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Abstract Background The current gastric cancer staging system relies on the number of metastatic lymph nodes (MLNs) for nodal stage determination. However, incorporating additional information such as topographic status may help address uncertainties. This study evaluated the appropriateness of the current staging system and relative significance of MLNs based on their anatomical location. Methods Patients who underwent curative gastrectomy for gastric cancer between 2000 and 2019 at six Catholic Medical Center-affiliated hospitals were included. Lymph node-positive patients were classified into the perigastric (stations 1–6, group P) or extragastric (stations 7–12) groups. The extragastric group was further subdivided into the near-extragastric (stations 7–9, group NE) and far-extragastric (stations 10–12, group FE) groups. Results We analyzed the data of 3,591 patients with positive lymph node metastases. No significant survival differences were found between group P and the extragastric group in each N stage. However, in N1 and N2, group FE showed significantly worse survival than the other groups (p = 0.013 for N1, p

Abstract Splenic hilar (no.10) lymph node dissection during total gastrectomy is no longer recommended for advanced proximal gastric cancer. However, the treatment efficacy of no.10 lymph node dissection in Borrmann type 4 tumors remains unclear. We enrolled 539 patients who underwent total gastrectomy for Borrmann type 4 tumors between 2006 and 2016 in four major institutions in Korea. We compared the long-term survival of the no.10 lymph node dissection (n = 309) and no-dissection groups (n = 230) using the propensity score (inverse probability of treatment weighting). The treatment effects of no.10 lymph node dissection were estimated in the weighted sample using the Cox proportional hazards regression model with a robust sandwich-type variance estimator. After inverse probability of treatment weighting, there were 540.4 patients in the no.10 lymph node dissection group and 532.7 in the no-dissection group. The two groups showed well-balanced baseline characteristics, including tumor node metastasis stage. The 5-year survival rates in the no.10 lymph node dissection and no-dissection groups were 45.7% and 38.6%, respectively (log-rank p = 0.036, hazard ratio 0.786, 95% confidence interval 0.630–0.982). Multivariate analysis revealed that no.10 lymph node dissection was an independent favorable prognostic factor (adjusted hazard ratio 0.747, 95% confidence interval 0.593–0.940) after adjusting for other prognostic factors. Sensitivity analyses in other inverse probability of treatment weighting models and the propensity score matching model showed similar results. Patients undergoing no.10 lymph node dissection showed improved survival compared to those without. No.10 lymph node dissection is recommended during total gastrectomy for patients with Borrmann type 4 gastric cancer.

Abstract Background Weight changes after gastrectomy affect not only quality of life but also prognosis and survival. However, it remains challenging to predict the weight changes of individual patients. Using clinicopathological variables, we built a user-friendly tool to predict weight change after curative gastrectomy for gastric cancer. Methods The clinical data of 984 patients who underwent curative gastrectomy between 2009 and 2013 were retrospectively reviewed and analyzed. Multivariate logistic regression was performed to identify variables predictive of postoperative weight change. A nomogram was developed and verified via bootstrap resampling. Results Age, sex, performance status, body mass index, extent of resection, pathological stage, and postoperative weight change significantly influenced postoperative weight recovery. Postoperative levels of hemoglobin, albumin, ferritin and total iron-binding capacity were significant covariates. The nomogram performed well (concordance index = 0.637); calibration curves indicated appropriate levels of agreement. We developed an online weight prediction calculator based on the nomogram ( http://gc-weightchange.com/en/front/ ). Conclusions The novel, Web-calculator based on the predictive model allows surgeons to explore patient weight patterns quickly. The model identifies patients at high risk for weight loss after gastrectomy; such patients require multidisciplinary medical support.

BackgroundDe novo malignancies are major causes of death after organ transplantation because the recipients subsequently receive immunosuppressant drugs. When gastric cancer develops, the clinical course of the tumor may be particularly aggressive. However, there are few reliable studies of gastric cancer treatment after organ transplantation. This study examined the clinicopathological characteristics of gastric cancer patients after organ transplantation and evaluated treatment outcomes after gastrectomy.MethodsClinical data were collected from 54 patients who were diagnosed with gastric cancer after organ transplantation. Of these, 30 who underwent surgery for gastric cancer while on immunosuppressant medications were compared with a control group of 625 gastric cancer patients. To compensate for clinical differences between the two groups, 1:1 propensity-score matching was performed.ResultsAmong the 30 gastric cancer patients on immunosuppressants, kidney transplantation was the most common procedure (19/30, 63.3%) followed by bone marrow (6) and liver transplantation (4); among all 54 patients, 45 were on one or two immunosuppressants. Up-migration to an advanced pathological stage was more frequent in the transplant group. In multivariate analysis, transplantation was a significant risk factor for up-migration from the T, M, and final stages after surgery. When the 30 patients on immunosuppressants who underwent gastric cancer surgery were compared with the matched controls, the total incidence (30.0 vs 40.0%, P = 0.417) and the number of severe postoperative complications (16.7 vs 13.4%, P = 0.417) did not differ significantly between groups after propensity score matching. In terms of overall survival, the transplant group showed significantly worse prognosis in stages I, II, and IV (P < 0.001, P = 0.039 and 0.007, respectively).ConclusionRadical gastrectomy can be a safe oncological procedure for gastric cancer patients on immunosuppressants after transplantation. Considering their immunosuppressed condition and the possibility of underestimation of the stage of gastric cancer, early detection with endoscopic screening is needed to allow curative treatment.

Abstract The prognostic role of soluble PD-L1 (sPD-L1) and exosomal PD-L1 (exoPD-L1) in patients with gastric cancer (GC) receiving systemic chemotherapy remains unelucidated. Thus, we examined their prognostic significance in patients with advanced GC. Blood samples were obtained from 99 patients with advanced GC receiving first-line chemotherapy. Serum-derived exosomes were isolated by centrifugation and polymer precipitation. The correlation between serum-derived exoPD-L1, plasma sPD-L1, immune-related markers, and circulating immune cells was evaluated. Patients were divided into two groups according to pretreatment sPD-L1 and exoPD-L1 levels: low sPD-L1 and high sPD-L1 groups, low exoPD-L1 and high exoPD-L1 groups. Patients with low sPD-L1 level before treatment (

