Tribo-Chemical Reactions in DLC-Zirconia Sliding under Ethanol Gas Environment.

A reactive force field (ReaxFF) molecular dynamics simulation is performed for the sliding of diamond-like carbon (DLC) and yttria-stabilized zirconia (YSZ) under an ethanol gas environment, motivated by the previous experiment of ultralow friction phenomenon (friction fade-out). We observe (i) dissociation of ethanol into ethoxy and hydrogen, both of which simultaneously adsorb on the YSZ surface, and (ii) dissociation of ethanol into ethyl and hydroxy, the former of which forms a bond with another ethanol molecule and the latter of which adsorbs on the DLC surface. Reaction (i) is enhanced by the sliding motion, but occurs even without it, while reaction (ii) only occurs during sliding with a sufficiently high load pressure. The potentials of mean force for the two reactions are also calculated combining the steered MD and Jarzynski equality. It is shown that the activation energies of reactions (i) and (ii) are significantly lowered by the YSZ and DLC surfaces, respectively, as compared to those in a vacuum. The resultant activation energy is higher for reaction (ii) than for reaction (i).

Enhanced epithelial-mesenchymal transition signatures are linked with adverse tumor microenvironment, angiogenesis and worse survival in gastric cancer.

Epithelial-mesenchymal transition (EMT) is a crucial mechanism that facilitates cancer cell metastasis. Despite its importance, the clinical significance of EMT in gastric cancer (GC) patients has yet to be clearly demonstrated. For gauging the extent of EMT in GC, we employed gene set variation analysis to score 807 patient samples from two large cohorts: TCGA and GSE84437. In both cohorts, EMT high GC showed a significant association with worse overall survival (hazard ratio (HR) = 1.74, p = 0.011 and HR = 2.01, p < 0.001, respectively). This association was stronger when considering the EMT signature score compared to the individual expressions of EMT-related genes (CDH1, CDH2, VIM, and FN1). While the EMT signature level did not differ among various cancers, high EMT signature specifically correlated with survival in GC alone. Mucinous and diffuse histological types exhibited higher EMT levels compared to others (p < 0.001), and the EMT signature level was correlated with tumor depth and AJCC stage (all p < 0.001). Interestingly, the EMT score was an independent factor for overall and disease-specific survival (multivariate; p = 0.006 and 0.032, respectively). EMT high GC displayed a lower fraction of Th1 cells and a higher fraction of dendritic cells, M1 macrophages and several stromal cells. EMT high GC exhibited an inverse correlation with cell proliferation-related gene sets. While they significantly enriched multiple pro-cancerous gene sets, such as TGF-ß signaling, hypoxia, and angiogenesis. The presence of EMT signature in a bulk tumor was linked to TGF-ß signaling, hypoxia, and angiogenesis, and was also associated with poorer survival outcomes in GC patients.

Ramucirumab Plus Paclitaxel as a Second-line Chemotherapy in Older Adults With Advanced Gastric Cancer (YCOG1601).

BACKGROUND/AIM: Ramucirumab plus paclitaxel has been widely used as a second-line chemotherapy for treating advanced gastric cancer. However, the real-world data of this regimen for older patients with gastric cancer (GC) remains unrevealed. The aim of this study was to clarify the feasibility and efficacy of this regimen for older patients with GC in a single-arm, phase II study. PATIENTS AND METHODS: Patients aged ≥70 years having unresectable or recurrent GC who met the eligible criteria were enrolled. Paclitaxel was administered at a dose of 80 mg/m2 on days 1, 8, and 15, and ramucirumab was administered at a dose of 8 mg/kg on day 1 and day 15 of a 4-week cycle. Primary endpoint was the incidence of adverse events and secondary endpoints were response rate, progression-free survival, and overall survival. A total of 25 patients were enrolled in the full-set analysis. RESULTS: Grade 3 or more adverse events were observed in 21 patients (84.0%). Neutropenia was most frequently observed (68.0%), followed by peripheral sensory neuropathy (12.0%), and febrile neutropenia (12.0%). Median progression-free survival and overall survival were 6.9 months and 13.4 months, respectively. Disease control rate was 88.0%, and response rate of patients with measurable lesions was 52.9%. Notably, no treatment-related deaths occurred. CONCLUSION: Ramucirumab plus paclitaxel as a second-line chemotherapy demonstrated acceptable oncological outcomes, despite the occurrence of frequent adverse events. It is necessary to carefully select patients and adjust treatment regimens in older patients with GC to safely administer chemotherapy and subsequently achieve satisfactory long-term outcomes.

