Comparison of the 6th and 7th editions of the AJCC/UICC TNM staging system for gastric cancer focusing on the "N" parameter-related survival: the monoinstitutional NodUs Italian study

LUM as a novel prognostic marker and its correlation with immune infiltration in gastric cancer: a study based on immunohistochemical analysis and bioinformatics

BACKGROUND

Gastric cancer (GC) is considered the sixth highly prevailing malignant neoplasm and is ranked third in terms of cancer mortality rates. To enable an early and efficient diagnosis of GC, it is important to detect the fundamental processes involved in the oncogenesis and progression of gastric malignancy. The understanding of molecular signaling pathways can facilitate the development of more effective therapeutic strategies for GC patients.

METHODS

The screening of genes that exhibited differential expression in early and advanced GC was performed utilizing the Gene Expression Omnibus databases (GSE3438). Based on this, the protein and protein interaction network was constructed to screen for hub genes. The resulting list of hub genes was evaluated with bioinformatic analysis and selected genes were validated the protein expression by immunohistochemistry (IHC). Finally, a competing endogenous RNA network of GC was constructed.

RESULTS

The three genes (ITGB1, LUM, and COL5A2) overexpressed in both early and advanced GC were identified for the first time. Their upregulation has been linked with worse overall survival (OS) time in patients with GC. Only LUM was identified as an independent risk factor for OS among GC patients by means of additional analysis. IHC results demonstrated that the expression of LUM protein was increased in GC tissue, and was positively associated with the pathological T stage. LUM expression can effectively differentiate tumorous tissue from normal tissue (area under the curve = 0.743). The area under 1-, 3-, and 5-year survival relative operating characteristics were greater than 0.6. Biological function enrichment analyses suggested that the genes related to LUM expression were involved in extracellular matrix development-related pathways and enriched in several cancer-related pathways. LUM affects the infiltration degree of cells linked to the immune system in the tumor microenvironment. In GC progression, the AC117386.2/hsa-miR-378c/LUM regulatory axis was also identified.

CONCLUSION

Collectively, a thorough bioinformatics analysis was carried out and an AC117386.2/hsa-miR-378c/LUM regulatory axis in the stomach adenocarcinoma dataset was detected. These findings should serve as a guide for future experimental investigations and warrant confirmation from larger studies.

Novel γδ T cell-based prognostic signature to estimate risk and aid therapy in hepatocellular carcinoma

BACKGROUND

Numerous studies have revealed that gamma delta (γδ) T cell infiltration plays a crucial regulatory role in hepatocellular carcinoma (HCC) development. Nonetheless, a comprehensive analysis of γδ T cell infiltration in prognosis evaluation and therapeutic prediction remains unclear.

METHODS

Multi-omic data on HCC patients were obtained from public databases. The CIBERSORT algorithm was applied to decipher the tumor immune microenvironment (TIME) of HCC. Weighted gene co-expression network analysis (WGCNA) was performed to determine significant modules with γδ T cell-specific genes. Kaplan-Meier survival curves and receiver operating characteristic analyses were used to validate prognostic capability. Additionally, the potential role of RFESD inhibition by si-RFESD in vitro was investigated using EdU and CCK-8 assays.

RESULTS

A total of 16,421 genes from 746 HCC samples (616 cancer and 130 normal) were identified based on three distinct cohorts. Using WGCNA, candidate modules (brown) with 1755 significant corresponding genes were extracted as γδ T cell-specific genes. Next, a novel risk signature consisting of 11 hub genes was constructed using multiple bioinformatic analyses, which presented great prognosis prediction reliability. The risk score exhibited a significant correlation with ICI and chemotherapeutic targets. HCC samples with different risks experienced diverse signalling pathway activities. The possible interaction of risk score with tumor mutation burden (TMB) was further analyzed. Subsequently, the potential functions of the RFESD gene were explored in HCC, and knockdown of RFESD inhibited cell proliferation in HCC cells. Finally, a robust prognostic risk-clinical nomogram was developed and validated to quantify clinical outcomes.

