RNA expression of 6 genes from metastatic mucosal gastric cancer serves as the global prognostic marker for gastric cancer with functional validation.

BACKGROUND: Molecular analysis of advanced tumors can increase tumor heterogeneity and selection bias. We developed a robust prognostic signature for gastric cancer by comparing RNA expression between very rare early gastric cancers invading only mucosal layer (mEGCs) with lymph node metastasis (Npos) and those without metastasis (Nneg). METHODS: Out of 1003 mEGCs, all Npos were matched to Nneg using propensity scores. Machine learning approach comparing Npos and Nneg was used to develop prognostic signature. The function and robustness of prognostic signature was validated using cell lines and external datasets. RESULTS: Extensive machine learning with cross-validation identified the prognostic classifier consisting of four overexpressed genes (HDAC5, NPM1, DTX3, and PPP3R1) and two downregulated genes (MED12 and TP53), and enabled us to develop the risk score predicting poor prognosis. Cell lines engineered to high-risk score showed increased invasion, migration, and resistance to 5-FU and Oxaliplatin but maintained sensitivity to an HDAC inhibitor. Mouse models after tail vein injection of cell lines with high-risk score revealed increased metastasis. In three external cohorts, our risk score was identified as the independent prognostic factor for overall and recurrence-free survival. CONCLUSION: The risk score from the 6-gene classifier can successfully predict the prognosis of gastric cancer.

Automated deep learning model for estimating intraoperative blood loss using gauze images.

The intraoperative estimated blood loss (EBL), an essential parameter for perioperative management, has been evaluated by manually weighing blood in gauze and suction bottles, a process both time-consuming and labor-intensive. As the novel EBL prediction platform, we developed an automated deep learning EBL prediction model, utilizing the patch-wise crumpled state (P-W CS) of gauze images with texture analysis. The proposed algorithm was developed using animal data obtained from a porcine experiment and validated on human intraoperative data prospectively collected from 102 laparoscopic gastric cancer surgeries. The EBL prediction model involves gauze area detection and subsequent EBL regression based on the detected areas, with each stage optimized through comparative model performance evaluations. The selected gauze detection model demonstrated a sensitivity of 96.5% and a specificity of 98.0%. Based on this detection model, the performance of EBL regression stage models was compared. Comparative evaluations revealed that our P-W CS-based model outperforms others, including one reliant on convolutional neural networks and another analyzing the gauze's overall crumpled state. The P-W CS-based model achieved a mean absolute error (MAE) of 0.25 g and a mean absolute percentage error (MAPE) of 7.26% in EBL regression. Additionally, per-patient assessment yielded an MAE of 0.58 g, indicating errors < 1 g/patient. In conclusion, our algorithm provides an objective standard and streamlined approach for EBL estimation during surgery without the need for perioperative approximation and additional tasks by humans. The robust performance of the model across varied surgical conditions emphasizes its clinical potential for real-world application.

Sex-dependent different clinicopathological characterization of Epstein-Barr virus-associated gastric carcinoma: a large-scale study.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been reported to account for approximately 5-16% of all GCs with good prognosis compared to EBV-negative GC. We evaluated the clinicopathological characteristics of EBVaGC including survival rate in South Korea. METHODS: A total of 4,587 patients with GC who underwent EBV in situ hybridization (EBV-ISH) were prospectively enrolled at the Seoul National University Bundang Hospital from 2003 to 2021. Age, sex, smoking status, cancer type and stage, tumor size and location, histological type, molecular features and survival information were analyzed. RESULTS: A total of 456 patients with GC (9.9%) were positive for EBV. The EBVaGC group displayed a higher proportion of males (P < 0.001), a predominant presence in the proximal stomach (P < 0.001), a higher proportion of undifferentiated cancer (P < 0.001), and a lower cancer stage (P = 0.004) than the EBV-negative group. Cox multivariate analyses revealed age (hazard ratio [HR] = 1.025, P < 0.001), tumor size (HR = 1.109, P < 0.001), and cancer stage (stage2 HR = 4.761, P < 0.001; stage3 HR = 13.286, P < 0.001; stage4 HR = 42.528, P < 0.001) as significant risk factors for GC-specific mortality, whereas EBV positivity was inversely correlated (HR = 0.620, P = 0.022). Furthermore, the EBVaGC group displayed statistically significant survival advantages over the EBV-negative cancer group in terms of both overall (P = 0.021) and GC-specific survival (P = 0.007) on the Kaplan-Meier survival curve. However, this effect was evident only in males. CONCLUSIONS: EBVaGC patients showed better prognoses despite their association with proximal location and poorly differentiated histology in male, probably due to the difference in immunity between males and females.

