Japanese Gastric Cancer Association Research Articles

Nationwide survey on HER2 and PD-L1 testing practices in gastric cancer across Japan.

Since HER2 and PD-L1 testing are key to selecting drugs for first-line treatments in advanced gastric cancer, evaluating differences in these tests among institutions is necessary to standardize treatment. A questionnaire survey was conducted targeting institutions certified by the Japanese Gastric Cancer Association. Responses were obtained from 155 institutions. Most institutions performed HER2 testing in-house, while PD-L1 tests were largely outsourced. HER2 scores and PD-L1 CPS rates showed greater variability across institutions than anticipated. In the pre-analytic phase, 10% neutral buffered formalin was commonly used, with fixation practices generally following guidelines. Overall, the impact of fixation-related factors was limited, but in surgical specimens, longer fixation was associated with a higher proportion of score 0/1+ and a lower proportion of score 3+. When examining HER2 scores by institution, if a particular score had a high (or low) frequency in biopsy, the same trend was also seen in surgical specimens. These findings suggest that not only factors related to specimen preparation, but also biases in evaluation criteria among pathologists may contribute to the significant variability among institutions. Standardization of pre- and post-analytic phases, coupled with appropriate training, is essential to achieve consistent gastric cancer therapy.

Analysis of risk factors for lymph node metastasis in 1096 patients with early gastric cancer and establishment of a predictive nomogram

Objective: To investigate the risk factors for lymph node metastasis in patients with early gastric cancer and establish a model for prediction of risk. Methods: The cohort of this retrospective observational study comprised 1096 patients who had undergone radical gastric cancer surgery combined with standard D1 lymphadenectomy and been diagnosed with early gastric cancer by postoperative pathology in Zhongshan Hospital affiliated with Fudan University from January 2016 to July 2022. The patients were allocated to groups with and without lymph node metastases. Clinicopathological characteristics were compared between the two groups and multi-factor logistic regression analysis used to identify independent risk factors for lymph node metastasis in patients with early gastric cancer. Indications for endoscopic resection in the Japanese Gastric Cancer Association (JGCA) guideline were also incorporated into construction of the model. The patient cohort was divided into training and validation sets in a 6:4 ratio. The identified independent risk factors were used to construct a predictive nomogram. Receiver operating characteristic curves were plotted separately and the difference between them in predictive efficacy was compared using the area under the curve (AUC). Results: A total of 1,096 patients with early gastric cancer were included, with 750 males and 346 females. Their average age was (61.4±10.9) years old, and the mean tumor diameter was (23.8±11.4) mm. Among them, 188 patients (17.2%) had positive lymph node metastasis, with 109 cases in N1 stage, 42 cases in N2 stage, and 37 cases in N3 stage. Additionally, 462 patients were in T1a stage, while 634 patients were in T1b stage. Univariate analysis showed that tumor diameter, location, Lauren classification, gross morphology, histological type, intravascular invasion, ulceration, differentiation type and tumor T stage were associated with lymph node metastasis after radical gastrectomy for early gastric cancer (all P<0.05). Multifactorial analysis showed that the presence of intravascular invasion (OR=14.822, 95%CI: 9.323-23.572, P<0.001), undifferentiated type (OR=3.095, 95%CI: 1.649-5.811, P<0.001), tumor T1b (OR=1.798, 95%CI: 1.053-3.079, P=0.032), and tumor diameter ≥2 cm (OR=1.229, 95%CI: 1.031-1.469, P=0.022) were independent risk factors for lymph node metastasis. The baseline data of the training set and validation set were consistent in terms of balance (all P>0.05). We used the above variables to establish a predictive nomogram for lymph node metastasis in patients with early gastric cancer. The AUC values obtained from the validation of the model in the training and validation sets were 0.880 (95%CI: 0.849-0.911) and 0.881 (95%CI: 0.841-0.921), respectively, and were significantly better than the predictive efficacy based on the JGCA guideline (AUC=0.777, 95%CI: 0.746-0.809, P<0.001). Conclusions: Patients with early gastric cancer and intravascular invasion, undifferentiated tumors, tumor T1b, and diameter ≥2 cm are at higher risk of postoperative lymph node metastasis than other patients. The predictive model developed in this study more accurately predicts lymph node metastasis in patients with early gastric cancer than previously proposed methods.