CONCLUSIONS

Collectively, comprehensive analyses focusing on γδ T cell patterns will provide insights into prognosis prediction, the mechanisms of immune infiltration, and advanced therapy strategies in HCC.

Prognostic Ferroptosis-Related lncRNA Signatures Associated With Immunotherapy and Chemotherapy Responses in Patients With Stomach Cancer

Ferroptosis is associated with the prognosis and therapeutic responses of patients with various cancers. LncRNAs are reported to exhibit antitumor or oncogenic functions. Currently, few studies have assessed the combined effects of ferroptosis and lncRNAs on the prognosis and therapy of stomach cancer. In this study, transcriptomic and clinical data were downloaded from TCGA database, and ferroptosis-related genes were obtained from the FerrDb database. Through correlation analysis, Cox analysis, and the Lasso algorithm, 10 prognostic ferroptosis-related lncRNAs (AC009299.2, AC012020.1, AC092723.2, AC093642.1, AC243829.4, AL121748.1, FLNB-AS1, LINC01614, LINC02485, LINC02728) were screened to construct a prognostic model, which was verified in two test cohorts. Risk scores for patients with stomach cancer were calculated, and patients were divided into two risk groups. The low-risk group, based on the median value, had a longer overall survival time in the KM curve, and a lower proportion of dead patients in the survival distribution curve. Potential mechanisms and possible functions were revealed using GSEA and the ceRNA network. By integrating clinical information, the association between lncRNAs and clinical features was analyzed and several features affecting prognosis were identified. Then, a nomogram was developed to predict survival rates, and its good predictive performance was indicated by a relatively high C-index (0.67118161) and a good match in calibration curves. Next, the association between these lncRNAs and therapy was explored. Patients in the low-risk group had an immune-activating environment, higher immune scores, higher TMB, lower TIDE scores, and higher expression of immune checkpoints, suggesting they might receive a greater benefit from immune checkpoint inhibitor therapy. In addition, a significant difference in the sensitivity to mitomycin. C, cisplatin, and docetaxel, but not etoposide and paclitaxel, was observed. In summary, this model had guiding significance for prognosis and personalized therapy. It helped screen patients with stomach cancer who might benefit from immunotherapy and guided the selection of personalized chemotherapeutic drugs.

Inflammation-Related Long Non-Coding RNA Signature Predicts the Prognosis of Gastric Carcinoma

Background: Gastric carcinoma (GC) is a molecularly and phenotypically highly heterogeneous disease, making the prognostic prediction challenging. On the other hand, Inflammation as part of the active cross-talk between the tumor and the host in the tumor or its microenvironment could affect prognosis.

Method: We established a prognostic multi lncRNAs signature that could better predict the prognosis of GC patients based on inflammation-related differentially expressed lncRNAs in GC.

Results: We identified 10 differently expressed lncRNAs related to inflammation associated with GC prognosis. Kaplan-Meier survival analysis demonstrated that high-risk inflammation-related lncRNAs signature was related to poor prognosis of GC. Moreover, the inflammation-related lncRNAs signature had an AUC of 0.788, proving their utility in predicting GC prognosis. Indeed, our risk signature is more precise in predicting the prognosis of GC patients than traditional clinicopathological manifestations. Immune and tumor-related pathways for individuals in the low and high-risk groups were further revealed by GSEA. Moreover, TCGA based analysis revealed significant differences in HLA, MHC class-I, cytolytic activity, parainflammation, co-stimulation of APC, type II INF response, and type I INF response between the two risk groups. Immune checkpoints revealed CD86, TNFSF18, CD200, and LAIR1 were differently expressed between lowand high-risk groups.

Conclusion: A novel inflammation-related lncRNAs (AC015660.1, LINC01094, AL512506.1, AC124067.2, AC016737.1, AL136115.1, AP000695.1, AC104695.3, LINC00449, AC090772.1) signature may provide insight into the new therapies and prognosis prediction for GC patients.

