Postoperative sarcopenia increases both gastric cancer and other-cause mortality in older adults undergoing radical gastrectomy for cancer.

BACKGROUND & AIMS: Preoperative sarcopenia in gastric cancer is associated with increased postoperative complications and reduced long-term survival. However, the association between postoperative sarcopenia and long-term outcomes remains unclear. Therefore, this study aims to clarify the association between sarcopenia after gastrectomy for gastric cancer and survival outcomes. METHODS: This retrospective study included 1512 patients aged ≥65 who underwent curative gastric resection for clinical stage I-III primary gastric cancer during 2008-2018. Sarcopenia was assessed preoperatively by measuring arm muscle area and grip strength, which was repeated 1 month after surgery. We compared the clinical characteristics, surgical treatments, and long-term outcomes between the postoperative normal and sarcopenia groups. RESULTS: Sarcopenia was observed in 173 and 305 patients pre- and postoperatively, respectively. Factors increasing the risk of postoperative sarcopenia included age of ≥75, lower preoperative body mass index, diabetes, and clinical stage II/III gastric cancer. Patients with postoperative sarcopenia after surgery had a significantly lower overall survival rate (hazard ratio [HR] 2.596, p < 0.001). Furthermore, postoperative sarcopenia was linked to decreased overall survival in patients with (HR 2.813, p = 0.002) and without (HR 1.925, p < 0.001) preoperative sarcopenia. Cumulative incidence showed significantly higher rates of deaths due to gastric cancer (HR 1.928, p < 0.001) and other causes (HR 2.736, p < 0.001) in the postoperative sarcopenia group. CONCLUSIONS: Postoperative sarcopenia in gastric cancer is linked to an increased risk of death due to cancer and other causes, underscoring the importance of perioperative sarcopenia management strategies.

Molecular features and prognostic factors of locally advanced microsatellite instability-high gastric cancer.

BACKGROUND: Microsatellite instability-high (MSI-H) tumors are distinct molecular subtypes in gastric cancer. However, a few studies have comprehensively reported the molecular features of MSI-H tumors and their prognostic factors in locally advanced gastric cancer. This study aimed to clarify the molecular features and prognostic factors of locally advanced MSI-H gastric cancer. METHODS: This study included 499 patients with locally advanced gastric cancer who underwent radical gastrectomy. We evaluated the MSI status and compared with previously published whole-exome sequencing, panel sequencing, and gene expression profiling data. Clinicopathological characteristics and molecular profiles were compared between patients with MSI-H and microsatellite stable (MSS) gastric cancer. A subgroup analysis of survival was performed in patients with MSI-H gastric cancer. RESULTS: MSI-H tumors were detected in 79 of 499 patients (15.8%). MSI-H tumors were associated with an increased tumor mutational burden, MLH1 downregulation, CD274 (PD-L1) upregulation, and enrichment of cell cycle pathways. Among patients with MSI-H gastric cancer, the disease-specific survival (DSS) tended to be better in the surgery plus tegafur, gimeracil, and oteracil potassium (S-1) adjuvant chemotherapy group than in the surgery alone group, especially for stage III patients. Furthermore, DSS was better in the T cell-inflamed gene expression signature-high group, and it tended to be worse in the non-solid type poorly differentiated adenocarcinoma group. CONCLUSIONS: The molecular features and prognostic factors of locally advanced MSI-H gastric cancer were clarified. S-1 adjuvant chemotherapy appears to be beneficial, and the T cell-inflamed gene expression signature and histopathological type are prognostic factors in MSI-H tumors.

Gastric inflammatory myofibroblastic tumor: a case report.