Risk factors and clinical significance of lower perigastric lymph node metastases in Siewert type II and III esophagogastric junction adenocarcinoma: a retrospective cohort study

BackgroundNo consensus has been concluded with regarding to the scope of lymph node (LN) dissection for Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). This study aimed to explore risk factors for lower perigastric LN (LPLN) metastases (including no. 4d, 5, 6, and 12a LN stations) and analyze the indications for LPLN dissection.MethodsIn total, 302 consecutive patients with Siewert type II and III AEG who underwent total gastrectomy (TG) were enrolled. The logistic regression model was used to perform uni- and multivariate analyses of risk factors for LPLN metastases. Kaplan–Meier curves were used for survival analysis, and log-rank tests were used for group comparisons. Basing on the guidelines of Japanese Gastric Cancer Association, the LN metastases (LNM) as well as the efficiency index (EI) of each LN station was further evaluated.ResultsThe independent risk factors for LPLN metastases in patients with Siewert type II and III AEG were distance from the esophagogastric junction (EGJ) to the distal end of the tumor (> 4.0 cm), preoperative carcinoembryonic antigen (CEA) ( +), pT4 stage, and HER-2 ( +). LPLN metastases was an independent risk factor for overall survival following TG. The LNM and EI of LPLN were 8.6% and 2.31%, respectively. The LNM of LPLN > 10% under the stratification of the distance from the EGJ to the distal end of the tumor (> 4.0 cm), pT4, preoperative CEA ( +), and HER-2 ( +) exhibited EI values of 3.55%, 2.09%, 2.51%, and 3.64%, respectively.ConclusionsLPLN metastases was a malignant factor for the prognosis of patients with Siewert type II and III AEG. For patients with preoperative CEA ( +), pT4 stage, HER-2 ( +), and the distance from the EGJ to the distal end of the tumor (> 4.0 cm), TG with LPLN dissection is prioritized for clinical recommendation.

Is there any difference between Eastern and Western clinical practice guidelines in management of gastric cancer?

Gastric cancer (GC) has been known as one of the most common causes of cancer mortality both in Western and Eastern countries. However, there might be differences between how it is managed in different countries. Thus, we aimed to investigate these differences. The most well-known clinical guidelines in field of GC management including Korean GC Association (KGCA), Japanese GC Association (JGCA), National Comprehensive Cancer Network (NCCN), European Society for Medical Oncology (ESMO), British Society of Gastroenterology (BSG), and National Institute for health and Care Excellence (NICE) have been reviewed. The contents of these guidelines were categorized under eight headings including (1) genetic predisposition, (2) prevention, (3) management of gastric polyp, atrophy, dysplasia and metaplasia, (4) diagnosis, (5) pathology and molecular biology, (6) treatment, (7) supportive and palliative care, and (8) follow up. Difference in each section was discussed. Considering KGCA and JGCA as Eastern and NCCN, ESMO, BSG, and NICE as Western guidelines, it is revealed that both sets of guidelines share common practices such as prioritizing comprehensive diagnostic evaluations, personalizing treatment plans, and palliative care. However, main differences can be seen in treatment regimens, the adoption of newer therapies like immunotherapy, and the utilization of emerging techniques such as HIPEC. These differences reflect the diverse clinical landscapes, research focuses, and healthcare systems within these regions.

Adjuvant and post-recurrent treatment patterns in patients with resectable gastric cancer in Japan: a retrospective database cohort study

BackgroundThis study examined temporal shifts in adjuvant therapy patterns in Japanese patients with resectable gastric cancer (GC) and treatment patterns of first-line and subsequent therapy among those with recurrent disease.MethodsThis retrospective analysis of hospital-based administrative claims data (April 1, 2008 to March 31, 2022) included adults (aged ≥ 20 years) with GC who started adjuvant therapy on or after October 1, 2008 (adjuvant cohort) and patients in the adjuvant cohort with disease recurrence (recurrent cohort), further defined by the time to recurrence (≤ 180 or > 180 days after adjuvant therapy).ResultsIn the adjuvant cohort (n = 17,062), the most common regimen during October 2008–May 2016 was tegafur/gimeracil/oteracil potassium (S-1; 95.7%). As new standard adjuvant regimen options were established, adjuvant S-1 use decreased to 65.0% and fluoropyrimidine plus oxaliplatin or docetaxel plus S-1 use increased to 15.0% and 20.0%, respectively, in September 2019–March 2022. In the recurrent cohort with no history of trastuzumab/trastuzumab deruxtecan treatment (n = 1257), the most common first-line regimens were paclitaxel plus ramucirumab (34.0%), capecitabine plus oxaliplatin (CapeOX; 17.0%), and nab-paclitaxel plus ramucirumab (10.1%) in patients with early recurrence, and S-1 plus oxaliplatin (26.3%), S-1 plus cisplatin (15.3%), CapeOX (14.0%), S-1 (13.2%), and paclitaxel plus ramucirumab (10.8%) in those with late recurrence.ConclusionsThis study demonstrated temporal shifts in adjuvant treatment patterns that followed the establishment of novel regimens, and confirmed that post-recurrent treatment patterns were consistent with the Japanese Gastric Cancer Association guideline recommendations.