Analysis of Characteristics and Risk Factors of Patients with Single Gastric Cancer and Synchronous Multiple Gastric Cancer among 14,603 Patients.

Background/Aims: Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC. Methods: A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC. Results: The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high. Conclusions: SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).

Genomic and Transcriptomic Characterization of Gastric Cancer with Bone Metastasis.

PURPOSE: Bone metastasis (BM) adversely affects the prognosis of gastric cancer (GC). We investigated molecular features and immune microenvironment that characterize GC with BM compared to GC without BM. MATERIALS AND METHODS: Targeted DNA and whole transcriptome sequencing were performed using formalin-fixed paraffin-embedded primary tumor tissues (gastrectomy specimens) of 50 GC cases with distant metastases (14 with BM and 36 without BM). In addition, immunohistochemistry (IHC) for mucin-12 and multiplex IHC for immune cell markers were performed. RESULTS: Most GC cases with BM had a histologic type of poorly cohesive carcinoma and showed worse overall survival (OS) than GC without BM (p < 0.05). GC with BM tended to have higher mutation rates in TP53, KDR, APC, KDM5A, and RHOA than GC without BM. Chief cell-enriched genes (PGA3, PGC, and LIPF), MUC12, MFSD4A, TSPAN7, and TRIM50 were upregulated in GC with BM compared to GC without BM, which was correlated with poor OS (p < 0.05). However, the expression of SERPINA6, SLC30A2, PMAIP1, and ITIH2 were downregulated in GC with BM. GC with BM was associated with PIK3/AKT/mTOR pathway activation, whereas GC without BM showed the opposite effect. The densities of helper, cytotoxic, and regulatory T cells did not differ between the two groups, whereas the densities of macrophages were lower in GC with BM (p < 0.05). CONCLUSION: GC with BM had different gene mutation and expression profiles than GC without BM, and had more genetic alterations associated with a poor prognosis.

Single-port intragastric wedge resection using the tunnel method: a novel surgical approach for treating endophytic gastric subepithelial tumors.

BACKGROUND: Intragastric wedge resection is an effective method for treating endophytic gastric subepithelial tumors (SETs). However, retracting the stomach wall to the umbilicus is difficult in certain patients. In response, we developed a novel surgical technique for single-port intragastric wedge resection, which we termed the "tunnel method." METHODS: A transumbilical incision is made, and a wound retractor is applied. After diagnostic laparoscopy, a gastrostomy is made on the greater curvature, lower body. Another small wound retractor is inserted into the gastrostomy, and extracted through the transumbilical incision, creating a tunnel from the gastrostomy site to the umbilicus. Articulating laparoscopic instruments are inserted via the tunnel, and intragastric wedge resection is performed. We collected and analyzed the clinicopathologic and operative data of patients who underwent intragastric wedge resection via the tunnel method. RESULTS: Twenty-seven patients who underwent single-port intragastric wedge resection via the tunnel method in a single tertiary referral hospital were included in this study. The mean age of the patients was 54.6 ± 11.4 years, body mass index was 26.5 ± 3.4 kg/m2. Twenty-four (88.9%) patients had tumors located in the upper third of the stomach. The average operative time was 65.0 ± 24.2 min. None of the patients experienced Clavien-Dindo grade IIIa or higher postoperative complications. The average postoperative hospital stay length was 2.5 ± 0.8 days. Thirteen gastrointestinal stromal tumors, nine leiomyomas, and one neuroendocrine carcinoma, schwannoma, lipoma, spindle cell proliferative lesion, and fibrotic lesion were pathologically diagnosed. The average tumor size was 2.6 ± 1.3 cm. All cases had negative resection margins. CONCLUSIONS: Single-port intragastric wedge resection by the tunnel method is a feasible and safe approach for treating endophytic gastric SETs.

The Shorr Versus Modified Ultrafast Papanicolaou Method for Intraoperative Diagnosis of Peritoneal Washing Cytology in Advanced Gastric Cancer: A Phase II Study.

