Early gastric cancer: diagnosis, staging, and clinical impact. Evaluation of 530 patients. New elements for an updated definition and classification

Genomic events stratifying prognosis of early gastric cancer

BACKGROUND

The purpose of the study was to conduct a comprehensive genomic characterization of gene alterations, microsatellite instability (MSI), and tumor mutational burden (TMB) in submucosal-penetrating (Pen) early gastric cancers (EGCs) with varying prognoses.

METHODS

Samples from EGC patients undergoing surgery and with 10-year follow-up data available were collected. Tissue genomic alterations were characterized using Trusight Oncology panel (TSO500). Pathway instability (PI) scores for a selection of 218 GC-related pathways were calculated both for the present case series and EGCs from the TCGA cohort.

RESULTS

Higher age and tumor location in the upper-middle tract are significantly associated with an increased hazard of relapse or death from any cause (p = 0.006 and p = 0.032). Even if not reaching a statistical significance, Pen A tumors more frequently present higher TMB values, higher frequency of MSI-subtypes and an overall increase in PI scores, along with an enrichment in immune pathways. ARID1A gene was observed to be significantly more frequently mutated in Pen A tumors (p = 0.006), as well as in patients with high TMB (p = 0.027). Tumors harboring LRP1B alterations seem to have a higher hazard of relapse or death from any cause (p = 0.089), being mutated mainly in relapsed patients (p = 0.093).

CONCLUSIONS

We found that the most aggressive subtype Pen A is characterized by a higher frequency of ARID1A mutations and a higher genetic instability, while LRP1B alterations seem to be related to a lower disease-free survival. Further investigations are needed to provide a rationale for the use of these markers to stratify prognosis in EGC patients.

Targeted plasma proteomic analysis uncovers a high-performance biomarker panel for early diagnosis of gastric cancer

BACKGROUND

Gastric cancer (GC) is characterized by high morbidity, high mortality and low early diagnosis rate. Early diagnosis plays a crucial role in radically treating GC. The aim of this study was to identify plasma biomarkers for GC and early GC diagnosis.

METHODS

We quantified 369 protein levels with plasma samples from discovery cohort (n = 88) and validation cohort (n = 50) via high-throughput proximity extension assay (PEA) utilizing the Olink-Explore-384-Cardiometabolic panel. The multi-protein signatures were derived from LASSO and Ridge regression models.

RESULTS

In the discovery cohort, 13 proteins (GDF15, ITIH3, BOC, DPP7, EGFR, AMY2A, CCDC80, CD163, GPNMB, LTBP2, CTSZ, CCL18 and NECTIN2) were identified to distinguish GC (Stage I-IV) and early GC (HGIN-I) groups from control group with AUC of 0.994 and AUC of 0.998, severally. The validation cohort yielded AUC of 0.930 and AUC of 0.818 for GC and early GC, respectively.

CONCLUSIONS

This study identified a multi-protein signature with the potential to benefit clinical GC diagnosis, especially for Asian and early GC patients, which may contribute to the development of a less-invasive, convenient, and efficient early screening tool, promoting early diagnosis and treatment of GC and ultimately improving patient survival.

Computed Tomography-Based Predictive Model for the Probability of Lymph Node Metastasis in Gastric Cancer: A Meta-analysis

OBJECTIVES

Whether or not a gastric cancer (GC) patient exhibits lymph node metastasis (LNM) is critical to accurately guiding their treatment and prognostic evaluation, necessitating the ability to reliably predict preoperative LNM status. The present meta-analysis sought to examine the diagnostic value of computed tomography (CT)-based predictive models as a tool to gauge the preoperative LNM status of patients with GC.

METHODS

Relevant articles were identified in the PubMed, Web of Science, and Wanfang databases. These studies were used to conduct pooled analyses examining sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) values, and area under the curve values were computed for summary receiver operating characteristic curves.

RESULTS

The final meta-analysis incorporated data from 15 studies, all of which were conducted in China, enrolling 3,817 patients with GC (LNM+: 1790; LNM-: 2027). The developed CT-based predictive model exhibited respective pooled sensitivity, specificity, PLR, and NLR values of 84% (95% confidence interval [CI], 0.79-0.87), 81% (95% CI, 0.76-0.85), 4.39 (95% CI, 3.40-5.67), and 0.20 (95% CI, 0.16-0.26). The identified results were not associated with significant potential for publication bias ( P = 0.071). Similarly, CT-based analyses of LN status exhibited respective pooled sensitivity, specificity, PLR, and NLR values of 62% (95% CI, 0.53-0.70), 77% (95% CI, 0.72-0.81), 2.71 (95% CI, 2.20-3.33), and 0.49 (95% CI, 0.40-0.61), with no significant risk of publication bias ( P = 0.984).

CONCLUSIONS

Overall, the present meta-analysis revealed that a CT-based predictive model may outperform CT-based analyses alone when assessing the preoperative LNM status of patients with GC, offering superior diagnostic utility.

Comparison of clinical outcomes and prognosis between surgery and endoscopic submucosal dissection in patients with synchronous multifocal early gastric cancer

BACKGROUND

Synchronous multiple early gastric cancer (SMEGC) refers to the simultaneous occurrence of two or more malignant cancer lesions in the stomach. For patients with multiple early gastric carcinomas, the choice of appropriate treatment remains controversial. This study is dedicated to comparing the clinical outcomes and prognosis of patients with SMEGC who underwent endoscopic submucosal dissection (ESD) or gastrectomy.

METHODS

A total of 180 patients with more than one malignant cancer lesion in the stomach who had received gastrectomy or ESD between 2012 and 2021 were retrospectively evaluated to determine their clinical outcomes and prognosis. Univariate and multivariate logistic regression were utilized to identify risk factors for tumor recurrence.

RESULTS

Over the 57.5 months median follow-up period for the 140 enrolled cases, tumor recurrence occurred in 8 (12%) in the ESD group but only 1 (1%) in the surgery group. Relapse-free survival (RFS) was higher in the surgery group (p = 0.023) in all cases; however, there was no significant difference in Overall survival (OS, p = 0.772). Complications were significantly higher in the surgery group than in the ESD group, but fewer in the radical distal gastrectomy group. Multivariate regression analysis revealed that ESD(p = 0.034), the main lesion size > 2 cm(p = 0.019), and undifferentiated tumor(p = 0.022) were independent risk factors for tumor recurrence.

CONCLUSIONS

For the treatment of simultaneous multifocal early gastric cancer, ESD has a good short-term effect and higher quality of life. However, ESD has a higher risk of recurrence than surgery. And we found that the partial gastrectomy appears to be considered as adequate treatment for some SMEGC patients.

Predictive factors of lymphatic metastasis and evaluation of the Japanese treatment guidelines for endoscopic resection of early gastric cancer in a high-volume center in Perú

Purpose

This study aimed to identify the predictive factors of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) and to evaluate the applicability of the Japanese treatment guidelines for endoscopic resection in the western population.

Methods

Five hundred-one patients with pathological diagnoses of EGC were included. Univariate and multivariate analyses were conducted to identify the predictive factors of LNM. EGC patients were distributed according to the indications for endoscopic resection of the Eastern guidelines. The incidence of LNM was evaluated in each group.