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) of the stomach is an uncommon mesenchymal neoplasm. We present a case of gastric submucosal tumor (SMT) where the final diagnosis was IMT. CASE PRESENTATION: A 69-year-old man presented with a 24-mm SMT on the posterior wall of the middle third of the stomach that was detected by screening upper gastrointestinal endoscopy. Abdominal contrast-enhanced computed tomography showed that the tumor was well-enhanced. Although endoscopic ultrasonography-guided biopsy was performed, the histological diagnosis was not confirmed preoperatively. Since the tumor was clinically suspected to be a gastrointestinal stromal tumor, we performed gastric wedge resection by laparoscopic-endoscopic cooperative surgery. Pathologically, proliferative spindle cells with a positive reaction for smooth muscle actin, negativity for c-kit, desmin, s-100, CD34, STAT-6, ß-catenin and anaplastic lymphoma kinase 1 were identified. Hence, the tumor was finally diagnosed as an IMT originating from the stomach. CONCLUSIONS: When an SMT of the stomach is identified, the possibility of gastric IMT should be considered.

The Effectiveness of Screening Total Colonoscopy for Preoperative Patients with Gastric Cancer.

BACKGROUND: Colorectal cancer (CRC) is the most common cancer that coincides with gastric cancer (GC). Although the usefulness of total colonoscopy (TCS) as a CRC screening tool has been reported in preoperative patients with GC, the long-term outcome of patients with synchronous CRC (SCRC) remains unclear. This study aims to clarify the significance of preoperative screening TCS for GC in terms of survival outcomes. PATIENTS AND METHODS: We included 796 patients who underwent preoperative screening TCS for GC. The risk factors, clinicopathological features, and survival outcome of SCRC were examined. Furthermore, the cost-effectiveness was evaluated from the perspective of improving the rates of mortality caused by CRC. RESULTS: SCRC was observed in 43 patients (5.4%). Endoscopic treatment for SCRC was performed on 30 patients. In total, 15 patients underwent surgical resection, including 2 patients requiring additional surgery after endoscopic treatment. Regarding pathological stages, 25 patients had stage 0, 12 patients had stage I, 5 patients had stage II, and 1 patient had stage IIIB disease. The cumulative mortality rates were as follows: GC-related deaths, 12.6%; deaths from cancers other than CRC, 1%; deaths from other causes, 5.5%. No deaths were attributed to SCRC. Comparing the patients who did not undergo TCS, an incremental cost-effectiveness ratio analysis suggested that a screening cost of 5.86 million yen was required to prevent one CRC death. CONCLUSIONS: Curative treatment was possible in all patients with SCRC. No deaths were attributed to SCRC, suggesting that screening TCS for GC is effective.

Impact of Mutations in Subunit Genes of the Mammalian SWI/SNF Complex on Immunological Tumor Microenvironment.

BACKGROUND/AIM: Recently, inactivating somatic mutations of SWI/SNF chromatin-remodeling genes in cancers have been reported. However, few studies have been performed regarding the immunological analysis of the tumor microenvironment (TME) in chromatin remodeling complex gene-mutated tumors. In the present study, we identified cancer patients harboring various mammalian SWI/SNF complex mutations and investigated the immunological features in those mutated cancers. PATIENTS AND METHODS: Cancer patients harboring any type of chromatin remodeling complex gene mutation were selected and clinicopathological features were compared between chromatin remodeling complex gene expression-low and expression-high groups. Specifically, expression levels of immune response-associated genes and cancer-associated genes were compared between the SMARCA4 expression-low and expression-high groups using volcano plot analysis. RESULTS: Among cancers harboring PBRM1, SAMRACA4 and ARID2 gene mutations, T-cell marker and mature B-cell marker genes were up-regulated in the tumor. Specifically, T-cell effector genes (CD8B, CD40LG), central memory marker genes (CD27, CCR7) and mature B-cell marker genes (CD20, CD38, CD79 and IRF4) were up-regulated, and cancer-associated genes including MYB, MYC and AURKB genes were down-regulated in the SMARCA4 expression-low group. Remarkably, heatmap of gene expression and immunohistochemistry (IHC) data demonstrated that the tertiary lymphoid structure (TLS) gene signature of mature B cells was up-regulated in SMACA4 gene-mutated stomach cancers. CONCLUSION: These results suggest that immune tumor microenvironment status, such as mature B cell recruitment featuring the TLS gene signature and immune activation mediated by cancer signal down-regulation, might contribute to the classification of SMARCA4 gene-mutated tumors as immune checkpoint blockade therapy-sensitive target tumors.

Molecular profiling of gastric neuroendocrine carcinomas.