PURPOSE: According to the American Joint Committee on Cancer cancer staging system, positive peritoneal washing cytology (PWC) indicates stage IV gastric cancer. However, rapid intraoperative diagnosis of PWC has no established reliable method. This study evaluated and compared the diagnostic accuracy of the Shorr and the modified ultrafast Papanicolaou (MUFP) methods for intraoperative PWC. MATERIALS AND METHODS: This study included patients with gastric cancer who were clinically diagnosed with stage cT3 or higher. The Shorr and MUFP methods were performed on all PWC specimens, and the results were compared with those of conventional Papanicolaou (PAP) staining with carcinoembryonic antigen immunohistochemistry. Sensitivity, specificity, and partial likelihood tests were used to compare the 2 methods. RESULTS: Forty patients underwent intraoperative PWC between November 2019 and August 2021. The average time between specimen reception and slide preparation using Shorr and MUFP methods was 44.4±4.5 minutes, and the average time between specimen reception and pathologic diagnosis was 53.9±8.9 minutes. Eight patients (20.0%) had positive cytology in PAP staining. The Shorr method had a sensitivity of 75.0% and specificity of 93.8%; the MUFP method had 62.5% sensitivity and 100.0% specificity. The area under the curve was 0.844 for Shorr and 0.813 for MUFP. In comparing the C-indices of each method with overall survival, no difference was found among the Shorr, MUFP, and conventional PAP methods. CONCLUSIONS: The Shorr and MUFP methods are acceptable for the intraoperative diagnosis of PWC in advanced gastric cancer.

Feasibility and safety of pure single-incision laparoscopic total and proximal gastrectomy for early gastric cancer: propensity score-matched comparison to multiport totally laparoscopic approach.

BACKGROUND: There have been few studies regarding the feasibility and safety of pure single-incision laparoscopic total gastrectomy (SITG) or proximal gastrectomy (SIPG) for early gastric cancer (EGC). The purpose of this study was to analyze the surgical outcome of all consecutive SITG or SIPG cases compared with multiport laparoscopic total gastrectomy (MLTG) or proximal gastrectomy (MLPG) for EGC. METHODS: We analyzed all consecutive SITG or SIPG cases with double-tract reconstruction for ECG, including the initial case, between March 2013 and December 2021. SITG/SIPG was performed on patients without significant systemic comorbidities through a 3-4 cm vertical transumbilical incision. SITG/SIPG was matched to multiport laparoscopic total or proximal gastrectomy (MLTG/MLPG) cases performed in the same period using a 1:3 propensity score matching, including sex, body mass index (BMI), age and type of resection, year of operation, and institution as covariates. We compared perioperative clinicopathological characteristics and early postoperative morbidity within 1 month after surgery between the SITG/SIPG and MLTG/MLPG groups. RESULTS: In total, 21 patients with SITG and 15 patients with SIPG were compared with those with MLTG (n = 264) and MLPG (n = 220). No conversion to an open or multiport approach occurred in the SITG/SIPG group. After matching, operation time was similar between SITG/SIPG and MLTG/MLPG (223.9 ± 63.5 min vs 234.8 ± 68.7 min, P = 0.402). Length of stay was not significantly different between SITG/SIPG and MLTG/MLPG (11.9 ± 15.4 days vs 8.4 ± 5.0 days, P = 0.210). The average number of retrieved lymph nodes was not significantly different between SITG and MLTG (53.1 ± 16.3 vs 63.2 ± 27.5, P = 0.115), but it was significantly higher in SIPG than MLPG (59.6 ± 27.2 vs 46.0 ± 19.7, P = 0.040). The overall complication rate (30.6% vs 25.9%, P = 0.666) and Clavien-Dindo grade III or higher complication rates (13.9% vs 6.5%, P = 0.175) were not significantly different between the SITG/SIPG and MLTG/MLPG groups. CONCLUSION: Cautious adoption of SITG/SIPG procedures for EGC is feasible and safe.

Feasibility of articulating laparoscopic instruments in laparoscopic gastrectomy using propensity score matching.