Development of an artificial intelligence algorithm for adjuvant chemotherapy based on a nationwide registry of patients with gastric cancer by the Japanese Gastric Cancer Association (JGCA).

4063 Background: Recent marked advances in machine learning have led to expectations of the clinical application of artificial intelligence (AI) to support medical care. Methods: A survival analysis model which consisted of 31 covariates was adopted for AI algorithms using machine learning and these were constructed using clinical data sets for training. The performance of AI algorithms was evaluated in order to determine the optimal chemotherapy including surgery alone without any adjuvant chemotherapy with the highest survival rate for each patient. This involved using clinical data for verification to compare survival of an AI-recommended treatment group, for which therapy recommended by AI was actually administered, with an AI-deprecated group, for which therapy recommended by AI was not administered. Results: The clinical characteristics of 23653 patients and treatment are described in the Table from 2011 to 2018 in a nationwide registry of gastric cancer patients in Japan by the Japanese Gastric Cancer Association and were made available for this study. S-1 monotherapy was used the most frequently of all adjuvant chemotherapy in this study. We used the "restricted mean overall survival time" (RMST) of all the patients as metrics. The RMST in the AI-recommended and the AI-deprecated groups were 51.4 and 47.5 months, respectively. Patient data for the verification were matched baseline characteristics by the propensity score. This model predicted effectively overall survival after gastrectomy. The RMST of over 80 years old patients were 43.9 in the AI-recommended and 38.3 months in the AI-deprecated, respectively. This AI algorithm recommended adjuvant S-1 more frequently for patients with higher age, male, American Society of Anesthesiologists – physical status 2, Eastern Cooperative Oncology Group performance status 1, pT3/pT4, pN2/pN3, more than the upper normal limit of preoperative blood urea nitrogen, macroscopic types 2/3, differentiated adenocarcinoma, Roux-en-Y reconstruction, and Clavien-Dindo classification grade II/III. The RMST for pStage IIA/IIB/IIIA/IIIB/IIIC were 55.7/53.9/50.3/45.7/42.2 months in the AI-recommended and 55.1/50.7/43.9/36.9/32.0 months in the deprecated. This AI algorithm showed a higher survival rate in pStage III patients particularly. Conclusions: The AI algorithm could readily be integrated into clinical practice to choose adequate adjuvant chemotherapy for each patient based on each patient's baseline data because it trained and verified the nationwide registry has good predictive performance. [Table: see text]

Evaluation of the widths of the mucosal strips in pathological examination of specimens of endoscopic submucosal dissection for early gastric cancer.

Endoscopic submucosal dissection (ESD) is the standard treatment for early gastric cancer in Japan. Pathological evaluation of ESD specimens is considered essential to determine if additional gastrectomy is necessary. Usually, specimens resected by ESD are sliced into 2-3mm wide sections, and each section is examined for depth of tumor and lymphovascular invasion. Nevertheless, in most cases of additional gastrectomy, lymph node metastasis is not present. Given that there are few-studies on how clinical-decisions based on the pathologic-evaluation-method, in particular the specimen cut-width, influence patient outcomes, we retrospectively evaluated whether reducing the number of cuts to one-half or one-third would result in underestimation of the real need for additional surgery. The effect of the actual cut-width on recommended treatment (referral to operation) and patient-outcomes was also assessed. Pathological records of 498 lesions from 439 patients were reviewed and re-evaluated. All pathological descriptions are based on the gastric cancer classification system of the Japanese Gastric Cancer Association, 15th edition. In 5.8% and 8.5% of the total specimens, underdiagnosis of tumor-depth and lymphovascular invasion occurred when the number of sections was reduced to one-half and one-third, respectively. Significantly more submucosal invasions were found in the group in which the cut-with was between 3 and 4mm than in the group in which the cut width was less than 3mm. Evaluation of the appropriate cut-width is important and should be discussed from the standpoint of labor costs and lost opportunities to search for molecular markers in ESD materials.