Gastric neuroendocrine carcinoma (G-NEC) usually has NEC and adenocarcinoma components and is considered to have a common origin in gastric adenocarcinoma because common pathogenic mutations are shared. However, G-NEC without adenocarcinoma also exists, and it may have a different mechanism of tumorigenesis. We aimed to elucidate the tumorigenesis of G-NEC by focusing on the proportion of NEC components. Thirteen patients with G-NEC were included in this study. Comprehensive genetic analysis using whole-exome sequencing was performed. G-NEC without an adenocarcinoma component was defined as pure NEC. TP53 was detected as the most frequent gene mutation (85% of the patients), independent of classification. RB1, KMT2C, LTBP1, and RYR2 mutations were identified in two of three pure NEC patients but were not detected in other G-NEC patients. Pure NEC has different somatic mutation profile than other NECs. This study provides insights into the mechanism of tumorigenesis in G-NEC.

Molecular profile of poorly cohesive gastric carcinoma with special reference to survival.

BACKGROUND: Patients with poorly cohesive gastric carcinoma (PCC) are known to have poor survival. However, detailed molecular biology of PCC has not been elucidated, except for mutations in CDH1 and RHOA. Additionally, the molecular profiles of signet-ring cell carcinoma (SRC) have not been fully investigated. We aimed to investigate the association between molecular profiles and survival in PCC and PCC subtypes. METHODS: The present study included 455 patients with gastric adenocarcinoma underwent radical gastrectomy. Whole-exome sequencing and gene expression profiling were conducted. Patients were classified according to the WHO classification as PCC or non-PCC, with PCC being further classified into SRC, combined, and PCC not-otherwise-specified (NOS). Clinicopathological factors and survival were compared with molecular profiles. RESULTS: Of the patients, 159 were classified with PCC, while 296 were classified with non-PCC. Among PCC, 44 were classified with SRC, 64 with combined, and 51 with PCC-NOS. Mutations in CDH1 and RHOA were remarkably more frequent in PCC than in non-PCC. PCC had worse overall survival (OS) and disease-specific survival (DSS) compared to non-PCC. For PCC, the SRC group had good OS and DSS, whereas PCC-NOS classification with CDH1 mutations was associated with extremely poor survival. In the PCC-NOS and combined groups, patients with mutations in the extracellular domain 1 of CDH1 had poor survival. CONCLUSIONS: Our findings suggest that PCC has poorer survival than non-PCC. Accumulation of CDH1 and RHOA mutations are unique profiles in PCC. Among PCC, CDH1 mutations may play a crucial role in the survival of non-SRC PCC.

Report of two patients in whom comparisons of the somatic mutation profile were useful for the diagnosis of metastatic tumors.

BACKGROUND: When a patient has multiple tumors in different organs, it is very important to identify whether the tumors are multiple cancers or metastasis from one tumor in order to establish an optimal treatment strategy. However, it is difficult to obtain an accurate diagnosis from conventional diagnostic strategies, including immunohistochemistry. We report two patients with multiple tumors in which a somatic mutation comparison using next-generation sequencing (NGS) was useful for the diagnosis of a metastatic tumor. CASE PRESENTATIONS: Patient 1: A 64-year-old man was diagnosed with gastric and lung cancer. After radical chemoradiotherapy for lung cancer, gastrectomy was planned for gastric cancer. At gastrectomy, the patient underwent a multiple omics analysis for "Project HOPE". The gene mutational signature of the gastric tumor showed signature 4 of COSMIC mutational signature version 2, which was associated with smoking and has not been found in gastric cancer. To confirm that the gastric tumor was metastasis from lung cancer, we conducted a somatic mutation comparison of the two tumors with 409-gene panel sequencing, which revealed that 28 of 97 mutations in the lung tumor completely matched those of the gastric tumor. Based on these findings, the gastric tumor was diagnosed as metastasis from lung cancer. Patient 2: A 47-year-old woman underwent distal gastrectomy for gastric cancer. A colon tumor was detected 6 years after gastrectomy. The colon lesion was a submucosal tumor-like elevated tumor, and was suspected to be metastasis from gastric cancer. The patient underwent sigmoidectomy, and participated in "Project HOPE". The possibility of primary colon cancer could not be ruled out, and we conducted a somatic mutation comparison of the two tumors as we did with Patient 1. Panel sequencing revealed 11 mutations in the gastric tumors, 4 of which completely matched those of the colon tumor. The colon tumor was diagnosed as metastasis from gastric cancer. CONCLUSION: We reported two patients with multiple tumors in which a somatic mutation comparison using NGS was useful for the diagnosis of a metastatic tumor.