Transcription factor KLF15 inhibits the proliferation and migration of gastric cancer cells via regulating the TFAP2A-AS1/NISCH axis

BACKGROUND

Recently, overwhelming evidence supports that long noncoding RNAs (lncRNAs) play crucial roles in the occurrence and progression of tumors. However, the role and mechanism of lncRNA TFAP2A-AS1 in human gastric cancer (GC) remains unclear. Thus, the biological role and regulatory mechanisms of TFAP2A-AS1 in GC were explored.

METHODS

Quantitative real-time PCR (qPCR) was applied to detect gene expression. Western blot was used to measure protein expression. Cell proliferation and migration were determined by functional assays. Fluorescence in situ hybridization (FISH) assays were performed to determine the subcellular distribution of TFAP2A-AS1 in GC. Mechanism investigations were conducted to explore the downstream genes of TFAP2A-AS1 and the upstream transcription factor of TFAP2A-AS1 in GC cells.

RESULTS

TFAP2A-AS1 inhibits the proliferation and migration of GC cells. In the downstream regulation mechanism, miR-3657 was verified as the downstream gene of TFAP2A-AS1 and NISCH as the target of miR-3657. NISCH also suppresses cell proliferation and migration in GC. In the upstream regulation mechanism, transcription factor KLF15 positively mediates TFAP2A-AS1 to suppress GC cell proliferation and migration.

CONCLUSION

KLF15-mediated TFAP2A-AS1 hampers cell proliferation and migration in GC via miR-3657/NISCH axis.

Prognostic Role of ceRNA Network in Immune Infiltration of Hepatocellular Carcinoma

Background: Increasing evidence supports that competing endogenous RNAs (ceRNAs) and tumor immune infiltration act as pivotal players in tumor progression of hepatocellular carcinoma (HCC). Nonetheless, comprehensive analysis focusing on ceRNAs and immune infiltration in HCC is lacking.

Methods: RNA and miRNA sequencing information, corresponding clinical annotation, and mutation data of HCC downloaded from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) project were employed to identify significant differentially expressed mRNAs (DEMs), miRNAs (DEMis), and lncRNAs (DELs) to establish a ceRNA regulatory network. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene ontology (GO) enrichment pathways were analyzed to functionally annotate these DEMs. A multigene-based risk signature was developed utilizing least absolute shrinkage and selection operator method (LASSO) algorithm. Moreover, survival analysis and receiver operating characteristic (ROC) analysis were applied for prognostic value validation. Seven algorithms (TIMER, XCELL, MCPcounter, QUANTISEQ, CIBERSORT, EPIC, and CIBERSORT-ABS) were utilized to characterize tumor immune microenvironment (TIME). Finally, the mutation data were analyzed by employing “maftools” package.

Results: In total, 136 DELs, 128 DEMis, and 2,028 DEMs were recognized in HCC. A specific lncRNA–miRNA–mRNA network consisting of 3 lncRNAs, 12 miRNAs, and 21 mRNAs was established. A ceRNA-based prognostic signature was established to classify samples into two risk subgroups, which presented excellent prognostic performance. In additional, prognostic risk-clinical nomogram was delineated to assess risk of individual sample quantitatively. Besides, risk score was significantly associated with contexture of TIME and immunotherapeutic targets. Finally, potential interaction between risk score with tumor mutation burden (TMB) was revealed.

Conclusion: In this work, comprehensive analyses of ceRNAs coexpression network will facilitate prognostic prediction, delineate complexity of TIME, and contribute insight into precision therapy for HCC.

Comparison of the sixth, seventh, and eighth editions of the American Joint Committee on Cancer Tumor-Node-Metastasis staging system for gastric cancer: A single institution experience