Long-term Outcomes of Neoadjuvant Chemotherapy With Docetaxel, Cisplatin and S-1 for Stage III Gastric Cancer.

BACKGROUND/AIM: In the previous phase I/II study, we established neoadjuvant chemotherapy (NAC) using bi-weekly docetaxel, cisplatin, and S-1 (DCS) for clinical stage III gastric cancer. This study aimed to clarify long-term outcomes of this treatment. PATIENTS AND METHODS: Relapse-free survival (RFS) and overall survival (OS) were calculated by the Kaplan-Meier method and prognostic factors for RFS and OS were identified by univariate analysis. RESULTS: A total of 47 patients with clinical stage III gastric cancer were enrolled in this study. The 5-year RFS and OS rates were 69.8% and 74.3%, respectively, in all registered patients. Moreover, the 5-year OS and RFS rates in patients receiving R0 gastrectomy were 68.0% and 79.4%, respectively. Neutrophil-lymphocyte ratio (NLR) before NAC ≥2.41, prognostic nutritional index (PNI) before NAC ≤50.4, Glasgow prognostic score before NAC classification 2, NLR after NAC ≥1.43, PNI after NAC <48.0, and Grade 1a/1b pathological response significantly worsened RFS. NLR after NAC ≥1.43, PNI before NAC ≤50.4, NLR after NAC ≥1.43, and body weight loss >5 kg after NAC significantly worsened OS. CONCLUSION: Although bi-weekly DCS therapy as neoadjuvant setting showed acceptable long-term outcomes, poor immune-nutritional status before and after NAC caused worse long-term survival in stage III gastric cancer patients. It is warranted to conduct a well-designed prospective randomized control study to compare long-term outcomes using the bi-weekly DCS regimen between patients with and without immune-nutritional support during peri-NAC.

The degree of satisfaction and level of learning in male and female surgical residents: a nationwide questionnaire survey of graduating residents in Japan.

PURPOSE: Since 2002, the Japan Surgical Society has established a board certification system for surgeons to be certified for a specialty. Surgery remains a male-dominated field in Japan. This study aimed to clarify if the Japanese surgical residency training system is equally suitable for female and male residents. METHODS: The Japan Surgical Society conducted the first questionnaire survey regarding the system of surgical training for the residents in 2016. The questionnaire included the degree of satisfaction with 7 aspects of the training system, including the number and variety of cases experienced and duration and quality of instruction, and the learning level for 31 procedures. The degree of satisfaction and level of learning were compared between female and male residents. RESULTS: The degree of satisfaction was similar for all items between female and male residents. Female residents chose breast surgery as their subspecialty more frequently than male residents and were more confident in breast surgery procedures than male residents. Conversely, fewer female residents chose gastrointestinal surgery and were less confident in gastrointestinal surgery procedures than male residents. CONCLUSION: Female residents were as satisfied with the current surgical training system as male residents. However, there may be room for improvement in the surgical system, considering that fewer applications for gastrointestinal surgery come from female residents than from males.

Higher intra-tumoral expression of pro-coagulation genes is a predictor of angiogenesis, epithelial mesenchymal transition and worse patient survival in gastric cancer.