Results

From 501 patients with EGC, 96 (19.2%) presented LNM. In 279 patients with tumors with submucosal infiltration (T1b), 83 (30%) patients had LNM. Among 219 patients who presented tumors > 3 cm, 63 (29%) patients had LNM. Thirty-one percent of patients with ulcerated tumors presented LMN (33 out of 105). In 76 patients and 24 patients with lymphovascular and perineural invasion, the percentage of LMN was 84% and 87%, respectively. In the multivariate analysis, a tumor diameter >3 cm, submucosal invasion, lymphovascular, and perineural invasion were independent predictors of LMN in EGC. No patient with differentiated, non-ulcerated mucosal tumors presented LNM regardless of tumor size. Three of 17 patients (18%) with differentiated, ulcerated mucosal tumors and ≤ 3 cm presented LNM. No LNM was evidenced in patients with undifferentiated mucosal tumors and ≤ 2 cm.

Conclusions

The presence of LNM in Western EGC patients was independently related to larger tumors (>3 cm), submucosal invasion, lymphovascular and perineural invasion. The Japanese absolute indications for EMR are safe in the Western population. Likewise, Western patients with differentiated, non-ulcerated mucosal tumors, and larger than 2 cm are susceptible to endoscopic resection. Patients with undifferentiated mucosal tumors smaller than 2 cm presented encouraging results and ESD could be recommended only for selected cases.

Establishment of a nomogram for predicting lymph node metastasis in patients with early gastric cancer after endoscopic submucosal dissection

Background

Endoscopic submucosal dissection (ESD) has been accepted as the standard treatment for the appropriate indication of early gastric cancer (EGC). Determining the risk of lymph node metastasis (LNM) is critical for the following treatment selection after ESD. This study aimed to develop a predictive model to quantify the probability of LNM in EGC to help minimize the invasive procedures.

Methods

A total of 952 patients with EGC who underwent radical gastrectomy were retrospectively reviewed. LASSO regression was used to help screen the potential risk factors. Multivariate logistic regression was used to establish a predictive nomogram, which was subjected to discrimination and calibration evaluation, bootstrapping internal validation, and decision curve analysis.

Results

Results of multivariate analyses revealed that gender, fecal occult blood test, CEA, CA19-9, histologic differentiation grade, lymphovascular invasion, depth of infiltration, and Ki67 labeling index were independent prognostic factors for LNM. The nomogram had good discriminatory performance, with a concordance index of 0.816 (95% CI 0.781–0.853). The validation dataset yielded a corrected concordance index of 0.805 (95% CI 0.770–0.842). High agreements between ideal curves and calibration curves were observed.

Conclusions

The nomogram is clinically useful for predicting LNM after ESD in EGC, which is beneficial to identifying patients who are at low risk for LNM and would benefit from avoiding an unnecessary gastrectomy.

Usefulness of linked color imaging for the detection of obscure early gastric cancer: Multivariate analysis of 508 lesions

OBJECTIVES

Early gastric cancers (EGCs) of the elevated type or with submucosal invasion are easily found by routine endoscopy. However, most early cancers are challenging to detect because of subtle morphological or color differences from surrounding atrophic mucosa and intestinal metaplasia. Linked color imaging (LCI) enhances mucosal color difference, making it easier to detect EGCs. The aim of this study is to clarify the advantages and possible disadvantages of LCI for screening for obscure EGC.

METHODS

A total of 665 malignant gastric lesions resected using endoscopic submucosal dissection between January 2015 and April 2018 were retrospectively reviewed. Obviously detectable lesions were not included in the main analysis when determining the target lesion. White light imaging (WLI)/LCI images of 508 endoscopically obscure malignant lesions were included in the final analysis and evaluated by three non-expert and three expert endoscopists using visibility scores for detection and extent.

RESULTS

The detection visibility scores using LCI were significantly higher than those using WLI regardless of lesion characteristics including location, size, histological type, depth of invasion, and Helicobacter pylori status. The detection score improved in 46.4% cases and deteriorated in 4.9% when the modality changed from WLI to LCI. A mixed-effects multivariate logistic regression analysis showed that use of LCI (odds ratio [OR] 2.57), elevated type (OR 1.92), invasion to submucosa (OR 2.18) were significantly associated with improved visibility of EGC.

CONCLUSIONS

Linked color imaging significantly improves visibility of EGC regardless of differences in lesion morphology, histology, location, depth of invasion, and H. pylori status compared to conventional WLI.

ESRRG, ATP4A, and ATP4B as Diagnostic Biomarkers for Gastric Cancer: A Bioinformatic Analysis Based on Machine Learning

Based on multiple bioinformatics methods and machine learning techniques, this study was designed to explore potential hub genes of gastric cancer with a diagnostic value. The novel biomarkers were detected through multiple databases of gastric cancer–related genes. The NCBI Gene Expression Omnibus (GEO) database was used to obtain gene expression files. Three hub genes (ESRRG, ATP4A, and ATP4B) were detected through a combination of weighted gene co-expression network analysis (WGCNA), gene–gene interaction network analysis, and supervised feature selection method. GEPIA2 was used to verify the differences in the expression levels of the hub genes in normal and cancer tissues in the RNA-seq levels of Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases. The objectivity of potential hub genes was also verified by immunohistochemistry in the Human Protein Atlas (HPA) database and transcription factor–hub gene regulatory network. Machine learning (ML) methods including data pre-processing, model selection and cross-validation, and performance evaluation were examined on the hub-gene expression profiles in five Gene Expression Omnibus datasets and verified on a GEO external validation (EV) dataset. Six supervised learning models (support vector machine, random forest, k-nearest neighbors, neural network, decision tree, and eXtreme Gradient Boosting) and one semi-supervised learning model (label spreading) were established to evaluate the diagnostic value of biomarkers. Among the six supervised models, the support vector machine (SVM) algorithm was the most effective one according to calculated performance metrics, including 0.93 and 0.99 area under the curve (AUC) scores on the test and external validation datasets, respectively. Furthermore, the semi-supervised model could also successfully learn and predict sample types, achieving a 0.986 AUC score on the EV dataset, even when 10% samples in the five GEO datasets were labeled. In conclusion, three hub genes (ATP4A, ATP4B, and ESRRG) closely related to gastric cancer were mined, based on which the ML diagnostic model of gastric cancer was conducted.

A novel robust nomogram based on preoperative hemoglobin and albumin levels and lymphocyte and platelet counts (HALP) for predicting lymph node metastasis of gastric cancer

BACKGROUND

Accurate assessment of lymph node status in gastric cancer (GC) patients can help to select appropriate treatment strategies for GC, but the diagnostic accuracy of conventional methods needs to be improved. The aim of this study was to investigate the predictive value of preoperative hemoglobin and albumin levels and lymphocyte and platelet counts (HALP) on lymph node status in GC patients and to construct a risk prediction model.

METHODS

This study retrospectively analyzed the clinicopathological characteristics of 349 patients with GC who underwent radical gastrectomy, among which 250 patients were recruited in the training cohort and 99 patients in the independent validation cohort. Significant risk factors in univariate analysis were further identified as independent variables in multivariate logistic regression analysis, which were then incorporated and presented in a nomogram. Receiver operating characteristic (ROC) curves, Calibration curve and decision curve analysis (DCA) curves were used to evaluate the discrimination, prediction accuracy and clinical effectiveness of the model.

RESULTS

Multifactorial logistic regression analysis showed that alcohol use (OR =2.203, P=0.036), Depth of invasion (OR =7.756, P<0.001), differentiation (OR =2.252, P=0.018), carcinoembryonic antigen (CEA) (OR =2.443, P=0.017), carbohydrate antigen 19-9 (CA199) (OR =2.715, P=0.008) and HALP (OR =2.276, P=0.032) were independent risk factors for lymph node metastasis (LNM) in GC. We used these factors to construct a nomogram for predicting LNM in GC patients, and the ROC curves showed good discrimination of the model with AUC values of 0.854 (training cohort) and 0.868 (validation cohort), respectively, and the calibration curves showed good predictive ability of the nomogram, in addition to the DCA curves results showed the clinical usefulness of the model.

