A nonrandomized controlled trial: long-term outcomes of LATG/LAPG for cStage I gastric cancer: Japan Clinical Oncology Group Study JCOG1401.

BACKGROUND: A previous report confirmed the safety of laparoscopy-assisted total and proximal gastrectomies (LATG and LAPG) (JCOG1401). This report demonstrates the 5-year relapse-free survival (RFS) and overall survival (OS) after long-term follow-up to confirm the efficacy of these surgical methods as key secondary endpoints for cStage I gastric cancer. METHODS: This study enrolled patients who had histologically proven gastric adenocarcinoma and were diagnosed with clinical T1N0, T1N(+), or T2N0 tumors according to the 14th edition of the Japanese Classification of Gastric Carcinoma (3rd English edition). RESULTS: Between April 2015 and February 2017, 246 patients were enrolled, although one patient was excluded because of misregistration. Meticulous follow-up was continued for > 5 years for each patient, and the data were analyzed in March 2022. The 5-year RFS was 90.0% (95% confidence interval [CI] 85.5-93.2%), and the 5-year OS was 91.2% (95% CI 86.9-94.2%) in all enrolled patients. Grade 3 or 4 late postoperative complications were detected in 12.7% of patients. CONCLUSIONS: This single-arm study showed that the long-term outcomes of LATG/LAPG for cStage I gastric cancer were acceptable, which is considered one of the standard treatments when performed by experienced surgeons. Trail registration UMIN000017155 ( http://www.umin.ac.jp/ctr/ ).

Perioperative TAS-118 plus oxaliplatin in patients with locally advanced gastric cancer: APOLLO-11 study.

BACKGROUND: We investigated the feasibility of perioperative chemotherapy with S-1 and leucovorin (TAS-118) plus oxaliplatin in patients with locally advanced gastric cancer. METHODS: Patients with clinical T3-4N1-3M0 gastric cancer received four courses of TAS-118 (40-60 mg/body, orally, twice daily for seven days) plus oxaliplatin (85 mg/m2, intravenously, day one) every two weeks preoperatively followed by gastrectomy with D2 lymphadenectomy, followed by postoperative chemotherapy with either 12 courses of TAS-118 monotherapy (Step 1) or eight courses of TAS-118 plus oxaliplatin (Step 2). The primary endpoints were completion rates of preoperative chemotherapy with TAS-118 plus oxaliplatin and postoperative chemotherapy with TAS-118 monotherapy (Step 1) or TAS-118 plus oxaliplatin (Step 2). RESULTS: Among 45 patients enrolled, the preoperative chemotherapy completion rate was 88.9% (90% CI 78.0-95.5). Major grade ≥ 3 adverse events (AEs) were diarrhoea (17.8%) and neutropenia (8.9%). The R0 resection rate was 95.6% (90% CI 86.7-99.2). Complete pathological response was achieved in 6 patients (13.3%). Dose-limiting toxicity was not observed in 31 patients receiving postoperative chemotherapy (Step 1, n = 11; Step 2, n = 20), and completion rates were 90.9% (95% CI 63.6-99.5) for Step 1 and 80.0% (95% CI 59.9-92.9) for Step 2. No more than 10% of grade ≥ 3 AEs were observed in patients receiving Step 1. Hypokalaemia and neutropenia occurred in 3 and 2 patients, respectively, receiving Step 2. The 3-year recurrence-free and overall survival rates were 66.7% (95% CI 50.9-78.4) and 84.4% (95% CI 70.1-92.3), respectively. CONCLUSIONS: Perioperative chemotherapy with TAS-118 plus oxaliplatin with D2 gastrectomy is feasible.

Late complication after gastrectomy for clinical stage I cancer: supplementary analysis of JCOG0912.