Background/Aims Lymphocytes are an important component of the cell-mediated immune system. As lymphopenia is reportedly associated with poor prognoses in patients with various cancers, we investigated this notion in patients who underwent curative gastrectomy. Methods We retrospectively analyzed the association between absolute lymphocyte count (ALC) and prognosis in patients with stage I–III gastric cancer who underwent curative surgical resection. Ever lymphopenic patients were defined as those with ALCs < 1,000/μL at any time post-diagnosis except within 30 days post-surgery. Adjusted multivariable regression models were used to evaluate the associations between lymphopenia and overall mortality, gastric cancer-specific mortality, and disease-free survival. Results We investigated 1,222 patients diagnosed between January 2011 and December 2015. Fifty-six patients (4.6%) were lymphopenic at diagnosis and nearly one-quarter (24.8%) were ever lymphopenic with a mean minimum ALC of 640/μL. Older age (odds ratio [OR], 1.02) and higher stage (stage III vs. I; OR, 3.01) were positively associated with ever lymphopenia. On multivariable analysis, ever lymphopenia predicted higher overall mortality (hazard ratio [HR], 1.83; p = 0.008), higher gastric cancer-specific mortality (HR, 1.58; p = 0.048), and shorter disease-free survival (HR, 1.83; p = 0.006). The 5-year gastric cancer-specific mortality rates for ever- and never lymphopenic patients were 10.9% and 3.7%, respectively; their 5-year cumulative recurrence rates were 15.1% and 4.6%, respectively. Conclusions This study demonstrate that ever lymphopenia is independent prognostic factor for overall mortality and recurrence in patients with potentially curable gastric cancer; hence, ALCs may be a biomarker for predicting the prognoses of patients with stage I–III gastric cancer who had curative gastrectomy.

Abstract Background We sought to assess the prognostic significance of lymph node ratio (LNR) and N stage in patients undergoing D2 gastrectomy and adjuvant chemotherapy, S-1, and XELOX and to compare the efficacy of them according to LNRs and N stages to evaluate the clinical impact of using LNRs compared with using N staging. Methods Patients undergoing D2 gastrectomy with adequate lymph node dissection and adjuvant chemotherapy for stage II/III gastric cancer between Mar 2011 and Dec 2016 were analysed. Of the 477 patients enrolled, 331 received S-1 and 146 received XELOX. LNR groups were segregated as 0, 0–0.1, 0.1–0.25, and > 0.25 (LNR0, 1, 2, and 3, respectively). Propensity score matching (PSM) was used to minimise potential selection bias and compare DFS and OS stratified by LNRs and N stages in the two treatment groups. Results After PSM, the sample size of each group was 110 patients, and variables were well balanced. All patients had more than 15 examined lymph nodes (median 51, range 16~124). In multivariate analysis, LNR (> 0.25) and N stage (N3) showed independent prognostic value in OS and DFS, but LNR (> 0.25) showed better prognostic value. In subgroup analysis, the LNR3 group showed better 5-year DFS (20% vs 54%; HR 0.29; p = 0.004) and 5-year OS (26% vs 67%; HR 0.28; p = 0.020) in the XELOX group. The N3 group showed better 5-year DFS (38% vs 66%; HR 0.40; p = 0.004) and 5-year OS (47% vs 71%; HR 0.45; p = 0.019) in the XELOX group. Stage IIIC showed better 5-year DFS (22% vs 57%; HR 0.32; p = 0.004) and 5-year OS (27% vs 68%; HR 0.32; p = 0.009) in the XELOX group. The LNR3 group within N3 patients showed better 5-year DFS (21% vs 55%; HR 0.31; p = 0.004) and 5-year OS (27% vs 68%; HR 0.34; p = 0.018) in the XELOX group. Conclusions LNR showed better prognostic value than N staging. LNR3, N3 and stage IIIC groups showed the superior efficacy of XELOX to that of S-1. And the LNR3 group within N3 patients showed more survival benefit from XELOX. LNR > 0.25, N3 stage and stage IIIC were the discriminant factors for selecting XELOX over S-1. Trial registration Not applicable (retrospective study).

Abstract Background KLASS (the Korean Laparoendoscopic Gastrointestinal Surgery Study) is a time-honored study group that has established laparoscopic surgery for gastrointestinal disease in Korea and has performed some important studies for the rationale of laparoscopic gastrointestinal surgery. A multi-center RCT (randomized controlled trial) to compare the quality of life (QOL) of patients undergoing totally laparoscopic distal gastrectomy (TLDG) and laparoscopy-assisted distal gastrectomy (LADG) for gastric cancer, named as KLASS 07, has been currently prepared in Korea. Methods Patients diagnosed as gastric cancer, with clinical stage IA (T1N0M0) or IB (T1N1M0 / T2N0M0) according to the 7th edition of the Americal Joint Committee on Cancer System, were randomized to receive either TLDG or LADG. For surgical quality control, the surgeons participating in this trial had to have performed at least 50 gastrectomies and at least 30 gastrectomies annually (regardless of open or laparoscopic surgery for gastric cancer). The patients who are allocated to TLDG group undergo intracorporeal anastomosis and those who are assigned to LADG undergo extracorporeal anastomosis for gastrointestinal reconstruction. Discussion Thirty-one surgeons from 26 institutions were engaged in this trial. The primary endpoint is 30-day morbidity, and secondary endpoint is QOL assessed by the questionnaire score. The KLASS 07 trial is the first multi-center RCT to investigate whether there are significant and quantifiable differences between the QOL of TLDG and LADG. The findings from this trial are expected to be the critical clues for designing the detailed procedures during laparoscopic surgery for gastric cancer. Trial registration The protocol of KLASS 07 (CKLASS 01) was registered in http://register.clinicaltrials.gov as NCT03393182 (Date of registration: January 2nd, 2018.).

Abstract Background The CD133 transmembrane protein is a well-recognized stem cell marker that has been used to isolate putative cancer stem cell populations from gastric cancers (GCs). However, the molecular features or biomarkers underlying CD133 are largely unknown in GCs. Methods We performed gene expression profiling of CD133+ and CD133- cells sorted by flow cytometry from three GC cell lines to identify the CD133 expression signatures of GC. The CD133 expression signatures were investigated across publicly available expression profiles of multiple tumor types including GC and also for their relationship with patient survival. Results The CD133 signature genes defined as 177 upregulated genes and 129 downregulated genes in CD133+ cells compared to CD133- cells were enriched with genes involving the cell cycle and cytoskeleton, implying that cancer stem cells with unlimited self-renewal play cancer-initiating roles. The CD133 expression signatures in GC expression profiles were positively correlated with those of brain tumors expressing CD133 and human embryonic stem cells, emphasizing the transcriptional similarities across stem cell-related expression signatures. We also found that these stem cell expression signatures were inversely correlated with those representing tumor infiltrating immune and stromal cells. Additionally, high CD133 expression signatures were found in intestinal subtypes and low tumor stage GCs as well as in those with microsatellite instabilities and high mutation burdens. As examined across 20 additional tumor types, both the expression signatures representing CD133 and stromal cells were unfavorable prognostic features; however, their impact were variable across tumor types. Conclusions The transcriptional activities of CD133 and those of stromal cells representing the activity of stem cells and level of epithelial-to-mesenchymal transition, respectively, may be inversely correlated with each other across multiple tumor types including GC. This relationship may be a confounding factor and should therefore be considered when evaluating the clinical relevance of stem cell-related markers.