In 2018, the eighth edition of the American Joint Committee on Cancer Tumor-Node-Metastasis classification and staging system was implemented. Few reports were made comparing the performance of different editions of the American Joint Committee on Cancer (AJCC) system. Therefore, this study aimed to examine the prognostic predictability from the sixth to the eighth editions of the AJCC staging system for gastric cancer.A total of 414 patients with gastric cancer who underwent surgery at Changhua Christian Hospital from January 2007 to December 2017 were enrolled in the study. To identify the prognostic factors for gastric cancer death, univariate and multivariate analyses were performed. The homogeneity and discrimination abilities of the sixth to eighth editions of the staging system were compared using the likelihood ratio chi-square test, linear trend chi-square test, and Akaike information criterion.The sixth edition of the staging system had the lowest Akaike information criterion value, suggesting a better prognostic stratification than other editions. From the result of the likelihood ratio chi-square test, the T and N staging systems of the seventh and eighth editions had better homogeneity and discriminatory ability than the sixth edition. The eighth edition had better prognostic performance in patients at stage III compared with the seventh edition.The AJCC seventh and eighth editions had improved prognostic predictability of the T and N factors compared with the sixth edition. However, the overall staging performance of the eighth edition is not superior compared to the sixth edition. Further studies with larger sample size should be conducted to compare the performance of different editions of the AJCC staging system for different ethnic populations.

Immunological Value of Prognostic Signature Based on Cancer Stem Cell Characteristics in Hepatocellular Carcinoma

Background: Liver cancer stem cells, characterized by self-renewal and initiating cancer cells, were decisive drivers of progression and therapeutic resistance in hepatocellular carcinoma (HCC). However, a comprehensive understanding of HCC stemness has not been identified.

Methods: RNA sequencing information, corresponding clinical annotation, and mutation data of HCC were downloaded from The Cancer Genome Atlas-LIHC project. Two stemness indices, mRNA expression-based stemness index (mRNAsi) and epigenetically regulated-mRNAsi, were used to comprehensively analyze HCC stemness. Estimation of Stromal and Immune Cells in Malignant Tumors using Expression Data and single-sample gene-set enrichment analysis algorithm were performed to characterize the context of tumor immune microenvironment (TIME). Next, differentially expressed gene (DEG) analysis and weighted gene co-expression network analysis (WGCNA) were employed to identify significant mRNAsi-related modules with hub genes. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment pathways were analyzed to functionally annotate these key genes. The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was performed to establish a prognostic signature. Kaplan–Meier survival curves and receiver operating characteristic (ROC) analysis were applied for prognostic value validation. Seven algorithms (XCELL, TIMER, QUANTISEQ, MCPcounter, EPIC, CIBERSORT, and CIBERSORT-ABS) were utilized to draw the landscape of TIME. Finally, the mutation data were analyzed by employing “maftools” package.

Results: mRNAsi was significantly elevated in HCC samples. mRNAsi escalated as tumor grade increased, with poor prognosis presenting the higher stemness index. The stemness-related (greenyellow) modules with 175 hub genes were screened based on DEGs and WGCNA. A prognostic signature was established using LASSO analysis of prognostic hub genes to classify samples into two risk subgroups, which exhibited good prognostic performance. Additionally, prognostic risk-clinical nomogram was drawn to estimate risk quantitatively. Moreover, risk score was significantly associated with contexture of TIME and immunotherapeutic targets. Finally, potential interaction between risk score with tumor mutation burden (TMB) was elucidated.

Conclusion: This work comprehensively elucidated that stemness characteristics served as a crucial player in clinical outcome, complexity of TIME, and immunotherapeutic prediction from both mRNAsi and mRNA level. Quantitative identification of stemness characteristics in individual tumor will contribute into predicting clinical outcome, mapping landscape of TIME further optimizing precision immunotherapy.

Multi-omics analysis reveals prognostic value of tumor mutation burden in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) was the sixth common malignancies characteristic with highly aggressive in the world. It was well established that tumor mutation burden (TMB) act as indicator of immunotherapeutic responsiveness in various tumors. However, the role of TMB in tumor immune microenvironment (TIME) is still obscure.