Advancements in minimally invasive surgery has led to the development of several surgical instruments, including the ArtiSential®. This new instrument provides a greater range of motion and improved dexterity to laparoscopic procedures, making it an alternative option to traditional straight instruments, and the Da Vinci robot system. The purpose of this study is to compare the postoperative outcomes of a prospective cohort of patients who underwent laparoscopic gastrectomy using articulating instruments with those of a historical cohort of patients who underwent the same procedure using straight instruments. The study was designed as a prospective observational cohort study matched to a retrospective historical cohort using propensity score matching. The primary outcome was the rate of early complications within 90 days of surgery. Other outcomes included the operation time, estimated blood loss, time to first flatus, time to first soft fluid diet, hospital stay, and mortality. After propensity score matching, 41 patients were enrolled in both groups. The mean age was 62.4 ± 12.3 years in the conventional group and 63.5 ± 9.6 years in the artisential group (p = 0.647). Mean operative time was significantly shorter in the artisential group compared to the conventional group (136.1 min vs. 163.9 min, p = 0.032). The time to first soft fluid diet was also significantly shorter in the artisential group (2.2 days vs. 2.8 days, p = 0.030), but there was no significant difference in the time to first flatus and overall hospital stay. The incidence of early complications was lower in the artisential group, but the difference was not significant (24.4% vs 7.3%, p = 0.070). There was no mortality in either group. The use of articulating instruments for laparoscopic gastrectomy did not increase postoperative morbidity compared to straight laparoscopic instruments. The use of articulating instruments may be associated with faster bowel recovery and less early complications.

Can prospective monitoring improve complication rates after gastrectomy? Experience of Billroth I reconstruction at a high-volume tertiary center.

INTRODUCTION: Prospective database is imperative in surgical outcome monitoring and has shown success in providing a comprehensive complication index to monitor surgical quality. This study aims to review whether prospective monitoring has an effect on postoperative complication rates, especially leakage after Billroth I (BI) anastomosis and to identify risk factors of anastomosis leakage after BI anastomosis. MATERIALS AND METHODS: Patients who underwent distal gastrectomy with BI reconstruction at Seoul National University Hospital between January 2018 and April 2021 were enrolled. Clinicopathological characteristics and perioperative variables were retrieved. The risk factor that was statistically significant in univariate analysis was further analyzed by binomial logistic regression analysis. RESULTS: BI leakage rate in three years has declined by half on a yearly basis from 5.7% to 1.8%. The leakage group patients were predominantly male (100%) when compared to the non-leakage group (67.6%) (p = 0.04). The BMI (25.00 ± 1.42 vs. 24.16 ± 3.15, p = 0.048) and CRP measured on POD#2 (16.47 ± 5.64 vs. 9.99 ± 5.42, p < 0.001) showed significant differences between the two groups. POD#2 CRP greater than 12.7 mg/dL was able to predict risk of anastomosis leak with sensitivity 73.3% and specificity 73.1%. CONCLUSION: Understanding variations in outcomes is important for improvements in surgical care, and through prospective monitoring and intra-departmental feedback, it is possible to reduce complication rates after gastrectomy. This study shows that age, gender and BMI are risk factors to BI leakage and POD#2 CRP greater than 12.7 mg/dL can be used to suspect leakage after BI anastomosis.

KRAS activation in gastric cancer stem-like cells promotes tumor angiogenesis and metastasis.

Our previous work showed that KRAS activation in gastric cancer cells leads to activation of an epithelial-to-mesenchymal transition (EMT) program and generation of cancer stem-like cells (CSCs). Here we analyze how this KRAS activation in gastric CSCs promotes tumor angiogenesis and metastasis. Gastric cancer CSCs were found to secrete pro-angiogenic factors such as vascular endothelial growth factor A (VEGF-A), and inhibition of KRAS markedly reduced secretion of these factors. In a genetically engineered mouse model, gastric tumorigenesis was markedly attenuated when both KRAS and VEGF-A signaling were blocked. In orthotropic implant and experimental metastasis models, silencing of KRAS and VEGF-A using shRNA in gastric CSCs abrogated primary tumor formation, lymph node metastasis, and lung metastasis far greater than individual silencing of KRAS or VEGF-A. Analysis of gastric cancer patient samples using RNA sequencing revealed a clear association between high expression of the gastric CSC marker CD44 and expression of both KRAS and VEGF-A, and high CD44 and VEGF-A expression predicted worse overall survival. In conclusion, KRAS activation in gastric CSCs enhances secretion of pro-angiogenic factors and promotes tumor progression and metastasis.

Comprehensive Study of Microsatellite Instability Testing and Its Comparison With Immunohistochemistry in Gastric Cancers.