CONCLUSIONS

In conclusion, we established a nomogram for predicting LNM in patients with GC.

Correlation between healing type of lesion and recurrence in gastric neoplastic lesions after endoscopic submucosal dissection

BACKGROUND/AIMS

To date, there are few reports on the clinical association between healing pattern of lesion and local recurrence after endoscopic resection (ER). We examined the risk factors associated with local recurrence after endoscopic submucosal dissection (ESD) and the correlation between healing type of lesion and recurrence.

MATERIALS AND METHODS

We retrospectively analyzed medical records of 293 patients who underwent ESD of early gastric cancer or gastric adenoma between April 2010 and January 2012. We analyzed the relationship among factors such as age, location of lesion, size, pathologic diagnosis, presence of Helicobacter pylori (H. pylori), and healing types of ulcers in patients with local recurrence through follow-up endoscopic surveillance (1, 6, and 12 months after ESD).

RESULTS

We analyzed 141 patients except for patients who had not undergone surveillance endoscopy, H. pylori test, and ambiguous healing patterns. There were no significant correlations between local recurrences concerning sex, age, tumor size, location, and pathologic diagnosis. When the healing type of the ulcer was divided into hypertrophic polypoid type (9 cases (6.4%)), scar type (122 cases (86.5%)), and nodular type (10 cases (7.1%)), the scar type was found to be most common. A total of eight patients (5.7%) developed local recurrence, of which five were of nodular type and statistically significant (p=0.000).

CONCLUSION

The most common type of ulcer healing was scar type after ESD, but nodular type was associated with local recurrence. When we perform follow-up endoscopy after ESD, we should pay attention to the lesion that has nodular change of mucosal surface.

Molecular Alterations in Gastric Preneoplastic Lesions and Early Gastric Cancer

Prognosis of gastric cancer is dramatically improved by early diagnosis. Correa's cascade correlates the expression of some molecular markers with the progression of preneoplastic lesions toward carcinoma. This article reviews the diagnostic and prognostic values of molecular markers in complete (MUC2) and incomplete (MUC2, MUC5AC, and MUC6) intestinal metaplasia, gastric dysplasia/intra-epithelial neoplasia, and early gastric cancer. In particular, considering preinvasive neoplasia and early gastric cancer, some studies have demonstrated a correlation between molecular alterations and prognosis, for example, mucins phenotype in gastric dysplasia, and GATA6, TP53 mutation/LOH and MUC6 in early gastric cancer. Moreover, this review considers novelties from the literature regarding the (immuno)histochemical characterization of diffuse-type/signet ring cell gastric cancer, with particular attention to clinical outcomes of patients. The aim of this review is the evaluation of the state of the art regarding suitable biomarkers used in the pre-surgical phase, which can distinguish patients with different prognoses and help decide the best therapeutic strategy.

Risk Factors and Prediction Model for Non-curative Resection of Early Gastric Cancer With Endoscopic Resection and the Evaluation

Background and Study Aim: EGC, also known as Early Gastric Cancer is known to lack the lymph node metastasis and confined along the mucosa, which is treated through an endoscopic resection procedure that includes ESD (Endoscopic Submucosal dissection) and EMR (Endoscopic Mucosal Resection). However, some cases underwent residual disease, recurrence, or additional gastrectomy because of non-curative resection. The following research aims to delineate the threat factors causing the non-curative resection as well as develop a predictive model.

Patient and Methods: Effort was taken to collect all the records about the health history of pathologically diagnosed EGC who experienced endoscopic treatment in the Department of Endoscopy, the Capital Medical University, and Beijing Friendship Hospital from January 2012 to January 2020. Patients were grouped into two categories primarily; a curative resection group and finally a non-curative resection group based on the outcomes of the postoperative pathological and immunohistochemical examination results. The statistical methods used included single factor analysis, a multivariate logistic regression analysis and a chi-square test. A nomogram for the prediction of non-curative resection was constructed, which included information on age, gender, resection method, postoperative pathology, tumor size, ulcer, treatment, and infiltration depth. Receiver operating characteristic (ROC) curve analysis and calibration were performed to present the predictive accuracy of the nomogram.

Results: Of 443 patients with 478 lesions who had undergone ESD or EMR for EGCs, 127 were identified as being treated non-curative resection. Older patients (>60 years), a large tumor size (>30 mm), submucosal lesion, piecemeal resection, EMR for treatment and undifferentiated tumor histology were associated with non-curative resection group. Our risk nomogram showed good discriminated performance in internal validation (bootstrap-corrected area under the receiver-operating characteristic curve, 0.881; P < 0.001).

Conclusions: A validated prediction model was developed to identify people who were subject to undergoing a non-curative resection for ESD. The predictive model that we formulated is essential in providing reliable information to guide the decision-making process on the treatment for EGC before undertaking an endoscopic resection.

Effect of endoscopic resection on short-term surgical outcomes of subsequent laparoscopic gastrectomy: a meta-analysis

BACKGROUND

Endoscopic resection (ER) might affect subsequent laparoscopic gastrectomy (LG) because of the electrical coagulation, but the effect remains controversial. The purpose of this meta-analysis was to analyze the effect of ER on the short-term surgical outcomes of subsequent LG.

MATERIALS AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched to find eligible studies published from inception to March 21, 2021. Short-term surgical outcomes were compared between the ER-LG group and the LG-only group. The registration ID of this current meta-analysis on PROSPERO is CRD42021238031.

RESULTS

Nine studies involving 3611 patients were included in this meta-analysis. The LG-only group had a higher T stage (T1-T2: OR=2.42, 95% CI=1.09 to 5.34, P=0.03; T3-T4: OR=0.41, 95% CI=0.19 to 0.91, P=0.03) than the ER-LG group. The ER-LG group showed a shorter operation time than the LG-only group (MD=-5.98, 95% CI=-10.99 to -0.97, P=0.02). However, no difference was found in operation time after subgroup analysis of propensity score matching studies. No significant difference was found in intraoperative blood loss, time to first oral feeding, or postoperative hospital stay between the ER-LG group and the LG-only group. And no significance was found in overall complications (OR=1.16, 95% CI=0.89 to 1.50, P=0.27), complications of grade ≥ II (OR=1.11, 95% CI=0.71 to 1.73, P=0.64), complications of grade ≥ III b (OR=1.47, 95% CI=0.49 to 4.43, P=0.49) between the ER-LG group and the LG-only group.

CONCLUSIONS

ER did not affect subsequent LG in terms of short-term outcomes, and the ER-LG group might have a shorter operation time than the LG-only group.

Early Gastric Cancer: identification of molecular markers able to distinguish submucosa-penetrating lesions with different prognosis

BACKGROUND

Early Gastric Cancer (EGC) reaches 25% of the gastric cancers surgically treated in some areas of Northeastern Italy and is usually characterized by a good prognosis. However, among EGCs classified according to Kodama's criteria, Pen A subgroup is characterized by extensive submucosal invasion, lymph node metastases and worse prognosis, whereas Pen B subgroup by better prognosis. The aim of the study was to characterize the differences between Pen A, Pen B and locally advanced gastric cancer (T3N0) in order to identify biomarkers involved in aggressiveness and clinical outcome.