BackgroundScreening endoscopy is considered to be the most accurate tool for early detection of gastric cancer, but it is both invasive and costly. It is therefore essential to develop cost-effective and non-invasive diagnostic tools for gastric cancer. The aim of this study is to investigate the presence of certain volatile organic compounds (VOCs) associated with gastric cancer and to survey the usefulness of VOCs as screening tools of gastric cancer.MethodsThe present study was conducted prospectively to identify the relationship between gastric cancer and specific VOCs quantified by mass spectrometry. Exhaled breath samples from a total of 43 participants were analysed. This study was approved by the Institutional Review Board of the College of Medicine, Catholic University of Korea (KC16TISI0598), and registered to clinical research information service (KCT0004356).ResultsNine VOCs differed significantly between the control and cancer patient groups. When participants were divided into control, early gastric cancer (EGC), and advanced gastric cancer (AGC) groups, seven VOCs remained significantly different. Of these, four (propanal, aceticamide, isoprene and 1,3 propanediol) showed gradual increases as cancer advanced, from normal control to EGC to AGC. In receiver operating characteristic curves for these four VOCs, the area under the curve for gastric cancer prediction was highest (0.842) when more than two VOCs were present.ConclusionsThe present study offers potential directions for non-invasive gastric cancer screening, and may inspire advanced diagnostic technologies in the era of smart home healthcare. However, despite the high accuracy, cancer-specific VOCs from several studies on different populations, and analytic methods show inconsistency, it is necessary to establish standards for each analytical method, and to validate on each population.

Abstract Background Dickkopf-1 (DKK1) is a Wnt/ß-catenin pathway antagonist related to gastric cancer (GC) carcinogenesis. However, the prognostic role of combined DKK1 and ß-catenin expression in advanced GC (AGC) is not clear. Methods In total, 158 patients with AGC who underwent gastric resection were enrolled in this study. DKK1 and ß-catenin expression was evaluated in whole tumor sections by immunohistochemistry. Results DKK1 expression was high in 73 (46.2%) patients, while ß-catenin expression was positive in 51 (32.3%) patients. The expression of DKK1 was positively correlated with that of ß-catenin (P

Purpose: To analyze the surgical trend and brief postoperative results of laparoscopic distal gastrectomy (LDG) in Korea on the basis of a multicenter cohort.Materials and Methods: Data of 812 patients who underwent LDG between January and December 2016 were collected from 14 surgeons at 7 institutions. Patients were divided into laparoscopy-assisted distal gastrectomy (LADG) group and totally laparoscopic distal gastrectomy (TLDG) group. Perioperative and clinicopathologic outcomes were compared retrospectively.Results: Among the patients [n = 222 (27.3%) LADG; n = 590 (72.7%) TLDG], there are no significant differences in patient's demographics (sex, age, body mass index, and American Society of Anesthesiologists score). Billroth-I anastomosis (84.7%) was most performed in the LADG group, but Billroth-II anastomosis (59.0%) in the TLDG group (p < 0.001). The mean operative time was longer in the TLDG group (197.3 ± 44.4 min vs. 222.0 ± 60.2 min, p < 0.001), and there was no statistical difference in the hospital stay between the two groups (9.6 ± 4.8 days vs. 8.9 ± 7.1 days, p = 0.149). There were no significant differences in morbidity and mortality between the two groups. The length of proximal margin was longer in the TLDG group (4.3 ± 3.1 cm vs. 6.0 ± 3.4 cm, p < 0.001), but the distal margin was longer in the LADG group (6.5 ± 3.7 cm vs. 5.5 ± 3.1 cm, p < 0.001). The distribution of operations among each institution was shown very heterogeneously.Conclusion: There was no significant difference related to surgical outcome between LADG and TLDG in pre-study survey prior to KLASS-07 trial. Therefore, to obtain more reliable data, well designed prospective randomized controlled study is needed.

Objective. Caveolin-1 (Cav-1), as the main component of caveolae, has complex roles in tumourigenesis in human malignancies. We investigated Cav-1 in primary and metastatic tumor cells of gastric cancer (GC) and its association with clinical outcomes. Methods. We retrieved 145 cases of GC who had undergone curative gastrectomy. The expression levels of Cav-1 was evaluated by immunohistochemistry, and its association with clinicopathological parameters and patient survival was analyzed. Results. High expression of Cav-1 protein of the GC in the stomach and metastatic lymph node was 12.4% (18/145) and 16.5% (15/91). In the multivariate analysis, tumoral Cav-1 protein in metastatic lymph node showed prognostic significance for relapse-free survival (RFS, HR, 3.934; 95% CI, 1.882–8.224; P=0.001) and cancer-specific survival outcome (CSS, HR, 2.681; 95% CI, 1.613–8.623; P=0.002). Among the GCs with metastatic lymph node, it remained as a strong indicator of poor prognosis for RFS (HR, 3.136; 95% CI, 1.444–6.810; P=0.004) and CSS (HR, 2.509; 95% CI, 1.078–5.837; P=0.032). Conclusion. High expression of tumoral Cav-1 protein in metastatic lymph node is associated with unfavorable prognosis of curative resected GC, indicating the potential of novel prognostic markers.