PURPOSE: In this study, polymerase chain reaction (PCR)-based microsatellite instability (MSI) testing was comprehensively analyzed and compared with immunohistochemistry (IHC) for mismatch repair (MMR) protein expression in patients with gastric cancer (GC). MATERIALS AND METHODS: In 5,676 GC cases, PCR-based MSI testing using five microsatellites (BAT-26, BAT-25, D5S346, D2S123, and D17S250) and IHC for MLH1 were performed. Re-evaluation of MSI testing/MLH1 IHC and additional IHC for MSH2, MSH6, and PMS2 were performed in discordant/indeterminate cases. RESULTS: Of the 5,676 cases, microsatellite stable (MSS)/MSI-low and intact MLH1 were observed in 5,082 cases (89.5%), whereas MSI-high (MSI-H) and loss of MLH1 expression were observed in 502 cases (8.8%). We re-evaluated the remaining 92 cases (1.6%) with a discordant/indeterminate status. Re-evaluation showed 1) 37 concordant cases (0.7%) (18 and 19 cases of MSI-H/MMR-deficient (dMMR) and MSS/MMR-proficient (pMMR), respectively), 2) 6 discordant cases (0.1%) (3 cases each of MSI-H/pMMR and MSS/dMMR), 3) 14 MSI indeterminate cases (0.2%) (1 case of dMMR and 13 cases of pMMR), and 4) 35 IHC indeterminate cases (0.6%) (22 and 13 cases of MSI-H and MSS, respectively). Finally, MSI-H or dMMR was observed in 549 cases (9.7%), of which 47 (0.8%) were additionally confirmed as MSI-H or dMMR by re-evaluation. Sensitivity was 99.3% for MSI testing and 95.4% for MMR IHC. CONCLUSIONS: Considering the low incidence of MSI-H or dMMR, discordant/indeterminate results were occasionally identified in GCs, in which case complementary testing is required. These findings could help improve the accuracy of MSI/MMR testing in daily practice.

Clinical Outcomes of Resectional Roux-en-Y Gastric Bypass, Compared to Sleeve Gastrectomy for Severe Obesity.

PURPOSE: Resectional Roux-en-Y gastric bypass (RRYGB) is considered an alternative bariatric surgery in countries with a high incidence of stomach cancer because there is no excluded stomach after RRYGB. This study aimed to evaluate the efficacy and safety of RRYGB. MATERIALS AND METHODS: This study included patients who underwent RRYGB and sleeve gastrectomy (SG) between 2011 and 2021. Surgical complications and metabolic and nutritional profiles were compared between the patients preoperatively and at 1, 6, and 12 months after surgery. RESULTS: Twenty and seventy-six patients underwent RRYGB and SG, respectively; 7 in the SG group were lost to follow-up within 1 year. Surgical complications and baseline characteristics were comparable between two groups, except for diabetes (90.0% vs. 44.7%, p < 0.001). The decrease of HbA1c levels and incidence of reflux esophagitis were lower in the RRYGB group compared to that of SG at 1-year postoperative (-3.0% vs. -1.8%, p = 0.014; 0% vs. 26.7%, p = 0.027). The percentage of total weight loss at 1- year postoperative and incidence of dumping syndrome were comparable between the two groups. The RRYGB group had significantly lower total cholesterol level (161.9 mg/dl vs. 196.4 mg/dl, p < 0.001), but higher incidence of vitamin B12 deficiency (30.0% vs. 3.6%, p = 0.003) at 1 year postoperative compared to those of the SG group. CONCLUSIONS: The RRYGB group had better postoperative outcomes for diabetes and dyslipidemia without increasing surgical complications compared to that of the SG group. Thus, RRYGB can be considered a safe and effective alternative in areas where gastric cancer is prevalent.

Comparison of perioperative outcomes between bipolar sealing, ultrasonic shears and a hybrid device during laparoscopic gastrectomy for early gastric cancer: a prospective, multicenter, randomized study.

