QOL assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and EORTC stomach module (STO22) and nutritional parameters at 3, 12, 24, and 36 months after surgery. Linear mixed model analyses was used to evaluate differences between the two groups. This trial is registered with ClinicalTrials.gov, NCT01804998. Results: From March 2013 to March 2017, a total of 580 patients were randomly assigned and 527 patients were included in the modified intention-to-treat analysis population (258 in LSNNS and 269 in LSG group). QOL questionnaires were available for 99.4% of patients at baseline and then for 92.2%, 83.2%, 72.8%, and 66.9% at 3, 12, 24, and 36 months after surgery, respectively. The LSNNS group had higher physical function score than the LSG group at all time points (p = 0.002). However, there were no significant differences in other scales of EORTC QLQ-C30. Regarding EORTC QLQ-STO22, pain, eating restriction, anxiety, and taste scores were lower (better QOL) at all time points in the LSNNS group than in the LSG group (p = 0.002, < 0.001, < 0.001, and < 0.001, respectively). The summary score of EORTC QLQ-STO22 was also higher in the LSNNS group representing better QOL (p < 0.001). Body mass index, hemoglobin and total protein were significantly higher in the LSNNS group compared with the LSG group. Conclusions: The LSNNS group had better physical function and less symptoms, including pain, eating restriction, anxiety, and taste change compared with the LSG group. Moreover, the nutritional parameters were better maintained in the LSNNS group than in the LSG group. These findings showed benefits of stomach preserving surgery in LSNNS and can be used to help decision making about treatment for patients with early gastric cancer. Clinical trial information: NCT01804998.

Purpose Negative Helicobacter pylori status has been identified as a poor prognostic factor for survival in gastric cancer (GC) patients who underwent surgery. The aim of this study was to examine the effect of H. pylori eradication on long-term outcomes after distal gastrectomy for GC. Materials and methods We analyzed the survival of 169 distal GC patients enrolled in a prospective randomized trial evaluating histologic changes of gastric mucosa after H. pylori eradication in the remnant stomach. The outcomes measured were overall survival (OS) and GC recurrence rates. Results The median follow-up duration was 9.4 years. In the modified intention-to-treat analysis including patients who underwent H. pylori treatment (n=87) or placebo (n=82), 5-year OS rates were 98.9% in the treatment group and 91.5% in the placebo group, and Kaplan-Meier analysis showed no significant difference in OS (p=0.957) between groups. In multivariate analysis, no difference in overall mortality was observed between groups (adjusted hazard ratio [aHR] for H. pylori treatment, 0.75; p=0.495) or H. pylori-eradicated status (aHR for positive H. pylori status, 1.16; p=0.715), while old age, male sex, and advanced stage ≥ IIIa were independent risk factors. Six patients in the treatment group (6.9%) and seven patients in the placebo group (8.5%) had GC recurrences, and GC recurrence rates were not different according to H. pylori treatment (5-year GC recurrence rates, 4.6% in the treatment group vs. 8.5% in the placebo group; p=0.652). Conclusion H. pylori eradication for GC patients who underwent distal gastrectomy did not compromise long-term survival after surgery.