Backgrounds: Strong evidence is lacking as no confirmatory randomized controlled trials (RCTs) have compared the efficacy of totally laparoscopic distal gastrectomy (TLDG) with laparoscopy-assisted distal gastrectomy (LADG). The authors performed an RCT to confirm if TLDG is different from LADG. Methods: The KLASS-07 trial is a multi-centre, open-label, parallel-group, phase III, RCT of 442 patients with clinical stage I gastric cancer. Patients were enroled from 21 cancer care centres in South Korea between January 2018 and September 2020 and randomized to undergo TLDG or LADG using blocked randomization with a 1:1 allocation ratio, stratified by the participating investigators. Patients were treated through R0 resections by TLDG or LADG as the full analysis set of the KLASS-07 trial. The primary endpoint was morbidity within postoperative day 30, and the secondary endpoint was quality of life (QoL) for 1 year. This trial is registered at ClinicalTrials.gov (NCT 03393182). Results: Four hundred forty-two patients were randomized (222 to TLDG, 220 to LADG), and 422 patients were included in the pure analysis (213 and 209, respectively). The overall complication rate did not differ between the two groups (TLDG vs. LADG: 12.2% vs. 17.2%). However, TLDG provided less postoperative ileus and pulmonary complications than LADG (0.9% vs. 5.7%, P=0.006; and 0.5% vs. 4.3%, P=0.035, respectively). The QoL was better after TLDG than after LADG regarding emotional functioning at 6 months, pain at 3 months, anxiety at 3 and 6 months, and body image at 3 and 6 months (all P<0.05). However, these QoL differences were resolved at 1 year. Conclusions: The KLASS-07 trial confirmed that TLDG is not different from LADG in terms of postoperative complications but has the advantages to reduce ileus and pulmonary complications. TLDG can be a good option to offer better QoL in terms of pain, body image, emotion, and anxiety at 3-6 months. [ABSTRACT FROM AUTHOR]

Purpose: We conducted a randomized prospective trial (KLASS-07 trial) to compare laparoscopy-assisted distal gastrectomy (LADG) and totally laparoscopic distal gastrectomy (TLDG) for gastric cancer. In this interim report, we describe short-term results in terms of morbidity and mortality. Methods and Methods: The sample size was 442 participants. At the time of the interim analysis, 314 patients were enrolled and randomized. After excluding patients who did not undergo planned surgeries, we performed a modified per-protocol analysis of 151 and 145 patients in the LADG and TLDG groups, respectively. Results: The baseline characteristics, including comorbidity status, did not differ between the LADG and TLDG groups. Blood loss was somewhat higher in the LADG group, but statistical significance was not attained (76.76±72.63 vs. 62.91±65.68 mL; P=0.087). Neither the required transfusion level nor the operation or reconstruction time differed between the 2 groups. The mini-laparotomy incision in the LADG group was significantly longer than the extended umbilical incision required for specimen removal in the TLDG group (4.79±0.82 vs. 3.89±0.83 cm; P<0.001). There were no between-group differences in the time to solid food intake, hospital stay, pain score, or complications within 30 days postoperatively. No mortality was observed in either group. Conclusions: Short-term morbidity and mortality rates did not differ between the LADG and TLDG groups. The KLASS-07 trial is currently underway. [ABSTRACT FROM AUTHOR]

Purpose: Peritoneal washing cytology (PWC) is a widely used diagnostic tool for detecting peritoneal metastasis of advanced gastric cancer. However, the prognosis of patients with positive PWC remains poor even after gastrectomy, and treatments vary among institutions and eras. In this study, we identified the clinical factors that can help predict cytologypositive (CY(+)) gastric cancer. Materials and Methods: We retrospectively reviewed the national data of patients with gastric cancer from 2019, as provided by the Information Committee of the Korean Gastric Cancer Association. Of the 13,447 patients with gastric cancer, 3,672 underwent PWC. Based on cytology results, we analyzed the clinicopathological characteristics and assessed the possibility of CY(+) outcomes in relation to T and N stages. Results: Of the 3,270 patients who underwent PWC without preoperative chemotherapy, 325 were CY(+), whereas 2,945 were negative. CY(+) was more commonly observed in patients with Borrmann type IV gastric cancer, an undifferentiated histological type, and advanced pathological stages. Multivariate analysis revealed Borrmann type IV (odds ratio [OR], 1.821), tumor invasion to T3-4 (OR, 2.041), and lymph node metastasis (OR, 3.155) as independent predictors of CY(+). Furthermore, for circular tumor location, the N stage emerged as a significant risk factor for CY(+), particularly when the tumor was located on the posterior wall (PW) side. Conclusions: Lymph node metastasis significantly affects CY(+) outcomes, particularly when the tumor is located on the PW side. Therefore, PWC should be considered not only in suspected serosal exposure cases but also in cases of lymph node metastasis. [ABSTRACT FROM AUTHOR]

Backgrounds: This study aimed to compare the incidence of bile reflux, quality of life (QoL), and nutritional status among Billroth II (BII), Billroth II with Braun anastomosis (BII-B), and Roux-en-Y (RY) reconstruction after laparoscopic distal gastrectomy (LDG). Materials and Methods: We reviewed the prospective data of 397 patients from a multicentre database who underwent LDG for gastric cancer between 2018 and 2020 at 20 tertiary teaching hospitals in Korea. Postoperative endoscopic findings, QoL surveys using the European Organization for Research and Treatment of Cancer questionnaire (C30 and STO22), and nutritional and surgical outcomes were compared among groups. Results: In endoscopic findings, bile reflux was the lowest in the RY group (n=67), followed by the BII-B (n=183) and BII groups (n =147) at 1 year (3.0 vs. 67.8 vs. 84.4%, all P<0.05). The anti-reflux capability of BII-B was statistically better than that of BII, but not as perfect as that of RY. From the perspective of QoL, BII-B was not inferior to RY, but better than BII reconstruction in causing fewer STO22 reflux symptoms at 6 and 12 months. However, only RY caused fewer C30 nausea symptoms than BII at 6 and 12 months, but not BII-B. Nutritional status and morbidities were similar among the three groups, and the operative time did not differ between the BII-B and RY groups. Conclusions: BII-B cannot substitute for RY in preventing bile reflux, shortening the operative time, or reducingmorbidities. Regarding short-term QoL, BII-B was sufficient to reduce STO22 reflux symptoms but failed to reduce C30 nausea symptoms postoperatively. [ABSTRACT FROM AUTHOR]

Purpose: Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC. Materials and Methods: From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups. Results: A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and shortterm morbidity and mortality rates did not differ between the 2 groups. The 5-year relapsefree survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003). Conclusions: T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2- stage tumors. [ABSTRACT FROM AUTHOR]