BACKGROUND: Although EBDs are essential for minimally invasive surgery, well-established prospective randomized studies comparing EBDs are scarce. This study aimed to compare the intraoperative inflammatory response and short-term surgical outcomes among different energy-based devices (EBDs) in laparoscopic distal gastrectomy (LDG). METHODS: Patients with clinical stage I gastric cancer scheduled for LDG at two different medical centers were prospectively randomized into three groups: ultrasonic shears (US), advanced bipolar (BP) and ultrasonic-bipolar hybrid (HB). The C-reactive protein (CRP) level, operation time, intraoperative blood loss (IBL), laboratory tests, cytokines (interleukin (IL)-6 and IL-10), hospital stay, and complication rate were analyzed. A novel semiquantitative measurement method using indocyanine green (ICG) and a near-infrared camera measured the amount of lymphatic leakage. RESULTS: The primary endpoint, the CRP level, was significantly lower in the BP (n = 60) group than in the US (n = 57) or HB (n = 57) group [9.03 ± 5.55 vs. 11.12 ± 5.02 vs. 12.67 ± 6.14, p = 0.001, on postoperative day (POD) 2 and 7.48 vs. 9.62 vs. 9.48, p = 0.026, on POD 4]. IBL was significantly lower in BP than in US or HB (26.3 ± 25.3 vs. 43.7 ± 42.0 vs. 34.9 ± 37.0, p = 0.032). Jackson-Pratt drainage triglycerides were significantly lower in BP than in US (53.6 ± 33.7 vs. 84.2 ± 59.0, p = 0.11; HB: 71.3 ± 51.4). ICG fluorescence intensity, operation time, laboratory results, cytokines, hospital stay, and complication rate were not significantly different among the 3 groups. CONCLUSION: BP showed a lower postoperative CRP level and less IBL than US and HB, suggesting less collateral thermal damage and better sealing function. Surgeons may consider this when selecting EBDs for laparoscopic surgery.

Postoperative major bleeding risk in patients using oral antiplatelets and/or anticoagulants after laparoscopic gastric cancer surgery.

Purpose: The use of antiplatelet and/or anticoagulant therapies has become common. In rare cases, these therapies may increase the risk of dangerous postoperative bleeding. We investigated the association of antiplatelets and/or anticoagulants with postoperative major bleeding risk in laparoscopic gastric cancer surgery. Methods: We retrospectively enrolled 3,663 gastric cancer patients (antiplatelet/anticoagulant group, 518; control group, 3,145) who had undergone laparoscopic surgery between January 2012 and December 2017. To minimize selection bias, 508 patients in each group were matched using propensity score matching (PSM) method. The primary outcome was postoperative major bleeding. Secondary outcomes were intraoperative, postoperative transfusion and early complications. Results: After PSM, postoperative major bleeding occurred in 10 (2.0%) and 3 cases (0.6%) in the antiplatelets/anticoagulants and control groups, respectively (P = 0.090). Intraoperative and postoperative transfusions were not significantly different between 2 groups (2.4% vs. 1.4%, P = 0.355 and 5.5% vs. 4.3%, P = 0.469). Early complications developed in 58 (11.4%) and 43 patients (8.5%) in the antiplatelets/anticoagulants and control groups, respectively (P = 0.142). The mean amounts of intraoperative and postoperative transfusions were not significantly different between the groups (366.67 ± 238.68 mL vs. 371.43 ± 138.01 mL, P = 0.962; 728.57 ± 642.25 mL vs. 508.09 ± 468.95 mL, P = 0.185). In multivariable analysis, male (P = 0.008) and advanced stage (III, IV) (P = 0.024) were independent significant risk factors for postoperative major bleeding. Conclusion: Preoperative antiplatelets and/or anticoagulants administration did not significantly increase the risk of postoperative major bleeding after laparoscopic gastric cancer surgery.

Effect of Laparoscopic Proximal Gastrectomy With Double-Tract Reconstruction vs Total Gastrectomy on Hemoglobin Level and Vitamin B12 Supplementation in Upper-Third Early Gastric Cancer: A Randomized Clinical Trial.

