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Competing Interests: The authors declare that they have no conflict of interest.

Background/aim: Diffuse-type gastric cancer (DGC) often forms peritoneal metastases, leading to poor prognosis. However, the underlying mechanism of DGC-mediated peritoneal metastasis is poorly understood. DGC is characterized by desmoplastic stroma, in which heterogeneous cancer-associated fibroblasts (CAFs), including myofibroblastic CAFs (myCAFs) and senescent CAFs (sCAFs), play a crucial role during tumor progression. This study investigated the CAF subtypes induced by GC cells and the role of sCAFs in peritoneal metastasis of DGC cells., Materials and Methods: Conditioned medium of human DGC cells (KATOIII, NUGC-4) and human intestinal-type GC (IGC) cells (MKN-7, N87) was used to induce CAFs. CAF subtypes were evaluated by analyzing the expression of α-smooth muscle actin (α-SMA), senescence-associated β-galactosidase (SA-β-gal), and p16 in human normal fibroblasts (GF, FEF-3). A cytokine array was used to explore the underlying mechanism of GC-induced CAF subtype development. The role of sCAFs in peritoneal metastasis of DGC cells was analyzed using a peritoneally metastatic DGC tumor model. The relationships between GC subtypes and CAF-related markers were evaluated using publicly available datasets., Results: IGC cells significantly induced α-SMA+ myCAFs by secreting transforming growth factor-β, whereas DGC cells induced SA-β-gal+/p16+ sCAFs by secreting interleukin (IL)-8. sCAFs further secreted IL-8 to promote DGC cell migration. In vivo experiments demonstrated that co-inoculation of sCAFs significantly enhanced peritoneal metastasis of NUGC-4 cells, which was attenuated by administration of the IL-8 receptor antagonist navarixin. p16 and IL-8 expression was significantly associated with poor prognosis of DGC patients., Conclusion: sCAFs promote peritoneal metastasis of DGC via IL-8-mediated crosstalk., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Epidural analgesia (EDA) is a main modality for postoperative pain relief in major open abdominal surgery within the Enhanced Recovery After Surgery protocol. However, it remains unclear whether EDA is an imperative modality in laparoscopic gastrectomy (LG). This study examined non-inferiority of patient-controlled intravenous analgesia (PCIA) to EDA in terms of postoperative pain and recovery in patients who underwent LG., Methods: In this open-label, non-inferiority, parallel, individually randomized clinical trial, patients who underwent elective LG for gastric cancer were randomized 1:1 to receive either EDA or PCIA after surgery. The primary endpoint was pain score using the Numerical Rating Scale at rest 24 h after surgery, analysed both according to the intention-to-treat (ITT) principle and per protocol. The non-inferiority margin for pain score was set at 1. Secondary outcomes were postoperative parameters related to recovery and adverse events related to analgesia., Results: Between 3 July 2017 and 29 September 2020, 132 patients were randomized to receive either EDA (n = 66) or PCIA (n = 66). After exclusions, 64 patients were included in the EDA group and 65 patients in the PCIA group for the ITT analysis. Pain score at rest 24 h after surgery was 1.94 (s.d. 2.07) in the EDA group and 2.63 (s.d. 1.76) in the PCIA group (P = 0.043). PCIA was not non-inferior to EDA for the primary endpoint (difference 0.69, one side 95% c.i. 1.25, P = 0.184) in ITT analysis. Postoperative parameters related to recovery were similar between groups. More EDA patients (21 (32.8%) versus 1 (1.5%), P < 0.001) developed postoperative hypotension as an adverse event., Conclusions: PCIA was not non-inferior to EDA in terms of early-phase pain relief after LG.Registration number: UMIN000027643 (https://www.umin.ac.jp/ctr/index-j.htm)., (© The Author(s) 2024. Published by Oxford University Press on behalf of BJS Foundation Ltd.)

Post-gastrectomy syndrome (PGS) and body weight loss (BWL) decrease quality of life (QOL) and survival of the patient undergoing gastrectomy. We have introduced perioperative and post-discharge continuous nutritional counseling (CNC) to prevent BWL and improve QOL after gastrectomy. In the present study, we evaluated the effect of CNC on QOL using the Post-gastrectomy Syndrome Assessment Scale-45 (PGSAS-45). Eighty-three patients with gastric cancer (GC) who underwent curative gastrectomy between March 2018 and July 2019 were retrospectively analyzed. Patients received either pre-discharge nutritional counseling alone (control group, n  = 45) or CNC (CNC group, n  = 38) after gastrectomy. QOL at 12 months after gastrectomy was compared between the two groups. In QOL assessment, change in body weight (-7.98% vs. -12.77%, p  = 0.0057), ingested amount of food per meal (7.00 vs. 6.07, p  = 0.042) and ability for working (1.89 vs. 2.36, p  = 0.049) were significantly better in CNC group than control group. Multiple regression analysis showed that CNC was a significantly beneficial factor for abdominal pain subscale ( p  = 0.028), diarrhea subscale ( p  = 0.047), ingested amount of food per meal ( p  = 0.012), Ability for working ( p  = 0.031) and dissatisfaction at the meal ( p  = 0.047). Perioperative and postoperative CNC could improve QOL in the patient undergoing gastrectomy in addition to preventing postoperative BWL.

Background/aim: Diffuse-type gastric cancer (GC) frequently exhibits peritoneal metastasis, leading to poor prognosis. However, efforts to develop antitumor strategies for preventing the peritoneal metastasis of GC have been unsuccessful. As diffuse-type GC cells often carry a genetic alteration in the tumor suppressor p53 gene, p53 restoration may be a potent strategy for preventing peritoneal metastasis of GC. In this study, we investigated the therapeutic potential of p53-expressing adenoviral vectors against peritoneal metastasis of diffuse-type GC cells., Materials and Methods: Three diffuse-type human GC cell types with different p53 statuses (p53-wild type NUGC-4, p53-mutant type GCIY, and p53-null type KATOIII) were used to evaluate the therapeutic potential of p53 activation induced by the p53-expressing, replication-deficient adenovirus Ad-p53 and oncolytic adenovirus OBP-702. Viability, apoptosis, and autophagy of virus-treated GC cells were analyzed under normal and sphere-forming culture conditions using the XTT assay and western blot analysis. The in vivo antitumor effects of OBP-702 and Ad-p53 were assessed using xenograft tumor models involving peritoneal metastasis of NUGC-4 and GCIY cells., Results: Under normal and sphere-forming culture conditions, OBP-702 induced a significantly greater antitumor effect in GC cells compared with Ad-p53 by strongly inducing p53-mediated apoptosis and autophagy and receptor tyrosine kinase suppression. In vivo experiments demonstrated that intraperitoneal administration of OBP-702 significantly suppressed the peritoneal metastasis of NUGC-4 and GCIY cells compared with Ad-p53, leading to prolonged survival of mice., Conclusion: Intraperitoneal administration of OBP-702 inhibits the peritoneal metastasis of GC cells by inducing p53-mediated cytopathic activity., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: Although proximal gastrectomy (PG) is commonly used in patients with upper gastric cancer (GC) and esophagogastric junction (EGJ) cancer, long-term prognostic factors in these patients are poorly understood. The double-flap technique (DFT) is an esophagogastrostomy with anti-reflux mechanism after PG; we previously conducted a multicenter retrospective study (rD-FLAP) to evaluate the short-term outcomes of DFT reconstruction. Here, we evaluated the long-term prognostic factors in patients with upper GC and EGJ cancer., Methods: The study was conducted as a secondary analysis of the rD-FLAP Study, which enrolled patients who underwent PG with DFT reconstruction, irrespective of disease type, between January 1996 and December 2015., Results: A total of 509 GC and EGJ cancer patients were enrolled. Univariate and multivariate analyses of overall survival demonstrated that a preoperative prognostic nutritional index (PNI) < 45 (p < 0.001, hazard ratio [HR]: 3.59, 95% confidential interval [CI]: 1.93-6.67) was an independent poor prognostic factor alongside pathological T factor ([pT] ≥2) (p = 0.010, HR: 2.29, 95% CI: 1.22-4.30) and pathological N factor ([pN] ≥1) (p = 0.001, HR: 3.27, 95% CI: 1.66-6.46). In patients with preoperative PNI ≥45, PNI change (<90%) at 1-year follow-up (p = 0.019, HR: 2.54, 95%CI: 1.16-5.54) was an independent poor prognostic factor, for which operation time (≥300 min) and blood loss (≥200 mL) were independent risk factors. No independent prognostic factors were identified in patients with preoperative PNI <45., Conclusions: PNI is a prognostic factor in upper GC and EGJ cancer patients. Preoperative nutritional enhancement and postoperative nutritional maintenance are important for prognostic improvement in these patients., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

