Real-world Nationwide Outcomes of Minimally Invasive Surgery for Advanced Gastric Cancer Based on Korean Gastric Cancer Association-Led Survey.

PURPOSE: The study aimed to investigate real-world surgical outcomes of minimally invasive surgery (MIS) for advanced gastric cancer using Korean Gastric Cancer Association (KGCA)-led nationwide data. MATERIALS AND METHODS: A nationwide survey of patients who underwent surgical treatment for gastric cancer in 2019 was conducted by the KGCA. A total of 14,076 patients from 68 institutions underwent surgery, and 4,953 patients diagnosed with pathological stages IB-III gastric cancer were included. Among them, 1,689 patients who underwent MIS (MIS group) and 1,689 who underwent the open approach (open group) were matched using propensity score in a 1:1 ratio. Surgical outcomes were compared, and multivariate analysis was performed to identify the independent factors for overall morbidity. RESULTS: The MIS group had a lower proportion of D2 lymphadenectomy, total omentectomy, and combined resection. However, the number of harvested lymph nodes was higher in the MIS group. Better surgical outcomes, including less blood loss and shorter hospital stay, were observed in the MIS group, and the overall morbidity rate was significantly lower in the MIS group (17.5% vs. 21.9%, P=0.001). The mortality rates did not differ significantly between the 2 groups. In the multivariate analysis, the minimally invasive approach was a significant protective factor against overall morbidity (odds ratio, 0.799; P=0.006). CONCLUSIONS: Based on the Korean nationwide data, MIS for stage IB-III gastric cancer had better short-term outcomes than the open approach, including lower rates of wound complications, intra-abdominal abscesses, and cardiac problems.

Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

BACKGROUND: During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. METHODS: A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-µm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. RESULTS: Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). CONCLUSIONS: The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Clinical Efficacy of Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: 5-year Results of the SENORITA Trial.

OBJECTIVE: This study aimed to compare laparoscopic standard gastrectomy (LSG) and laparoscopic sentinel node navigation surgery (LSNNS) for EGC in terms of 5-year long-term oncologic outcomes. SUMMARY BACKGROUND DATA: The oncological safety of LSNNS for early gastric cancer (EGC) has not been confirmed. Three-year disease-free survival (DFS), which is the primary endpoint of the phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial), did not show the non-inferiority of LSNNS relative to LSG. METHODS: The SENORITA trial, a multicenter randomized clinical trial, was designed to show that LSNNS is non-inferior to LSG in terms of 3-year DFS. In the present study, we collected 5-year follow-up data from 527 patients recruited in the SENORITA trial as the full analysis set (FAS). Disease-free survival (DFS), overall survival (OS), disease-specific survival (DSS), and recurrence patterns were evaluated using the FAS of both LSG (n=269) and LSNNS (n=258). RESULTS: The 5-year DFS was not significantly different between the LSG and LSNNS groups (P=0.0561). During the 5-year follow-up, gastric cancer-related events, such as metachronous cancer, were more frequent in the LSNNS group than in the LSG group. However, ten recurrent cancers in the remnant stomach of both groups were curatively resected by additional gastrectomy and one by additional endoscopic resection. Two of the 198 patients who underwent local resection for stomach preservation based on the LSNNS results developed distant metastasis. However, there was no statistically significant difference in the 5-year OS and DSS (P=0.7403 and P=0.9586, respectively) between the two groups. CONCLUSION: The 5-year DFS, DSS and OS did not differ significantly between the two groups. Considering the benefits of LSNNS on postoperative quality of life, LSNNS could be recommended as an alternative treatment option for EGC.

Real-World Compliance of Surgical Treatment According to the Korean Gastric Cancer Guideline 2018: Evaluation From the Nationwide Survey Data 2019 in Korea.