BACKGROUND: Late complications following gastric cancer surgery, including postgastrectomy syndromes, are complex problems requiring a solution. Reported risk factors for developing late complications include surgery-related factors, such as the surgical approach and the extent of resection and reconstruction. However, this has not been assessed in a prospective study with a large sample size. Therefore, this study aimed to evaluate associations between surgery-related factors and the development of late complications. Data from the JCOG0912 trial were used. It compared laparoscopy-assisted distal gastrectomy (LADG) to open distal gastrectomy (ODG) in clinical stage I gastric cancer patients. METHODS: This study included 881/921 patients enrolled in the JCOG0912 trial. The incidence of late complications was compared between the ODG and the LADG arms. In addition, associations between surgery-related factors and the development of late complications were assessed by multivariable analyses using the proportional odds model to identify relevant risk factors. RESULTS: There was no difference in the type or number of patients with late complications between the LADG and the ODG arms. The multivariable analysis for each late complication revealed that the Billroth-I reconstruction (vs. R-en-Y or Billroth-II) had a lower risk of cholecystitis [odds ratio (OR) 0.187, 95% confidence interval (CI) 0.039-0.905, P = 0.037] or ileus (OR 0.116, 95%CI 0.033-0.406, P < 0.001), and pylorus-preserving gastrectomy (vs. R-en-Y or Billroth-II) had a higher risk of reflux esophagitis (OR 3.348, 95% CI 1.371-8.176, P = 0.008). The surgical approach was not a risk factor for any late complications. CONCLUSION: Differences in surgical approaches did not constitute a risk for developing late complications after gastrectomy. Billroth-I reconstruction reduced the risk of ileus and cholecystitis, but pylorus-preserving gastrectomy carried a risk for reflux esophagitis.

Acceleration of sarcopenia in elderly patients who develop asymptomatic pneumonia shadow within one year after surgery for early gastric cancer.

BACKGROUND: Although early gastric cancer is curable with local treatment, the overall survival in elderly patients did not reach 80% at five years after surgery. The major cause of death in elderly patients with early gastric cancer is not cancer itself but is related to postoperative sarcopenia. Elderly patients frequently develop postoperative asymptomatic pneumonia shadow, which is associated with a poor prognosis. However, why asymptomatic pneumonia shadow worsens the prognosis remains unclear. We investigated whether sarcopenia is accelerated in patients who developed asymptomatic pneumonia shadow. METHODS: We retrospectively examined patients of > 75 years of age who underwent R0 gastrectomy for gastric cancer and were diagnosed with T1 disease at National Cancer Center Hospital between 2005 and 2012. The diagnosis of asymptomatic pneumonia shadow was defined by diagnostic findings of pneumonia (consolidation type, reticular type, and nodular type) which were newly observed on chest computed tomography performed one year after surgery in comparison to preoperative computed tomography. Postoperative muscle loss was assessed by a computed tomography-based analysis using the L3 skeletal muscle index before and two years after surgery and the rate of decrease was calculated. Patients were classified into two groups according to the rate of decrease (cut-off value: 10%). RESULTS: Of the 3412 patients who underwent gastrectomy in our hospital during the study period, 142 were included in this study. Asymptomatic pneumonia shadow was found in 26 patients (18%). Patients who developed asymptomatic pneumonia shadow showed a significantly greater loss of muscle volume in comparison to patients who did not develop asymptomatic pneumonia shadow. In the multivariate analysis, total gastrectomy and asymptomatic pneumonia shadow were the independent risk factors for severe muscle loss. However, there was no significant difference in prognosis between the two groups. CONCLUSIONS: Sarcopenia was accelerated in elderly patients who developed asymptomatic pneumonia shadow after surgery for early gastric cancer. However, the poor prognosis in these patients may not be related to accelerated sarcopenia.

A retrospective 5-year survival analysis of surgically resected gastric cancer cases from the Japanese Gastric Cancer Association nationwide registry (2001-2013).