METHODS

We selected 33 Pen A, 34 Pen B and 20 T3N0 tumors and performed immunohistochemistry of mucins, copy number variation analysis of a gene panel, microsatellite instability (MSI), TP53 mutation and loss of heterozygosity (LOH) analyses.

RESULTS

Pen A subgroup was characterized by MUC6 overexpression (p = 0.021). Otherwise, the Pen B subgroup was significantly associated with the amplification of GATA6 gene (p = 0.002). The higher percentage of MSI tumors was observed in T3N0 group (p = 0.002), but no significant differences between EGC types were found. Finally, TP53 gene analysis showed that 32.8% of Pen tumors have a mutation in exons 5-8 and 50.0% presented LOH. Co-occurrence of TP53 mutation and LOH mainly characterized Pen A tumors (p = 0.022).

CONCLUSIONS

Our analyses revealed that clinico-pathological parameters, microsatellite status and frequency of TP53 mutations do not seem to distinguish Pen subgroups. Conversely, the amplification of GATA6 was associated with Pen B, as well as the overexpression of MUC6 and the TP53^mut/LOH significantly characterized Pen A.

Transcriptional Profile of Helicobacter pylori Virulence Genes in Patients with Gastritis and Gastric Cancer

Introduction

Numerous molecular epidemiology studies have been performed about the frequency of Helicobacter pylori virulence genes in patients with H. pylori infection so far. This study was conducted to detect transcriptional profile by cDNA of H. pylori virulence genes in gastric biopsy samples of gastritis and gastric carcinoma patients.

Materials and Methods

In a case-control study, based on the prevalence of gastritis and gastric cancer in Sanandaj city during 2018 and 2019, 23 and 11 gastric antral biopsy samples with H. pylori infection were collected from gastritis and gastric carcinoma patients by the consecutive and available sampling method. Pathological characters, including tumor grades and tumor areas for gastric carcinoma biopsy samples prepared from gastric cancer areas, were determined by the pathologist. Total RNA of gastric antral biopsy samples was extracted, and their cDNA was synthesized by TaKaRa kit. H. pylori virulence genes' cDNA using specific primers and PCR was detected. This study's results were analyzed by SPSS version 25 and statics chi-square tests for determination of relationship and correlation between cDNAs of H. pylori transcriptional profile and clinical outcomes of H. pylori infection, including gastritis, gastric carcinoma, tumor grades, and tumor area.

Results

The positive statistical correlations were observed between transcripts of cagA, cagA-EPIYAC, cagE, and cagY genes and H. pylori infection clinical outcomes (P < 0.05).

Conclusion

Detection of the H. pylori virulence genes' cDNA in gastric biopsy samples can help provide the prognosis of clinical outcomes.

Establishment of Decision Rules and Risk Assessment Model for Preoperative Prediction of Lymph Node Metastasis in Gastric Cancer

Background: Preoperative accurate prediction of lymph node status is especially important for the formulation of treatment plans for patients with gastric cancer (GC). The purpose of this study was to establish decision rules and a risk assessment model for lymph node metastasis (LNM) in GC using preoperative indicators. Methods: The clinical data of 554 patients who underwent gastrectomy with D2 lymphadenectomy were collected. A 1:1 propensity score matching (PSM) system was used, and the clinical data of the matched 466 patients were further analyzed. The important risk factors for LNM were extracted by the random forest algorithm, and decision rules and nomogram models for LNM were constructed with a classification tree and the "rms" package of R software, respectively. Results: Tumor size (OR: 2.058; P = 0.000), computed tomography (CT) findings (OR: 1.969; P = 0.001), grade (OR: 0.479; P = 0.000), hemoglobin (Hb) (OR: 1.211; P = 0.005), CEA (OR: 1.111; P = 0.017), and CA19-9 (OR: 1.040; P = 0.033) were independent risk factors for LNM in GC. Tumor size did rank first in the ranking of important factors for LNM in GC and was the first-level segmentation of the two initial branches of the classification tree. The accuracy, sensitivity, specificity, and positive predictive value of the decision rules in diagnosing preoperative LNM in GC were 75.6, 85.7, 73.9, 73.5, and 79.3%, respectively. The accuracy, sensitivity, and specificity of the risk assessment model in predicting preoperative LNM in GC were 79.3, 80.3, and 79.4%, respectively. Conclusion: Tumor size was the most important factor for evaluating LNM in GC. This decision rules and nomogram model constructed to take into account tumor size, CT findings, grade, hemoglobin, CEA, and CA19-9 effectively predicted the incidence of LNM in preoperative GC.

Precancerous lesions of the stomach, gastric cancer and hereditary gastric cancer syndromes

Gastric cancer accounts for about 6% of cancers worldwide, being the fifth most frequently diagnosed malignancy and the third leading cause of cancer related death. Gastric carcinogenesis is a multistep and multifactorial process and is the result of the complex interplay between genetic susceptibility and environmental factors. The identification of predisposing conditions and of precancerous lesions is the basis for screening programs and early stage treatment. Furthermore, although most gastric cancers are sporadic, familial clustering is observed in up to 10% of patients. Among them, hereditary cases, related to known cancer susceptibility syndromes and/or genetic causes are thought to account for 1-3% of all gastric cancers. The pathology report of gastric resections specimens therefore requires a standardized approach as well as in depth knowledge of prognostic and treatment associated factors.

SNAI1 is a prognostic biomarker and correlated with immune infiltrates in gastrointestinal cancers

Epithelial-mesenchymal transition (EMT)-related genes play an important role in immunosuppression. However, the correlations of EMT-related genes to prognosis and tumor-infiltrating lymphocytes in different cancers remain unclear. TCGA, GEO databases were used to analyze the expression, prognosis, and immune infiltration of EMT markers in cancer. RT-qPCR, immunohistochemistry, and western blot were used to analysis the expression and prognosis of SNAI1 in gastrointestinal cancers. High SNAI1 expression was closely related with poorer overall survival in gastrointestinal cancers in TCGA cohort. High SNAI1 expression was closely related with poorer overall survival in gastrointestinal cancers, and was validated in GEO database. Simultaneously, high expression of SNAI1 correlates with clinical relevance of gastric cancer. Moreover, SNAI1 expression was associated with tumor-infiltrating immune cells in gastrointestinal cancers. In addition, RT-qPCR, immunohistochemistry, and western blot showed SNAI1 expression was higher in gastrointestinal cancers compared to the normal tissues. Finally, high SNAI1 expression was closely related with poorer overall survival and correlates with clinical relevance of gastrointestinal cancers in an independent validation cohort. In summary, the results approaches to suggest that SNAI1 can be used as a prognostic biomarker for determining prognosis and immune infiltration in gastrointestinal cancers.

Large population-based study using the SEER database: is endoscopic resection appropriate for early gastric cancer patients in the United States?

AIM

To investigate whether endoscopic treatment is applicable to American patients and explores the predictors of lymph node metastasis (LNM) in early gastric cancer (EGC).

METHODS

Patients with EGC confined to either mucosa (T1a, n = 1799) and submucosa (T1b, n = 1689) were identified from the Surveillance, Epidemiology, and End Result database. Multivariate logistic regression, Kaplan-Meier method, and univariate/multivariate Cox regression were used to assess the correlation between invasion depth and LNM or prognosis. A nomogram for predicting LNM was constructed and internally validated.