Molecular classification of gastric cancer predicts survival in patients undergoing radical gastrectomy based on project HOPE.

BACKGROUND: Gastric cancer (GC) has been classified based on molecular profiling like The Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG), and attempts have been made to establish therapeutic strategies based on these classifications. However, it is difficult to predict the survival according to these classifications especially in radically resected patients. We aimed to establish a new molecular classification of GC which predicts the survival in patients undergoing radical gastrectomy. METHODS: The present study included 499 Japanese patients with advanced GC undergoing radical (R0/R1) gastrectomy. Whole-exome sequencing, panel sequencing, and gene expression profiling were conducted (High-tech Omics-based Patient Evaluation [Project HOPE]). We classified patients according to TCGA and ACRG subtypes, and evaluated the clinicopathologic features and survival. Then, we attempted to classify patients according to their molecular profiles associated with biological features and survival (HOPE classification). RESULTS: TCGA and ACRG classifications failed to predict the survival. In HOPE classification, hypermutated (HMT) tumors were selected first as a distinctive feature, and T-cell-inflamed expression signature-high (TCI) tumors were then extracted. Finally, the remaining tumors were divided by the epithelial-mesenchymal transition (EMT) expression signature. HOPE classification significantly predicted the disease-specific and overall survival (p < 0.001 and 0.020, respectively). HMT + TCI showed the best survival, while EMT-high showed the worst survival. The HOPE classification was successfully validated in the TCGA cohort. CONCLUSIONS: We established a new molecular classification of gastric cancer that predicts the survival in patients undergoing radical surgery.

Long-term outcomes of robotic gastrectomy for clinical stage I gastric cancer: a single-center prospective phase II study.

INTRODUCTION: The outcomes of robotic gastrectomy (RG) for gastric cancer remain unclear due to a lack of prospective studies. We had previously designed and conducted a prospective phase II study of RG that showed favorable short-term outcomes. Herein, we aimed to determine the long-term outcomes of RG for clinical stage I gastric cancer. PATIENTS AND METHODS: This single-center, prospective phase II study enrolled patients with clinical stage I gastric cancer undergoing RG. The survival outcomes, which were the secondary endpoints of the study, were evaluated. RESULTS: Between December 2012 and April 2015, 120 patients were enrolled in this study. The 5-year overall survival (OS) was 96.7% (95% confidence interval [CI] 91.5-98.7%). The 5-year recurrence-free (RFS) and disease-specific survival (DSS) rates were 96.7% (95% CI 91.5-98.7%) and 99.2% (95% CI 94.3-99.9%), respectively. When confining the analysis to distal and pylorus-preserving gastrectomy, the 5-year OS, RFS, and DSS were 98.1% (95% CI 92.7-99.5%), 98.1% (95% CI 92.7-99.5%), and 100%, respectively. Only one patient died due to relapse of gastric cancer, while three died from other causes. CONCLUSIONS: Long-term outcomes of RG was comparable to those of open and laparoscopic gastrectomy when the surgeries were performed by experienced surgeons in a high-volume center.

Optimal extent of lymph node dissection in patients with gastric cancer who underwent non-curative endoscopic submucosal dissection with a positive vertical margin.