BACKGROUND: The nationwide registry of the Japanese Gastric Cancer Association collected data of surgically resected cases of gastric cancer between 2001 and 2013. These retrospective analyses aimed to delineate tumor characteristics, surgical history, and survival distribution. METHODS: Data from 254,706 patients with primary gastric cancer were included. The 5-year survival rates were calculated for various subsets of prognostic factors. RESULTS: The number of patients over 70 years old increased from 2001 to 2013. The frequency with which laparoscopic gastrectomy was opted for increased dramatically (from 3.5 to 40.8%) in 13 years. We focused on the patients registered between 2010 and 2013, for whom data collection was based on the 3rd edition of the Japanese classification and guidelines. Five-year overall survival (OS) rate among 92,305 patients with resected tumors was 70.6%. The 5-year OS rates of patients with pathological stage IA, IB, IIA, IIB, IIIA, IIIB, IIIC, and IV disease were 89.6%, 83.2%, 77.6%, 68.1%, 59.3%, 45.6%, 29.9%, and 14.0%, respectively. CONCLUSION: Our detailed analysis highlights the historical changes in outcomes of surgically treated gastric malignancies in Japan, and provides robust dataset for future analysis.

Prediction of tissue origin of adenocarcinomas in the esophagogastric junction by DNA methylation.

BACKGROUND: Prediction of tissue origin of esophagogastric junction (EGJ) adenocarcinomas can be important for therapeutic decision, but no molecular marker is available. Here, we aimed to develop such a marker taking advantage of tissue-specific profiles of DNA methylation. METHODS: DNA methylation profiles of gastric adenocarcinomas (GACs) were obtained by an Infinium HumanMethylation450 BeadChip array, and those of esophageal adenocarcinoma (EACs) were obtained from the TCGA database. DNA from formalin-fixed paraffin-embedded (FFPE) samples was analyzed by bisulfite pyrosequencing. RESULTS: In the screening set, 51 of 145,841 CpG sites in CpG islands were methylated at significantly higher levels in 30 GACs compared to those in 30 EACs. Among them, SLC46A3 and cg09177106 were unmethylated in all the 30 EACs. Predictive powers of these two markers were successfully confirmed in an independent validation set (18 GACs and 18 EACs) (SLC46A3, sensitivity = 77.8%, specificity = 100%; cg09177106, sensitivity = 83.3%, specificity = 94.4%), and could be applied to FFPE samples (37 GACs and 18 EACs) (SLC46A3, P = 0.0001; cg09177106, P = 0.0028). On the other hand, EAC-specific markers informative in the FFPE samples could not be isolated. Using these GAC-specific markers, nine of 46 (19.6%) TCGA EGJ adenocarcinomas were predicted to be GACs. CONCLUSIONS: Two GAC-specific markers, SLC46A3 and cg09177106, had a high specificity for identifying the tissue origin of EGJ adenocarcinoma.

Impact of tumor-related factors and inter-institutional heterogeneity on preoperative T staging for gastric cancer.

Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.

Additional chemotherapy before surgery is expected to have potentially beneficial effects on prognosis compared with chemotherapy only after surgery for advanced gastric cancer. The consideration of chemotherapy before surgery depends on preoperative diagnosis of the depth of tumor invasion in the stomach wall. Overdiagnosis of the depth of tumor invasion may lead to unnecessary administration of chemotherapy that is harmful to the patient. Tumor-related factors such as tumor location, macroscopic type and histological type may affect the diagnosis. Therefore, these factors should be considered with special care for the diagnosis, which may lead to higher accuracy in diagnosing the depth of tumor invasion in gastric cancer.

Management of elderly patients with early gastric cancer in Japan.