Outcomes after endoscopic local excision of early-stage gastric adenocarcinoma in the United States

Background and objectivesLocal excision (LE) for early-stage gastric cancer has expanded in the United States over recent years, however, national outcomes are unknown. The objective of the study was to evaluate national survival outcomes following LE for early-stage gastric cancer. MethodsPatients with resectable gastric adenocarcinoma between 2010 and 2016 were identified from the National Cancer Database then classified by LE curability into eCuraA (high) and eCuraC (low) according to Japanese Gastric Cancer Association guidelines. Demographics, clinical/provider descriptors, and perioperative/survival outcomes were extracted. Propensity-weighted cox proportional hazards regression assessed factors associated with overall survival. ResultsPatients were stratified into eCuraA (N = 1167) and eCuraC (N = 13,905) subgroups. Postoperative 30-day mortality (0% vs 2.8%, p < 0.001) and readmission (2.3% vs 7.8%, p = 0.005) favored LE. Local excision was not associated with survival on propensity-weighted analyses. However, among eCuraC patients, LE was associated with higher likelihood of positive margins (27.1% vs 7.0%, p < 0.001), which was the strongest predictor of poor survival (HR 2.0, p < 0.001). ConclusionsAlthough early morbidity is low, oncologic outcomes following LE are compromised for eCuraC patients. These findings support careful patient selection and treatment centralization in the early adoption phase of LE for gastric cancer.

Indications and technical aspects of proximal gastrectomy.

According to the World Health Organization, gastric cancer is the fifth most common type of tumor, and is the third most common cause of tumor-associated death. Although gastric cancer incidence rates have decreased in the past few decades, the prevalence of proximal gastric cancer has been steadily rising in developed countries. Techniques regarding the improvement of treatment options must thus be developed. This can be achieved through incorporating both a wider use of endoscopic surgery (endoscopic mucosal resection-EMR, endoscopic submucosal dissection-ESD) and a review of applied surgical interventions. Even though there is no single international consensus available, the Japanese Gastric Cancer Association (JGCA) recommends proximal gastrectomy with D1+ lymphadenectomy in early gastric tumors. Despite recommendations from Asian guidelines and the short term outcomes of the KLASS 05 trial, surgical treatments in Western countries still rely on total gastrectomy. This is mostly due to technical and oncological challenges regarding surgical interventions in a proximal gastrectomy. However, the residual stomach after a proximal gastrectomy has been shown to diminish the incidence of dumping syndrome and anemia, and even improve postoperative quality of life (QoL). Therefore, it is necessary to define the place of proximal gastrectomy in the treatment of gastric cancers.

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

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

Reciprocity between lymphadenectomy quality and adjuvant chemotherapy compliance in gastric cancer: post hoc analysis of two randomized controlled trials.

To investigate the effect of intraoperative lymph node (LN) dissection and postoperative adjuvant chemotherapy on the overall survival (OS) of gastric cancer (GC) patients and their reciprocity. LN noncompliance was defined as the absence of more than one LN station, as described in the protocol for D2 lymphadenectomy in the Japanese Gastric Cancer Association. The definition of adjuvant chemotherapy (AC) noncompliance was that the chemotherapy planned dose does not meet the requirements. Kaplan-Meier survival curves showed that the OS of patients with major LN noncompliance was significantly lower than that of patients with nonmajor LN noncompliance, and the OS of AC noncompliance patients was significantly lower than that of AC compliance patients. If there was nonmajor LN noncompliance during surgery, the OS of patients with AC compliance was significantly higher than that of patients with AC noncompliance (P = 0.035). In the case of major LN noncompliance during surgery, there was no statistically significant difference in OS between those with AC compliance and those with AC noncompliance (P = 0.682). Multivariate Cox regression analysis including AC noncompliance indicated that major LN noncompliance was an independent prognostic factor for poor OS (P = 0.012), while AC noncompliance was not an independent prognostic factor for OS (P = 0.609). Adequate lymph node dissection and adjuvant chemotherapy are both key steps to improve the awful prognosis of GC patients. Adjuvant chemotherapy may fail to remedy the poor prognosis caused by major LN noncompliance.