Key Points Question Under what clinical conditions is proximal gastrectomy associated with low risk of metastasis to regional lymph nodes? Findings In this cohort study, including 655 patients who underwent total gastrectomy for gastric carcinoma in the upper third of the stomach, the rate of lymph node metastasis at station 5 was 0 for cT1-T3N0/1M0 regardless of tumor size and differentiation; rates for stations 4d and 6 for category cT1-T3N0/1M0 differentiated tumors were also 0. Tumor size of 4.1 cm or greater was associated with significantly increased lymph node metastasis compared with smaller tumors. Meaning These findings suggest that proximal gastrectomy can be performed for category cT1-T2N0/1M0 tumors less than 4.1 cm with any histologic differentiation and for T3 category differentiated tumors less than 4.1 cm., Importance It is unclear whether proximal gastrectomy (PG) can replace total gastrectomy (TG), even in cases of advanced gastric carcinoma. Objectives To evaluate the oncologic safety of PG based on the lymph node (LN) metastasis rate and develop a selection diagram for PG eligibility. Design, Setting, and Participants In this cohort study, a retrospective analysis of a prospective database of gastric carcinoma surgery was performed including procedures that took place between December 1, 2000, and December 31, 2015, in the National Cancer Center, Korea, a high-volume carcinoma center with a structured database and accurate long-term follow-up. Among 9952 patients who underwent surgery for gastric carcinoma, 2347 underwent TG. Six-hundred fifty-five (564 in a second statistical analysis) had gastric carcinoma in the upper third of the stomach. The inclusion criteria were age 18 to 85 years, histologically proven adenocarcinoma (any size or differentiation) located in the upper third of the stomach, curative R0 TG performed, and postoperative follow-up for at least 3 years. Exclusion criteria included Borrmann type 4 carcinoma, T4 category, use of neoadjuvant chemotherapy, and a history of other carcinomas. Data analysis was performed from December 1, 2019, to May 30, 2020. Exposures Total gastrectomy and LN dissection. Main Outcomes and Measures The primary end point was the rate of LN metastasis at LN stations 4d, 5, and 6, which are usually not dissected during PG. Results Among the 655 study patients, the mean (SD) age was 57.7 (11.9) years, and 462 (70.5%) were men. Only those with poorly differentiated cT3 category carcinomas had an increased incidence of LN metastasis at stations 4d (2 of 32 [6.3%]) and 11d (T3N0: 2 of 22 [9.1%], T3N1: 3 of 27 [11.1%]), independent of tumor size. For cT1-T3N0/1M0 category carcinomas, the incidence of station 5 LN metastasis was 0, irrespective of tumor size and differentiation. The LN metastasis rate at stations 4d and 6 for cT1-T3N0/1M0 differentiated tumors was also 0. Tumor size greater than or equal to 4.1 cm was associated with significantly increased LN metastasis compared with tumors less than 4.1 cm (40.0% vs 20.4%, P = .001). Conclusions and Relevance The findings of this study suggest that PG can be safely performed for cT1-T2N0/1M0 tumors less than 4.1 cm in diameter that are located in the upper third of the stomach. The cT3N0/1M0-differentiated tumors less than 4.1 cm may also be eligible for PG, whereas poorly differentiated cT3 tumors and any cT4 or cN2/3 diseases require TG., This cohort study evaluates the risk of lymph node metastasis of gastric carcinoma by category and size of the tumor and develops a selection diagram for use in determining whether proximal gastrectomy could be indicated.

Background: The incidence of gastric cancer increases in the remnant stomach after partial gastrectomy, however, its pathogenesis remains controversial. The clinicopathological features and immunohistochemical subtype were evaluated in patients with remnant gastric cancer considering the initial cause of partial gastrectomy. Methods: We categorized 59 cases of remnant gastric cancer who underwent curative surgery between 2001 and 2016 according to initial pathologies of benign (n = 24) or malignant (n = 35). Histological changes including pyloric metaplasia and intestinal metaplasia in the mucosa around the anastomosis site and the background mucosa of carcinomas were compared between the groups. Results: In the malignant group, the proportion of male patients was substantially lower, with a shorter interval. In background mucosa around the carcinomas, incidence of high-grade pyloric metaplasia was significantly higher in the benign group (13/20, 65.0% vs. 10/28, 35.7%), while high-grade intestinal metaplasia was only observed in the malignant group (0/20, 0% vs. 7/28, 25.0%). Conclusions: The cancers in the initial benign disease are mainly associated with pyloric metaplasia at the anastomosis site, reflecting reflux, but not with intestinal metaplasia. On the other hand, in the initial malignant disease group, intestinal metaplasia has an equally important role as reflux-associated pyloric metaplasia.

Intestinal-type gastric cancer often results from