Management of elderly patients with early gastric cancer is an important issue in an aging society such as Japan. While endoscopic resection is recommended as the standard treatment for early gastric cancers with extremely low risk of lymph node metastasis (<1%), gastrectomy with lymphadenectomy is recommended for the other early gastric cancers as the standard treatment even in elderly patients. Endoscopic submucosal dissection is the most recommended endoscopic resection procedure because of its high ability for 'en bloc' resection. Endoscopic submucosal dissection can reportedly provide favorable short-term outcomes in elderly patients. In terms of patient prognosis, the importance of considering patients' physical and nutritional conditions before endoscopic submucosal dissection has recently attracted attention. With respect to gastrectomy, the nationwide data in Japan have demonstrated relatively low 5-year overall survival and non-negligible post-operative 90-day mortality in men aged ≥75 years and women aged ≥80 years compared with those in younger patients. Among these elderly patients, 20% or more reportedly died within 5 years after gastrectomy mostly due to other diseases. These facts suggested the necessity of a less invasive management option for the elderly patients. Efforts are being made to provide a non-invasive follow-up option without gastrectomy following endoscopic resection in elderly patients. To avoid the increase in gastric cancer-related deaths, the selection of patients with relatively low lymph node metastasis risk is essential, and several tools to estimate the lymph node metastasis risk from early gastric cancers have been developed. To avoid overtreatment with gastrectomy in more elderly early gastric cancer patients, new endoscopic submucosal dissection indications for them are also warranted.

Long-term postoperative pneumonia in elderly patients with early gastric cancer.

BACKGROUND: Pneumonia is a major cause of death in the elderly population. Considering body weight loss, muscle loss, and reflux after gastrectomy, elderly patients are considered to be at very high risk for pneumonia, which could decrease overall survival because early gastric cancer is mostly curable only by surgery. We aimed to clarify the incidence of pneumonia in the long-term period after gastrectomy in elderly patients who were diagnosed with early gastric cancer and its risk factors. METHODS: We retrospectively examined patients of > 75 years of age who underwent R0 gastrectomy for gastric cancer and who were diagnosed with T1 disease at National Cancer Center Hospital between 2005 and 2012. Long-term postoperative pneumonia was diagnosed by chest computed tomography every year until 2 years after surgery. The presence of preoperative sarcopenia was assessed using preoperative L3 skeletal muscle index. RESULTS: 167 patients were included in this study. Long-term postoperative pneumonia was observed in 44 (26%) patients. Of the 44 people diagnosed with long-term postoperative pneumonia, 33 were diagnosed in the 1st year and 11 in the 2nd year. 117 patients (70%) were diagnosed with sarcopenia which was significantly frequently found in the patients who developed long-term postoperative pneumonia (91%) than those without (63%). Preoperative sarcopenia was the only independent risk factor in multivariate analysis. Type of gastrectomy was not a significant risk factor. CONCLUSIONS: Long-term postoperative pneumonia was frequently observed in the elderly patients. Preoperative sarcopenia was associated with long-term postoperative pneumonia in elderly patients who underwent curative surgery for gastric cancer. After gastrectomy, long-term special care would be required for elderly patients, especially with sarcopenia.

The prognostic impact of macroscopic serosal change on resectable advanced gastric cancer.

BACKGROUND: Advanced gastric cancer sometimes causes macroscopic serosal change (MSC) due to direct invasion or inflammation. However, the prognostic significance of MSC remains unclear. METHODS: A total of 1410 patients who had been diagnosed with deeper-than-pathological-T2 gastric cancer and undergone R0 gastrectomy with lymph node dissection at the National Cancer Center Hospital during January 2000 and December 2012 were restrospectively reviewed. RESULTS: MSC was not found in 108 of the 506 patients with pathological T4a (21.3%), whereas it was detected in 250 of the 904 patients with pathological T2-T3 (27.7%). The sensitivity, specificity and accuracy for diagnosing pathological serosa exposed (SE) by MSC were 78.7, 72.3 and 74.6%, respectively. The MSC-positive cases had a worse 5-year overall survival (OS) than the MSC-negative cases in pT3 (72.9% vs. 84.3%, p = 0.001), pT4a (56.2% vs. 73.4%, p = 0.001), pStageIIB (76.0% vs. 88.4%, p = 0.005), pStageIIIA (63.4% vs. 75.6%, p = 0.019), pStageIIIB (53.6% vs. 69.2%, p = 0.029) and pStage IIIC (27.6% vs. 50.0%, p = 0.062). A multivariate analysis showed that MSC was a significant independent predictor for the OS (hazard ratio [HR]: 1.587, 95%CI 1.209-2.083, p = 0.001) along with the tumor depth (HR: 7.742, 95%CI: 2.935-20.421, p < 0.001), nodal status (HR:5.783, 95% CI 3.985-8.391, p < 0.001) and age (HR:2.382, 95%CI: 1.918-2.957, p < 0.001). Peritoneal recurrence rates were higher in the MSC-positive cases than in the MSC-negative cases at each pT stage. CONCLUSIONS: In this study, the MSC was one of the independent prognostic factors in patients with resectable locally advanced gastric cancer.