METHOD

The mutation data was analyzed by employing "maftools" package. Weighted gene co-expression network analysis (WGCNA) was implemented to determine candidate module and significant genes correlated with TMB value. Differential analysis was performed between different level of TMB subgroups employing R package "limma". Gene ontology (GO) enrichment analysis was implemented with "clusterProfiler", "enrichplot" and "ggplot2" packages. Then risk score signature was developed by systematical bioinformatics analyses. K-M survival curves and receiver operating characteristic (ROC) plot were further analyzed for prognostic validity. To depict comprehensive context of TIME, XCELL, TIMER, QUANTISEQ, MCPcounter, EPIC, CIBERSORT, and CIBERSORT-ABS algorithm were employed. Additionally, the potential role of risk score on immune checkpoint blockade (ICB) immunotherapy was further explored. The quantitative real-time polymerase chain reaction was performed to detect expression of HTRA3.

RESULTS

TMB value was positively correlated with older age, male gender and early T status. A total of 75 intersection genes between TMB-related genes and differentially expressed genes (DEGs) were screened and enriched in extracellular matrix-relevant pathways. Risk score based on three hub genes significantly affected overall survival (OS) time, infiltration of immune cells, and ICB-related hub targets. The prognostic performance of risks score was validated in the external testing group. Risk-clinical nomogram was constructed for clinical application. HTRA3 was demonstrated to be a prognostic factor in HCC in further exploration. Finally, mutation of TP53 was correlated with risk score and do not interfere with risk score-based prognostic prediction.

CONCLUSION

Collectively, a comprehensive analysis of TMB might provide novel insights into mutation-driven mechanism of tumorigenesis further contribute to tailored immunotherapy and prognosis prediction of HCC.

A four-lncRNA signature for predicting prognosis of recurrence patients with gastric cancer

Purpose

This study aimed to develop a multi-long noncoding RNA (lncRNA) signature for the prediction of gastric cancer (GC) based on differential gene expression between recurrence and nonrecurrence patients.

Methods

By repurposing microarray expression profiles of RNAs from The Cancer Genome Atlas (TCGA), we performed differential expression analysis between recurrence and nonrecurrence patients. A prognostic risk prediction model was constructed based on data from TCGA database, and its reliability was validated using data from Gene Expression Omnibus database. Furthermore, the lncRNA-associated competing endogenous RNA (ceRNA) network was constructed, namely, DIANA-LncBasev2 and starBase database.

Results

We identified 363 differentially expressed RNAs (317 mRNAs, 18 lncRNAs, and 28 microRNAs [miRNAs]). Principal component analysis showed that the seven-feature lncRNAs screened by support vector machine-recursive feature elimination algorithm was more informative for predicting recurrence of GC in comparison with the eight-feature lncRNAs screened by random forest-out-of-bag algorithm. Four of the seven-feature lncRNAs including LINC00843, SNHG3, C21orf62-AS1, and MIR99AHG were chosen to develop a four-lncRNA risk score model. This risk score model was able to distinguish patients with high and low risk of recurrence, and was tested in two independent validation sets. The ceRNA network of this four-lncRNA signature included 10 miRNAs and 178 mRNAs. The mRNAs significantly related to the Wnt-signaling pathway and relevant biological processes.

Conclusion

A useful four-lncRNA signature recurrence was established to distinguish GC patients with high and low risk of recurrence. Regulating the relevant miRNAs and Wnt pathway might partly affect GC metastasisby.

Differential prognostic implications of gastric adenocarcinoma based on Lauren's classification: a Surveillance, Epidemiology, and End Results (SEER)-based cohort study

Background

Our study aims to analyze the association between Lauren's classification and gastric adenocarcinoma prognosis using comprehensive statistical analyses.

Methods

According to the selection criteria, patients were included from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression, propensity score matching, and a multivariate competing risk model were used to investigate the association between Lauren's classification and prognosis. Subgroup analysis was used to investigate the role of confounding factors on the association between Lauren types and prognosis.

Results

After exclusion, a total of 20,218 patients from the SEER database were included, with 14,374 intestinal types and 5,844 diffuse types. The univariate Cox regression analysis revealed that the diffuse type had a poorer cancer-specific survival (CSS) rate [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.38-1.50]. After adjusting for confounding variables, the diffuse type also showed a higher risk of cancer-specific death (HR, 1.20; 95% CI, 1.15-1.20). Sensitivity analysis showed that after propensity score matching, the diffuse type had a poorer CSS rate (HR, 1.23; 95% CI, 1.10-1.36), and the competing risk model further validated these results [subdistribution HR (SHR), 1.32; 95% CI, 1.23-1.41]. Moreover, subgroup analysis demonstrated stable results in the subgroups, except for patients with T1 stage (HR, 1.06; 95% CI, 0.87-1.28) and a tumor size <2 cm (HR, 1.00; 95% CI, 0.83-1.21).