PURPOSE: This study evaluated real-world compliance with surgical treatment according to Korea's gastric cancer treatment guidelines. MATERIALS AND METHODS: The 2018 Korean Gastric Cancer Treatment Guidelines were evaluated using the 2019 national survey data for surgically treated gastric cancer based on postoperative pathological results in Korea. In addition, the changes in surgical treatments in 2019 were compared with those in the 2014 national survey data implemented before the publication of the guidelines in 2018. The compliance rate was evaluated according to the algorithm recommended in the 2018 Korean guidelines. RESULTS: The overall compliance rates in 2019 were 83% for gastric resection extent, 87% for lymph node dissection, 100% for surgical approach, and 83% for adjuvant chemotherapy, similar to 2014. Among patients with pathologic stages IB, II, and III disease who underwent total gastrectomy, the incidence of splenectomy was 8.08%, a practice not recommended by the guidelines. The survey findings revealed that 48.66% of the patients who underwent gastrectomy had pathological stage IV disease, which was not recommended by the 2019 guidelines. Compared to that in 2014, the rate of gastrectomy in stage IV patients was 54.53% in 2014. Compliance rates were similar across all regions of Korea, except for gastrectomy in patients with stage IV disease. CONCLUSIONS: Real-world compliance with gastric cancer treatment guidelines was relatively high in Korea.

Long-term Functional and Patient-reported Outcomes Between Intra-corporeal Delta-shaped Gastroduodenostomy and Gastrojejunostomy After Laparoscopic Distal Gastrectomy.

PURPOSE: This study aimed to compare the long-term functional and patient-reported outcomes between intra-corporeal delta-shaped gastroduodenostomy and gastrojejunostomy after laparoscopic distal gastrectomy for gastric cancer. MATERIALS AND METHODS: We retrospectively reviewed clinicopathological data from 616 patients who had undergone laparoscopic distal gastrectomy for stage I gastric cancer between January 2015 and September 2020. Among them, 232 patients who had undergone delta-shaped anastomosis and another 232 who had undergone Billroth II anastomosis were matched using propensity scores. Confounding variables included age, sex, body mass index, physical status classification, tumor location, and T classification. Postoperative complications, nutritional outcomes, endoscopic findings, and quality of life (QoL) were compared between the 2 groups. RESULTS: No significant differences in postoperative complications or nutritional parameters between the two groups were observed. Annual endoscopic findings revealed more residual food and less bile reflux in the delta group (P<0.001) than in the Billroth II group. Changes of QoL were significantly different regarding emotional function, insomnia, diarrhea, reflux symptoms, and dry mouth (P=0.007, P=0.002, P=0.013, P=0.001, and P=0.03, respectively). Among them, the delta group had worse insomnia, reflux symptoms, and dry mouth within three months postoperatively. CONCLUSIONS: Long-term nutritional outcomes and QoL were comparable between the delta and Billroth II groups. However, more residual food and worse short-term QoL regarding insomnia, reflux symptoms, and dry mouth were observed in the delta group. Longer fasting time before endoscopic evaluation and short-term symptom management would have been helpful for the delta group.

Effect of Vitamin B12 Replacement Intervals on Clinical Symptoms and Laboratory Findings in Gastric Cancer Patients after Total Gastrectomy.

The management of patients with vitamin B12 deficiency after total gastrectomy (TG) remains controversial. We aimed to evaluate the effect of vitamin B12 replacement intervals on the clinical characteristics in these patients. The data from patients who received vitamin B12 supplementation after TG between 2007 and 2018 at the National Cancer Center, Korea, were retrospectively evaluated. Vitamin B12 deficiency was defined as a serum vitamin B12 level of <200 pg/mL or urine methylmalonic acid level > 3.8 mg/gCr. The patients were divided into a regular replacement group (patients received an intramuscular injection or oral medication regularly), and a lab-based replacement group (patients received vitamin B12 intermittently after checking the level). The symptoms and biochemical parameters were compared between these groups. The regular and lab-based replacement groups included 190 and 216 patients, respectively. The median vitamin B12 replacement intervals were 1 and 9 months, respectively (p < 0.001). After replacement, the regular replacement group had higher vitamin B12 levels than the lab-based replacement group (p < 0.001). However, the serum hemoglobin level showed no significant changes. After replacement, there was no significant difference in the proportion of the symptomatic patients between the groups. Replacing vitamin B12 with a lab-based protocol may be sufficient for TG patients.