A novel combination of serum microRNAs for the detection of early gastric cancer.

BACKGROUND: The aim of this study was to identify serum miRNAs that discriminate early gastric cancer (EGC) samples from non-cancer controls using a large cohort. METHODS: This retrospective case-control study included 1417 serum samples from patients with EGC (seen at the National Cancer Center Hospital in Tokyo between 2008 and 2012) and 1417 age- and gender-matched non-cancer controls. The samples were randomly assigned to discovery and validation sets and the miRNA expression profiles of whole serum samples were comprehensively evaluated using a highly sensitive DNA chip (3D-Gene®) designed to detect 2565 miRNA sequences. Diagnostic models were constructed using the levels of several miRNAs in the discovery set, and the diagnostic performance of the model was evaluated in the validation set. RESULTS: The discovery set consisted of 708 samples from EGC patients and 709 samples from non-cancer controls, and the validation set consisted of 709 samples from EGC patients and 708 samples from non-cancer controls. The diagnostic EGC index was constructed using four miRNAs (miR-4257, miR-6785-5p, miR-187-5p, and miR-5739). In the discovery set, a receiver operating characteristic curve analysis of the EGC index revealed that the area under the curve (AUC) was 0.996 with a sensitivity of 0.983 and a specificity of 0.977. In the validation set, the AUC for the EGC index was 0.998 with a sensitivity of 0.996 and a specificity of 0.953. CONCLUSIONS: A novel combination of four serum miRNAs could be a useful non-invasive diagnostic biomarker to detect EGC with high accuracy. A multicenter prospective study is ongoing to confirm the present observations.

Surgically treated gastric cancer in Japan: 2011 annual report of the national clinical database gastric cancer registry.

BACKGROUND: The National Clinical Database (NCD) nationwide registry program of gastric cancer started in 2018. The purpose of this study was to report the treatment results of the NCD registry in the form of treatment results of the real world in Japan. METHODS: Patients' characteristics, tumor features, treatments, and outcomes were collected using a web-based data entry system. We analyzed the initial NCD database for data on surgically treated gastric cancer patients in 2011. RESULTS: A total of 30,257 patients with malignant gastric tumors were enrolled by the NCD registry program from 501 hospitals in all 47 prefectures. Of these, the status of data entry was not approved in 8.8% of the registered data, and follow-up information was missing in 1.2% of the approved cases. Excluding 1777 cases, which were not resected for primary gastric cancer, 25,306 resected cases included 44.4% of stomach surgeries recorded in the NCD. The 5 year survival rate of the resected cases was 71.3% and the operative mortality rate was 0.41%. The stage-specific 5 year survival rates were as follows: 89.6% for stage IA, 83.8% for stage IB, 77.3% for stage IIA, 69.1% for stage IIB, 58.7% for stage IIIA, 44.1% for stage IIIB, 30.1% for stage IIIC, and 13.4% for stage IV. CONCLUSIONS: The NCD gastric cancer registry program demonstrated validity for database construction. The gastric cancer registry is expected to become a nationwide registry with the dissemination of data entry system and method in the NCD.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study.