Coagulation regulates angiogenesis in cancer, and is associated with tumor development and metastasis. To date, there have been no studies quantifying the state of intra-tumoral coagulation. We measured intra-tumoral coagulation gene expression using the "Hallmark-COAGULATION" gene set in the MSigDB, performing gene set variation analysis and then assigning a "coagulation score" to quantify gene expression. Clinical, histologic, and genetic data were analyzed in 807 gastric cancer patients from the TCGA_STAD and GSE84437 databases. Tumors with increased expression of pro-coagulation genes were consistently associated with higher AJCC T-categories (p = 0.018), lymph node metastasis (p = 0.036), and stage (p = 0.006) in both cohorts. Patients with high coagulation scores were found to have worse disease-specific survival and overall survival (OS) (p = 0.019 and 0.011, respectively) in TCGA, and worse OS in GSE84437 cohort (p = 0.012). Higher expression of pro-coagulation genes correlated with increased intra-tumoral angiogenesis, as well as increased proportions of lymphatic and microvascular endothelial cells, endothelial cells, and pericytes, calculated by xCell algorithm. High coagulation scores were significantly associated with low tumor mutation burden, but not with intratumor heterogeneity and homologous recombination deficiency. Gastric cancers with high coagulation scores contained higher amounts of M1 macrophages and dendritic cells, and low numbers of Th1 cells (all P<0.001). Genes for epithelial mesenchymal transition (EMT), myogenesis, apical junction, transforming growth factor (TGF)-ß signaling, and angiogenesis were enriched in high coagulation score-gastric cancers (all false discovery rate <0.25). In conclusion, gastric cancers expressing higher levels of pro-coagulation genes demonstrate increased angiogenesis, EMT, TGF-ß signaling and worse patient prognosis.

Is Prophylactic Splenectomy Necessary for Proximal Advanced Gastric Cancer Invading the Greater Curvature with Clinically Negative Splenic Hilar Lymph Node Metastasis? A Multi-Institutional Cohort Study (YCOG2003).

BACKGROUND: Prophylactic splenectomy for hilar lymph node (#10) dissection has shown no survival benefit for patients with proximal advanced gastric cancer that does not invade the greater curvature. However, the survival benefit of prophylactic splenectomy for proximal advanced gastric cancer invading the greater curvature side, particularly for clinically negative #10 lymph node metastasis (#10[-]) cases remains controversial. METHODS: This multi-institutional retrospective study enrolled 146 consecutive patients with proximal advanced gastric cancers invading the greater curvature side with clinical #10(-) who underwent R0 total gastrectomy. For 33 of these patients, splenectomy was performed, and the remaining 113 underwent spleen-preservation gastrectomy. Short- and long-term results were compared between the splenectomy and spleen-preservation groups, with the incidence of #10 metastasis in the splenectomy group and recurrence in the spleen-preservation group compared. RESULTS: In the splenectomy group, longer operative time, greater blood loss, more frequent postoperative abdominal infection, and longer hospital stay were observed than in the spleen-preservation group. The two groups exhibited no differences in median relapse-free survival time (31.1 vs 59.8 months; P = 0.684) or median overall survival time (64.9 vs 65.1 months; P = 0.765). The pathologic #10 lymph node metastasis rate was 3% in the splenectomy group, and the #10 lymph node recurrence rate was 2.7% in the spleen-preservation group. CONCLUSIONS: Prophylactic splenectomy showed more frequent postoperative morbidities and a longer hospital stay than spleen preservation, without any long-term survival benefits.

Prognostic Factors Affecting Short- and Long-Term Outcomes of Gastrectomy for Gastric Cancer in Older Patients.