A 70-year-old Japanese man with a submucosal gastric mass that continued to increase in size underwent endoscopic submucosal dissection using the pocket creation method. Histologically, some epithelial cell nuclei were enlarged, but there was little atypia overall and no sign of malignancy, suggesting a diagnosis of submucosal heterotopic gastric gland (SHGG). SHGG that enlarges over time has been associated with gastric cancer, but a preoperative diagnosis is difficult. This case was very valuable, as it enabled us to follow the course of SHGG over a period of about nine years, from the onset to enlargement.

Background: Although the safety of robotic distal gastrectomy has been studied in several single-center trials, the nationwide outcomes of robotic distal gastrectomy that meet the requirements of Japanese national health insurance, such as facility case volume and skill level of the surgeon, are still not clear. The objective of this study was to evaluate the short-term outcomes of robotic distal gastrectomy, which was covered by national health insurance, compared to laparoscopic distal gastrectomy., Methods: We retrieved gastric cancer cases with cStage I to III who underwent laparoscopic distal gastrectomy (15,539 patients) and robotic distal gastrectomy (1,312 patients) between April 2018 and March 2020 from the Diagnosis Procedure Combination database. We compared the frequency of postoperative complications, anesthesia time, and postoperative hospitalization days between laparoscopic distal gastrectomy and robotic distal gastrectomy using propensity score matching analysis., Results: The postoperative complication rate were not different between laparoscopic distal gastrectomy and robotic distal gastrectomy (odds ratio = 0.90, 95% confidence interval: 0.66 to 1.23, P = .52). The anesthesia time (minutes) was significantly longer (coefficient = 70.2, 95% confidence interval: 63.8 to 76.7, P < .001) and postoperative hospitalization (days) was significantly shorter (coefficient = -0.89, 95% confidence interval: -1.48 to -0.31, P = .003) in robotic distal gastrectomy than laparoscopic distal gastrectomy., Conclusions: Robotic distal gastrectomy that met strict national health insurance coverage requirements in Japan was performed as safely as laparoscopic distal gastrectomy with reduced hospitalization days., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Although proximal gastrectomy (PG) with the double-flap technique (DFT) is a function-preserving surgery that prevents esophagogastric reflux, there is a risk of developing metachronous remnant gastric cancer (MRGC). Moreover, details of MRGC and appropriate postoperative follow-up after PG with DFT are unclear., Methods: We reviewed the medical records of 471 patients who underwent PG with DFT for cancer in a preceding, multicenter, retrospective study (rD-FLAP Study). We investigated the incidence of MRGC, frequency of follow-up endoscopy, and eradication of Helicobacter pylori (H. pylori) infection., Results: MRGC was diagnosed in 42 (8.9%) of the 471 patients, and 56 lesions of MRGC were observed. The cumulative 5- and 10-year incidence rates were 5.7 and 11.4%, respectively. There was no clinicopathological difference at the time of primary PG between patients with and without MRGC. Curative resection for MRGC was performed for 49 (88%) lesions. All patients with a 1-year, follow-up, endoscopy interval were diagnosed with early-stage MRGC, and none of them died due to MRGC. Overall and disease-specific survival rates did not significantly differ between patients with and without MRGC. The incidence rate of MRGC in the eradicated group after PG was 10.8% and that in the uneradicated group was 19.6%, which was significantly higher than that in patients without H. pylori infection at primary PG (7.6%) (p = 0.049)., Conclusions: The incidence rate of MRGC after PG with DFT was 8.9%. Early detection of MRGC with annual endoscopy provides survival benefits. Eradicating H. pylori infection can reduce the incidence of MRGC., (© 2023. Society of Surgical Oncology.)

Background: The guidelines recommend additional gastrectomy after noncurative endoscopic resection for early gastric cancers (EGCs). However, no additional treatment might be acceptable in some patients aged ≥ 85 years. We aimed to identify this patient group using the data in a highly aged area., Methods: We enrolled patients aged ≥ 85 years after noncurative endoscopic resection for EGCs at 30 institutions of the Tohoku district in Japan between 2002 and 2017. Treatment selection and prognosis after noncurative endoscopic resection were investigated. Fourteen candidates were evaluated using the Cox model to identify risk factors for poor overall survival (OS) in patients with no additional treatment., Results: Of 1065 patients aged ≥ 85 years, 143 underwent noncurative endoscopic resection. Despite the guidelines' recommendation, 88.8% of them underwent no additional treatment. The 5-year OS rates in those with additional gastrectomy and those with no additional treatment were 63.1 and 65.2%, respectively. Multivariate analysis showed independent risk factors for poor OS in patients with no additional treatment were the high-risk category in the eCura system (hazard ratio [HR], 2.91), Charlson comorbidity index (CCI) ≥ 3 (HR, 2.78), and male (HR, 2.04). In patients with no additional treatment, nongastric cancer-specific survival was low (69.0% in 5 years), whereas disease-specific survival rates were very high in the low- and intermediate-risk categories of the eCura system (100.0 and 97.1%, respectively, in 5 years)., Conclusions: No additional treatment may be acceptable in the low- and intermediate-risk categories of the eCura system in patients aged ≥ 85 years with noncurative endoscopic resection for EGCs., (© 2023. Japanese Society of Gastroenterology.)

Purpose: Little is known about the prognostic factors for survival after endoscopic submucosal dissection (ESD) in elderly patients with early gastric cancer (EGC). The aim of this study is to determine prognostic factors and a prediction model of 3-year survival after ESD for EGC in patients aged ≥ 85 years., Methods: We retrospectively evaluated the clinical outcomes of 740 patients with EGC aged ≥ 85 years, who were treated by ESD at 30 institutions in Japan. Overall survival (OS) and disease-specific survival (DSS) were calculated with the Kaplan-Meier method. Prediction models for 3-year OS after ESD were estimated using the Cox proportional hazards model based on Uno's C-statistics., Results: During the follow-up period, 309 patients died of any cause and 10 patients died of gastric cancer. OS and DSS after 3 years were 82.7% and 99.2%, respectively. No significant differences in OS were found among curability categories. The Cox proportional hazards model revealed the geriatric nutritional risk index (GNRI) and the Charlson comorbidity index (CCI) to be predictors of 3-year survival. We established a final model (EGC-2 model) expressed by GNRI - (2.2×CCI) with a cutoff value of 96. The overall survival rate was significantly lower in the model value < 96 group than in the model value ≥ 96 group (P < 0.001)., Conclusions: The prediction model using GNRI and CCI will be useful to support decision-making for the treatment of EGC in elderly patients aged ≥ 85 years., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: A research subgroup was established by the Japanese Society of Gastroenterological Surgery to improve the health care quality in the Chushikoku area of Western Japan., Methods: The records of four surgical procedures were extracted from the Japanese National Clinical Database and analyzed retrospectively to establish the association between hospital characteristics, defined using a combination of hospital case-volume and patients' hospital travel distance, and the incidences of perioperative complications of ≥ Grade 3 of the Clavien-Dindo classification after gastroenterological surgery., Results: This study analyzed 11,515 cases of distal gastrectomy for gastric cancer, 4,705 cases of total gastrectomy for gastric cancer, 4,996 cases of right hemicolectomy for colon cancer, and 5,243 cases of lower anterior resection for rectal cancer, with composite outcome incidences of 5.6%, 10.2%, 5.5%, and 10.7%, respectively. After adjusting for patient characteristics and surgical procedures, no association was identified between the hospital category and surgical outcomes., Conclusion: The findings of our study of the Chushikoku region did not provide positive support for the consolidation and centralization of hospitals, based solely on hospital case volume. Our grouping was unique in that we included patient travel distance in the analysis, but further investigations from other perspectives are needed., (© 2022. The Author(s) under exclusive licence to Springer Nature Singapore Pte Ltd.)