RESULTS

EGC limited to T1a exhibited a 2.4% incidence of LNM, which increased to 11.1% when the depth invaded T1b.LNM was present at 1.4%, 5.2%, and 5.0% for sizes ≤2, 2-5, and >5cm of low-grade T1a EGC, respectively, (p = .019) and at 4.8%, 12.4%, and 28.6% of T1b EGC, respectively (p  < .001).The multivariate logistic model revealed that older age, T1b invasion, larger tumor size, and high-grade lesions were associated with a higher risk of LNM. Moreover, the T1a EGC patients had better cancer-specific survival (OS) and overall survival(CSS) compared with the T1b EGC patients (5-year OS: 77.2% versus 67.4%, p < .001; 5-year CSS: 90.6% versus 81.4%, p < .001). The discrimination of the prediction model was 0.745.

CONCLUSIONS

Endoscopic treatment may only be suitable for patients in the US population who have low-grade T1a lesions of less than 2 cm in size. Patients with T1a lesions of greater than 2 cm in size, lesions with high-grade, and all T1b lesions may benefit from radical surgical resection with lymphadenectomy.

The optimal timing of additional surgery after non-curative endoscopic resection to treat early gastric cancer: long-term follow-up study

Patients with early gastric cancer (EGC) who undergo non-curative endoscopic resection (ER) require additional surgery. The aim of the study was to validate surgical and oncological outcomes according to the timing of additional surgery after non-curative endoscopic resection. We retrospectively analyzed long-term follow-up data on the 302 patients enrolled between January 2007 and December 2014. We validated our earlier suggestion that the optimal time interval from non-curative ER to additional surgery was 29 days. All patients were divided into two groups by reference to time intervals from ER to additional surgery of ≤29days (n = 133; group A) and >29 days (n = 169; group B). The median follow-up duration was 41.98 ± 21.23 months. As in our previous study, group B exhibited better surgical outcomes. A total of 10 patients developed locoregional or distant recurrences during the follow-up period, but no significant difference was evident between the two groups. Interestingly, the survival rate was better in group B. Group B (>29 days) exhibited better surgical and oncological outcomes. Thus, additional gastrectomy after non-curative ER should be delayed for 1 month to ensure optimal surgical and oncological outcomes.

Progress in prevention and treatment of gastric cancer with traditional Chinese medicine

Gastric cancer (GC) is one of the most common malignant tumors of the upper digestive tract, threatening the health of Chinese people seriously. It is often diagnosed at the late stage of the disease because of the lack of specific symptoms and signs in the early stage. However, traditional Chinese medicine (TCM) has good effects in the prevention and treatment of GC. This article reviews the etiology, pathogenesis, syndrome differentiation, and classification of GC, as well as the application of TCM in precancerous lesions of GC, preoperative neoadjuvant chemotherapy of GC, postoperative chemotherapy, and prolonging the life span of GC patients.

Laparoscopic gastrectomy for early gastric cancer and the risk factors of lymph node metastasis

Objective:

Lymph node metastasis (LNM) is one of the important prognostic factors of early gastric cancer (EGC). Moreover, LNM is also important when choosing therapeutic intervention for EGC patients. The purpose of this study is to explore the risk factors of LNM in EGC and to discuss the corresponding treatment.

Design:

We retrospectively reviewed the medical records of 253 patients with EGC who underwent surgical therapy in our department between 2012 and 2015. Univariate analysis and Multivariate Cox regression were used to evaluate the independent risk factors of LNM.

Results:

LNM was present in 38 cases among 253 patients (15%). Univariate analysis showed an obvious correlation between LNM and tumour location, tumour size, depth of invasion, morphological classification, gross type of the lesion and venous invasion. Multivariate analysis indicated that poorly differentiated carcinoma, submucosal cancer, tumour size ≥2 cm and venous invasion were the independent risk factors for LNM.

Conclusion:

Tumour size, depth of invasion, morphological classification and blood vessel invasion were predictive risk factors for LNM in EGC. We propose that EGC patients with those risk factors should be accepted gastrectomy with LN dissection.

An aggressive early gastric cancer: Kodama's PenA type

BACKGROUND

To investigate the role of Kodama PenA subtype in influencing survival in patients with early gastric cancer (EGC).

METHODS

All patients surgically treated for EGC at 7 Italian centers (Forlì, Varese, Siena, Verona, Milan, Rome and Perugia) belonging to the Italian Research Group for Gastric Cancer (GIRCG) from January 1982 and December 2009 were included.

RESULTS

PenA patients were 230 (21.5%) while other types were 839 (78.5%). Nodal metastases were more common in PenA (30.7%) than non-PenA (10.4%) EGCs. Among preoperative variables, only age (OR 1.02; 95% CI 1.00-1.03, p = 0.009) and macrotype III (OR 1.95; 95% CI 1.39-2.75, p = 0.0001) were significantly associated with Pen A type. Survival analysis performed on N0 patients demonstrated that only size >2 cm (HR 1.85; 95% CI 1.12-3.05, p = 0.017) and age (HR 1.06; 95% CI 1.03-1.08, p < 0.0001) were independent poor prognostic factor. Among N+ patients age (HR 1.04; 95% CI 1.00-1.07, p = 0.048), number of positive lymph nodes (HR 1.13; 95% CI 1.05-1.20, p = 0.0002) and PenA (HR 4.23; 95% CI 1.70-10.55, p = 0.002) were significantly correlated with poor prognosis at multivariate analysis.

CONCLUSIONS

Kodama PenA subtype was the most powerful independent prognostic factor in patients with nodal metastases. Its status should always be investigated in EGCs patients.

Early Gastric Cancer: Clinical Behavior and Treatment Options. Results of an Italian Multicenter Study on Behalf of the Italian Gastric Cancer Research Group (GIRCG)

BACKGROUND

Early gastric cancer (EGC) generally has a good prognosis. However, the current definition of EGC includes various subgroups of patients with different pathological characteristics and different prognoses, some of whom have aggressive disease with a biological behavior similar to that of advanced carcinoma.

MATERIALS AND METHODS

We retrospectively evaluated 1,074 patients with EGC who had undergone surgery between 1982 and 2009. The cumulative incidence function of cancer-specific mortality and competing mortality were estimated using the Fine and Gray method.

RESULTS

The median follow-up period was 193 months (range 1-324). Five hundred and sixty-two (52.3%) patients died, 96 (8.9%) from EGC. The 5-, 10-, and 15-year cumulative incidence rates for mortality of all causes were 20.5% (95% confidence interval [CI] 18.0-22.9), 37.1% (95% CI 34.7-40.7), and 52.6% (95% CI 49.1-56.0), respectively; for cancer-specific mortality, 6.0% (95% CI 4.5-7.6), 9.9% (95% CI 7.9-11.9), and 11.1% (95% CI 8.8-13.3), respectively; and for mortality of other causes, 14.4% (95% CI 12.1-16.6), 27.2% (95% CI 24.2-30.2), and 41.5% (95% CI 38.1-43.3), respectively. A significant increase in the risk of cancer-specific mortality was observed for lesions >2 cm (adjusted hazard ratio [HR] = 1.44, 95% CI 1.07-1.94), Pen A-type disease (adjusted HR = 1.73, 95% CI 1.15-2.61), and node-positive cancers (adjusted HR = 2.28, 95% CI 1.61-3.21).

CONCLUSION

Patients with EGC with tumors >2 cm, Pen A-type disease according to Kodama, or lymph node metastases show a poorer prognosis and an increased risk of cancer-specific mortality.