INTRODUCTION: The benefits of surgery in older patients with gastric cancer are controversial. This single-institution retrospective study in Japan aimed to evaluate the impact of gastrectomy in older patients with gastric cancer. METHODS: A series of 234 patients aged ≥80 years with histologically confirmed gastric cancer had indications for surgical treatment at the Gastroenterological Center, Yokohama City University Medical Center, between April 2002 and December 2018. Patients who were lost to follow-up (n = 27), had tumors not eligible for surgery (n = 14), and could not achieve R0 resection (n = 7) were excluded from this retrospective study. The remaining 186 patients were included. Patient characteristics, intraoperative outcomes, postoperative complications, and long-term survival were evaluated. RESULTS: The incidence of postoperative complications with Clavien-Dindo grade ≥ II was observed in 61 patients (32.8%). The 5-year relapse-free survival and overall survival (OS) rates were 84.2% and 63.4%, respectively. Multivariate analysis showed that geriatric nutritional risk index (<98) (odds ratio, 1.97; p = 0.047), neutrophil/lymphocyte ratio (>2.36) (odds ratio, 1.94; 95% confidence interval, 1.02-3.67; p = 0.043), and total gastrectomy (TG) (odds ratio, 1.97; p = 0.042) significantly predicted postoperative complications. Moreover, TG (hazard ratio, 1.91; p = 0.036) was an independent prognostic factor of OS. CONCLUSIONS: Poor immunonutritional status and TG led to worse short-term outcomes. Moreover, TG was an independent prognostic factor of OS in older patients with gastric cancer. It is necessary to provide effective perioperative care, including nutritional support, to clarify whether short-term outcomes would be improved.

Chemoradiotherapy for Locally Advanced Esophageal Squamous Cell Carcinoma.

PURPOSE: Few studies have reported the impact of chemoradiotherapy (CRT) on the objective response of patients with locally advanced unresectable esophageal squamous cell carcinoma (ESCC). We evaluated the factors predicting therapeutic effectiveness and the short- and long-term outcomes in patients with T4b ESCC treated with CRT. METHODS: We included 155 patients with T4b ESCC who underwent CRT at the Department of Surgery, Gastroenterological Center, Yokohama City University, between January 2000 and December 2018. Responders were defined as patients who demonstrated a complete response (CR) or partial response (PR). Multivariate analysis for objective response was performed using a logistic regression model, and prognostic factors were evaluated by univariate and multivariate analyses. RESULTS: Among the 155 patients included, 20 and 84 patients demonstrated a CR and PR, respectively, resulting in a response rate of 67.1%. The median overall survival (OS) was 15.2 months, and the 3-year survival rate was 32.1%. High Glasgow prognostic score (GPS) and advanced N-category independently predicted the objective response to CRT. GPS and objective response were independent prognostic factors for OS. There was no significant difference in the long-term survival of responders who received subsequent chemotherapy or salvage surgery. CONCLUSIONS: High GPS and advanced N-category predicted a poor objective response to CRT in patients with T4b ESCC. Therefore, chemotherapeutic regimens with a higher efficacy are required. The indications for salvage surgery for responders should be carefully considered, with care taken to avoid complications. To confirm this, prospective randomized controlled studies are necessary.

Psoas muscle depletion during preoperative chemotherapy for advanced gastric cancer has a negative impact on long-term outcomes after gastrectomy.

AIM: The significance of sarcopenia in cancers has been widely recognized. However, few studies have focused on chronological changes in sarcopenia in cancer patients. This study aimed to clarify the clinical significance of changes in the psoas muscle area before and after preoperative chemotherapy. METHODS: This study included 39 patients who underwent gastrectomy followed by preoperative chemotherapy for advanced gastric cancer between January 2010 and December 2016 in our hospital. The psoas muscle area was measured at the umbilical level before and after chemotherapy, and the relationship between its chronological changes and the long-term prognosis was examined. RESULTS: Patients were classified into two groups according to changes in the psoas muscle area before and after preoperative chemotherapy: remarkable muscle depletion and normal groups. No significant differences were observed in clinicopathological factors. Notably, the remarkable muscle depletion group included significantly more male patients (P = .018) and showed a high weight loss rate (P < .001). Although no significant difference was observed in the recurrence-free survival between the two groups (P = .484), overall survival was significantly worse in the remarkable muscle depletion group (P < .001). Multivariate analysis for prognosis revealed that pathological stage III or higher (P = .022) and decreased psoas muscle area (P = .038) were independent prognostic factors. CONCLUSIONS: The present findings suggest that psoas muscle depletion during preoperative chemotherapy is a prognostic factor for poor long-term outcomes in patients who underwent gastrectomy followed by preoperative chemotherapy for advanced gastric cancer.