BACKGROUND: The optimal extent of lymph node dissection in patients receiving non-curative endoscopic submucosal dissection (ESD) and diagnosed with a positive vertical margin is unclear. This study attempted to identify optimal candidates for D2 lymph node dissection among these patients. METHODS: This study included patients who underwent gastrectomy for primary gastric cancer following non-curative ESD with a positive vertical margin between January 2002 and December 2018. We classified the patients according to the positive vertical margin pattern into an obvious exposure group and a non-obvious exposure group. We developed a score model for predicting lymph node metastasis (LNM) using factors selected by multivariate analyses and beta regression coefficients, and the incidence of LNM was evaluated. RESULTS: This study included 110 patients. LNM was detected in 17 patients (15%). We developed a predictive scoring system as follows: tumor size >30 mm (0, No; 1, Yes) + undifferentiated type tumor in the invasive front (0, No; 2, Yes) + depth of submucosal invasion > 1500 µm (0, No; 1, Yes) + obvious tumor exposure at the vertical margin (0, No; 1, Yes). In patients with 5 points, the incidence rates of all and group 2 LNM were as high as 60% and 40%, respectively. Conversely, in patients with fewer than 5 points, the incidence rates of all and group 2 LNM were just 11% and 5%, respectively. CONCLUSION: In patients with 5 points according to our score model for predicting LNM, gastrectomy with D2 lymph node dissection is recommended.

A phase II study of ramelteon for the prevention of postoperative delirium in elderly patients undergoing gastrectomy.

PURPOSE: The growing number of cases of gastric cancer being diagnosed in elderly patients highlights the importance of preventing postoperative delirium. This phase II study aimed to evaluate the efficacy of perioperative treatment with ramelteon for preventing postoperative delirium in elderly patients undergoing gastrectomy. METHODS: This study was designed as a single-institute prospective phase II study. Patients ≥ 75 years old were eligible. Ramelteon 8 mg/day was administered from 8 days before the operation until discharge. Postoperative delirium was evaluated using the Confusion Assessment Method-Intensive Care Unit flow sheet. RESULTS: Between September 2015 and July 2017, a total of 83 patients were enrolled, 76 of whom were eligible and included in the analysis. Postoperative delirium was observed in four patients (5%) (60% confidence interval: 3.0-8.7). The upper margin of the confidence interval was lower than the prespecified threshold of 13%; therefore, the null hypothesis was rejected. CONCLUSION: This phase II study suggested that the perioperative administration of ramelteon is safe and feasible for preventing postoperative delirium in elderly patients undergoing gastrectomy. Trial registration This study was registered at UMIN (UMIN 000018697).

Prediction of S-1 adjuvant chemotherapy benefit in Stage II/III gastric cancer treatment based on comprehensive gene expression analysis.

BACKGROUND: Studies to identify predictive biomarkers of adjuvant chemotherapy with S-1 after gastrectomy in Stage II/III gastric cancer patients have been done; however, more clarity and understanding are needed. Our aim in the present study was to identify biomarkers predicting benefit due to S-1 adjuvant chemotherapy using comprehensive gene expression analysis. METHODS: We retrospectively analyzed 102 patients receiving adjuvant chemotherapy with S-1 and 46 patients not receiving S-1 adjuvant chemotherapy after gastrectomy for gastric cancer treatment between January 2014 and December 2016. Hierarchical clustering analysis was performed based on the gene expression data obtained using cDNA microarray. Differentially expressed genes (DEGs) were identified using thresholds of absolute fold changes of > 4.0 and a false discovery rate P value of < 0.01. Gene Ontology (GO) analysis and GO network visualization were performed using the ClueGO app in Cytoscape. RESULTS: Hierarchical clustering analysis in patients treated with S-1 adjuvant chemotherapy revealed two clusters with favorable and unfavorable survival outcomes. We identified 147 upregulated DEGs and 192 downregulated DEGs in the favorable outcome group. GO analysis to identify significantly upregulated genes showed enrichment in immune-related genes and GO terms. Upregulation of these immune-related genes was not associated with survival in patients not receiving S-1 adjuvant chemotherapy. CONCLUSIONS: The upregulation and enrichment of immune-related genes and GO terms may be predictive biomarkers in patients who would benefit from adjuvant S-1 chemotherapy to treat Stage II/III gastric cancer.

Adenocarcinosarcoma at the esophagogastric junction with long esophageal invasion: a case report.