Background: Body weight loss (BWL) and skeletal muscle loss (SML) are inevitable after gastrectomy for gastric cancer (GC) and can decrease patients' quality of life (QOL) and survival., Objective: The aim of this retrospective study was to evaluate the effect of perioperative and post-discharge patient participation in continuous nutritional counseling (CNC) on post-gastrectomy BWL and SML., Methods: Ninety-three patients with GC who underwent curative gastrectomy between March 2018 and July 2019 were analyzed. Patients received either pre-discharge nutritional counseling alone (control group, n = 49) or patient-participation CNC (CNC group, n = 44) after gastrectomy. Differences between percentage BWL (%BWL), percentage SML (%SML), and nutrition-related blood parameters between the preoperative values and those at 12 months after surgery were compared between the groups., Results: Compared with the control group, %BWL was significantly lower in the CNC group at 1 month (-6.2 ± 2.5% vs. -7.9 ± 3.3%, p = 0.005), 6 months (-7.8 ± 6.6% vs. -12.3 ± 6.4%, p = 0.001) and 12 months (-7.9 ± 7.6% vs. -13.2 ± 8.2%, p = 0.002), and %SML was significantly lower in the CNC group at 12 months (-5.3 ± 10.3% vs. -12.8 ± 12%, p = 0.002). Regarding nutrition-related blood parameters, change in total cholesterol was significantly lower in the CNC group than the control group at 12 months after surgery (p = 0.02). Multivariate analysis identified no CNC as an independent risk factor for severe BWL (p = 0.001) and SML (p = 0.006) at 12 months after surgery., Conclusions: Following gastrectomy, patient-participation CNC prevented postoperative BWL and SML after surgery. These results support the induction of such a CNC program in these patients., (© 2022. Society of Surgical Oncology.)

Introduction: Gastric cancer is divided into four subtypes by their molecular features linked with genetic alterations, e.g., Epstein-Barr virus (EBV), microsatellite instability-high (MSI-high), chromosomal instability (CIN), and genomically stable (GS), called as TCGA classification. In this study, we tried to clarify the epigenetic features of the four GC subtypes according to aberrant methylation status in 23 loci., Methods: A total of 98 gastric cancers and their normal gastric mucosa samples were included in this study. We divided gastric cancers into TCGA subtypes which were determined in line with MSI-high, EBV, CIN, to GS by their molecular features. The 13 loci of polymorphic microsatellite sequences were used to determine loss of heterogeneity for the detection of CIN. The MSI status was determined by three mononucleotide repeat markers. Infection of EBV was determined by recovering EBV BNRF1 sequence from genomic DNA collected from gastric cancers. Methylation status of 23 loci was investigated by the combined bisulfite restriction analysis. Status of other findings, e.g., KRAS mutations, HER2 expression status, and infection of helicobacter pylori were confirmed., Results: Gastric cancers were divided into MSI (13%), EBV (7%), CIN (53%), and GS (27%). By histological classification, poorly differentiated adenocarcinoma was more in tumors categorized in MSI-high, and GS and signet-ring cell carcinoma (sig) were more in GS. Among the 23 loci investigated their methylation status, 18 loci were significantly hypermethylated in caner tissues. An unsupervised clustering divided gastric cancers into two clusters and revealed that most GS tumors clustered together in a cluster that exhibited lower methylation levels, distinct from the other subtypes. The inter-variable clustering revealed that a cluster contained the three loci (SFRP2-region 1/2 and APC) belonging to the Wnt signal cascade (Wnt-associated loci). The mean methylation score of Wnt-associated loci was the lowest in GS tumors (MSI-high: 2.7 [95% confidence interval, 2.3-2.9]; EBV: 2.1 [1.2-3.1]; CIN: 2.4 [2.2-2.7]; GS: 1.3 [0.8-0.7]). In contrast, the mean methylation score of the other 15 loci was significantly higher in MSI-high, while that in GS was as same as that in EBV or CIN (MSI-high: 10.4 [8.3-12.4]; EBV: 5.7 [1.7-9.7]; CIN: 4.4 [3.6-5.1]; GS: 3.4 [2.2-4.6]). Additionally, the lower methylation score of Wnt-associated loci was observed only in sig tumors., Conclusions: GS subtype tumors have the potential to possess distinct signatures in DNA hypomethylation profiles in Wnt signaling pathway, especially in sig., (© 2022 S. Karger AG, Basel.)

Background/aim: It has recently been recognized that preoperative sarcopenia contributes to postoperative complications and overall survival in gastric cancer (GC). However, few studies have investigated the relationship between postoperative skeletal muscle loss (SML) and survival in GC, despite the inevitability of body weight loss after gastrectomy in most GC patients. Herein, we studied the impact of postoperative SML on GC prognosis., Patients and Methods: A total of 370 patients with GC who underwent curative gastrectomy were retrospectively evaluated in this study. Postoperative SML was assessed on computed tomography (CT) images taken before surgery and 1 year after surgery. The impact of postoperative SML on survival was evaluated., Results: Postoperative severe SML was significantly associated with presence of comorbidities, higher tumor stage, higher postoperative complication rate and longer hospital stay. Univariate and multivariate analyses of prognostic factors for overall survival revealed that SML was an independent indicator of poor prognosis, along with age, tumor stage, preoperative sarcopenia, and operation time (hazard ratio, 2.65; 95% confidence interval, 1.68-4.20, p<0.0001). There was a strong association of severe postoperative SML with decreased overall survival in patients with preoperative sarcopenia., Conclusion: To improve the prognosis of GC patients after surgery, it is important to prevent postoperative SML as well as preoperative sarcopenia. Perioperative multimodal interventions including nutritional counseling, oral nutritional supplements, and exercise are required to prevent SML after gastrectomy., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Remnant gastric cancer (RGC) has been increasing for various reasons such as a longer life span, medical progress, and others. It generally has a poor prognosis, and its mechanism of occurrence is unknown. The purpose of this study was to evaluate the clinicopathological features of and clarify the oncological features of RGC., Methods: Between January 2002 and January 2017, 39 patients with RGC following distal gastrectomy underwent curative surgical resection at the Okayama University Hospital; their medical records and immunohistochemically stained extracted specimens were used for retrospective analysis., Results: On univariate analysis, initial gastric disease, pathological lymph node metastasis, and pathological stage were the significant factors associated with poor overall survival (p=0.014, 0.0061, and 0.016, respectively). Multivariate analysis of these 3 factors showed that only initial gastric disease caused by malignant disease was an independent factor associated with a poor prognosis (p=0.014, hazard ratio: 4.2, 95% confidence interval: 1.3-13.0). In addition, tumor-infiltrating CD8 + T cells expression was higher in the benign disease group than in the malignant group (p=0.046)., Conclusions: Initial gastrectomy caused by malignant disease was an independent poor prognostic factor of RGC, and as one of the causes, lower level of tumor-infiltrating CD8 + T cells in RGC may involve in., (© 2022. The Author(s).)