IMPLICATIONS FOR PRACTICE

Early gastric cancer generally has a good prognosis, and some patients can be treated radically by endoscopic resection. However, the current definition of early gastric cancer includes subgroups of patients with an aggressive disease. In particular, patients with lymph node metastases and Pen A-type tumors according to Kodama's classification need a more invasive treatment, such as subtotal or total gastrectomy with an extended D2 lymphadenectomy, plus eventual adjuvant chemotherapy.

Construction and external validation of a nomogram that predicts lymph node metastasis in early gastric cancer patients using preoperative parameters

Objective

To create a nomogram to predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients and to externally validate the nomogram.

Methods

To construct the nomogram, we retrospectively analyzed a primary cohort of 272 EGC patients. Univariate analysis and a binary logistic regression were performed. A nomogram predicting the incidence of LNM in EGC patients was created. The discrimination ability of the nomogram was measured using the concordance index (c-index), and the nomogram was also calibrated. Then, another prospective cohort of 81 patients was analyzed to validate the nomogram.

Results

In the primary cohort, LNM was pathologically confirmed in 37 (13.6%) patients. In multivariate analysis, the presence of an ulcer, the maximum lesion diameter observed via gastroscopy, the thickness of the lesion observed via endoscopic ultrasonography, and the presence of enlarged lymph nodes on computed tomography (CT) were independent risk factors for LNM. A nomogram was then created based on the regression model with the c-index of 0.905, and the calibration curve of the nomogram fell approximately on the ideal 45-degree line. The cut-off score of the nomogram was 110, and the sensitivity, specificity, positive predictive and negative predictive values of the nomogram in the primary cohort were 81.1%, 86.0%, 47.6% and 96.7%, respectively, and in the prospective validation cohort were 75.0%, 91.0%, 60.0% and 95.5%, respectively. The calibration curve of the external validation cohort was almost on the 45-degree line.

Conclusions

We developed an effective nomogram predicting the incidence of LNM for EGC patients.

Prediction model for non-curative resection of endoscopic submucosal dissection in patients with early gastric cancer

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a useful method for complete resection of early gastric cancer (EGC). However, there are still some patients who undergo additional gastrectomy after ESD because of non-curative resection. There is no model that can accurately predict non-curative resection of ESD. We aimed to create a model for predicting non-curative resection of ESD in patients with EGC.

PATIENTS AND METHODS

We reviewed the medical records, including all gross findings of EGC, of patients who underwent ESD for EGCs. We divided the patients into a non-curative resection group and a curative resection group. The clinicopathologic characteristics were compared between the groups to identify the risk factors for non-curative resection of ESD. We created a scoring system based on logistic regression modeling and bootstrap validation.

RESULTS

Of 1639 patients who had undergone ESD for EGCs, 272 were identified as being treated non-curatively with ESD. A large tumor size (≥20 mm), tumor location in the upper body of the stomach, the presence of ulcer, fusion of gastric folds, the absence of mucosal nodularity, spontaneous bleeding, and undifferentiated tumor histology were associated with non-curative resection of ESD. Points of risk scores were assigned for these variables based on the β coefficient as follows: tumor size (≥20 mm), 2 points; tumor location in the upper body of the stomach, 1 point; ulcer, 2 points; fusion of gastric folds, 2 points; absence of mucosal nodularity, 1 point; spontaneous bleeding, 1 point; and undifferentiated histology, 2 points. Our risk scoring model showed good discriminatory performance on internal validation (bootstrap-corrected area under the receiver operating characteristic curve, 0.7004; 95% confidence interval, 0.6655-0.7353).

CONCLUSIONS

We developed a validated prediction model that can be used to identify patients who will undergo non-curative resection of ESD. Our prediction model can provide useful information for making decisions about the treatment of EGC before performing ESD.

Preoperative Metabolic Syndrome Is Predictive of Significant Gastric Cancer Mortality after Gastrectomy: The Fujian Prospective Investigation of Cancer (FIESTA) Study

Metabolic syndrome (MetS) has been shown to be associated with an increased risk of gastric cancer. However, the impact of MetS on gastric cancer mortality remains largely unknown. Here, we prospectively examined the prediction of preoperative MetS for gastric cancer mortality by analyzing a subset of data from the ongoing Fujian prospective investigation of cancer (FIESTA) study. This study was conducted among 3012 patients with gastric cancer who received radical gastrectomy between 2000 and 2010. The latest follow-up was completed in 2015. Blood/tissue specimens, demographic and clinicopathologic characteristics were collected at baseline. During 15-year follow-up, 1331 of 3012 patients died of gastric cancer. The median survival time (MST) of patients with MetS was 31.3months, which was significantly shorter than that of MetS-free patients (157.1months). The coexistence of MetS before surgery was associated with a 2.3-fold increased risk for gastric cancer mortality (P<0.001). The multivariate-adjusted hazard ratios (HRs) were increased with invasion depth T1/T2 (HR=2.78, P<0.001), regional lymph node metastasis N0 (HR=2.65, P<0.001), positive distant metastasis (HR=2.53, P<0.001), TNM stage I/II (HR=3.00, P<0.001), intestinal type (HR=2.96, P<0.001), negative tumor embolus (HR=2.34, P<0.001), and tumor size ≤4.5cm (HR=2.49, P<0.001). Further survival tree analysis confirmed the top splitting role of TNM stage, followed by MetS or hyperglycemia with remarkable discrimination ability. In this large cohort study, preoperative MetS, especially hyperglycemia, was predictive of significant gastric cancer mortality in patients with radical gastrectomy, especially for early stage of gastric cancer.

Histology-based prediction of lymph node metastases in early gastric cancer as decision guidance for endoscopic resection

Background

Selected cases of early gastric cancer (EGC) can be successfully treated by endoscopic therapy if the risk of concurrent lymph node metastases (LNM) is negligible. Criteria for endoscopic resection based on risk factor analyses for LNM have been established mainly in Asia. However, it is not clear to what extent these recommendations can be transferred to Western collectives. The aim of this study was to analyze predictors for LNM in EGC in a Western study population.

Methods

From our institutional archive, we selected all patients with gastric adenocarcinoma who had undergone gastrectomy with lymphadenectomy (1972 – 2005). Among 1970 patients 275 cases with EGC were identified. Clinical and pathological data were collected and logistic regression analyses performed.

Results

LNM were present in 36/275 (13.1%) patients. With deeper invasion proportion of LNM increased. At submucosa level (sm1), patients were almost five times more likely to have LNM than at mucosa levels.

Multivariable logistic regression analysis revealed lymphovascular invasion, diffuse- and mixed-type, and invasion depth as significant independent histopathological predictors of LNM. In patients with intestinal type according to Lauren and no lymphovascular invasion, we found only one LNM-positive case out of 43 patients in the pT1b (sm1 and sm2) groups.

Conclusions

Our results underline the recommendation of most guidelines that endoscopic resection is sufficient for pT1a ECG because of the low incidence of LNM in this group. However, there seems also a role for endoscopic therapy in cases of pT1b (sm1/2) EGC with intestinal type differentiation and no lymphovascular invasion.

Poorly Differentiated Medullary Phenotype Predicts Poor Survival in Early Lymph Node-Negative Gastro-Esophageal Adenocarcinomas

BACKGROUND

5-year survival rate in patients with early adenocarcinoma of the gastro-esophageal junction or stomach (AGE/S) in Caucasian patients is reported to be 60-80%. We aimed to identify prognostic markers for patients with UICC-I without lymph-node involvement (N0).