The new prognostic score for unresectable or recurrent gastric cancer treated with nivolumab: A multi-institutional cohort study.

BACKGROUND: Real-world outcomes of nivolumab treatment for gastric cancer and associated prognostic factors remain unclear; the present study aimed to evaluate both items. METHODS: A total of 278 consecutive patients treated with nivolumab for gastric cancer during 2017-2019 were enrolled in this multi-institutional retrospective cohort study. The impact of laboratory findings, immune-related adverse events (irAEs), and clinicopathological factors on long-term survival was evaluated using the Cox proportional hazards model. RESULTS: The response rate was 11.7% in patients with measurable lesions. The overall and progression-free survival estimates were 6.77 and 2.53 months, respectively. The incidence of irAEs was 30.6% (6.8% for grade ≥3). There were no treatment-related deaths. Multivariate analysis revealed that C-reactive protein level of ≤0.5 mg/dL (hazard ratio = 0.476, P < .001), irAE occurrence (hazard ratio = 0.544, P < .001), albumin level of >3.5 g/dL (hazard ratio = 0.688, P = .045), performance status 0 (hazard ratio = 0.711, P = .028), lymphocyte count >1000/µL (hazard ratio = 0.686, P = .027), and differentiated histological type (hazard ratio = 0.740, P = .046) were independently associated with improved survival. The median survival of patients with four or more good prognostic factors was 18.3 months. CONCLUSION: Nivolumab showed safety and survival benefits in patients with previously treated unresectable or recurrent gastric cancer. Low C-reactive protein level, irAE occurrence, high albumin level, high lymphocyte count, and differentiated histological type may affect outcomes. The presence of four or more good prognostic factors may help identify likely long-term survivors.

Feasibility of esophagectomy for esophageal cancer in elderly patients: a case-control study.

PURPOSE: Surgery in elderly patients with esophageal cancer is challenging due to high mortality and limited survival. This study aimed to evaluate the safety and effectiveness of curative esophagectomy in elderly patients with esophageal cancer. METHODS: This study included 77 and 112 patients with esophageal cancer aged ≥ 70 and 40-64 years, respectively, who underwent R0 esophagectomy between January 1998 and December 2016. Patient characteristics, intraoperative outcomes, postoperative complications, and long-term survival were compared. RESULTS: The proportions of comorbid diseases (85.7% vs. 57.1%; P < 0.001), the American Society of Anesthesiologists score (1/2/3; 2.6%/94.8%/2.6% vs. 42.9%/57.1%/0%; P < 0.001), the preoperative systemic inflammation score (SIS) (0/1/2; 20.8%/48.1%/31.2% vs. 38.4%/38.4%/23.2%; P = 0.036), and postoperative complications (Clavien-Dindo grade ≥ III) (33.8% vs. 20.5%; P = 0.041) were significantly higher in the elderly group than those in the non-elderly group. However, long-term overall survival (OS) and relapse-free survival were not significantly different between the groups. On multivariate analysis, SIS (hazard ratio, 3.06; P = 0.037) and severe postoperative complications (hazard ratio, 2.01; P = 0.039) were significantly correlated with OS in the elderly group. CONCLUSIONS: As SIS and severe postoperative complications lead to poor prognosis after R0 esophagectomy in elderly patients, selecting appropriate patients for esophagectomy and preventing severe postoperative complications is essential.