Conclusions

Diffuse-type gastric adenocarcinoma had an overall poorer prognosis compared to the intestinal type. However, in patients with T1 stage and tumor size <2 cm, the diffuse type had a comparable survival rate with the intestinal type.

Development and validation of a novel staging system integrating the number and location of lymph nodes for gastric adenocarcinoma

Background

Evidence suggests that the anatomic extent of metastatic lymph nodes (MLNs) affects prognosis, as proposed by alternative staging systems. The aim of this study was to establish a new staging system based on the number of perigastric (PMLN) and extra-perigastric (EMLN) MLNs.

Methods

Data from a Chinese cohort of 1090 patients who had undergone curative gastrectomy with D2 or D2 plus lymphadenectomy for gastric cancer were retrospectively analysed. A Japanese validation cohort (n = 826) was included. Based on the Cox proportional hazards model, the regression coefficients of PMLN and EMLN were used to calculate modified MLN (MMLN). Prognostic performance of the staging systems was evaluated.

Results

PMLN and EMLN were independent prognostic factors in multivariate analysis (coefficients: 0.044, 0.115; all P < 0.001). MMLN was calculated as follows: MMLN = PMLN + 2.6 × EMLN. The MMLN staging system showed superior prognostic performance (C-index: 0.751 in the Chinese cohort; 0.748 in the Japanese cohort) compared with the five published LN staging systems when MMLN numbers were grouped as follows: MMLN0 (0), MMLN1 (1–4), MMLN2 (5–8), MMLN3 (9–20), and MMLN4 (>20).

Discussion

The MMLN staging system is suitable for assessing overall survival among patients undergoing curative gastrectomy with D2 or D2 plus lymphadenectomy.

Impact of the 8th edition of the AJCC TNM classification on gastric cancer prognosis-study of a western cohort

Introduction

The 8th edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer introduced changes, mainly in stage III, with the incorporation of the pN3 sub-classification in the final staging group. The goal was to compare the 7th and 8th editions to evaluate the discriminative capacity of the new edition.

Methods

This study was a retrospective review of patients with gastric cancer treated with surgery in 2013 and 2014.

Results

We analysed 310 patients, with a median age of 66 years and out of which 55.5% were male. The most commonly performed surgery was subtotal gastrectomy (n = 158; 51%), with a median of 30 lymph nodes removed. With a median follow-up of 39.5 months, the 1- and 3-year overall survival (OS) was 82% and 59%, respectively. In stage III (n = 115), there was stage migration in 40 cases (34.8%), with upstage in 11 cases and downstage in 29 cases. In this group, there was a statistically significant difference in OS between N3a and N3b patients (p = 0.002), as well as a statistically significant difference in OS between stages IIIA, IIIB and IIIC when the 8th edition was applied (p = 0.001), which was not verified with the 7th edition (p = 0.057). In multivariate analysis, both extracapsular extension and N classification from TNM were independent prognostic factors (p = 0.033 and p = 0.024, respectively).

Conclusion

The 8th edition of the AJCC TNM classification allows for a better prognostic refinement, namely in the new stage III groups after the stratification of lymph node disease in N3a and N3b. Factors that evaluate the biological behaviour of the disease remain excluded from this edition, such as extracapsular extension, which had a prognostic impact in our series.

Proposal of a novel subclassification of pN3b for improvement the prognostic discrimination ability of gastric cancer patients

INTRODUCTION

In the recent edition of TNM staging system, pN3b gastric cancer were separated into the staging system for better prognosis accuracy. The definition of pN3b contains a large range of metastasis lymph nodes (mLNs). However, few studies have evaluated the prognosis of pN3b patients and it remains unknown whether these patients were reasonably assigned into the same substage.