Background/aim: Postoperative body weight loss (BWL) and skeletal muscle loss (SML) after gastrectomy are associated with a decline in quality of life and worse longterm prognosis in gastric cancer (GC) patients. This study aimed to evaluate the efficacy of amino acids nutrition on BWL and SML in the early period following gastrectomy., Patients and Methods: The parameters of body composition were measured by bioelectrical impedance analysis in the patients undergoing radical gastrectomy for GC and analyzed retrospectively. Patients received either peripheral parenteral nutrition (PPN) of 4.3% glucose fluid with regular diet (control group, n=43) or PPN of 7.5% glucose fluid containing amino acids plus oral nutritional supplement (ONS) rich in protein with regular diet (amino acids group, n=40) following gastrectomy. The percentages of BWL and SML from preoperative values to those at 7 days and 1 month after surgery were compared between the two groups., Results: The %BWL and %SML at 7 days after surgery were significantly lower in the amino acids group than those in the control group (%BWL, -2.4±1.7% vs. -4.2±1.8%; p<0.0001, %SML, -4.1±3.8 vs. -6.5±3.8; p=0.006). Moreover, the %BWL at 1 month after surgery was significantly lower in the amino acids group compared to that in the control group (- 4.6±2.9% vs. -6.1±2.6%; p=0.01); however, the %SML was similar between the two groups. The hematological nutritional parameters were similar between the two groups., Conclusion: Amino acids nutrition by PPN and ONS following gastrectomy prevented postoperative BWL and SML in the early period after surgery in GC patients., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: Although D2 lymphadenectomy is currently considered a standard procedure for advanced gastric cancer (GC) worldwide, there is room for discussion about the appropriate range of suprapancreatic D2 lymphadenectomy. Focusing on the posterior hepatic plexus (PHP), which is not well recognized, we developed a surgical technique of suprapancreatic D2 lymphadenectomy, which we have called PHP-D2, and its short-term and long-term efficacies were evaluated in comparison with non-PHP-D2., Methods: GC patients who underwent distal gastrectomy with D2 lymphadenectomy between July 2006 and May 2013 were enrolled, from which patients who had peritoneal metastasis and/or were peritoneal cytology-positive during surgery were excluded. Their medical records were retrospectively reviewed., Results: Ninety-two patients (non-PHP-D2: 48, PHP-D2: 44) were enrolled. Shorter operation time (330 min vs 275 min, p < 0.0001) and less blood loss (290 mL vs 125 mL, p < 0.0001) were observed in PHP-D2, and no pancreatic fistulas were observed in PHP-D2. More lymph nodes of #11p (1 vs 1.5, p = 0.0328) and #12a lymph nodes (0 vs 1, p = 0.0034) were retrieved in PHP-D2, with no significant differences in #8a and #9 lymph nodes. Lymphatic recurrence was significantly less in PHP-D2 (p = 0.0166), and univariate and multivariate analyses showed that non-PHP-D2 was a significant risk factor for lymphatic recurrence (p = 0.0158), although there were no significant differences between non-PHP-D2 and PHP-D2 in 5-year overall survival and 5-year relapse-free survival., Conclusion: PHP-D2 was a safe and feasible procedure that had the potential to reduce lymphatic recurrence, and it can be a standard procedure of D2 lymphadenectomy for advanced GC., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Aim: Recently, artificial intelligence (AI) has been used in endoscopic examination and is expected to help in endoscopic diagnosis. We evaluated the feasibility of AI using convolutional neural network (CNN) systems for evaluating the depth of invasion of early gastric cancer (EGC), based on endoscopic images., Methods: This study used a deep CNN model, ResNet152. From patients who underwent treatment for EGC at our hospital between January 2012 and December 2016, we selected 100 consecutive patients with mucosal (M) cancers and 100 consecutive patients with cancers invading the submucosa (SM cancers). A total of 3508 non-magnifying endoscopic images of EGCs, including white-light imaging, linked color imaging, blue laser imaging-bright, and indigo-carmine dye contrast imaging, were included in this study. A total of 2288 images from 132 patients served as the development dataset, and 1220 images from 68 patients served as the testing dataset. Invasion depth was evaluated for each image and lesion. The majority vote was applied to lesion-based evaluation., Results: The sensitivity, specificity, and accuracy for diagnosing M cancer were 84.9% (95% confidence interval [CI] 82.3%-87.5%), 70.7% (95% CI 66.8%-74.6%), and 78.9% (95% CI 76.6%-81.2%), respectively, for image-based evaluation, and 85.3% (95% CI 73.4%-97.2%), 82.4% (95% CI 69.5%-95.2%), and 83.8% (95% CI 75.1%-92.6%), respectively, for lesion-based evaluation., Conclusions: The application of AI using CNN to evaluate the depth of invasion of EGCs based on endoscopic images is feasible, and it is worth investing more effort to put this new technology into practical use., (© 2021 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Purpose: The Endoscopic Surgical Skill Quantification System for qualified surgeons (QSs) was introduced in Japan to improve surgical outcomes. This study reviewed the surgical outcomes after initial experience performing laparoscopic distal gastrectomy (LDG) and evaluated the improvement in surgical outcomes following accreditation as a QS., Methods: Eighty-seven consecutive patients who underwent LDG for gastric cancer by a single surgeon were enrolled in this study. The cumulative sum method was used to analyze the learning curve for LDG. The surgical outcomes were evaluated according to the two phases of the learning curve (learning period vs. mastery period) and accreditation (non-QS period vs. QS period)., Results: The learning period for LDG was 48 cases. Accreditation was approved at the 67th case. The operation time and estimated blood loss were significantly reduced in the QS period compared to the non-QS period (230 vs. 270 min, p < 0.001; 20.5 vs. 59.8 ml, p = 0.024, respectively). Furthermore, the major complication rate was significantly lower in the QS period than in the non-QS period (0 vs. 10.6%, p = 0.044)., Conclusions: Experience performing approximately 50 cases is required to reach proficiency in LDG. After receiving accreditation as a QS, the surgical outcomes, including the complication rate, were improved., (© 2021. Springer Nature Singapore Pte Ltd.)

Introduction: Intracorporeal Billroth I (B-I) reconstruction using an endoscopic linear stapler (ELS) is widely performed in total laparoscopic distal gastrectomy. However, conventional procedures require many ELSs for anastomosis. Here, we introduce the novel intracorporeal semi-hand-sewn (SHS) B-I reconstruction., Materials and Surgical Technique: After the transection of stomach and duodenum using ELS following adequate lymph node dissection, small entry holes were made on the anterior wall in the greater curvature of the stomach and the duodenal stump. The posterior walls of both the remnant stomach and the duodenum were attached with the ELS and fired to create the posterior wall of the B-I anastomosis. All the transection line of the duodenum and one-third of the transection line of the stomach were dissected; finally the anterior wall suturing at the anastomotic site was performed by the laparoscopic hand-sewn technique., Discussion: SHS procedure was performed for 17 gastric cancer patients. There were no intraoperative complications or conversions to open surgery. One intra-abdominal abscess was observed although there was no anastomotic leakage. The median reconstruction time was 48 minutes (32-63). The SHS procedure was safe, feasible, and economical, although it requires sufficient laparoscopic suturing and ligation skill., (© 2020 Asia Endosurgery Task Force and Japan Society of Endoscopic Surgery and John Wiley & Sons Australia, Ltd.)