BACKGROUND: Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a. METHODS: We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment. RESULTS: A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group. CONCLUSIONS: Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Gastrectomy with or without neoadjuvant S-1 plus cisplatin for type 4 or large type 3 gastric cancer (JCOG0501): an open-label, phase 3, randomized controlled trial.

BACKGROUND: Specific treatment strategies are sorely needed for scirrhous-type gastric cancer still, which has poor prognosis. Based on the promising results of our previous phase II study (JCOG0210), we initiated a phase III study to confirm the efficacy of neoadjuvant chemotherapy (NAC) in type 4 or large type 3 gastric cancer. METHODS: Patients aged 20-75 years without a macroscopic unresectable factor as confirmed via staging laparoscopy were randomly assigned to surgery followed by adjuvant chemotherapy with S-1 (Arm A) or NAC (S-1plus cisplatin) followed by D2 gastrectomy plus adjuvant chemotherapy with S-1 (Arm B). The primary endpoint was overall survival (OS). RESULTS: Between October 2005 and July 2013, 316 patients were enrolled, allocating 158 patients to each arm. In Arm B, in which NAC was completed in 88% of patients. Significant downstaging based on tumor depth, lymph node metastasis, and peritoneal cytology was observed using NAC. Excluding the initial 16 patients randomized before the first revision of the protocol, 149 and 151 patients in arms A and B, respectively, were included in the primary analysis. The 3-year OS rates were 62.4% [95% confidence interval (CI) 54.1-69.6] in Arm A and 60.9% (95% CI 52.7-68.2) in Arm B. The hazard ratio of Arm B against Arm A was 0.916 (95% CI 0.679-1.236). CONCLUSIONS: For type 4 or large type 3 gastric cancer, NAC with S-1 plus cisplatin failed to demonstrate a survival benefit. D2 surgery followed by adjuvant chemotherapy remains the standard treatment.

Determinant Factors on Differences in Survival for Gastric Cancer Between the United States and Japan Using Nationwide Databases.

BACKGROUND: Although the incidence and mortality have decreased, gastric cancer (GC) is still a public health issue globally. An international study reported higher survival in Korea and Japan than other countries, including the United States. We examined the determinant factors of the high survival in Japan compared with the United States. METHODS: We analysed data on 78,648 cases from the nationwide GC registration project, the Japanese Gastric Cancer Association (JGCA), from 2004-2007 and compared them with 16,722 cases from the Surveillance, Epidemiology, and End Results Program (SEER), a United States population-based cancer registry data from 2004-2010. We estimated 5-year relative survival and applied a multivariate excess hazard model to compare the two countries, considering the effect of number of lymph nodes (LNs) examined. RESULTS: Five-year relative survival in Japan was 81.0%, compared with 45.0% in the United States. After controlling for confounding factors, we still observed significantly higher survival in Japan. Among N2 patients, a higher number of LNs examined showed better survival in both countries. Among N3 patients, the relationship between number of LNs examined and differences in survival between the two countries disappeared. CONCLUSION: Although the wide differences in GC survival between Japan and United States can be largely explained by differences in the stage at diagnosis, the number of LNs examined may also help to explain the gaps between two countries, which is related to stage migration.

Does staged surgical training for minimally invasive esophagectomy have an impact on short-term outcomes?