The Journal of Gastric Cancer explores the use of multiple disciplinary approaches in the prevention, diagnosis, and treatment of gastric cancer. The articles in this issue discuss the benefits of a multidisciplinary approach, which integrates insights from various disciplines, such as surgical treatment and systemic therapy. The issue also highlights the role of endoscopic procedures in managing post-gastrectomy complications and explores recent advances in endoscopic techniques for early gastric cancer. Additionally, the articles discuss the importance of interdisciplinary and transdisciplinary approaches in gastric cancer research, including the use of liquid biopsy and the impact of chemotherapy and immunotherapy on the gut microbiome. The journal aims to serve as a bridge between multiple disciplines until the transdisciplinary approach becomes standard practice. [Extracted from the article]

Purpose: Reduced port surgery (RPS) for gastric cancer has been frequently reported in distal gastrectomies but rarely in total gastrectomies. This study aimed to determine the feasibility of 3-port totally laparoscopic total gastrectomy (TLTG) with overlapping esophagojejunal (EJ) anastomosis. Materials and Methods: A total of 81 patients who underwent curative TLTG for gastric cancer (36 and 45 patients with 3-port and 5-port TLTG, respectively) were evaluated. All 3-port TLTG procedures were performed with the same method as 5-port TLTG, including EJ anastomosis with the intracorporeal overlap method using a linear stapler, except for the number of ports and assistants. Short-term outcomes, including the number of lymph nodes (LNs) harvested by station and postoperative complications, were analyzed retrospectively. Results: Clinical characteristics were not significantly different among the groups, except that the 3-port TLTG group was younger and had a lower rate of pulmonary comorbidity. There were no cases of open conversion or additional port placement. All operative details and the number of harvested LNs did not differ between the groups, but the rate of suprapancreatic LN harvest was higher in the 3-port TLTG group. No significant differences were observed in the overall complication rates between the 2 groups. Conclusions: Three-port TLTG with overlapping EJ anastomoses using a linear stapler is a feasible RPS procedure for total gastrectomy to treat gastric cancer. [ABSTRACT FROM AUTHOR]

Background: There are no clear guidelines to determine whether to perform D1 or D1+ lymph node dissection in early gastric cancer (EGC). This study aimed to develop a nomogram for estimating the risk of extraperigastric lymph node metastasis (LNM). Materials and Methods: Between 2009 and 2019, a total of 4,482 patients with pathologically confirmed T1 disease at 6 affiliated hospitals were included in this study. The basic clinicopathological characteristics of the positive and negative extraperigastric LNM groups were compared. The possible risk factors were evaluated using univariate and multivariate analyses. Based on these results, a risk prediction model was developed. A nomogram predicting extraperigastric LNM was used for internal validation. Results: Multivariate analyses showed that tumor size (cut-off value 3.0 cm, odds ratio [OR]=1.886, P=0.030), tumor depth (OR=1.853 for tumors with sm2 and sm3 invasion, P=0.010), cross-sectional location (OR=0.490 for tumors located on the greater curvature, P=0.0303), differentiation (OR=0.584 for differentiated tumors, P=0.0070), and lymphovascular invasion (OR=11.125, P<0.001) are possible risk factors for extraperigastric LNM. An equation for estimating the risk of extraperigastric LNM was derived from these risk factors. The equation was internally validated by comparing the actual metastatic rate with the predicted rate, which showed good agreement. Conclusions: A nomogram for estimating the risk of extraperigastric LNM in EGC was successfully developed. Although there are some limitations to applying this model because it was developed based on pathological data, it can be optimally adapted for patients who require curative gastrectomy after endoscopic submucosal dissection. [ABSTRACT FROM AUTHOR]

The Journal of Gastric Cancer published a study on compliance with gastric cancer treatment guidelines in Eastern countries, specifically focusing on the 2018 Korean Gastric Cancer Treatment Guidelines. The study found that overall compliance with the guidelines exceeded 80% across all aspects of the nationwide survey data. This high level of compliance suggests that gastric cancer treatment in Korea is well-standardized nationwide. The study highlights the excellence of the guidelines and the importance of compliance in improving patient outcomes. [Extracted from the article]

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) is a function-preserving procedure performed for treating upper early gastric cancer (EGC). However, few studies have compared the outcomes of LPG-DTR with those of laparoscopic total gastrectomy (LTG). This study aimed at comparing the short-term outcomes of LPGDTR between LTG and upper EGC. Materials and Methods: For upper-third EGC, a multicenter, prospective, randomized trial was performed to compare those who underwent LPG-DTR with those who underwent LTG. Short-term outcomes, including clinicopathologic results, morbidity, mortality, and postoperative courses, were evaluated using a full analysis set based on the intention-to-treat principle and the per-protocol set. Results: Of the patients, 138 who fulfilled the criteria were randomized to each group. One patient in the LPG-DTR group withdrew consent. Sixty-eight patients underwent LPGDTR and 69 underwent LTG. The operative time (LPG-DTR=219.4 minutes; LTG=201.8 minutes; P=0.085), estimated blood loss (LPG-DTR=76.0 mL; LTG=66.1 mL; P=0.413), and the morbidity rate (LPG-DTR=23.5%; LTG=17.4%; P=0.373) between the groups were not significantly different. No mortality occurred in either of the study groups. Two weeks post operation, the Visick scores for postprandial symptoms, including reflux symptoms, were not significantly different between the groups (P=0.749). Laboratory findings on postoperative day 5 were not significantly different between the groups. Conclusions: The short-term outcomes of LPG-DTR for upper EGC were comparable to those of LTG. Trial Registration: ClinicalTrials.gov Identifier: NCT02892643 [ABSTRACT FROM AUTHOR]

Purpose: Tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) are standard adjuvant chemotherapies (ACs) administered after gastrectomy to patients with stage II or III gastric cancer. However, the efficacy of AC in elderly patients remains unclear. The objective of this retrospective multicenter cohort study was to compare the efficacies of S-1 and CAPOX AC in patients aged ≥70 years. Materials and Methods: Nine hundred eighty-three patients who were treated with AC using S-1 (768 patients) or CAPOX (215 patients) were enrolled in this study. Each patient underwent AC after curative gastrectomy for stage II or III gastric cancer at one of 27 hospitals in the Republic of Korea between January 2012 and December 2013. Relapse-free survival (RFS) and overall survival (OS) were analyzed according to AC regimen and age group. Results: Of the 983 patients, 254 (25.8%) were elderly. This group had a similar RFS (P=0.099) but significantly poorer OS (p=0.003) compared with the non-elderly group. Subgroup analysis of the non-elderly group revealed no AC-associated differences in survival. Subgroup analysis of the elderly group revealed significantly better survival in the S-1 group than in the CAPOX group (RFS, P<0.001; OS, P<0.001). Multivariate analysis revealed that the CAPOX regimen was an independent poor prognostic factor for RFS (hazard ratio [HR], 1.891; 95% confidence interval [CI], 1.072–3.333; P=0.028) and OS (HR, 2.970; 95% CI, 1.550–5.692; P=0.001). Conclusions: This multicenter observational cohort study found significant differences in RFS and OS between S-1 and CAPOX AC among patients with gastric cancer aged ≥70 years. [ABSTRACT FROM AUTHOR]