Magnetic hyperthermia (MHT), which combines magnetic nanoparticles (MNPs) with an alternating magnetic field (AMF), holds promise as a cancer therapy. There have been many studies about hyperthermia, most of which have been performed by direct injection of MNPs into tumor tissues. However, there have been no reports of treating peritoneal disseminated disease with MHT to date. In the present study, we treated peritoneal metastasis of gastric cancer with MHT using superparamagnetic iron oxide (Fe 3 O 4 ) nanoparticle (SPION) coated with carboxydextran as an MNP, in an orthotopic mouse model mimicking early peritoneal disseminated disease of gastric cancer. SPIONs of an optimal size were intraperitoneally administered, and an AMF (390 kHz, 28 kAm -1 ) was applied for 10 minutes, four times every three days. Three weeks after the first MHT treatment, the peritoneal metastases were significantly inhibited compared with the AMF-alone group or the untreated-control group. The results of the present study show that MHT can be applied as a new treatment option for disseminated peritoneal gastric cancer. Abbreviations : AMF: alternating magnetic field; Cy1: cytology-positive; DMEM: Dulbecco's Modified Eagle's Medium; FBS: fetal bovine serum; H&E: hematoxylin and eosin; HIPEC: hyperthermic intraperitoneal chemotherapy; MEM: Minimum Essential Medium; MHT: magnetic hyperthermia; MNPs: magnetic nanoparticles; P0: macroscopic peritoneal dissemination; RFP: red fluorescent protein; SPION: superparamagnetic iron oxide (Fe 3 O 4 ) nanoparticle.

Background: Peritoneal dissemination often develops in gastric cancer. Tumor-associated macrophages (TAMs) are present in the peritoneal cavity of gastric cancer patients with peritoneal dissemination, facilitating tumor progression. However, the mechanism by which macrophages differentiate into tumor-associated macrophages in the peritoneal cavity is not well understood. In this study, the interplay between gastric cancer-derived extracellular vesicles (EVs) and macrophages was investigated., Methods: The association between macrophages and EVs in peritoneal ascitic fluid of gastric cancer patients, or from gastric cancer cell lines was examined, and their roles in differentiation of macrophages and potentiation of the malignancy of gastric cancer were further explored., Results: Immunofluorescent assays of the ascitic fluid showed that M2 macrophages were predominant along with the cancer cells in the peritoneal cavity. EVs purified from gastric cancer cells, as well as malignant ascitic fluid, differentiated peripheral blood mononuclear cell-derived macrophages into the M2-like phenotype, which was demonstrated by their morphology and expression of CD163/206. The macrophages differentiated by gastric cancer-derived EVs promoted the migration ability of gastric cancer cells, and the EVs carried STAT3 protein., Conclusion: EVs derived from gastric cancer play a role by affecting macrophage phenotypes, suggesting that this may be a part of the underlying mechanism that forms the intraperitoneal cancer microenvironment.

Background: Incidence of esophagogastric junction (EGJ) carcinoma has been increasing worldwide. Several studies revealed that the distance from the EGJ to the proximal edge of the primary tumor (esophageal invasion: EI) may be a significant indicator of metastasis in the mediastinal lymph nodes in patients with Siewert type II carcinomas. However, few studies have been conducted in patients with carcinomas located at Siewert type II sequentially to upper carcinomas (Siewert type I) for mediastinal metastasis regardless of histological types., Methods: This was a single-center retrospective cohort study. EGJ carcinomas located at Siewert type I and II regions including both squamous cell carcinoma (SCC) and adenocarcinoma were analyzed in terms of lymph node metastasis patterns., Results: We included 121 patients in this study. Thirty-three (27.3%) patients had SCC. In multivariate analysis, the distance of EI (> 20 mm) was an independent risk factor (OR 11.80, p = 0.005) for lower mediastinal lymph node metastasis. In terms of above the middle mediastinal metastasis, the distance of EI (> 30 m), histological type (SCC), and tumor size (> 40 mm) were risk factors in univariate analysis. Furthermore, EI was significant (OR 13.50, p = 0.026) in multivariate analysis., Conclusions: The distance of EI was the independent risk factor for mediastinal lymph node metastasis, especially > 20 mm related with a higher risk for mediastinal lymph node metastasis. Furthermore, EGJ carcinoma patients who have EI > 30 mm, large SCC carcinoma, and multiple lymph node metastasis might be considered the middle-upper mediastinal lymph node dissection by transthoracic approach.

Background: Although proximal gastrectomy (PG) is a recognized surgical procedure for early proximal gastric cancer, total gastrectomy (TG) is sometimes selected due to concern about severe gastroesophageal reflux. Esophagogastrostomy by the double-flap technique (DFT) is an anti-reflux reconstruction after PG, and its short-term effectiveness has been reported. However, little is known about the long-term effects on nutritional status and quality of life (QOL)., Methods: Gastric cancer patients who underwent laparoscopy-assisted PG (LAPG) with DFT or laparoscopy-assisted TG (LATG) between April 2011 and March 2014 were retrospectively analyzed. Body weight (BW), body mass index (BMI), and prognostic nutritional index (PNI) were reviewed to assess nutritional status, and the Postgastrectomy Syndrome Assessment Scale (PGSAS)-45 was used to assess QOL., Results: A total of 36 patients (LATG: 17, LAPG: 19) were enrolled. Four of 17 LATG patients (24%) were diagnosed with Stage ≥II after surgery, and half received S-1 adjuvant chemotherapy. BW and PNI were better maintained in LAPG than in LATG patients until 1-year follow-up. Seven of 16 LATG patients (44%) were categorized as "underweight (BMI<18.5 kg/m2)" at 1-year follow-up, compared to three of 18 LAPG patients (17%; p = 0.0836). The PGSAS-45 showed no significant difference in all QOL categories except for decreased BW (p = 0.0132). Multivariate analysis showed that LATG was the only potential risk factor for severe BW loss (odds ratio: 3.03, p = 0.0722)., Conclusions: LAPG with DFT was superior to LATG in postoperative nutritional maintenance, and can be the first option for early proximal gastric cancer., Competing Interests: The authors have declared that no competing interests exist.

Purpose: Epidural analgesia (EDA) is an imperative modality for postoperative pain relief after major open abdominal surgery. However, whether EDA has benefits in laparoscopic surgery has not been clear. In this study, the effects of EDA and patient-controlled intravenous analgesia (PCIA) after laparoscopic distal gastrectomy (LDG) were compared., Methods: This was a retrospective study that included 82 patients undergoing LDG for gastric cancer. Patients received either EDA (n=67) or PCIA (n=15) for postoperative pain relief. Postoperative outcomes and analgesia-related adverse events were compared between the two modalities., Results: EDA and PCIA patients showed no differences in the incidence of complications [9 (13%) vs. 2 (13%); P=0.99] and the length of postoperative hospital stay (9.6±4.5 d vs. 9.7±4.0 d; P=0.90), although the PCIA included poorer preoperative physical status (PS) patients. The number of additional doses of analgesics was higher in the EDA than in the PCIA (1.8±2.4 vs. 0.9±1.0; P=0.01), although postoperative pain scores were similar in the 2 groups. Though the time to first passage of flatus was shorter in the EDA (P<0.05), more EDA patients developed postoperative hypotension as an adverse event (P<0.01). The full mobilization day and the day of oral intake tolerance were not significantly different between the 2 groups after surgery., Conclusions: After LDG, EDA may not be indispensable, while PCIA may be the optimal modality for providing safe and effective postoperative analgesia and recovery.