BACKGROUND: sophageal cancer has a low incidence, and the anatomy is difficult to understand during esophagectomy. This necessitates a precise and lengthy operation. Therefore, the establishment of a training system in esophageal surgery is of critical importance. In this study, we compared the short-term outcomes of minimally invasive esophagectomy (MIE) performed by consultants versus trainees and explored the factors that impacted the thoracic operation time for each group. METHODS: We have introduced standardized MIE surgical techniques to our trainees in 2016. Our procedure consists of a laparoscopic phase and a thoracoscopic phase and is systematically designed to be learned in a step-by-step manner in each phase. We retrospectively identified 308 patients who underwent MIE from April 2016 to April 2018. The patients were divided into those who underwent MIE by consultants and those who underwent MIE by trainees. The preoperative background factors, operation-related factors, and postoperative complications were compared between the two groups. We also assessed the association between a prolonged thoracic operation time and tumor-and patient-related factors in each of the consults and trainees. RESULTS: Significantly more patients had stage ≥ III cancer in the consultant than trainee group. However, the postoperative complications were comparable, specifically pneumonia (11% vs. 18%), anastomotic leakage (11% vs. 13%), and mortality (0.6% vs. 1.3%). There was no significant difference in the lymph node yield (20 vs. 17) or R0 resection rate (94% vs. 91%) between the two groups. However, the trainees had a significantly longer thoracic operation time (143 ± 34 vs. 190 ± 28 min) and significantly greater blood loss (93 vs. 183 ml). Oncological factors were correlated with a prolonged thoracic operation time in the consultants, but not in the trainees. CONCLUSIONS: Under standardized surgical management using a stepwise educational program, performance of MIE by trainees has no impact on short-term outcomes.

Intraoperative blood loss as an independent prognostic factor for curative resection after neoadjuvant chemotherapy for gastric cancer: a single-center retrospective cohort study.

PURPOSE: Surgery-induced factors such as postoperative infectious complications (PICs) and intraoperative blood loss (IBL) have a negative impact on the survival of patients undergoing surgery for gastric cancer. A recent study showed that neoadjuvant chemotherapy (NAC) could reduce the negative impact of PICs; hence, we conducted the present study to investigate if NAC can also reduce the negative prognostic impact of IBL. METHODS: We reviewed 115 gastric cancer patients treated with NAC and radical gastrectomy. The cut-off for IBL predicting the long-term survival was assessed by a receiver operating characteristic curve. The Cox proportional hazard model was used to evaluate the association between patient characteristics including IBL, overall survival, and disease-free survival. RESULTS: The cut-off for IBL was set at 990 ml. Twenty-six patients had excessive IBL exceeding 990 ml (22.6%) and PICs developed in 33 patients (28.7%). The body mass index, IBL, ypT, and ypN were significant independent prognostic predictors, but PICs were not. CONCLUSION: NAC did not decrease the risk induced by excessive IBL. The prophylactic effect of NAC on surgery-induced risk was inconsistent.

Risk for lymph node metastasis in Epstein-Barr virus-associated gastric carcinoma with submucosal invasion.

OBJECTIVES: Epstein-Barr virus-associated gastric cancer (EBVGC) has been reported to be associated with a low risk for lymph node metastasis (LNM). However, the curative criteria for endoscopic submucosal dissection (ESD) for submucosal EBVGC (pT1b-EBVGC) remain unclear. Our study aimed to investigate the risk factors for LNM in pT1b-EBVGC. METHODS: This was a retrospective multicenter study at five institutes in Japan. We reviewed medical records and extracted all pT1b-EBVGC cases that met the following criteria: (i) histologically proven submucosal gastric cancer; (ii) surgical or endoscopic resection between January 2000 and December 2016; and (iii) presence of Epstein-Barr virus (EBV) in tumor cells verified by EBV-encoded small RNA in situ hybridization (EBER-ISH). The association between clinicopathological factors and LNM were assessed using multivariable logistic regression analysis. RESULTS: A total of 185 pT1b-EBVGC cases were included in the analysis. LNM was found in nine cases (4.9%). Multivariable logistic regression analysis demonstrated that lymphatic invasion (OR 9.1; 95% CI 2.1-46.1) and submucosal invasion ≥4000 µm (OR 9.2; 95% CI 1.3-110.3) were significant risk factors for LNM. When we focused on pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 µm, the rate of LNM was 0% (0/96, 95% CI 0-3.8%). CONCLUSIONS: Our findings indicated that lymphatic invasion and submucosal invasion ≥4000 µm were significant risk factors for LNM. ESD could be an appropriate option for pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 µm.