Purpose: The benefits of robotic gastrectomy remain controversial. We designed this study to elucidate the advantages of a hybrid robot and laparoscopic gastrectomy over conventional laparoscopic surgery. Materials and Methods: A total of 176 patients who underwent gastrectomy for gastric cancer were included in this study. We compared 88 patients treated with hybrid robotic and laparoscopic gastrectomy (HRLG) and 88 patients who underwent conventional laparoscopic gastrectomy (CLG). In HRLG, suprapancreatic lymph node (LN) dissection was performed in a robotic setting. Clinicopathological characteristics, operative details, and short-term outcomes were analyzed for the patients. Results: The number of LNs retrieved from the suprapancreatic area was significantly greater in the HRLG group (11.27±5.46 vs. 9.17±5.19, P=0.010). C-reactive protein levels were greater in the CLG group on both postoperative day (POD) 1 (5.11±2.64 vs. 4.29±2.38, P=0.030) and POD 5 (9.86±6.51 vs. 7.75±5.17, P=0.019). In addition, the neutrophil-to-lymphocyte ratio was significantly greater in the CLG group on both POD 1 (7.44±4.72 vs. 6.16±2.91, P=0.031) and POD 5 (4.87±3.75 vs. 3.81±1.87, P=0.020). Pulmonary complications occurred only in the CLG group (4/88 [4.5%] vs. 0/88 [0%], P=0.043). Conclusions: HRLG is superior to CLG in terms of suprapancreatic LN dissection and postoperative inflammatory response. [ABSTRACT FROM AUTHOR]

Purpose: With advances in surgical techniques, reduced-port laparoscopic surgery is increasingly being performed for the treatment of gastric carcinoma. Many studies have reported satisfactory short-term outcomes after reduced 3-port laparoscopic gastrectomy (LG). The aim of this study was to investigate the long-term oncological outcomes of 3-port LG in patients with gastric carcinoma. Materials and Methods: We reviewed the medical records of 1,117 patients who underwent LG for gastric carcinoma in three major institutions between 2012 and 2015. The data showed that 460 patients underwent 3-port LG without assistance, and 657 underwent conventional 5-port LG. We compared the overall and disease-free survival rates between the 2 groups. Results: There were 642 male and 475 female patients with a mean age of 56.1 years. Among them, 1,028 (92.0%) underwent distal gastrectomy and 89 (8.0%) underwent total gastrectomy. In the final pathologic examination, 1,027 patients (91.9%) were stage I, 73 (6.5%) were stage II, and 17 (1.5%) were stage III, and there were no significant difference in the pathologic stage between groups. The 3- and 5-port LG groups showed no significant differences in the 5-year overall survival (94.3% vs. 96.7%, P=0.138) or disease-free survival (94.3% vs. 95.9%, P=0.231). Stratified analyses according to pT and pN stages also showed no significant differences in overall or disease-free survival between the two groups. Conclusions: Long-term survival after 3- and 5-port LG was comparable in patients with early-stage gastric carcinoma. The 3-port technique requiring limited surgical assistance may be an appropriate surgical option for this patient population. [ABSTRACT FROM AUTHOR]

Purpose: To date, no studies have been performed on staging based on the lymph node ratio (LNR) in elderly patients with gastric cancer who may require limited lymph node (LN) dissection due to morbidity and tissue fragility. We aimed to develop a new N staging system using the LNR in elderly patients with gastric cancer. Materials and Methods: The present study included patients aged over 75 years who underwent curative gastrectomy between January 1989 and December 2018. Clinicopathological data including the number of retrieved and metastatic LNs were collected and the LNR values were obtained (LNR = the number of metastatic LNs/the number of retrieved LNs). Eleven LNR groups with intervals of 0.1 were divided into four stages based on the inflection points at which the hazard ratio (HR) increased. Survival analysis was performed to evaluate the prognostic value of the LNR. Results: The four LNR stages included LNR0 (n=364), LNR1 (n=128), LNR2 (n=103), and LNR3 (n=10). In the multivariate analysis, both N staging and LNR staging exhibited significant prognostic values for predicting survival outcomes. However, the incremental change in the hazard ratio (HR) between consecutive stages was greater for the LNR staging than for the N staging (HRs: 1.607, 2.758, and 3.675 for N staging; 1.583, 3.514, and 10.261 for LNR staging). Conclusions: LNR staging is more useful than N staging in predicting the prognosis in elderly patients with gastric cancer and may be used as a complement or alternative to N staging. [ABSTRACT FROM AUTHOR]

Purpose: Isoform 2 of tight junction protein claudin-18 (CLDN18.2) is a potential target for gastric cancer treatment. A treatment targeting CLDN18.2 has shown promising results in gastric cancer. We investigated the clinical significance of CLDN18.2 and other cell-adherens junction molecules (Rho GTPase-activating protein [RhoGAP] and E-cadherin) in metastatic diffuse-type gastric cancer (mDGC). Materials and Methods: We evaluated CLDN18.2, RhoGAP, and E-cadherin expression using two-plex immunofluorescence and quantitative data analysis of H-scores of 77 consecutive mDGC patients who received first-line platinum-based chemotherapy between March 2015 and February 2017. Results: CLDN18.2 and E-cadherin expression was significantly lower in patients with peritoneal metastasis (PM) than those without PM at the time of diagnosis (P=0.010 and 0.013, respectively), whereas it was significantly higher in patients who never developed PM from diagnosis to death than in those who did (P=0.001 and 0.003, respectively). Meanwhile, CLDN18.2 and E-cadherin expression levels were significantly higher in patients with bone metastasis than in those without bone metastasis (P=0.010 and 0.001, respectively). Moreover, we identified a positive correlation between the expression of CLDN18.2 and E-cadherin (P<0.001), RhoGAP and CLDN18.2 (P=0.004), and RhoGAP and E-cadherin (P=0.001). Conversely, CLDN18.2, RhoGAP, and E-cadherin expression was not associated with chemotherapy response and survival. Conclusions: CLDN18.2 expression was reduced in patients with PM but significantly intact in those with bone metastasis. Furthermore, CLDN18.2 expression was positively correlated with other adherens junction molecules, which is clinically associated with mDGC and PM pathogenesis. [ABSTRACT FROM AUTHOR]