High postoperative neutrophil-lymphocyte ratio and low preoperative lymphocyte-monocyte ratio predict poor prognosis in gastric cancer patients receiving gastrectomy with positive lavage cytology: a retrospective cohort study.

BACKGROUND: Long-term outcomes in gastric cancer patients with positive lavage cytology (CY1) are generally poor. This multi-institutional retrospective cohort study aims to evaluate the clinical significance of the neutrophil-lymphocyte ratio (NLR) and the lymphocyte-monocyte ratio (LMR) in CY1 gastric cancer patients. METHODS: A total of 121 CY1 gastric cancer patients without other non-curative factors, who underwent macroscopically curative resection, were enrolled in this study. The cutoff values of preoperative NLR (pre-NLR), postoperative NLR (post-NLR), preoperative LMR (pre-LMR), and postoperative LMR (post-LMR) were defined by the Contal and O'Quigley method as 2.3, 3.0, 2.5, and 3.2, respectively. A Cox proportional hazard model was used to identify the independent prognostic factors among NLR, LMR, and other clinicopathological factors. RESULTS: There were significant differences in the overall survival (OS) between the two groups: high post-NLR groups vs. low post-NLR group (median survival time, months) (10.9 vs. 22.8, P = 0.006) and high pre-LMR group vs. low pre-LMR group (21.3 vs. 11.0, P = 0.001). The LMR value elevated significantly after gastrectomy (P = 0.020), although not in the NLR value (P = 0.733). On multivariate analysis, high post-NLR (hazard ratio = 1.506; 95% confidence interval = 1.047-2.167; P = 0.027), low pre-LMR (1.773; 1.135-2.769, 0.012), and no postoperative chemotherapy (1.558; 1.053-2.305, 0.027) were found to be independent prognostic factors for adverse OS. CONCLUSIONS: Because a combination of high post-NLR and low pre-LMR may be an adverse prognostic marker in resectable CY1 gastric cancer patients, it is necessary to conduct a prospective trial to confirm a useful perioperative chemotherapeutic regimen for these patients.

Prognostic impact of dimensional factors in pT1 gastric cancer.

BACKGROUND: The significance of the dimensional factors (tumor diameter, area and volume) as the prognostic factor has not been precisely evaluated in pT1 gastric cancer. OBJECTIVES: This study aimed to identify the clinical impact and to confirm the clinical feasibility of the dimensional factors as prognostic factors in pT1 gastric cancer. METHODS: We analyzed prognostic factors for disease-specific survival (DSS), overall survival (OS) using clinicopathological factors by univariate and multivariate analyses and the pattern of recurrence in 2011 pT1 gastric cancer (mucosal and submucosal cancers) undergoing R0 gastrectomy. The cut-off values of each dimensional factor was decided by the ROC curve. RESULTS: Cox proportional hazard regression model showed that older age (≥75) and more advanced pN stage were adverse independent prognostic factors for DSS, and revealed that older age (≥75), greater preoperative co-morbid diseases, proximal and total gastrectomy, operative method and Clavien-Dindo classification (≥grade III) were independent adverse factors for OS. Any dimensional factors were not independent prognostic factors for any survival. CONCLUSIONS: The dimensional factors do not influence both OS and DSS in pT1 gastric cancer patients and so it is difficult to apply these dimensional factors for conducting therapeutic strategies.

Real-World Therapeutic Outcomes of S-1 Adjuvant Chemotherapy for pStage II/III Gastric Cancer in the Elderly.