Exploring Connections between Oral Microbiota, Short-Chain Fatty Acids, and Specific Cancer Types: A Study of Oral Cancer, Head and Neck Cancer, Pancreatic Cancer, and Gastric Cancer.

The association between oral microbiota and cancer development has been a topic of intense research in recent years, with compelling evidence suggesting that the oral microbiome may play a significant role in cancer initiation and progression. However, the causal connections between the two remain a subject of debate, and the underlying mechanisms are not fully understood. In this case-control study, we aimed to identify common oral microbiota associated with several cancer types and investigate the potential mechanisms that may trigger immune responses and initiate cancer upon cytokine secretion. Saliva and blood samples were collected from 309 adult cancer patients and 745 healthy controls to analyze the oral microbiome and the mechanisms involved in cancer initiation. Machine learning techniques revealed that six bacterial genera were associated with cancer. The abundance of Leuconostoc, Streptococcus, Abiotrophia, and Prevotella was reduced in the cancer group, while abundance of Haemophilus and Neisseria enhanced. G protein-coupled receptor kinase, H+-transporting ATPase, and futalosine hydrolase were found significantly enriched in the cancer group. Total short-chain fatty acid (SCFAs) concentrations and free fatty acid receptor 2 (FFAR2) expression levels were greater in the control group when compared with the cancer group, while serum tumor necrosis factor alpha induced protein 8 (TNFAIP8), interleukin-6 (IL6), and signal transducer and activator of transcription 3 (STAT3) levels were higher in the cancer group when compared with the control group. These results suggested that the alterations in the composition of oral microbiota can contribute to a reduction in SCFAs and FFAR2 expression that may initiate an inflammatory response through the upregulation of TNFAIP8 and the IL-6/STAT3 pathway, which could ultimately increase the risk of cancer onset.

Predictive Value of KLASS-02-QC Assessment Score on KLASS-02 Surgical Outcomes: Validation of Surgeon Quality Control and Standardization for D2 Lymphadenectomy.

OBJECTIVE: The aim of this study was to audit the 22 items and assessed each item's predictive value on surgical outcomes. BACKGROUND: The KLASS-02 trial revealed that the oncologic outcomes of laparoscopic distal gastrectomy are not inferior to open distal gastrectomy in patients with advanced gastric cancer. The surgeons participating in this trial were chosen based on the assessment scores from the KLASS-02-QC trial, which used 22 items for standardization of D2 lymphadenectomy and quality control. METHODS: We reviewed proficiency scores (PSs) for 22 items for 20 surgeons who participated in KLASS-02. The surgeons were divided into 2 groups according to PS, and the perioperative outcomes of 924 patients enrolled in KLASS-02 were compared between groups. Each item's predictive value for perioperative outcome was then assessed using multivariable regression models. RESULTS: Of the total 924 patients, 529 were operated on by high-score surgeons (high PS) and 395 were operated on by low-score surgeons (low-PS). High-PS group had less intraoperative blood loss, longer operation times, and fewer complications, major complications, reoperations, and shorter first flatus and hospital stay than low-PS group ( P =0.006, P <0.001, P <0.001, P <0.001, P =0.042, P =0.013, and P <0.001, respectively). Some items used in KLASS-02-QC predicted perioperative outcomes, such as intraoperative blood loss, major complications, reoperation, and hospital stay. CONCLUSIONS: Although this study only analyzed data associated with qualified surgeons, the 22 items effectively assessed the surgeons based on PS. A high score was associated with longer operation times, but better perioperative outcomes.

Standard follow-up after curative surgery for advanced gastric cancer: secondary analysis of a multicentre randomized clinical trial (KLASS-02).