METHODS

Clinical data and tissue specimen from patients with AGE/S stage UICC-I-N0, treated by surgery only, were collected retrospectively. Tumor size, lymphatic vessel or vein invasion, grading, classification systems (WHO, Lauren, Ming), expression of BAX, BCL-2, CDX2, Cyclin E, E-cadherin, Ki-67, TP53, TP21, SHH, Survivin, HIF1A, TROP2 and mismatch repair deficiency were analyzed using tissue microarrays and correlated with overall and tumor related survival.

RESULTS

129 patients (48 female) with a mean follow-up of 129.1 months were identified. 5-year overall survival was 83.9%, 5-year tumor related survival was 95.1%. Poorly differentiated medullary cancer subtypes (p<0.001) and positive vein invasion (p<0.001) were identified as risk factors for decreased overall-and tumor related survival. Ki-67 (p = 0.012) and TP53 mutation (p = 0.044) were the only immunohistochemical markers associated with worse overall survival but did not reach significance for decreased tumor related survival.

CONCLUSION

In the presented study patients with AGE/S in stage UICC-I-N0 had a better prognosis as previously reported for Caucasian patients. Poorly differentiated medullary subtype was associated with reduced survival and should be considered when studying prognosis in these patients.

Histomorphologic features of early gastric carcinoma treated by endoscopic submucosal dissection: relation to efficiency of endoscopic resection

OBJECTIVE

Early gastric cancer (EGC) is defined as cancer invasion confined to the mucosa or submucosa, irrespective of lymph node metastasis. Recently endoscopic submucosal dissection (ESD) has been widely accepted for the treatment for dysplasia and EGC without lymph node metastases. While the method has been advanced in Far East countries, ESD is still being developed in Europe and has not gained enough popularity although it has been recommended as the treatment of choice for superficial gastric neoplastic lesions by European Society of Gastrointestinal Endoscopy (ESGE) in 2015.

METHODS

The aim of the study was to perform a retrospective analysis of clinical and histomorphologic features of 58 cases of EGCs removed by ESD in a university hospital in Western Pomerania in Poland and to evaluate factors related to the efficiency of ESD resection.

RESULTS

With univariate analysis, indications for ESD with the highest R0 rate were found in EGCs limited to mucosa (T1a, small mucosal, M), without muscularis mucosa invasion, localised in the middle/lower part of stomach and intestinal type in histological examination. The R0 complete resection rate was significantly (p < 0.0001) lower for T1b than that for T1a tumours (21.4% vs. 100%). Tumours with submucosal involvement were associated with lower efficiency of ESD procedure.

CONCLUSIONS

Our data showed that in EGCs with favourable histomorphologic characteristics, ESD seemed to be a totally efficient and safe method of treatment in a European small-volume centre. R0 resection rate reached 81.1% of cases and median time of the ESD procedure was 61.5 min.

A nomogram composed of clinicopathologic features and preoperative serum tumor markers to predict lymph node metastasis in early gastric cancer patients

Predicting lymph node metastasis (LNM) accurately is of great importance to formulate optimal treatment strategies preoperatively for patients with early gastric cancer (EGC). This study aimed to explore risk factors that predict the presence of LNM in EGC. A total of 697 patients underwent gastrectomy enrolled in this study, were divided into training and validation set, and the relationship between LNM and other clinicopathologic features, preoperative serum combined tumor markers (CEA, CA19-9, CA125) were evaluated. Risk factors for LNM were identified using logistic regression analysis, and a nomogram was created by R program to predict the possibility of LNM in training set, while receiver operating characteristic (ROC) analysis was applied to assess the predictive value of the nomogram model in validation set. Consequently, LNM was significantly associated with tumor size, macroscopic type, differentiation type, ulcerative findings, lymphovascular invasion, depth of invasion and combined tumor marker. In multivariate logistic regression analysis, factors including of tumor size, differentiation type, ulcerative findings, lymphovascular invasion, depth of invasion and combined tumor marker were demonstrated to be independent risk factors for LNM. Moreover, a predictive nomogram with these independent factors for LNM in EGC patients was constructed, and ROC curve demonstrated a good discrimination ability with the AUC of 0.847 (95% CI: 0.789-0.923), which was significantly larger than those produced in previous studies. Therefore, including of these tumor markers which could be convenient and feasible to obtain from the serum preoperatively, the nomogram could effectively predict the incidence of LNM for EGC patients.

Sentinel Lymph Node Navigation Surgery for Early Gastric Cancer: Is It a Safe Procedure in Countries with Non-Endemic Gastric Cancer Levels? A Preliminary Experience

Purpose

Early diagnosis of gastric cancer is still the exception in Western countries. In the East, as in Japan and Korea, this disease is an endemic disorder. More conservative surgical procedures are frequently performed in early gastric cancer cases in these countries where sentinel lymph node navigation surgery is becoming a safe option for some patients. This study aims to evaluate preliminary outcomes of patients with early gastric cancer who underwent sentinel node navigation surgeries in Brazil, a country with non-endemic gastric cancer levels.

Materials and Methods

From September 2008 to March 2014, 14 out of 205 gastric cancer patients underwent sentinel lymph node navigation surgeries, which were performed using intraoperative, endoscopic, and peritumoral injection of patent blue dye.

Results

Antrectomies with Billroth I gastroduodenostomies were performed in seven patients with distal tumors. The other seven patients underwent wedge resections. Sentinel basin resections were performed in four patients, and lymphadenectomies were extended to stations 7, 8, and 9 in the other 10. Two patients received false-negative results from sentinel node biopsies, and one of those patients had micrometastasis. There was one postoperative death from liver failure in a cirrhotic patient. Another cirrhotic patient died after two years without recurrence of gastric cancer, also from liver failure. All other patients were followed-up for 13 to 79 months with no evidence of recurrence.

Conclusions

Sentinel lymph node navigation surgery appears to be a safe procedure in a country with non-endemic levels of gastric cancer.

A nomogram for predicting the likelihood of lymph node metastasis in early gastric patients

Background

Early gastric cancer is defined as a lesion confined to the mucosa or submucosa, regardless of the size or lymph node metastasis. Treatment methods include endoscopic mucosal resection or endoscopic submucosal dissection, wedge resection, laparoscopically assisted gastrectomy and open gastrectomy. Lymph node metastasis is strong related with survival and recurrence. Therefore, the likelihood of lymph node metastasis is one of the most important factors when determining the most appropriate treatment.

Methods

We retrospectively analyzed 597 patients who underwent D2 gastrectomy for early gastric cancer. The relationship between lymph node metastasis and clinicopathological features was analyzed. Using multivariate logistic regression analyses, we created a nomogram to predict the lymph node metastasis probability for early gastric cancer. Receiver operating characteristic analyses was performed to assess the predictive value of the model.

Results

In the present study, 58 (9.7 %) early gastric cancer patients were histologically shown to have lymph node metastasis. The multivariate logistic regression analysis demonstrated that the age at diagnosis, differentiation status, the presence of ulcers, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in early gastric cancer. Additionally, the tumor macroscopic type, size and histology type significantly correlated with these important independent factors. We constructed a predictive nomogram with these factors for lymph node metastasis in early gastric cancer patients, and the discrimination was good with the AUC of 0.860 (95 % CI: 0.809–0.912).

Conclusions

We developed an effective nomogram to predict the incidence of lymph node metastasis for early gastric cancer patients.