Cancer cell niche factors secreted from cancer-associated fibroblast by loss of H3K27me3.

OBJECTIVE: Cancer-associated fibroblasts (CAFs), a major component of cancer stroma, can confer aggressive properties to cancer cells by secreting multiple factors. Their phenotypes are stably maintained, but the mechanisms are not fully understood. We aimed to show the critical role of epigenetic changes in CAFs in maintaining their tumour-promoting capacity and to show the validity of the epigenomic approach in identifying therapeutic targets from CAFs to starve cancer cells. DESIGN: Twelve pairs of primary gastric CAFs and their corresponding non-CAFs (NCAFs) were established from surgical specimens. Genome-wide DNA methylation and H3K27me3 analyses were conducted by BeadArray 450K and ChIP-on-Chip, respectively. Functions of potential a therapeutic target were analysed by inhibiting it, and prognostic impact was assessed in a database. RESULTS: CAFs had diverse and distinct DNA methylation and H3K27me3 patterns compared with NCAFs. Loss of H3K27me3, but not DNA methylation, in CAFs was enriched for genes involved in stem cell niche, cell growth, tissue development and stromal-epithelial interactions, such as WNT5A, GREM1, NOG and IGF2. Among these, we revealed that WNT5A, which had been considered to be derived from cancer cells, was highly expressed in cancer stromal fibroblasts, and was associated with poor prognosis. Inhibition of secreted WNT5A from CAFs suppressed cancer cell growth and migration. CONCLUSIONS: H3K27me3 plays a crucial role in defining tumour-promoting capacities of CAFs, and multiple stem cell niche factors were secreted from CAFs due to loss of H3K27me3. The validity of the epigenetic approach to uncover therapeutic targets for cancer-starving therapy was demonstrated.

Cooperative participation of epigenomic and genomic alterations in the clinicopathological diversity of gastric adenocarcinomas: significance of cell adhesion and epithelial-mesenchymal transition-related signaling pathways.

The present study was conducted to clarify the cooperative significance of epigenomic and genomic abnormalities during gastric carcinogenesis. Using 21 samples of normal control gastric mucosa (C), 109 samples of non-cancerous gastric mucosa (N) and 105 samples of cancerous tissue (T) from 109 patients with primary gastric adenocarcinomas, genome-wide DNA methylation analysis was performed using Infinium assay. Among these samples, 66 paired N and corresponding T samples were subjected to whole-exome and single nucleotide polymorphism array analyses. As had been shown in our previous study, 109 patients were clustered clinicopathologically into least aggressive Cluster A (n = 20), most aggressive Cluster B1 (n = 20) and Cluster B2 (n = 69). Most DNA methylation alterations in each cluster had already occurred even in N samples compared with C samples, and DNA methylation alterations at the precancerous N stage were inherited by the established cancers themselves. Recurrent single nucleotide variants and insertions/deletions resulting in functional disruption of the proteins encoded by the ABCA10, BNC2, CDH1, CTNNB1, SMAD4 and VAV2 genes were specific to Cluster B1, whereas those of the APC, EGFR, ERBB2, ERBB3, MLH1 and MUC6 genes were specific to Cluster A. MetaCore pathway analysis revealed that the epigenomically affected TWIST1 gene and genomically affected CDH1, CTNNB1, MMP9, TLN2, ROCK1 and SMAD4 genes were accumulated in signaling pathways related to cell adhesion, cytoskeleton remodeling and epithelial-mesenchymal transition in Cluster B1. These data indicate that epigenomic alterations at the precancerous stage are important in gastric carcinogenesis and that epigenomic and genomic alterations cooperatively underlie the aggressiveness of gastric adenocarcinomas.