Increasing utilization of endoscopic local excision for early-stage gastric cancers in the United States

BackgroundThe Japanese Gastric Cancer Association provided updated criteria for endoscopic local excision of early-stage gastric cancer in 2018. The purpose of this study was to evaluate utilization patterns for endoscopic local excision in the United States for resectable gastric adenocarcinoma. MethodsPatients with resectable gastric adenocarcinoma were identified from the National Cancer Database between 2010 and 2017. Patients were classified into strict appropriate criteria, expanded criteria, and inappropriate based on the Japanese Gastric Cancer Association guidelines. Factors associated with endoscopic local excision were identified using univariate and logistic multivariate regression. ResultsWithin the National Cancer Database, 46,334 patients were stratified into strict appropriate criteria (n = 1,405), expanded criteria (n = 727), and inappropriate (n = 43,675). Annual cases of local excision increased by 76.9% over the study period, from 273 in 2010 to 483 in 2017. Among patients who underwent local excision, 10.1% were classified as strict appropriate criteria, 1.6% were classified as expanded criteria, and 84.5% were classified as inappropriate. Among inappropriate patients, factors associated with endoscopic local excision were: more recent year of diagnosis, increasing age, female sex, tumor located in the cardia, smaller size, low-grade, absence of lymphovascular invasion, and treatment at an academic facility. ConclusionThe use of endoscopic local excision for gastric cancer has nearly doubled since 2010. However, most patients do not satisfy consensus criteria for endoscopic therapy.

Surgeon-Pathologist Team Approach Dramatically Affects Lymph Nodes Detection and Improves Patients' Short-Term Outcome.

Simple SummaryAppropriate lymph node harvesting for patients with gastric cancer is fundamental for a correct staging and is strongly related to survival. In this study, we present a new protocol for on-site macroscopic evaluation and sampling of lymph nodes for gastric cancer patients. With the joint collaboration of surgeons and pathologists, our method aims to provide the largest possible number of analyzed lymph nodes per patient, allowing for a better staging. We are convinced that this approach is routinely feasible, and our preliminary results seem to confirm better patient stratification compared to other lymph node dissection methods.The downstaging of gastric cancer has recently gained particular attention in the field of gastric cancer surgery. The phenomenon is mainly due to an inappropriate sampling of lymph nodes during standard lymphadenectomy. Hence, collection of the maximum number of lymph nodes is a critical factor affecting the outcome of patients. None of the techniques proposed so far have demonstrated a real efficiency in increasing the number of identified lymph nodes. To harvest the maximum number of lymph nodes, we designed a protocol for on-site macroscopic evaluation and sampling of lymph nodes according to the Japanese Gastric Cancer Association protocol. The procedure was carried out by a surgeon/pathologist team in the operating room. We enrolled one hundred patients, 50 of whom belonged to the study group and 50 to a control group. The study group included patients who underwent lymph node dissection following the proposed protocol; the control group encompassed patients undergoing standard procedures for sampling. We compared the number and maximum diameter of lymph nodes collected in both groups, as well as some postoperative variables, the 30-day mortality and the overall survival. In the study group, the mean number of lymph nodes harvested was higher than the control one (p = 0.001). Moreover, by applying the proposed technique, we sampled lymph nodes with a very small diameter, some of which were metastatic. Noticeably, no difference in terms of postoperative course was identified between the two groups, again supporting the feasibility of an extended lymphadenectomy. By comparing the prognosis of patients, a better overall survival (p = 0.03) was detected in the study group; however, to date, no long-term follow-up is available. Interestingly, patients with metastasis in node stations number 8, 9, 11 or with skip metastasis, experienced a worse outcome and died. Based on our preliminary results, the pathologist/surgeon team approach seems to be a reliable option, despite of a slight increase in sfaff workload and technical cost. It allows for the harvesting of a larger number of lymph nodes and improves the outcome of the patients thanks to more precise staging and therapy. Nevertheless, since a higher number of patients are necessary to confirm our findings and assess the impact of this technique on oncological outcome, our study could serve as a proof-of-concept for a larger, multicentric collaboration.