BACKGROUND: The predictive factors for discontinuation of S-1 administration and prognostic factors in elderly patients with pStage II/III gastric cancer receiving S-1 adjuvant chemotherapy remain unclear. METHODS: Between January 2004 and December 2016, 80 elderly gastric cancer patients (≥70 years) undergoing curative D2 gastrectomy were enrolled in this study. Predictive factors for completion of S-1 administration over 1 year, adverse events due to S-1 administration, and prognostic factors for overall survival (OS) and relapse-free survival (RFS) were evaluated. RESULTS: Twenty-eight patients (35%) completed 8 courses of S-1. The median relative dose intensity was 82.1% (IQR 31.1-100%). The incidence rates of hematological and nonhematological adverse events were acceptable. Distal gastrectomy was an independent predictive factor for completion of S-1 administration (odds ratio [OR] 0.364; 95% confidence interval [CI] 0.141-0.939; p = 0.037). Higher postoperative neutrophil count/lymphocyte count (N/L) ratio and more advanced stage adversely influenced OS. Multivariate analysis revealed that a higher postoperative N/L ratio and more advanced stage adversely affected RFS. CONCLUSION: To complete adjuvant S-1 administration to elderly patients with pStage II/III gastric cancer, total gastrectomy should be avoided if possible. A new regimen for elderly gastric cancer patients with higher postoperative N/L ratios and more advanced stage should be established.

Comparison of Converse Ω Anastomosis and Extracorporeal Anastomosis After Laparoscopic Distal Gastrectomy for Gastric Cancer.

BACKGROUND: Converse Ω anastomosis is a recently developed technique of delta-shaped anastomosis for intracorporeal gastroduodenostomy to simplify the anastomotic procedures and reduce their potential risks. This study aimed to evaluate the safety and effectiveness of converse Ω anastomosis, comparing it with conventional extracorporeal Billroth-I anastomosis after laparoscopic distal gastrectomy (LDG) for gastric cancer. PATIENTS AND METHODS: Among 169 gastric cancer patients who underwent LDG with Billroth-I anastomosis anastomosis between April 2013 and March 2018, we selected 100 patients by propensity score matching (50 in the converse Ω anastomosis group and 50 in the extracorporeal anastomosis group). Patients' characteristics, intraoperative outcomes, postoperative complications, and survival time were compared between the 2 groups. RESULTS: Median anastomosis time was significantly longer in the converse Ω group than in the extracorporeal group (40.0 vs. 30.5 min, P=0.005). However, the total procedure time did not differ significantly between the groups. Intraoperative blood loss volume was significantly lower in the converse Ω group than in the extracorporeal anastomosis group (40 vs. 120 mL, P<0.001). There were no significant differences in the number of dissected lymph nodes, postoperative morbidity, mortality, or length of hospital stay. The postoperative body mass index and the prognostic nutritional index did not differ between the groups 1 year after surgery. There were no significant differences in overall survival and relapse-free survival between the 2 groups. CONCLUSIONS: Converse Ω anastomosis is feasible and safe. This novel technique can be adopted as a treatment option for reconstruction after LDG in patients with early-stage gastric cancer. Therefore, the risks and benefits of converse Ω anastomosis after LDG should be confirmed in larger cohorts.

[Nutritional Status after Laparoscopic-Assisted Pylorus-Preserving Gastrectomy].

PATIENTS AND METHODS: Patients with gastric cancer who underwent laparoscopic-assisted pylorus-preserving gastrectomy (LAPPG group)or laparoscopic-assisted distal gastrectomy(LADG group)between January 2010 and December 2019 were reviewed and their postoperative nutritional status and long-term outcomes retrospectively evaluated. RESULTS: In total, 83 patients(LAPPG group, n=23; LADG group, n=60)were included. Weight loss rates 1, 6, 12, and 24 months postoperatively in the LAPPG and LADG groups were 5.7% and 7.1%, 6.6% and 9.6%, 5.8% and 10.1%, and 5.2% and 8.7%, respectively. The LADG group exhibited a significantly higher weight loss than the LAPPG group at 6, 12, and 24 months (p=0.007, 0.002, and 0.022, respectively). No recurrence was observed in either group within 5 years of surgery. The 5- year overall survival rate of patients with pathological Stage Ⅰ cancer( LAPPG group, n=23, LADG group, n=51) was higher in the LAPPG group than in the LADG group(100% vs 82.9%, p=0.027). There were 6 cases of death from other diseases in the LADG group(pneumonia, n=2, other cancer, n=2, postoperative bleeding, n=1, and heart failure, n=1)but none in the LAPPG group. CONCLUSION: The weight loss after LAPPG was significantly lower than that after LADG. Furthermore, the former showed a good prognosis without death from other diseases, such as pneumonia.