BACKGROUND: The benefit of regular follow-up after curative resection for gastric cancer is controversial as there is no evidence that it will improve survival. This study assessed whether regular follow-up leads to improved survival in patients after surgery for gastric cancer. METHODS: A secondary analysis was undertaken of patients who participated in an RCT of laparoscopic versus open distal gastrectomy for advanced gastric cancer between November 2011 and April 2015. Depending on whether patients were compliant with the initial trial follow-up protocol or not, they were analysed as having had either regular or irregular follow-up. Clinicopathological characteristics, recurrence patterns, detection, treatments, and survival were compared between the groups. RESULTS: The regular and irregular follow-up groups comprised 712 and 263 patients respectively. Disease recurrence within 36 months was more common in the regular group than in the irregular group (17.0 versus 11.4 per cent; P = 0.041). Recurrence patterns did not differ between the groups. The 3-year recurrence-free survival rate was worse in the regular than in the irregular group (81.2 versus 86.5 per cent; P = 0.031). However, the 5-year overall survival rate was comparable (84.5 versus 87.5 per cent respectively; P = 0.160). Multivariable analysis revealed that type of follow-up was not an independent factor affecting 5-year overall survival. CONCLUSION: Regular follow-up after radical gastrectomy was not associated with improved overall survival.

Determining the precise extent of sentinel basins during laparoscopic gastrectomy for early gastric cancer.

PURPOSE: By analyzing sentinel basin dissection (SBD) data from the SEntinel Node ORIented Tailored Approach (SENORITA) trial, we sought to determine the precise extent of the sentinel basin (SB) without a tracer. MATERIALS AND METHODS: This study investigated SB length in patients (n = 25) who underwent laparoscopic SBD for early gastric cancer (EGC) in the SENORITA trial. SB length along the greater curvature (GC) and lesser curvature (LC) was measured intraoperatively before performing SBD. RESULTS: In all 25 cases, along the LC of the stomach, the lengths of the SB were 3.7 cm [2.0-5.0] (median [min-max]) proximally and 3.0 cm [2.3-5.5] distally; along the GC side, the lengths of the SB were 6.8 cm [3.5-11.0] proximally and 7.0 cm [3.8-9.5] distally from the tumors. The SB length at the GC or LC side was not significantly different between subgroups categorized by tumor depth, size, and longitudinal location. When tumors were located at the anterior wall of the stomach, the length of the proximal SB (10.0 cm [9.0-11.0]) at the GC side was the longest. In cases with several sentinel lymph nodes (SLNs), the lengths of the SB at the GC side were significantly longer than those with fewer SLNs. However, the lengths of the SB were similar on the LC side regardless of the number of SLNs. CONCLUSIONS: This pilot study had some limitations of a small number of enrolled patients, the lack of research on the specific station of SLNs, and the inaccurate indication for sentinel node navigation surgery (SNNS) without tracer. Nevertheless, the present study which reported the extents of SBs might be the first step towards simplifying procedures in laparoscopic SNNS for stomach preservation in EGC.

Risk prediction model of peritoneal seeding in advanced gastric cancer: A decision tool for diagnostic laparoscopy.

BACKGROUND: Selective diagnostic laparoscopy in gastric cancer patients at high risk of peritoneal metastasis is essential for optimal treatment planning. In this study available clinicopathologic factors predictive of peritoneal seeding in advanced gastric cancer (AGC) were identified, and this information was translated into a clinically useful tool. METHODS: Totally 2833 patients underwent surgery for AGC between 2003 and 2013. The study identified clinicopathologic factors associated with the risk of peritoneal seeding for constructing nomograms using a multivariate logistic regression model with backward elimination. A nomogram was constructed to generate a numerical value indicating risk. Accuracy was validated using bootstrapping and cross-validation. RESULTS: The proportion of seeding positive was 12.7% in females and 9.6% in males. Of 2833 patients who underwent surgery for AGC, 300 (10.6%) were intraoperatively identified with peritoneal seeding. Multivariate analysis revealed the following factors associated with peritoneal seeding: high American Society of Anesthesiologists score, fibrinogen, Borrmann type 3 or 4 tumors, the involvement of the middle, anterior, and greater curvature, cT3 or cT4cN1 or cN2 or cN3, cM1, and the presence of ascites or peritoneal thickening or plaque or a nodule on the peritoneal wall on computed tomography. The bootstrap analysis revealed a robust concordance between mean and final parameter estimates. The area under the ROC curve for the final model was 0.856 (95% CI, 0.835-0.877), which implies good performance. CONCLUSIONS: This nomogram provides effective risk estimates of peritoneal seeding from gastric cancer and can facilitate individualized decision-making regarding the selective use of diagnostic laparoscopy.