Upgrading the definition of early gastric cancer: better staging means more appropriate treatment

Since Murakami defined early gastric cancer (EGC) as a "carcinoma limited to the gastric mucosa and/or submucosa regardless of the lymph node status", several authors have focused on the most influential histopathological parameters for predicting the development of lymph node metastases by considering the lymph node status as an important prognostic factor. A few authors have also considered the depth of invasion as one of the keys to explaining the existence of subgroups of patients affected by EGC with poor prognoses. In any case, EGC is still considered an initial phase of tumor progression with good prognosis. The introduction of modern endoscopic devices has allowed a precise diagnosis of early lesions, which can lead to improved definitions of tumors that can be radically treated with endoscopic mucosal resection or endoscopic submucosal dissection (ESD). Given the widespread use of these techniques, the Japanese Gastric Cancer Association (JGCA) identified in 2011 the standard criteria that should exclude the presence of lymph node metastases. At that time, EGCs with nodal involvement should have been asserted as no longer fitting the definition of an early tumor. Some authors have also demonstrated that the morphological growth pattern of a tumor, according to Kodama's classification, is one of the most important prognostic factors, thereby suggesting the need to report it in histopathological drafts. Notwithstanding the acquired knowledge regarding the clinical behavior of EGC, Murakami's definition is still being used. This definition needs to be upgraded according to the modern staging of the disease so that the appropriate treatment would be selected.

Overexpression of PI3K p110α contributes to acquired resistance to MET inhibitor, in MET-amplified SNU-5 gastric xenografts

Gastric cancer is one of the most virulent malignant diseases and is the second leading cause of cancer mortality in the world. The receptor tyrosine kinase MET is constitutively activated in many gastric cancers and its expression is strictly required for survival of some gastric cancer cells. Targeting gastric cancers with amplified or abnormally activated MET may have therapeutic benefit based on nonclinical and emerging clinical findings. However, one of the major problems of therapies targeting tyrosine kinases is that many tumors are not responsive to treatment or eventually develop resistance to the drugs. This study aims to understand the mechanisms of MET resistance in gastric SNU-5 xenografts which developed resistance to PHA665752, a MET inhibitor, through long-period tyrosine kinase inhibitor exposure. In the current study, we found that PI3K p110α is overexpressed in PHA665752-resistant SNU-5 xenografts. These findings showed that high PI3K p110α expression contributes to tyrosine kinase inhibitor resistance. In addition, we reported the development of a carcinogen-induced gastric cancer model that recapitulates PI3K p110α expression in human disease, which will serve as a useful model to study PI3K p110α's biology and its effectiveness as a novel biomarker and a molecular target for gastric cancer. Ultimately, PI3K p110α represents a novel target for gastric cancer.

Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer

AIM: To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors.

METHODS: Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis.

RESULTS: LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups.

CONCLUSION: LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

Evaluation of a novel high-resolution magnifying videoendoscope that is capable of photodynamic diagnosis and therapy for gastric cancer

OBJECTIVE

To evaluate the usefulness of a novel high-resolution magnifying videoendoscope called the XG-0001 (Fujifilm, Tokyo, Japan) that is capable of PDD and PDT in experimental and clinical situations.

MATERIALS AND METHODS

The fluorescences of three photosensitizers (i.e., porfimer sodium (Photofrin), protoporphyrin IX and talaporfin sodium (Laserphyrin)) were studied experimentally via excitation with a purple diode laser (VDL, wavelength 405nm). Five consecutive patients with superficial early gastric cancer not indicated for surgery or other curative endoscopic treatment due to complicated serious diseases were enrolled in this study. After close endoscopic examinations, 2mg/kg of Photofrin were intravenously injected into the patients for PDT, and 5-aminolevulinic acid (ALA; 15-20mg/kg) was orally taken for PDD. PDD using VDL and PDT using an excimer-dye laser (630nm, 4mJ, 60Hz) were performed with the XG-0001.

RESULTS

Photofrin and Laserphyrin had experimentally the lowest and highest fluorescence intensities, respectively. The five patients comprised four men and one woman with a mean age 75.2 year and an age range of 56-83 years. Two additional cancerous lesions were newly detected by magnifying pharmacoendoscopy. In each patient, PDD was successfully performed. PDT could also safely performed and CR was obtained in 71.4% (5/7) of the cancerous lesions in five patients, and no serious complications were encountered.

CONCLUSION

The XG-0001, which is based on a simultaneous videoendoscopy method that uses an RGB color chip CCD, proved extremely useful in routine use and also in PDD and PDT for gastric cancer.

Histopathology-based prognostic score is independent prognostic factor of gastric carcinoma

Background

The aim of our study was to evaluate the histological characteristics and prognosis of gastric cancer.

Methods

Clinicopathlogical variables of 932 patients with gastric carcinoma admitted to the Department of Surgical Oncology at the First Hospital of China Medical University were analyzed retrospectively. Different histological characteristics of gastric cancer were summarized and assigned score according to the malignancy defined by WHO classification, the scores were stratified into 4 stage, the prognosis of different stages were analyzed by Kaplan-Meier analysis and cox regression.

Results

Among the 932 patients, 246 (26.39%) had mixed histology type of gastric cancer. Compared to the pure histological type, mixed histological type of gastric cancer was significant associated with tumor size, lymph node metastasis and depth of invasion (all P < 0.05). The 5-year survival rates of advanced and early gastric cancer patients with mixed type were 40.8% and 83.5% respectively, which were lower than those with pure type (50.0% and 95.8%, P < 0.01). Statistically significant difference with stratification of early and advanced stage could be observed between patients with the histological grading score. The data showed that the histological score could be the independent factor of prognosis.

Conclusions

The histological score is an independent factor of gastric cancer, it exerts an excellent ability to classify survival of patients with gastric carcinoma. It also provides a new strategy and parameter for evaluating the biological behavior and prognosis of gastric cancer.

Characterization of lymph node metastasis and its clinical significance in the surgical treatment of gastric cancer

This study aimed to characterize lymph node metastasis and determine its clinical significance in the surgical treatment of gastric cancer. The medical charts of 920 gastric cancer patients who underwent radical surgical resection between March, 2010 and March, 2013, were retrospectively reviewed and statistically analyzed. Lymphatic metastasis was observed in 69.6% of the patients (640/920). The frequency of lymph node metastasis in patients with early-stage gastric cancer was 21.4% (18/84). Lymph node metastasis was observed in all the patients with stage IIIC-IV gastric cancer. The incidence of lymph node metastasis was higher among patients with tumors >7 cm in size. The most frequently affected lymph nodes in patients with proximal, central and distal gastric cancer were station no. 1 (34.2%), no. 3 (33.8%) and no. 6 (34.3%) lymph nodes, respectively. The frequency of lymph node metastasis in patients with Borrmann type IV cancer was significantly higher compared to that in patients with other Borrmann type cancers. Our study further demonstrated that lymphatic metastasis is closely correlated with TNM stage, location, depth of invasion and size of gastric tumors. Therefore, we recommend that a sufficient number of lymph nodes be examined from each patient to determine the extent of lymph node dissection based on Borrmann type, location, size, depth of invasion and histology of the cancer.

Treatment of early gastric cancer in the Western World

The incidence rate of gastric cancer is much higher in Asia than in the Western industrial nations. According to the different screening programs in Japan and Korea about fifty percent of treated patients had an early tumor stage. In contrast, European and American patients with gastric cancer had an advanced tumor stage. Therefore, the experience for the various therapeutic options for gastric cancer may be different between these regions. In this review we tried to point out the treatment modalities in Western industrial countries for early gastric cancer.