Systemic Review and Meta-analysis of Impact of Splenectomy for Advanced Gastric Cancer.

BACKGROUND/AIM: Prophylactic splenectomy has shown no inferiority for tumors not invading the greater curvature side. Despite this, the clinical impact of prophylactic splenectomy for proximal advanced gastric cancer is not clear. This review aimed to clarify the impact of splenectomy for advanced gastric cancer in the upper third of the stomach. MATERIALS AND METHODS: A systematic review and meta-analysis were conducted based on PubMed and EMBASE databases. The following search terms were used: "gastric cancer" OR "splenectomy" OR upper third of the stomach" OR preservation of the spleen. RESULTS: Out of 765 articles, 18 studies (combined n=6,341) were included in the analysis. Four randomized controlled trials (RCT) and eight retrospective studies suggested the benefits of spleen-preserving gastrectomy. Six retrospective studies showed no significant benefit of spleen-preserving gastrectomy. Prophylactic splenectomy showed a close association with a higher incidence of postoperative morbidity (pancreatic fistula and anastomotic leakage) with no concomitant improvement in overall survival. Prophylactic splenectomy should not be routinely performed and RCTs are necessary to confirm the impact of splenectomy for cN(+) at the splenic hilum tumors and tumors invading the greater curvature.

Laparoscopic Total Gastrectomy for Gastric Cancer in Elderly Patients.

BACKGROUND/AIM: The purpose of this study was to evaluate the safety and efficacy of laparoscopic total gastrectomy (LTG) for elderly patients. PATIENTS AND METHODS: We retrospectively analyzed 136 patients who underwent LTG. We divided the patients into elderly patients (>75 years of age) and non-elderly patients (≤75 years of age). RESULTS: The American Society of Anesthesiologists score, Charlson comorbidity index, Glasgow Prognostic Score and rate of comorbidities were higher in the elderly group; the rates of other clinicopathological characteristics did not differ between the two groups. Regarding the nutritional status, the body weight loss rate in the elderly group was higher in comparison to the non-elderly group (81% vs. 84%, p=0.004). The disease-specific survival (DSS) did not differ between two groups to a statistically significant extent (3-year DSS rates: 83.7 vs. 94.5%; p=0.152). CONCLUSIONS: LTG was acceptable for elderly patients as the elderly and non-elderly groups showed comparable short-term and long-term outcomes.

Is there disparity between regions and facilities in surgical resident training in Japan? Insights from a national survey.

PURPOSE: This study sought to assess the disparity between regions and facilities in surgical resident training in Japan via a national level needs-assessment. METHODS: A survey was sent to all 909 graduating residents of 2016. Residents trained in the six prefectures with a population of 7 million or more were included in the large prefecture (LP) group. Residents trained in the other 41 prefectures were included in the small prefecture (SP) group. Each group was further divided into a university hospital (UH) group and a non-university hospital (NUH) group. RESULTS: The response rate was 56.3% (n = 512). Excluding nine residents who did not report their prefectures and facilities, surveys from 503 residents were analyzed. The UH group received significantly more years of training. In the SP and UH groups, there were significantly fewer residents who had performed 150 procedures or more under general anesthesia in comparison to the LP and NUH groups, respectively. Self-assessed competencies for several procedures were significantly lower in the SP and UH groups. CONCLUSION: Disparity in surgical resident training was found between regions and facilities in Japan. The surgical residency curriculum in Japan could be improved to address this problem.