Cancer treatment, especially that for breast and lung cancer, has entered a new era and continues to evolve, with the development of genome analysis technology and the advent of molecular targeted drugs including tyrosine kinase inhibitors. Nevertheless, acquired drug resistance to molecular targeted drugs is unavoidable, creating a clinically challenging problem. We recently reported the antitumor effect of a pan-HER inhibitor, afatinib, against human epidermal growth factor receptor 2 (HER2)-amplified gastric cancer cells. The purpose of the present study was to identify the mechanisms of acquired afatinib resistance and to investigate the treatment strategies for HER2-amplified gastric cancer cells. Two afatinib-resistant gastric cancer cell lines were established from 2 HER2-amplified cell lines, N87 and SNU216. Subsequently, we investigated the molecular profiles of resistant cells. The activation of the HER2 pathway was downregulated in N87-derived resistant cells, whereas it was upregulated in SNU216-derived resistant cells. In the N87-derived cell line, both MET and AXL were activated, and combination treatment with afatinib and cabozantinib, a multikinase inhibitor that inhibits MET and AXL, suppressed the cell growth of cells with acquired resistance both in vitro and in vivo. In the SNU216-derived cell line, YES1, which is a member of the Src family, was remarkably activated, and dasatinib, a Src inhibitor, exerted a strong antitumor effect in these cells. In conclusion, we identified MET and AXL activation in addition to YES1 activation as novel mechanisms of afatinib resistance in HER2-driven gastric cancer. Our results also indicated that treatment strategies targeting individual mechanisms of resistance are key to overcoming such resistance., (© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Sarcopenia is a complex syndrome defined by progressive and generalized loss of skeletal muscle mass and strength. Although sarcopenia is mainly associated with aging, cancer is also one of its causes. Sarcopenia is now drawing attention as a poor prognostic factor in cancer. In patients with gastric cancer associated with eating disorders that often leads to loss of weight and muscle, sarcopenia is particularly important. Its definition and method of assessment, however, vary between studies, thus these need to be standardized. Nevertheless, emerging evidence suggests that sarcopenia contributes independently to postoperative complications and overall survival in gastric cancer. Interventions preventing sarcopenia with targeted nutrition and exercise are currently explored. This review aims to provide an understanding of sarcopenia, emphasizing its importance in the management of gastric cancer., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: The details of gastric cancer in young patients remain unclear because of the low prevalence of the disease. This study aimed to clarify the clinicopathological features and prognosis of gastric cancer in young patients., Methods: From January 2007 to January 2016, patients in their 20s and 30s who were diagnosed with primary gastric cancer at 4 hospitals were enrolled. Their clinical characteristics and prognosis were evaluated., Results: The total number of patients was 72. The median age was 36 years, and the ratio of males to females was 1:1. The dominant histological type was undifferentiated type (66/72, 92%). Helicobacter pylori (H. pylori) was positive in 81% (54/67). Although there were some asymptomatic patients in stages I-III, all stage IV patients had some clinical symptoms at the diagnosis. The percentage of stage IV was significantly higher in patients in their 20s than in those in their 30s (75% vs. 25%, P < 0.001). The Kaplan-Meier method showed that the overall survival of patients in their 20s was significantly lower than that of patients in their 30s (P = 0.037)., Conclusions: A high rate of H. pylori infection was revealed in young gastric cancer patients. The patients in their 20s had a worse prognosis than those in their 30s. We should consider examining the H. pylori infection status for young patients as well as older patients to identify high-risk populations.

While the importance of programmed death-ligand 1 (PD-L1), mutation burden caused by microsatellite instability (MSI), and CD8+ tumor infiltrating lymphocytes (TILs) has become evident, the significance of PD-L1 expression on prognosis still remains controversial. We evaluated the usefulness of combined markers of PD-L1 and MSI or CD8+ TILs as a prognostic biomarker in gastric cancer. A total of 283 patients with gastric cancer were reviewed retrospectively. PD-L1 expression on >5% tumor cells was defined as PD-L1-positive. PD-L1-positive rate was 15.5% (44/283). PD-L1 positivity was significantly correlated with invasive and advanced cancer and also significantly correlated with MSI, whereas no significance was observed with CD8+ TILs. Kaplan-Meier analysis showed that PD-L1 positivity significantly correlated with a poor prognosis (p = 0.0025). Multivariate analysis revealed that PD-L1 positivity was an independent poor prognostic factor (hazard ratio [HR]: 1.97, p = 0.0106) along with diffuse histological type and lymph node metastases. Combinations of PD-L1 and MSI (HR: 2.18) or CD8+ TILs (HR: 2.57) were stronger predictive factors for prognosis than PD-L1 alone. In conclusion, combined markers of PD-L1 and MSI or CD8+ TILs may be more useful prognostic biomarkers in gastric cancer, and better clarify the immune status of gastric cancer patients.

Gastric cancer patients positive for peritoneal cytology are at increased risk of tumor recurrence, but although a certain proportion of cytology-positive patients relapse rapidly with aggressive progression, others survive longer with conventional chemotherapies. This heterogeneity makes it difficult to stratify patients for more intensive therapy and poses a substantial challenge for the implementation of precision medicine. We developed a new approach to identify biologically malignant subpopulations in cytology-positive gastric cancer patients, using a green fluorescent protein (GFP)-expressing attenuated adenovirus in which the telomerase promoter regulates viral replication (TelomeScan, OBP-401). The fluorescence emitted from TelomeScan-positive cells was successfully quantified using a multi-mode microplate reader. We then analyzed clinical peritoneal washes obtained from 68 gastric cancer patients and found that patients positive for TelomeScan had a significantly worse prognosis. In 21 cytology-positive patients, the median survival time of those who were TelomeScan positive (235 days) was significantly shorter than that for those who were TelomeScan negative (671 days; P = 0.0062). This fluorescent virus-guided cytology detects biologically malignant cancer cells from the peritoneal washes of gastric cancer patients and may thus be useful for both therapy stratification and precision medicine approaches based on genetic profiling of disseminated cells., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

An issue of concern is that no current HER2-targeted therapeutic agent is effective against Trastuzumab (Tmab)-resistant gastric cancer. Gold nanoparticles (AuNPs) are promising drug carriers with unique characteristics of a large surface area available for attachment of materials such as antibodies. Here, we created HER2-targeted AuNPs (T-AuNPs) and examined their therapeutic efficacy and cytotoxic mechanisms using HER2-postive Tmab-resistant (MKN7) or Tmab-sensitive (NCI-N87) gastric cancer cell lines. In vitro, T-AuNPs showed stronger cytotoxic effects than controls against MKN7 and NCI-N87 cells although Tmab had no effect on MKN7 cells. Autophagy played an important role in T-AuNP cytotoxic mechanisms, which was considered to be driven by internalization of T-AuNPs. Finally, T-AuNPs displayed potent antitumor effects against NCI-N87 and MKN7 subcutaneous tumors in in vivo mouse models. In conclusion, HER2-targeted AuNPs with conjugated Tmab is a promising strategy for the development of novel therapeutic agents to overcome Tmab resistance in gastric cancer., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Gastric cancer is the second most common malignancy, overlapping with thoracic esophageal cancer (TEC). Among them, metachronous gastric tube cancers after TEC surgery have been increasing. The aims of this study were to examine the clinicopathological factors and treatment outcomes of gastric tube cancer (GTC) after TEC surgery., Methods: Thirty-three GTCs in 30 cases after TEC treated between 1997 and 2016 were investigated retrospectively., Results: Most cases were males. The median interval from TEC surgery to GTC occurrence was 57 (6.5-107.5) months. Almost 2/3 lesions occurred in the lower third of the gastric tube (21/33); 29 lesions (in 26 cases) were superficial cancers, and 4 lesions were advanced cancers. Twenty-two lesions of superficial cancer were differentiated type, and the remaining seven lesions were undifferentiated type. Treatment for superficial cancer had previously been performed with partial gastric tube resection (10 lesions), and the number of cases undergoing endoscopic submucosal dissection (ESD) had increased recently (19 lesions). Most cases with superficial cancer survived without relapse. Four lesions of advanced cancer were found after a relatively long interval following TEC surgery. Most lesions of advanced cancer were scirrhous, undifferentiated type, and they died due to GTC., Conclusion: GTCs may occur late in the postoperative course following TEC surgery. If they are discovered at an early stage, these lesions can be cured with ESD. Long-term periodic endoscopic examinations after TEC surgery are important.