ASO Visual Abstract: Impact of Surgical Margins on Overall Survival After Gastrectomy for Gastric Cancer: A Validation of Japanese Gastric Cancer Association Guidelines on a Western Series

ASO Visual Abstract: Impact of Surgical Margins on Overall Survival After Gastrectomy for Gastric Cancer: A Validation of Japanese Gastric Cancer Association Guidelines on a Western Series

Impact of Surgical Margins on Overall Survival after Gastrectomy for Gastric Cancer: A Validation of Japanese Gastric Cancer Association Guidelines on a Western Series

PurposeNo consensus exists on the resection extent needed to ensure oncological safety in gastrectomy for gastric adenocarcinoma (GAC). This study aims to assess the impact of margin adequacy according to Japanese Gastric Cancer Association (JGCA) guidelines on overall survival (OS).Patients and MethodsPatients who underwent surgery for stage I–III GAC at our institution between 2010 and 2017 were included. Margin adequacy according to JGCA, National Comprehensive Cancer Network (NCCN), and European Society for Medical Oncology (ESMO) guidelines was assessed, and their predictive value on OS was evaluated with Harrell’s C-index. Patients were analyzed according to their margins’ adherence to JGCA guidelines, and a propensity score matching (PSM) was run. Indication to either total gastrectomy (TG) or distal gastrectomy (DG) according to each guideline was also assessed.ResultsA total of 279 patients were included, of whom 220 (79%) underwent DG. Adequate margins according to JGCA were obtained in 209 patients (75%). On multivariate analysis, JGCA margin adequacy was independently associated with OS, together with American Society of Anesthesiologist class, neoadjuvant chemotherapy, lymphadenectomy extent, R0 resection, and postoperative N stage. After PSM, patients with JGCA adequate margins showed better OS, recurrence-free survival (RFS), and local RFS than patients with JGCA inadequate margins. For 220 DG, JGCA guidelines would have recommended TG in 25 patients (11%), NCCN in 30 (14%), and ESMO in 90 (41%) (p < 0.001).ConclusionAdequacy of surgical resection margins to JGCA guidelines leads to improved survival outcomes and allows for a more organ-preserving approach than Western guidelines.

Comparison of tumor regression grading systems for locally advanced gastric adenocarcinoma after neoadjuvant chemotherapy.

BACKGROUNDCurrent tumor regression grade (TRG) evaluations are based on various systems which brings confusion for oncologists and pathologists when interpreting results. The recent six-tier system (JGCA2017-TRG) recommended by the Japanese Gastric Cancer Association (JGCA) is worth investigating, as four-tier TRG systems are favored in various parts of the world. AIMTo compare the predictive accuracies of five published TRG systems.METHODSData were retrospectively collected from patients with locally advanced gastric cancer (LAGC) who underwent neoadjuvant chemotherapy followed by D2 Lymphadenectomy between January 2005 and January 2014 at our institution. Outcomes were overall survival (OS) and disease-free survival (DFS), which were evaluated separately using the following TRG systems: JGCA2017, JGCA, Becker, AJCC/CAP, and Mandard.RESULTSAll five published TRG systems were independent predictors for OS and DFS. Concordance indices of the JGCA2017, JGCA, Becker, AJCC/CAP-TRG, and Mandard systems were 0.651/0.648 0.652/0.649, 0.693/0.695, 0.688/0.685, and 0.674/0.675 for OS and DFS, respectively. The four-tier Becker system showed the highest c-index, which was significantly greater than that of the six-tier JGCA2017 and five-tier JGCA systems (P < 0.05 in OS and DFS). When residual tumor percentages were reset as: “no residual tumor”, < 10%, < 100%, and “no response”, the rearranged cutoff values achieved a maximum c-index with 0.728 for OS and 0.737 for DFS, which was superior to the other five systems. CONCLUSIONThe newly introduced six-tier JGCA-TRG system cannot increase prognostic stratification. The four-tier Becker system is more suitable for LAGC patients. A population-based study is warranted to define the optimal criterion for TRG in LAGC patients.

Magnifying endoscopy for the diagnosis of early gastric cancer: Establishment of technique, diagnostic system, and scientific evidence from Japan

Magnifying endoscopy for the diagnosis of early gastric cancer: Establishment of technique, diagnostic system, and scientific evidence from Japan

ROLE OF COMPUTED TOMOGRAPHY WITH PNEUMOGASTROGRAPHY IN DETERMINING THE REGRESSION GRADE OF LOCALLY ADVANCED GASTRIC CANCER AFTER NEOADJUVANT CHEMOTHERAPY