Gastric cancer surgery in South Korea: Past, present, and future.

Gastric cancer remains a significant global health concern and its surgical management approaches have undergone significant changes in South Korea and worldwide. Subtotal or total gastrectomy with D2 lymph node dissection is well established as a standard surgical procedure for gastric cancer. With the active implementation of cancer screening in South Korea, the proportion of early gastric cancer cases has significantly increased over the past few decades, leading to a steady increase in the survival rate among patients. Furthermore, recent advances in surgical instruments and techniques have made minimally invasive surgery increasingly prevalent, not only for early but also for advanced gastric cancer. We aim to provide a comprehensive overview of the evolution and current status of gastric cancer surgery in South Korea.

Endoscopic submucosal dissection for papillary early gastric carcinoma: Insights from a large-scale analysis of post-gastrectomy pathology specimens.

Gastric papillary adenocarcinoma is considered a differentiated adenocarcinoma in the current endoscopic submucosal dissection indication guidelines. However, the safety of endoscopic submucosal dissection remains controversial. Currently, data regarding which papillary early gastric cancer should be considered for endoscopic submucosal dissection are unavailable. Thus, the aim of this study was to investigate lymph node metastasis and the safety of endoscopic submucosal dissection in patients with papillary early gastric cancer. This observational study recruited 4264 consecutive patients with early gastric cancer who underwent curative gastrectomy between October 2000 and December 2017 at the National Cancer Center, Korea. Of these, 45 had pathologically confirmed papillary early gastric cancer, 2106 had differentiated non-papillary early gastric cancer, and 2113 had undifferentiated early gastric cancer. Logistic regression analysis was performed to identify risk factors for lymph node metastasis. Mucosal tumors were less common in papillary early gastric cancer (37.9%) than in differentiated non-papillary early gastric cancer (48.8%) and undifferentiated early gastric cancer (60.4%) (both P < .001). Lymph node metastasis was more common in papillary early gastric cancer (20.0%) than in differentiated non-papillary early gastric cancer (9.2%) and undifferentiated early gastric cancer (11.7%; both P < .001). In multivariate analysis, non-mixed-type papillary early gastric cancer showed marginally increased odds of lymph node metastasis than differentiated early gastric cancer (odds ratio [OR]: 2.5, 95% confidence interval [CI]: 1.0-6.3). Rates of lymph node metastasis (1/10, 10%) and angiolymphatic invasion (2/10, 20%) for papillary early gastric cancer meeting expanded criteria were higher than those for other histology types meeting endoscopic submucosal dissection absolute or expanded criteria (P = .03 and P < .001, respectively). Endoscopic submucosal dissection should be considered carefully for papillary early gastric cancer, especially if it meets expanded endoscopic submucosal dissection indications since it is associated with high rates of submucosal invasion and lymph node metastasis.

An early interactive human coaching via a mobile application to improve quality of life in patients who underwent gastrectomy for gastric cancer: Design and protocol of a randomized controlled trial.