Purpose: To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC). Materials and Methods: This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively. Results: The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693-4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664-1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595-85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502-5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618-3.028; P<0.001) were determined as independent prognostic factors for DFS. Conclusions: S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence. [ABSTRACT FROM AUTHOR]

The prevalence of gastroesophageal reflux disease (GERD) is increasing in Korea, and physicians, including surgeons, have been focusing on its treatment. Indeed, in Korea, medical treatment using a proton pump inhibitor is the mainstream treatment for GERD, while awareness of surgical treatment is limited. Accordingly, to promote the understanding of surgical treatment for GERD, the Korean Anti-Reflux Surgery Study Group published the Evidence-Based Practice Guideline for the Surgical Treatment of GERD. The guideline consists of 2 sections: fundamental information such as the definition, symptoms, and diagnostic tools of GERD and a recommendation statement about its surgical treatment. The recommendations presented 5 debates regarding fundoplication: 1) comparison of the effectiveness of medical and surgical treatments, 2) effectiveness of surgical treatment in cases of refractory GERD, 3) effectiveness of surgical treatment of extraesophageal symptoms, 4) comparison of effectiveness between total and partial fundoplication, and 5) effectiveness of fundoplication in cases of hiatal hernia. The present guideline is the first to demonstrate the efficacy of the surgical treatment GERD in Korea. [ABSTRACT FROM AUTHOR]

Purpose: The surgical outcomes of end-stage renal disease (ESRD) patients undergoing radical gastrectomy for gastric cancer were inferior compared with those of non-ESRD patients. This study aimed to evaluate the short- and long-term surgical outcomes of ESRD patients undergoing laparoscopic gastrectomy (LG) and open gastrectomy (OG) for gastric cancer. Materials and Methods: Between 2004 and 2014, 38 patients (OG: 21 patients, LG: 17 patients) with ESRD underwent gastrectomy for gastric cancer. Comparisons were made based on the clinicopathological characteristics, surgical outcomes, and long-term survival rates. Results: No significant differences were noted in the clinicopathological characteristics of either group. LG patients had lower estimated blood loss volumes than OG patients (LG vs. OG: 94 vs. 275 mL, P=0.005). The operation time and postoperative hospital stay were similar in both the groups. The postoperative morbidity for LG and OG patients was 41.1% and 33.3%, respectively (P=0.873). No significant difference was observed in the long-term overall survival rates between the 2 groups (5-year overall survival, LG vs. OG: 82.4% vs. 64.7%, P=0.947). Conclusions: In ESRD patients, LG yielded non-inferior short- and long-term surgical outcomes compared to OG. Laparoscopic procedures might be safely adopted for ESRD patients who can benefit from the advantages of minimally invasive surgery. [ABSTRACT FROM AUTHOR]

Purpose: This study sought to examine whether near total gastrectomy (nTG) confers a longterm nutritional benefit when compared with total gastrectomy (TG) for the treatment of gastric cancer. Materials and Methods: Patients who underwent nTG or TG for gastric cancer were included (n=570). Using the 1:2 matched propensity score, 25 patients from the nTG group and 50 patients from the TG group were compared retrospectively for oncologic outcomes, including long-term survival and nutritional status. Results: The length of the proximal resection margin, number of retrieved lymph nodes and tumor nodes, metastasis stage, short-term postoperative outcomes, and long-term survival were not significantly different between the groups. The body mass index values, and serum total protein and hemoglobin levels of the patients decreased significantly until postoperative 6 months, and then recovered slightly over time (P<0.05); however, there was no difference in the levels between the groups. The prognostic nutritional index values and serum albumin levels decreased significantly until postoperative 6 months and then recovered (P<0.05); the levels decreased more in the nTG group than in the TG group (P<0.05). The mean corpuscular volumes and serum transferrin levels increased significantly until postoperative 1 year and then recovered slightly over time (P<0.05); however, there was no difference between the groups. Serum vitamin B12, iron, and ferritin levels of the patients did not change significantly over time, and no difference existed between the groups. Conclusions: A small remnant stomach after nTG conferred no significant nutritional benefits over TG. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer is commonly treated via minimally invasive surgery. The present study explored the feasibility of right-side approach-duet (R-duet) totally laparoscopic distal gastrectomy using a three-port compared with a four- or five-port.Methods: A total of 251 patients who underwent curative totally laparoscopic distal gastrectomy for gastric cancer (72 R-duet, 74 four-port, and 105 five-port) at the Catholic Medical Center were enrolled. All operations were performed using conventional laparoscopic instruments. The clinicopathological characteristics, operative details, and postoperative short-term outcomes were analyzed retrospectively.Results: The clinicopathological characteristics did not differ significantly among the groups, except that the N stage was higher in the five-port group. The operating time was significantly longer in the four-port than the R-duet group (R-duet, four-port, and five-port 148.2 ± 30.7, 162.4 ± 30.6, and 159.9 ± 31.5 min, respectively; p = 0.024). The estimated blood loss did not differ significantly. Postoperatively, the times to flatus and to soft diet consumption and the hospital stay were significantly longer in the five-port group. The extent of postoperative complications did not differ among the groups.Conclusions: R-duet totally laparoscopic distal gastrectomy is a reliable form of reduced-port surgery when used to treat gastric cancer; no special instruments are required. [ABSTRACT FROM AUTHOR]

Purpose: The aims of this study were to compare the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging manuals on tumor, node, and metastasis (TNM) staging systems and to evaluate whether the 8th edition represents a better refinement of the 7th staging system, when applied for the classification of gastric cancers. Materials and Methods: A total of 5,507 gastric cancer patients, who underwent treatment from January 1989 to December 2013 at a single institute, were included. We compared patient survival rates across the disease groups classified according to the 7th and 8th editions of the AJCC TNM staging systems. Results: Stage migration was observed in 6.4% (n=355) of the patients. Of these, 3.5% (n=192) and 2.9% (n=158) of patients showed a higher stage and lower stage, respectively. According to the 8th edition of the AJCC TNM staging criteria, the 5-year overall survival rates of the patients with stage IIIB and IIIC showed a significant difference (40.8% vs. 20.2%, P<0.001) whereas no significant differences in the 5-year overall survival rates were observed according to the 7th edition criteria (37.6% vs. 33.2%, P=0.381). Conclusions: Restaging stage III cancers according to the 8th edition of the AJCC TNM classification criteria improved survival rate discrimination, particularly, in institutes where the stage III patients were not distinctly categorized. [ABSTRACT FROM AUTHOR]