Background: Sarcopenia is recognized as an important prognostic factor in various types of cancer, including gastric cancer. While long-term survival analyses typically focus on overall and disease-specific survival, death from other causes has received far less attention., Methods: We reviewed medical records of 491 gastric cancer patients who underwent gastrectomy from January 2005 to March 2014 and whose preoperative computed tomography (CT) images were available for evaluation of sarcopenia. Sarcopenia was defined as the SMA/BSA index (skeletal muscle area divided by body surface area) below the sex-specific lowest quartile., Results: Sarcopenia was significantly associated with age, high body mass index (BMI), presence of comorbidity, high American Society of Anesthesiologists physical status (ASA-PS), high T score, advanced stage, large blood loss, and long hospital stay, but was not significantly associated with postoperative complications. Univariate and multivariate analyses of prognostic factors for overall survival revealed that sarcopenia is an independent predictor of poor prognosis [hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.01-2.09, p  =  0.0454]. Our analysis of death due to other causes found that non-gastric cancer-related deaths were more frequent among sarcopenia patients with comorbidities than in the rest of our study population (p  =  0.0001), while univariate and multivariate analyses revealed that sarcopenia with comorbidity was an independent risk factor for non-gastric cancer-related death (HR 1.84, 95% CI 1.31-3.61, p  =  0.0308), as was age., Conclusion: For gastric cancer patients, sarcopenia increases the risk of death from other causes following surgery, which reveals the importance of developing treatment strategies based not only on cancer status but also on other clinical factors, including sarcopenia and comorbidity.

Molecularly targeted therapy has enabled outstanding advances in cancer treatment. Whereas various anti-human epidermal growth factor receptor 2 (HER2) drugs have been developed, trastuzumab is still the only anti-HER2 drug presently available for gastric cancer. In this study, we propose novel treatment options for patients with HER2-positive gastric cancer. First, we determined the molecular profiles of 12 gastric cancer cell lines, and examined the antitumor effect of the pan-HER inhibitors afatinib and neratinib in those cell lines. Additionally, we analyzed HER2 alteration in 123 primary gastric cancers resected from Japanese patients to clarify possible candidates with the potential to respond to these drugs. In the drug sensitivity analysis, both afatinib and neratinib produced an antitumor effect in most of the HER2-amplified cell lines. However, some cells were not sensitive to the drugs. When the molecular profiles of the cells were compared based on the drug sensitivities, we found that cancer cells with lower mRNA expression levels of IGFBP7, a tumor suppressor gene that inhibits the activation of insulin-like growth factor-1 receptor (IGF-1R), were less sensitive to pan-HER inhibitors. A combination therapy consisting of pan-HER inhibitors and an IGF-1R inhibitor, picropodophyllin, showed a notable synergistic effect. Among 123 clinical samples, we found 19 cases of HER2 amplification and three cases of oncogenic mutations. In conclusion, afatinib and neratinib are promising therapeutic options for the treatment of HER2-amplified gastric cancer. In addition to HER2 amplification, IGFBP7 might be a biomarker of sensitivity to these drugs, and IGF-1R-targeting therapy can overcome drug insensitiveness in HER2-amplified gastric cancer., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: Trastuzumab when combined with fluoropyrimidine and cisplatin was proven to improve survival in patients with human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) in the ToGA study. The safety and efficacy of trastuzumab in combination with docetaxel and S-1 have not yet been evaluated., Methods: This study was a multicenter, phase II study. Patients with chemotherapy-naïve HER2-positive advanced or metastatic GC were eligible. Trastuzumab was administered intravenously on day 1 of the first cycle at 8 and 6 mg/kg in subsequent cycles. Docetaxel was administered intravenously at 40 mg/m 2 on day 1 of each cycle. S-1 was administered at a dosage based on body surface area for 14 days in a 3-weekly cycle. The primary endpoint was progression-free survival (PFS)., Results: A total of 23 patients were enrolled. Median PFS was 6.7 months (95% CI 4.1-10.1). The response rate (RR) was 39.1%. Median overall survival (OS) and time to treatment failure (TTF) were 17.5 and 4.4 months, respectively. Major grade 3-4 adverse events were neutropenia (39.1%), leukopenia (30.4%), and febrile neutropenia (8.7%)., Conclusion: Trastuzumab in combination with docetaxel and S-1 showed effective antitumor activity and manageable toxicities as first-line treatment for patients with HER2-positive GC.

We have established an orthotopic nude-mouse model of gastric cancer carcinomatosis peritonitis, a recalcitrant disease in human patients. Human MKN45 poorly-differentiated human gastric cancer cells developed carcinomatosis peritonitis upon orthotopic transplantation in nude mice. The MKN45 cells expressed the fluorescent ubiquitination-based cell cycle indicator (FUCCI) that color codes the phases of the cell cycle. The intra-peritoneal tumors and ascites contained mostly quiescent G 1 /G o cancer cells visualized as red by FUCCI imaging. Cisplatinum (CDDP) treatment did not reduce bloody ascites, and larger tumors formed in the peritoneal cavity after CDDP treatment in an early-stage carcinomatosis peritonitis orthotopic mouse model. Paclitaxel-treated mice had reduced ascites, but also had large tumor masses in the peritonium after treatment with cancer cells mostly in G 0 /G 1 , visualized by FUCCI red. In contrast, OBP-301 telomerase-dependent adenovirus-treated mice had no ascites and only small tumor nodules consisting of cancer cells mostly in S/G 2 phases in the early-stage carcinomatosis peritonitis model, visualized by FUCCI green. Furthermore, OBP-301 significantly reduced the size of tumors (P < 0.01) and ascites even in a late-stage carcinomatosis peritonitis model. These results suggest that quiescent peritoneally-disseminated gastric cancer cells are resistant to conventional chemotherapy, but OBP-301 significantly reduced the weight of the tumors and increased survival, suggesting clinical potential. J. Cell. Biochem. 118: 3635-3642, 2017. © 2016 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Trastuzumab(Tmab), a humanized monoclonal antibody that selectively targets human epidermal growth factor receptor 2(HER2), is currently used in the clinical setting for the treatment of both breast and gastric cancer. While Tmab has shown improvements in patient prognoses, acquired resistance to this agent remains an issue. While some novel HER2-targeted agents have been approved for clinical use in breast cancer, no such agent has shown treatment efficacy for gastric malignancies with Tmab-resistance. Nanotechnology, which has progressed rapidly, has been applied to medical fields in recent years. Gold nanoparticles, which are characterized by their in vivo stability and ease of surface modification, have been reported to show efficacy as the carriers of therapeutic agents, such as drugs, antibodies, peptides, and nucleic acids. In this work, we developed Tmab-conjugated gold nanoparticles and demonstrate their efficacy for the treatment of HER2-positive, Tmabresistant gastric cancer cell lines. Our findings demonstrate that Tmab-conjugated gold nanoparticles have the potential to be a novelHER2 -targeted therapeutic agent.

Purpose: Laparoscopy-assisted distal gastrectomy (LADG) is likely to become a standard procedure for gastric cancer, which highlights the importance of establishing a training system in which even inexperienced surgeons can perform this procedure safely. This study assesses our training system for LADG based on short-term surgical outcomes., Methods: We evaluated retrospectively the short-term outcomes of 100 consecutive LADGs with curative D1/D1+ lymph node dissection. Our training system was assessed based on the learning curve of trainees, and factors related to achieving good-quality operations were analyzed statistically., Results: Overall, postoperative complications developed in 10 patients (10%), and included one case of anastomotic leakage (1%) and one case of pancreatic fistula (1%). The learning curve of the trainees plateaued after 10 operator cases in terms of operation time. The importance of the trainer's position was also confirmed by the result that the operation time was significantly longer when trainees with ≤10 operator cases performed LADG with a trainer as scopist vs. a trainer as the first assistant. Univariate and multivariate analyses revealed that >10 operator cases were the most important factor for achieving good-quality operations., Conclusion: These results show that our current LADG procedure and training system are appropriate and effective.