BACKGROUND: After gastrectomy, patients may experience the postgastrectomy syndrome and face difficulties adapting to everyday diet. Recently, human health coaching via a mobile application (app) has been used for obese patients or patients with chronic diseases, with significant improvements in clinical outcomes. The aim of this study is to evaluate and compare the effects of human health coaching via a mobile app and conventional face-to-face counseling in patients who underwent gastrectomy for gastric cancers. METHODS: This study is a single-institution, prospective randomized controlled trial comparing the mobile health and face-to-face counselling groups. After randomization, participants assigned to the mobile health coaching group will receive health coaching via a mobile app for 3 months after discharge, and the assigned coaches will provide personalized advice based on the self-recorded health data. Participants in the face-to-face group will have 1- and 3-months postoperative dietary consultations with a clinical dietitian. The primary endpoint is the food restriction score on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-STO22, and secondary endpoints included all other quality of life scale scores and nutritional parameters. The calculated sample size is 180, and the outcomes will be measured until 1-year post-surgery. SIGNIFICANCE: This study will show the efficacy of human health coaching via a mobile app on dietary adaptation in patients who underwent gastrectomy. A relational approach based on personal data and timely intervention using a mobile platform could reduce patients' trial and error and improve quality of life. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04394585, Registered 19 May, 2020 -Retrospectively registered, http://clinicaltrials.gov/ct2/show/NCT040394585.

Accuracy of preoperative clinical staging for locally advanced gastric cancer in KLASS-02 randomized clinical trial.

Purpose: The discrepancy between preoperative and final pathological staging has been a long-standing challenge for the application of clinical trials or appropriate treatment options. This study aimed to demonstrate the accuracy of preoperative staging of locally advanced gastric cancer using data from a large-scale randomized clinical trial. Materials and methods: Of the 1050 patients enrolled in the clinical trial, 26 were excluded due to withdrawal of consent (n = 20) or non-surgery (n = 6). The clinical and pathological staging was compared. Risk factor analysis for underestimation was performed using univariate and multivariate analyses. Results: Regarding T staging by computed tomography, accuracy rates were 74.48, 61.62, 58.56, and 85.16% for T1, T2, T3 and T4a, respectively. Multivariate analysis for underestimation of T staging revealed that younger age, ulcerative gross type, circular location, larger tumor size, and undifferentiated histology were independent risk factors. Regarding nodal status estimation, 54.9% of patients with clinical N0 disease were pathologic N0, and 36.4% of patients were revealed to have pathologic N0 among clinical node-positive patients. The percentage of metastasis involvement at the D1, D1+, and D2 lymph node stations significantly increased with the advanced clinical N stage. Among all patients, 29 (2.8%), including 26 with peritoneal seeding, exhibited distant metastases. Conclusions: Estimating the exact pathologic staging remains challenging. A thorough evaluation is mandatory before treatment selection or trial enrollment. Moreover, we need to set a sufficient case number when we design the clinical trial considering the stage migration.

Risks and benefits of additional surgery for early gastric cancer in the upper third of the stomach meeting non-curative resection criteria after endoscopic submucosal dissection.

BACKGROUND: Additional surgery is recommended after non-curative endoscopic submucosal dissection for early gastric cancer. However, it is not easy to recommend for tumors located in the upper third of the stomach, because it would be a total or proximal gastrectomy. This study aimed to evaluate the actual risks and benefits of additional gastrectomy for upper third tumors. METHODS: We reviewed the clinicopathological data of patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach between March 2002 and January 2021. The incidence of lymph node metastasis and postoperative complications were calculated, and risk factors for lymph node metastasis were identified using logistic regression analysis. Survival rates were analyzed using the Kaplan-Meier method and log-rank test. RESULTS: A total of 523 patients underwent total or proximal gastrectomy for early gastric cancer; 379 of them had tumors meeting the non-curative resection criteria for endoscopic submucosal dissection. The overall lymph node metastasis rate was 9.5%, and lymphovascular invasion was the only significant risk factor for lymph node metastasis (p < 0.001). The most common sites of lymph node metastasis were stations 1, 3, and 7, with their rates being 3.2%, 3.7%, and 3.2%, respectively. Overall and severe (Clavien-Dindo grade III or higher) postoperative complication rates were 21.1% and 14.0%, respectively, while postoperative mortality was 0.5% (2/379). The 5-year overall survival rates for patients with and without lymph node metastasis were 96.1% and 81.1%, respectively (p = 0.076). CONCLUSIONS: Before planning an additional gastrectomy after non-curative endoscopic resection for the upper third tumor, we should consider both the benefit of the 9.5% curability for lymph node metastasis and the risks of the 21% postoperative complications and 0.5% mortality.