BACKGROUND: Carcinosarcoma of the esophagus or esophagogastric junction (EGJ) is a rare malignancy with both carcinomatous and sarcomatous components. There is no report of carcinosarcoma arising from the EGJ wherein the carcinomatous element was adenocarcinoma. We describe a patient with carcinosarcoma of the EGJ in which the carcinomatous element was adenocarcinoma. CASE PRESENTATION: A 52-year-old man was diagnosed with carcinoma on his EGJ after complaining of appetite loss. All tumor markers (carcinoembryonic antigen, squamous cell carcinoma antigen, alpha-fetoprotein, and carbohydrate antigen 19-9) were within the respective normal ranges. Esophagogastroduodenoscopy showed a 150-mm (100 mm esophageal side and 50 mm gastric side) type 1 tumor on his EGJ. A histopathological examination of a biopsy specimen revealed well-differentiated tubular adenocarcinoma at the gastric side; however, only necrotic tissue was noted on the esophageal side. Contrast-enhanced computed tomography did not reveal any invasion of the adjacent structures; however, it did show five swollen regional lymph nodes. 18F-Fluorodeoxyglucose positron emission tomography with computed tomography did not reveal distant metastases. We performed thoracic subtotal esophagectomy, total gastrectomy, and two-field plus left cervical paraesophageal lymphadenectomy. Macroscopically, the lesion consisted of two components: a 7.5-cm type 2 tumor and a 9-cm type 1 tumor at the proximal end of the type 2 tumor. Microscopically, the type 2 tumor showed predominantly solid or cribriform proliferation of tumor cells with clear cytoplasm, which was moderately differentiated adenocarcinoma with enteroblastic-like differentiation. The tumor cells of the adenocarcinoma component had periodic acid-Schiff (PAS)-positive globules and were positive for sal-like protein 4 (SALL 4) and negative for α-fetoprotein (AFP) or human epidermal growth factor receptor type 2 (HER2). The type 1 tumors consisted of the adenocarcinoma-like type 2 tumor and spindle cells (sarcomatous component). Part of the sarcomatous component showed cartilage differentiation. The type 2 and type 1 lesions were continuous lesions. The epicenter of the tumor was located at the EGJ. The adenocarcinoma component was present in 10 of 27 resected lymph nodes. The tumor was diagnosed as carcinosarcoma of the EGJ. CONCLUSIONS: We report a rare patient with carcinosarcoma of the EGJ wherein the carcinomatous element was adenocarcinoma.

Preventive effect on delayed gastric emptying of preserving the infra-pyloric vein in laparoscopic pylorus-preserving gastrectomy for early gastric cancer.

BACKGROUND: Pylorus-preserving gastrectomy (PPG) has the postoperative advantages of a better quality of life and less weight loss than distal gastrectomy. However, postoperative delayed gastric emptying (DGE) due to antral hypomotility can be a problem. Although preserving the infra-pyloric vein (IPV) is reported to improve congestion of the antrum and prevent DGE, the benefits of this procedure have not been confirmed. The present study aimed to clarify the preventive effect on DGE of preserving the IPV. METHODS: A total of 148 patients [IPV-preserved (IPVP): 78 patients and IPV-non-preserved (IPVN): 70 patients] who underwent laparoscopic and robotic PPG (LRPPG) for early gastric cancer were enrolled in this study. The clinicopathologic characteristics and incidence of DGE were compared between the groups. The nutritional risk index (NRI) at 1, 2, and 3 years after the operation and the relapse-free survival (RFS) were also compared. RESULTS: There were no significant differences in the clinicopathological characteristics between the two groups. DGE was observed in 15 of 148 patients (10.1%). The incidence of DGE did not differ markedly between the 2 groups (IPVP vs. IPVN; 11.5% vs. 8.6% p = 0.596). There were no significant differences in other complications between the groups either (IPVP vs. IPVN; 19.2% vs. 21.4%; p = 0.838). The NRI and 3-year RFS were not significantly different between the two groups. CONCLUSION: Regarding LRPPG, preserving the IPV did not help prevent DGE and resulted in no significant difference in the outcomes.

Safety of prolonged wait time for gastrectomy in clinical stage I gastric cancer.