MATERIALS AND METHODS

A total of 642 pN3b patients from a multi-institutional cohort in China were included. Disease-specific survival (DSS) was estimated using the Kaplan-Meier method and the Cox proportional hazards regression analysis was used to identify the independent prognostic factors. Restricted cubic spine model was used to specify the association between the continuous variables and the logarithm Hazard ratios (HRs). The optimal cut-off value of mLNs for DSS was identified using the X-tile software.

RESULTS

The 5-year DSS rate of total pN3b cohort was 15.4%. The smooth curves showed a non-linear association between the mLNs and the logarithm HRs. All pN3b gastric cancer patients were divided into two subclassifications (pN3b1: 16-24 mLNs, pN3b2: ≥25 mLNs). Significant survival difference was observed between two subclassifications (P = 0.048). Additionally, more LNs examined could decrease the death risk of pN3b patients and bring survival benefit only in pN3b1 patients, but not in pN3b2 patients.

CONCLUSIONS

We proposed a novel subclassification of pN3b patients, which assigned patients into two subclassifications with significant survival difference. Future study should explore the prognosis value based on this novel subclassification in TNM staging system.

Patterns of recurrence in adenocarcinoma of the esophagogastric junction: a retrospective study

Background

The prognosis of adenocarcinoma of the esophagogastric junction (AEG) is poor. Understanding the postoperative recurrence pattern of AEG is helpful to verify the effectiveness of treatment and optimize subsequent treatment, so as to improve prognosis.

Methods

This single-center retrospective study included patients with stage III AEG who underwent surgical treatment between January 2009 and December 2016. According to the different postoperative treatment arm, patients were divided into surgery and surgery plus chemotherapy groups. Recurrence-free survival was used as the outcome to compare the recurrence site and pattern between the groups.

Results

In total, were 306 patients enrolled, 123 in the surgery group and 183 in the surgery plus chemotherapy group. During follow-up (median 17.1 months) of 24 months after surgery, 62.0% of patients had tumor recurrence. The overall recurrence rates in the surgery and surgery plus chemotherapy groups were 86.9% and 77.0%, respectively. The recurrence patterns of both groups were mainly distant metastasis. Postoperative chemotherapy reduced the incidence of hematogenous dissemination from 51.2 to 42.0%. Multivariate Cox analysis showed that the pN stage increased the risk of recurrence, while surgery plus chemotherapy reduced the risk.

Conclusions

Patients with AEG have a risk of hematogenous dissemination after surgery. Postoperative treatment arm and pN stage were independent risk factors in patients with AEG. Surgery plus chemotherapy can improve recurrence-free survival and reduce distant metastasis, but they do not have a beneficial role in controlling local recurrence.

Development and validation of a novel nomogram to predict overall survival in gastric cancer with lymph node metastasis

Gastric cancer (GC) with lymph node metastasis (LNM) at diagnosis is associated with a unstable prognosis and indefinite survival times. The aim of the present study was to construct and validate a model for the Overall survival (OS) estimation for patients with LNM. The nomogram was constructed to predict the OS for LNM-positive GC using the primary group of 836 patients and validated using an independent cohort of 411 patients. Factors in the nomogram were identified by multivariate Cox hazard analysis. The predictive capability of nomogram was evaluated by calibration analysis and decision curve analysis. Multivariate analysis suggested that eight pre-treatment characteristics were used for developing the nomogram. In the primary cohort, the C-index for OS prediction was 0.788 (95% CI: 0.753-0.823), while in validation cohort, the C-index for OS prediction was 0.769 (95% CI: 0. 720-0.818). The calibration plot for the probability of OS and decision curve analyses showed an optimal agreement. Based on the nomogram, we could divided patients into three groups: low-risk group, middle-risk group and a high-risk group(p <0.001).Taken together, we have provided an easy-to-used and accurate tool for predicting OS, furthermore could be used for risk stratification of OS of LNM-positive GC patients.