Background: We evaluated the feasibility of a three-port totally laparoscopic distal gastrectomy (TLDG) as a reduced port laparoscopic surgery for the treatment of early gastric cancer (EGC).Materials and Methods: In total, 110 patients who underwent three-port TLDG (n = 25) and four-port TLDG (n = 85) were enrolled. A propensity score matching analysis was used to compensate for the differences between the groups in age, gender, body mass index, Eastern Cooperative Oncology Group classification, and comorbidity. After the matching, operative details, pathological features, and short-term postoperative outcomes were compared between groups.Results: By propensity score matching, 25 matched pairs were created, and no characteristic difference was observed between the groups. Operating time was significantly shorter in the three-port TLDG group than in the four-port TLDG group (139.4 ± 39.4 minutes versus 184.8 ± 42.1 minutes, respectively; P < .001). Duration until discharge was significantly shorter in the three-port TLDG group than in the four-port TLDG group (8.2 ± 5.6 days versus 10.2 ± 6.6 days, respectively; P < .046). Regarding pathological features, including TNM stage, no significant difference was observed between the groups.Conclusions: The three-port TLDG is a practical method as a reduced port surgery and has better short-term outcomes than the four-port TLDG for the treatment of EGC. [ABSTRACT FROM AUTHOR]

C-kit-negative gastrointestinal stromal tumors (GISTs) are uncommon, and there have been few reports about the diagnosis and treatment of c-kit-negative GISTs in the stomach. We report the case of a patient who was diagnosed with a huge and atypical GIST in the stomach. The GIST was completely resected and finally diagnosed as c-kit-negative GIST based on immunohistochemical staining of tumor cells, which were negative for CD117 and CD34 and positive for Discovered on GIST-1 (DOG1). C-kit-negative GISTs could be treated by complete resection and/or imatinib, which is the same treatment for c-kit-positive GISTs. [ABSTRACT FROM AUTHOR]

Purpose: Since there are no proven tumor markers that reflect the course of gastric cancer, carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are commonly used alternatives. However, the degree of progression that corresponds to an increase in these markers, and the values of these markers at different cancer stages, remains unclear. Materials and Methods: This study enrolled 1,733 gastric cancer patients who underwent surgery and whose pre-operative CEA and CA19-9 levels were known. Survival curves and mean values of the two markers were compared according to the degree of cancer progression: serosa-unexposed (SU), serosa-exposed (SE), direct invasion (DI), localized seeding (P1), and extensive seeding (P2). Results: The 5-year overall survival rates at each stage differed significantly, except between DI and P1 patients (17.1% vs. 10.5%, P=0.344). The mean CEA values in SU, SE, DI, P1, and P2 patients were 5.80, 5.48, 13.36, 8.06, and 22.82, respectively. The CA19-9 values for these patients were 49.40, 38.97, 101.67, 73.77, and 98.57, respectively. The increase in CEA in P2 patients was statistically significant (P=0.002), and the increases in CA19-9 in DI and P2 patients were significant (P=0.025, 0.007, respectively). There was a fair correlation between the two markers in P2 patients (r=0.494, P<0.001). Conclusions: CA19-9 can be used to assess DI of gastric cancer into adjacent organs. Both markers are useful for predicting the presence of extensive peritoneal seeding. [ABSTRACT FROM AUTHOR]

Background: The prognostic value of the three constituents of undifferentiated-type gastric adenocarcinoma remains unclear. The present study assessed the clinicopathological characteristics and prognosis of undifferentiated-type mucinous adenocarcinoma (uMAC) and signet ring cell carcinoma (SRC) compared with those of poorly differentiated adenocarcinoma (PDAC). Methods: In total, 1,376 patients with undifferentiated-type gastric adenocarcinoma were included, consisting of 1,002 patients diagnosed with PDAC, 54 with uMAC and 320 with SRC. Clinicopathological factors and survival rates were compared among the three histological types. Results: Significant differences in the distribution of pathological stages were observed among the groups. Patients with SRC had a significantly better survival rate than those with PDAC or uMAC, in both the all patients including non-curative resected patients and curative-resected groups. In addition, there was significant difference in survival between the PDAC and uMAC groups. Multivariate analysis suggested that age, gender, tumor depth, lymph node metastasis and curability significantly affected survival. Histological type was not an independent prognostic factor. There was no significant difference in the pattern of recurrence among the three groups. Conclusions: The uMAC and SRC had worse and favorable prognosis compared with PDCA, respectively. However, there were no differences in survival by pathological stage, thus histological type was not an independent predictor of prognosis. [ABSTRACT FROM AUTHOR]

Background: The accuracy of endoscopic ultrasonography (EUS) for preoperative staging of gastric cancer varies. The aim of this study was to investigate the accuracy of EUS tumor (T) and node (N) staging, and to identify the histopathological factors influencing accuracy based on the detailed tumor depth of gastric cancer. Methods: In total, 309 patients with gastric cancer with confirmed pathological staging underwent EUS examination for preoperative staging at Seoul St. Mary’s Hospital, Korea, between January and December 2009. The T and N staging of EUS and the pathologic report were compared. Results: The overall accuracies of EUS for T stage and the detailed T stages were 70.2% and 43.0%, respectively. In detailed stage, tumors greater than 50 mm in diameter were significantly associated with T overstaging (odds ratio (OR) = 2.094). The overall accuracy of EUS for N staging was 71.2%. Tumor size (20 mm ≤ size < 50 mm, OR = 4.389; and 50 mm ≤ size, OR = 8.170), cross-sectional tumor location (circumferential, OR = 4.381) and tumor depth (submucosa, OR = 3.324; muscular propria, OR = 6.923; sub-serosa, OR = 4.517; and serosa-exposed, OR = 6.495) were significant factors affecting incorrect nodal detection. Conclusions: Careful attention is required during EUS examination of large-sized gastric cancers to increase accuracy, especially for T staging. [ABSTRACT FROM AUTHOR]