Background: Endoscopic resection (ER) has been widely accepted as the standard treatment for early gastric cancer (EGC). However, in patients considered to have undergone non-curative ER due to their potential risk of lymph node metastasis (LNM), additional gastrectomy is recommended. The aim of the present study was to identify EGC patients after non-curative ER at high risk of LNM., Methods: A total of 150 patients who had undergone ER for EGC were diagnosed as non-curative ER due to their potential risk of LNM. Clinicopathological data and clinical outcomes were examined retrospectively., Results: Additional gastrectomy with lymph node dissection was performed in 73 patients, and the remaining 77 patients were followed-up without additional gastrectomy. In patients who underwent additional gastrectomy, 8 patients had local residual tumor, and 8 patients had LNM, which were limited in the peritumoral nodes. Only lymphatic invasion (p = 0.012) was a statistically significant factor for LNM. The 5-year overall survival and recurrence-free survival were not significantly different between patients with and without additional gastrectomy., Conclusion: Additional gastrectomy with lymph node dissection is recommended for patients who were diagnosed as non-curative ER with lymphatic invasion, and minimizing the extent of lymph node dissection may be allowed for these patients.

Laparoscopic and endoscopic cooperative surgery (LECS) is increasingly applied for gastric submucosal tumors (SMTs) such as gastrointestinal stromal tumors. However, the conventional LECS procedure has the potential risk that gastric contents and even tumor cells could spread into the abdominal cavity because the gastric wall has to be opened during the resection. To avoid this problem, we have developed a modified LECS procedure named "closed LECS." Ten patients underwent closed LECS for the resection of gastric SMTs. Closed LECS consists of the following steps: endoscopic submucosal layer dissection around the tumor, laparoscopic marking of a resection line on the serosal surface along submucosal dissection line, seromuscular suturing with the marked lesion inverted into the inside of the stomach, endoscopic circumferential seromuscular dissection, and peroral retrieval. In three of the initial five cases, the closed LECS procedure was not completed as planned because of the tumor size and endoscopic inappropriate seromuscular dissection. After modification of the procedure, the entire procedure was successful in all five cases. The mean resected tumor diameter was 24.1 ± 7.6 mm. The mean operation time was 253 ± 45 min. One patient experienced an intra-abdominal abscess potentially related to delayed perforation as a postoperative complication. The closed LECS procedure for gastric SMTs can theoretically be applied without contamination and tumor cell dissemination into the abdominal cavity.

A 70-year-old man who underwent gastrectomy for Stage III C gastric cancer developed lymph node(LN)metastasis posterior to the pancreatic head 3 years after the radical surgery.He was first treated with radiotherapy(RT)followed by chemotherapy.The irradiated tumor regressed completely.However, the cancer relapsed in a single para-aortic LN and he was treated with RT to the lesion followed by chemotherapy.Although it completely regressed, later, lung metastasis was observed.The lung lesions were well suppressed by switching to docetaxel; however, the cancer relapsed again in a mediastinal LN, and it was not responsive to docetaxel.The growing mediastinal lesion was irradiated again, which resulted in stable disease.The patient has been treated for 4 years and 7 months with all lesions being well-managed, and chemotherapy is being continued.Recurrent gastric cancer after surgery tends to present as multiple lesions; therefore, the principle therapy is systemic chemotherapy and RT is unlikely to be suitable.However, especially in cases of a solitary lesion that is chemo-resistant, RT could be an optimal option and contribute to long-term survival even in patients with recurrent gastric cancer.

A 63-year-old man underwent proximal gastrectomy for early gastric cancer(pT1bN0M0, pStage I A). Twenty months after surgery, abdominal CT scans revealed multiple liver metastases. S-1 plus CDDP therapy was administered as first-line chemotherapy. After treatment, CT scans revealed tumor progression and nab-PTX was administrated. This treatment was ineffective; therefore, CPT-11 was administrated as third-line chemotherapy. Treatment with CPT-11 resulted in marked tumor reduction and improved the QOL of the patient; partial response was maintained for 8 months. After 17 courses of CPT-11 treatment, tumor regrowth was detected, and the patient was treated with S-1 plus oxaliplatin, DTX, and ramucirumab. Subsequently, the patient died of cancer 31 months after tumor recurrence. CPT-11 is potentially a key drug for the prevention of liver metastasis of gastric cancer, and using all active agents in patients with advanced gastric cancer over several lines of therapy could prolong survival.

Although intermittent pneumatic compression (IPC) has become common as perioperative prophylaxis for venous thromboembolism (VTE) consisting of pulmonary thromboembolism (PE) and deep vein thrombosis (DVT), the prophylactic effect against VTE, especially lethal PE, is not yet satisfactory. Therefore, pharmacologic prophylaxis, such as with enoxaparin, is desirable. While the efficacy and safety of enoxaparin have been proven in several clinical trials, concern about bleeding with longterm (at least 7 days) use have potentially decreased its widespread adoption. We have launched a phase II study to evaluate the efficacy and safety of short-term (3 days) enoxaparin, in which a total of 70 gastric cancer patients undergoing gastrectomy will be recruited, and the primary endpoint is the incidence of DVT. This study could contribute to making pharmacologic prophylaxis for VTE more common.

Trastuzumab(Tmab)is a humanized monoclonalantibody that binds to the human epidermalgrowth factor receptor 2 (HER2). It is clinically used for HER2-positive breast and gastric cancers; however, the use of Tmab is restricted to tumors expressing high levels of HER2(accounting for only 20%of tumors), and Tmab cannot be used for tumors resistant to Tmab. Although novel HER2-targeted agents have been developed to treat Tmab-resistant tumors, none of these have shown clinical efficacy in gastric cancer patients. Recent developments in nanotechnology have had a significant impact on the field of medicine. Gold nanoparticles(AuNPs), which show characteristics such as in vivo stability and ease of surface functionalization, have been developed as therapeutic and contrast agents for medical applications. Previous studies show that AuNPs exert cytotoxic effects through autophagy and apoptosis; therefore, AuNPs in combination with tumor-targeting antibodies are attractive therapeutic agents. In this study, we developed HER2-targeted AuNPs(Tmab-AuNPs)and showed that they had a potent antitumor effect on Tmab-resistant cell lines. In addition, Tmab-AuNPs were effective against HER2-negative gastric cancer cell lines when HER2 was artificially overexpressed. Thus, our results indicate that Tmab-AuNPs may overcome the shortcomings of Tmab-based therapy.

Background: Bochdalek hernia (BH) is generally congenital, presenting with respiratory distress. However, this pathology is rarely detected in adults. Some adult cases of BH present with symptoms attributed to the hernia, but incidental detection of BH is increasing among asymptomatic adults due to advances in imaging modalities. This report presents the management of incidental BH patients detected in the preoperative period of gastric cancer., Case Presentation: An asymptomatic 76-year-old woman was diagnosed with advanced gastric cancer during follow-up after radiotherapy for uterine cervical cancer. Computed tomography (CT) was performed to exclude metastatic gastric cancer, incidentally detecting right-sided BH. We planned distal gastrectomy with lymph node dissection for gastric cancer and simultaneous repair of BH using a laparoscopic approach. We performed laparoscopic gastrectomy for gastric cancer and investigated the right-sided BH to assess whether repair during surgery was warranted. Herniation of the liver into the right hemithorax was observed, but was followed-up without surgical repair because the right hepatic lobe was adherent to the remnant right anterior hemidiaphragm and covered the huge defect in the right hemidiaphragm. No intra- or postoperative pneumothorax was observed during pneumoperitoneum., Conclusion: Regardless of symptoms, repair of adult BH is generally recommended to prevent visceral incarceration. However, BH in asymptomatic adults appears to be more common than previously reported in the literature. Surgeons need to consider the management of incidental BH encountered during thoracic or abdominal surgery.