Introduction. A multimodal approach to the treatment of locally advanced gastric cancer with the addition of systemic or local treatment methods, such as chemotherapy and radiation therapy, reduces the risk of cancer recurrence, thus improving survival of patients. Advances in anticancer therapy dictate the need to develop systems for assessing tumor response to new treatment modalities.Material and Methods. The study included 162 patients with locally advanced gastric cancer who received treatment at the N.N. Petrov National Medical Research Center of Oncology from 2015 to 2018. All patients underwent subtotal gastric resection or gastrectomy with lymph node dissection and previously received neoadjuvant polychemotherapy. Patients were in the age range 30 to 80 years old. The tumor pathomorphological response to chemotherapy was assessed in all patients using a pathomorphological response rate system according to the classification of the Japanese Gastric Cancer Association (JGCA, 3rd English edition). All patients underwent computed tomography with pneumogastrography before neoadjuvant chemotherapy and immediately before surgery. For each of 162 patients, 96 qualitative and quantitative biomarkers of tumor and paragastric lymph node imaging were analyzed.Results. The accuracy of determining the tumor response rate using computed tomography with pneumogastrography was 82.6 % for TRG-0/1, 90 % for TRG-1/2, and 88 % for TRG-2/3. Discussion. The tumor pathomorphological response to treatment is a predictor of long-term results; however, it can be assessed only after analyzing the surgical specimen, and this marker cannot be used in inoperable cases and for correction of palliative chemotherapy. The study of imaging biomarkers based on quantitative and qualitative data reflecting the histopathological features of the tumor and lymph nodes can help determine the tumor regression grade and optimize treatment.Conclusion. The proposed algorithm for assessing the response grade of locally advanced gastric cancer to chemotherapy using imaging biomarkers is a promising prognostic marker and requires further study.

Management of early gastric cancer meeting criteria for endoscopic resection: US population-based study

Background and study aims The goal of this study was to assess surgical resection (SR) of early gastric cancer (EGC) fitting Japanese Gastric Cancer Association (JGCA) endoscopic resection (ER) criteria. Patients and methods We analyzed EGC data from the national Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. Results A total of 2219 EGC cases were identified (1074 T1a and 1145 T1b). Of them, 409 met absolute criteria, 219 met expanded 1, 529 expanded 2, and 229 expanded 3. 259 lesions were treated endoscopically while 1007 were surgically resected (20.5 % vs 79.5 %, P = 0.0001). Temporal analysis showed that the frequency of ER steadily increased while SR proportionally decreased during the study period. Cox proportion regression analysis adjusting for confound variables (including age, gender, and race) showed no significant difference in the risk of mortality following either surgery or endoscopy. Conclusions EGC can be safely treated with ER. However, EGC meeting JGCA ER criteria is largely treated with SR in the United States.

The efficacy of the application of the curative criteria of the 5rd edition Japanese gastric cancer treatment guidelines for early adenocarcinoma of the esophagogastric junction treated by endoscopic submucosal dissection.

Background:The curative criteria after endoscopic submucosal dissection for early gastric carcinoma were updated by the Japanese Gastric Cancer Association. No study has shown promising results with endoscopic submucosal dissection for early adenocarcinoma of esophagogastric junction based on the new curative criteria. The purpose of this study was to validate clinical efficacy of the application of the curative criteria of the 5th edition Japanese gastric cancer treatment guidelines for early adenocarcinoma of esophagogastric junction after endoscopic submucosal dissection.Methods:Patients who underwent endoscopic submucosal dissection for Siewert type II adenocarcinoma between January 2013 and June 2018 were eligible for this study. Clinical and pathological features and treatment outcomes were retrospectively reviewed using medical records.Results:The success rate for en-bloc resection was 97.2% (172/177) and the curative resection rate was 71.2% (126/177). Additional endoscopic submucosal dissection or radical surgery was conducted in 10 patients (5.6%) who did not fulfil the curative resection criteria, while one patient with curative resection remedied with endoscopic submucosal dissection because of recurrence. According to eCura scoring system, 94 patients (53.1%) were categorized into eCura A, 34 patients (19.2%) into eCura B, 11 patients (6.2%) into eCura C-1, and 38 patients (21.5%) into eCura C-2. Five patients categorized as eCura C-2 underwent radical surgery, two of whom have lymph node metastasis.Conclusions:Endoscopic submucosal dissection for early adenocarcinoma of esophagogastric junction that met the expanded criteria of the 5th edition Japanese gastric cancer treatment guidelines were acceptable and should be the standard treatment instead of surgical resection.