Importance: Patients undergoing proximal gastrectomy (PG) with double-tract reconstruction (DTR) have been reported to have an incidence of reflux esophagitis that is as low as that observed after total gastrectomy (TG). It is unclear whether PG has an advantage over TG for the treatment of patients with upper early gastric cancer (GC). Objective: To evaluate the effect of laparoscopic PG with DTR (LPG-DTR) vs laparoscopic TG (LTG) on levels of hemoglobin and vitamin B12 supplementation required among patients with clinically early GC in the upper third of the stomach (upper-third early GC). Design, Setting, and Participants: This multicenter open-label superiority randomized clinical trial was conducted at 10 institutions in Korea. A total of 138 patients with upper-third cT1N0M0 GC were enrolled between October 27, 2016, and September 9, 2018. Follow-up ended on December 3, 2020. Interventions: Patients were randomized to undergo either LPG-DTR or LTG. Main Outcomes and Measures: The primary co-end points were change in hemoglobin level and cumulative amount of vitamin B12 supplementation at 2 years after LPG-DTR or LTG. The secondary end points included morbidity, postoperative reflux esophagitis, quality of life, overall survival, and disease-free survival. Quality of life outcomes were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) 30-item core questionnaire (C30) and the EORTC QLQ stomach cancer-specific questionnaire at 3 months, 12 months, and 24 months. Results: Among 138 patients (mean [SD] age, 60.0 [10.9] years; 87 men [63.0%]; all of Asian race and Korean ethnicity), 68 (mean [SD] age, 56.7 [10.4] years; 39 men [57.4%]) were randomized to receive LPG-DTR and 69 (mean [SD] age, 61.3 [11.3] years; 48 men [69.6%]) were randomized to receive LTG. The mean (SD) changes in hemoglobin levels from baseline to month 24 were -5.6% (7.4%) in the LPG-DTR group and -6.9% (8.3%) in the LTG group, for an estimated difference of -1.3% (95% CI, -4.0% to 1.4%; P = .35). The mean (SD) cumulative amount of vitamin B12 supplementation was 0.4 (1.3) mg in the LPG-DTR group and 2.5 (3.0) mg in the LTG group, for an estimated difference of 2.1 mg (95% CI, 1.3-2.9 mg; P < .001). The late complication rates in the LPG-DTR and LTG groups were 17.6% and 10.1%, respectively (P = .31). The incidence of reflux esophagitis was not different between the LPG-DTR and LTG groups (2.9% vs 2.9%; P = .99). Compared with the LTG group, the LPG-DTR group had better physical functioning scores (85.2 [15.6] vs 79.9 [19.3]; P = .03) and social functioning scores (89.5 [17.9] vs 82.4 [19.4]; P = .03) on the EORTC QLQ-C30. Two-year overall survival (98.5% vs 100%; P = .33) and disease-free survival (98.5% vs 97.1%; P = .54) did not significantly differ between the LPG-DTR vs LTG groups. Conclusions and Relevance: In this study, patients with upper-third early GC who received LPG-DTR required less vitamin B12 supplementation than those who received LTG, with no increase in complication rates and no difference in overall and disease-free survival rates. There was no difference in change in hemoglobin level between groups. In addition, the LPG-DTR group had better physical and social functioning than the LTG group. These findings suggest that LPG-DTR may be as safe as LTG and may be a function-preserving procedure for the treatment of patients with upper-third early GC. Trial Registration: ClinicalTrials.gov Identifier: NCT02892643.

Comparison between laparoscopic pylorus-preserving gastrectomy and laparoscopic distal gastrectomy for overweight patients with early gastric cancer.

Purpose: Laparoscopic pylorus-preserving gastrectomy (LPPG) has a nutritional advantage over laparoscopic distal gastrectomy (LDG), however, may be less beneficial in overweight patients in terms of weight loss. The purpose of this study was to compare LPPG and LDG in overweight patients with early gastric cancer. Methods: Clinicopathologic data of overweight patients (body mass index [BMI], ≥25 kg/m2) who underwent LPPG (n = 63) or LDG (n = 183) in 2016-2018 were retrospectively reviewed. In the LDG group, patients with Billroth-II anastomosis were separately grouped (LDG B-II, n = 66). Changes in BMI, hemoglobin, albumin, and total protein were compared among groups. Results: Changes in BMI were not significant different among groups. The LPPG group had significantly higher albumin than the LDG group at postoperative 6 months and 1 year. The LPPG group had higher total protein than the LDG group at postoperative 2 years. The LPPG group had a higher complication rate of Clavien-Dindo classification III or higher (20.6%) than the LDG group (8.2%, P = 0.007). However, after excluding pyloric stenosis, there was no significant difference among groups (LPPG vs. LDG, P = 0.290; LPPG vs. LDG B-II, P = 0.921). Conclusion: LPPG and LDG groups showed similar weight loss. However, the LPPG group had higher albumin and protein levels than the LDG group of overweight patients. Thus, it is not necessary to select LDG only for weight loss. LPPG may be selected as one option due to its potential nutritional benefit when pyloric stenosis is properly managed.

The Clinicopathological Features of Mixed Carcinoma in 7,215 Patients with Gastric Cancer in a Tertiary Hospital in South Korea.

Background/Aims: There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients. Methods: A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (well-moderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC. Results: The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance. Conclusions: Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).