Prognostic Value of Preoperative Systemic Inflammatory Parameters in Advanced Gastric Cancer.

BACKGROUND: The predictive value of various systemic inflammatory parameters has been reported. However, it is still unclear which inflammatory parameters are the best predictors of prognosis in advanced gastric cancer and what are their mechanisms of action. The aim of this study was to evaluate the association between preoperative systemic inflammatory parameters and overall survival (OS) in patients with advanced gastric cancer. METHODS: This retrospective study included 489 patients with stage II/III advanced gastric cancer treated at the National Cancer Center, Republic of Korea, between January 2012 and December 2015. We divided the patients into survivors and non-survivors and compared their clinicopathological characteristics. Univariate and multivariate analyses using the Cox proportional hazards model were performed to evaluate the prognostic value of inflammatory parameters. RESULTS: The absolute lymphocyte count was significantly higher in survivors (2.07 ± 0.62 × 103/µL vs. 1.88 ± 0.63 × 103/µL, p = 0.001). The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) were marginally lower in survivors. Survival analysis revealed that the NLR and PLR were independent prognostic factors for OS. Survival was significantly different depending on NLR and PLR in the same pathologic stages. CONCLUSIONS: NLR and PLR were independent prognostic factors for OS in patients with advanced gastric cancer. Regarding single inflammatory parameters, an elevated lymphocyte count was the only factor associated with a favorable prognosis. These results suggest that the enhanced immune function of patients affects their prognosis more than the increased systemic inflammatory response.

Postoperative Complications and Their Risk Factors of Completion Total Gastrectomy for Remnant Gastric Cancer Following an Initial Gastrectomy for Cancer.

PURPOSE: Completion total gastrectomy (CTG) for remnant gastric cancer (RGC) is a technically demanding procedure and associated with increased morbidity. The present study aimed to evaluate postoperative complications and their risk factors following surgery for RGC after initial partial gastrectomy due to gastric cancer excluding peptic ulcer. MATERIALS AND METHODS: We retrospectively reviewed the data of 107 patients who had previously undergone an initial gastric cancer surgery and subsequently underwent CTG for RGC between March 2002 and December 2020. The postoperative complications were graded using the Clavien-Dindo classification. Logistic regression analyses were used to determine the risk factors for complications. RESULTS: Postoperative complications occurred in 34.6% (37/107) of the patients. Intra-abdominal abscess was the most common complication. The significant risk factors for overall complications were multi-visceral resections, longer operation time, and high estimated blood loss in the univariate analysis. The independent risk factors were multi-visceral resection (odds ratio [OR], 2.832; 95% confidence interval [CI], 1.094-7.333; P=0.032) and longer operation time (OR, 1.005; 95% CI, 1.001-1.011; P=0.036) in the multivariate analysis. Previous reconstruction type, minimally invasive approach, and current stage were not associated with the overall complications. CONCLUSIONS: Multi-visceral resection and long operation time were significant risk factors for the occurrence of complications following CTG rather than the RGC stage or surgical approach. When multi-visceral resection is required, a more meticulous surgical procedure is warranted to improve the postoperative complications during CTG for RGC after an initial gastric cancer surgery.

Necessity of Individualized Approach for Gastric Subepithelial Tumor Considering Pathologic Discrepancy and Surgical Difficulty Depending on the Gastric Location.