BACKGROUND: Patients with stage I gastric cancer tend to wait for surgery. Although the cancer may progress during such a delay, effects of wait time for surgery on survival remain inconsistent. Here, we evaluated the safety of surgical wait time on survival of patients with clinical stage I gastric cancer. METHODS: The outcomes of 556 patients who underwent gastrectomy for clinical stage I gastric cancer between January 2007 and December 2011 were retrospectively evaluated. Patients were stratified into three groups based on wait time: short- (<61 days, n = 185), intermediate- (61-90 days, n = 218), and long-wait (91-180 days, n = 153) groups. Clinicopathological findings and survival were compared among the groups. RESULTS: The median wait time was 72 days. Age and comorbidities differed among the groups, but clinical and pathological cancer stages did not. Overall survival was comparable; the 5-year overall survival was 90.2%, 93.6%, and 88.8% in the short-, intermediate-, and long-wait groups, respectively. Multivariate analysis revealed that wait time was not an independent prognostic factor for overall survival. Adjusted hazard ratios (HRs) were 0.69 (p = 0.262) and 1.03 (p = 0.926) in the intermediate- and long-wait groups, respectively, with short wait time as the reference. Relapse-free survival was comparable among the groups (intermediate-wait HR = 0.80, p = 0.476; long-wait HR = 1.10, p = 0.740). CONCLUSION: A half-year wait time for surgery was not independently associated with survival of patients with clinical stage I gastric cancer and may therefore be acceptable.

Impact of preoperative wait time on survival in patients with clinical stage II/III gastric cancer.

BACKGROUND: Preoperative wait time is affected by various factors, and a certain time is needed before surgery. There is a concern that cancer treatment delay can lead to poor survival. The present study aimed to evaluate the impact of preoperative wait time on survival in patients with clinical stage (cStage) II/III gastric cancer. METHODS: The study included patients with cStage II/III primary gastric cancer undergoing surgery between 2002 and 2012. Preoperative wait time was defined as the time from endoscopy for initial diagnosis to surgery. Patients were divided into the following three groups according to wait time: short wait group (≤ 30 days), intermediate wait group (> 30 and ≤ 60 days), and long wait group (> 60 and ≤ 90 days). Patient characteristics and survival were compared among the groups. RESULTS: This study included 467 male (67%) and 229 female (33%) patients, and the median patient age was 67 years. The numbers of cStage II and III patients were 332 (48%) and 364 (52%), respectively. The median wait time was 45 days. The body mass index was lower in the short wait group than in the other groups. A shorter wait time tended to be associated with a more advanced cStage. Although survival was significantly worse in the short wait group than in the long wait group, wait time was not identified as an independent prognostic factor in multivariate analysis. CONCLUSION: Preoperative wait time up to 90 days does not affect survival in patients with cStage II/III gastric cancer.

[The Current Status and Future Perspective about Robotic Surgery for Gastric Cancer].

Robotic surgery using da Vinci®Surgical System which has the high resolution 3-dimensional images, the forceps with 7 degrees freedom, the function for prevention of tremors and motion scaling enables to perform meticulous operation circumventing the action of forceps movement which is the major problem in conventional laparoscopic surgery. In 2003, initial robotic gastrectomy for gastric cancer has been reported. Since then robotic gastrectomy has been developed mainly in Japan, Korea and Italy. From January 2012, we launched robotic gastrectomy at our institute as prospective clinical phase II trials to clarify the safety of robotic gastrectomy. The results of these trials have already been published and the safety of robotic gastrectomy was confirmed. In the several retrospective analyses, robotic gastrectomy has been reported to show longer operation time, less blood loss and lower morbidity compared with conventional laparoscopic surgery. However, the superiority of robotic gastrectomy to laparoscopic gastrectomy has not yet been demonstrated in terms of short- and long-term outcomes in a randomized controlled trial. Since robotic gastrectomy has been approved in Japanese health insurance system at April 2018, it is expected to rapidly expand throughout the country in the near future. Therefore, it is urgent matter to establish an evidence and educational program. In this article, the current status and future perspective about robotic surgery for gastric cancer are presented.