Background: Depending on the location of gastric subepithelial tumors (SETs), surgical access is difficult with a risk of postoperative complications. This study aimed to evaluate the clinicopathological characteristics of small-sized gastric SETs and their surgical outcomes depending on location and provide considering factors for their treatment plans. Methods: This single-center, retrospective study reviewed patients who underwent surgical resection for gastric SETs (size < 5 cm). SETs were divided into benign SETs and gastrointestinal stromal tumors (GISTs) for comparison. The clinicopathological characteristics of SETs in the cardia were compared to those in the other regions. Results: Overall, 191 patients with gastric SETs (135 GISTs, 70.7%; and 56 benign SETs, 29.3%) were included. In multivariate analysis, age > 65 years (odds ratio (OR), 3.183; 95% confidence interval (CI), 1.310−7.735; p = 0.011), and non-cardiac SETs (OR, 2.472; 95% CI, 1.110−5.507; p = 0.030) were associated with a significant risk of malignancy. Compared to SETs in other locations, cardiac SETs showed more complications (3 versus 0; p = 0.000), and open conversion rates (2 versus 0; p = 0.003). However, the proportion of GISTs of SETs in the cardia is not negligible (52.9%). Conclusions: Considering the malignancy risk of SETs, active surgical resection should be considered in old age and/or location in the non-cardiac area. However, in young patients, SETs located in the gastric cardia have a considerably benign nature and are associated with poor short-term surgical outcomes. An individualized surgical approach for asymptomatic small SETs according to the gastric location is warranted.

Laparoscopic vs Open Distal Gastrectomy for Locally Advanced Gastric Cancer: 5-Year Outcomes of the KLASS-02 Randomized Clinical Trial.

Importance: The long-term safety of laparoscopic distal gastrectomy for locally advanced gastric cancer (AGC) remains uncertain given the lack of 5-year follow-up results. Objective: To compare the 5-year follow-up results in patients with clinically AGC enrolled in the Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-02 randomized clinical trial who underwent laparoscopic or open distal gastrectomy. Design, Setting, and Participants: The KLASS-02, a multicenter randomized clinical trial, showed that laparoscopic surgery was noninferior to open surgery for patients with locally AGC. The present study assessed the 5-year follow-up results, including 5-year overall survival (OS) and relapse-free survival (RFS) rates and long-term complications, in patients enrolled in KLASS-02. From November 21, 2011, to April 29, 2015, patients aged 20 to 80 years diagnosed preoperatively with locally AGC were enrolled. Final follow-up was on June 15, 2021. Data were analyzed June 24 to September 9, 2021. Interventions: Patients were treated with R0 resection either by laparoscopic gastrectomy or open gastrectomy as the full analysis set of the KLASS-02 trial. Main Outcomes and Measures: Five-year OS and RFS rates, recurrence patterns, and long-term surgical complications were evaluated. Results: This study enrolled a total of 1050 patients. A total of 974 patients were treated with R0 resection; 492 (50.5%) in the laparoscopic gastrectomy group (mean [SD] age, 59.8 [11.0] years; 351 men [71.3%]) and 482 (49.5%) in the open gastrectomy group (mean [SD] age, 59.4 [11.5] years; 335 men [69.5%]). In patients who underwent laparoscopic and open distal gastrectomy, the 5-year OS (88.9% vs 88.7%) and RFS (79.5% vs 81.1%) rates did not differ significantly. The most common types of recurrence were peritoneal carcinomatosis (73 of 173 [42.1%]), hematogenous metastases (36 of 173 [20.8%]), and locoregional recurrence (23 of 173 [13.2%]), with no between-group differences in types of recurrence at each cancer stage. The correlation between 3-year RFS and 5-year OS at the individual level was highest in patients with stage III gastric cancer (ρ = 0.720). The late complication rate was significantly lower in the laparoscopic than in the open surgery group (32 of 492 [6.5%] vs 53 of 482 [11.0%]). The most common type of complication in both groups was intestinal obstruction (13 of 492 [2.6%] vs 24 of 482 [5.0%]). Conclusions and Relevance: The 5-year outcomes of the KLASS-02 trial support the 3-year results, which is the noninferiority of laparoscopic surgery compared with open gastrectomy for locally AGC. The laparoscopic approach can be recommended in patients with locally AGC to achieve the benefit of low incidence of late complications. Trial Registration: ClinicalTrials.gov Identifier: NCT01456598.