Proposal of a novel stage grouping of the Eighth Edition of American Joint Committee on Cancer TNM Staging System for Gastric Cancer: results from a retrospective study of 30 years clinical data from a single institute in China

Objectives: To improve the prognostic accuracy of 8th edition of American Joint Committee on Cancer TNM staging system for gastric cancer by reclassifying N3a category.Methods: 1446 patients who underwent R0 surgery for histologically proven gastric cancers with ≥16 lymph nodes retrieved were selected.Results: Significant prognostic difference was observed among patients in N3a category ('7-10' group vs '11-15' group; P = 0.029). We proposed a revised pN category in which patients with '7-10' metastatic lymph nodes were categorized as r-N3a, '11-15' as r-N3b, and '>15' as r-N3c. Prognosis for patients in T2r-N3aM0 was similar to that of patients in T4aN0M0/T3N1M0/T2N2M0/T1r-N3bM0 (P = 0.584), but significantly better than that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.031). Similarly, prognoses for patients in T3r-N3aM0 and T4ar-N3aM0 were similar to that of patients in T4bN0M0/T4aN1-2M0/T3N2M0/T2r-N3bM0 (P = 0.136; P = 0.193), but significantly better than that of patients in T4bN1-2M0/T4ar-N3bM0/T3r-N3bM0/T1-2r-N3cM0 (P = 0.011; P = 0.017). A revised TNM system was also proposed, in which T2r-N3aM0 was incorporated into stage IIB, T3r-N3aM0 and T4ar-N3aM0 into stage IIIA. The revised TNM system had better homogeneity, discriminatory ability, and monotonicity of gradients than the 8th edition system.Conclusion: Patients with 7-10 metastatic lymph nodes in T2-T4a categories should be considered lower stage in the final TNM stage.

LncRNA MINCR regulates irradiation resistance in nasopharyngeal carcinoma cells via the microRNA-223/ZEB1 axis

Emerging evidence suggests long non-coding RNA (lncRNA) could sponge microRNAs (miRs) and monitor gene expression. In this study, we intended to search the network involving lncRNA MINCR/miR-223/ZEB1 in nasopharyngeal carcinoma (NPC) cell radiosensitivity. MINCR expression in NPC tissues, precancerous lesions and chronic nasopharyngeal mucosal inflammation tissues, and in NP460, CNE2 and CNE2R cells was detected. The associations between MINCR expression and prognosis and radiotherapy efficacy of NPC patients were evaluated. The interactions among MINCR, miR-223 and ZEB1 were verified via dual luciferase reporter gene assay, RNA pull-down and FISH assays. The gain- and loss-of-functions were performed to explore their effects on NPC cell viability, apoptosis and radiosensitivity. Levels of MINCR, miR-223, ZEB1, and AKT/PI3K-related proteins were detected after different treatments. An in vivo analysis was carried out in nude mice. Consequently, MINCR was upregulated in NPC, and linked with worse prognosis and radiotherapy efficacy. MINCR intervention weakened NPC cell radioresistance. MINCR sponged miR-223 to regulate ZEB1. Inactivating AKT eliminated the increased radioresistance of CNE2 cells induced by overexpressing MINCR. Briefly, MINCR diminished NPC cell radiosensitivity by sponging miR-223, increasing ZEB1 and activating the AKT/PI3K axis. This study may offer novel insight for NPC treatment.

Integrated analysis reveals potential long non-coding RNA biomarkers and their potential biological functions for disease free survival in gastric cancer patients

Background

Increasing evidences supported the association between long non-coding RNA (lncRNA) and disease free survival in gastric cancer (GC) patients. The purpose of the current study was to construct and verify a noninvasive preoperative predictive tool for disease free survival in GC patients.

Methods

There were 265 and 300 GC patients in model dataset and validation dataset respectively. The associations between the lncRNA biomarkers and disease free survival were evaluated by univariate and multivariate Cox regression.

Results

Thirteen lncRNA biomarkers (GAS5-AS1, AL109615.3, KDM7A-DT, AP000866.2, KCNJ2-AS1, LINC00656, LINC01777, AC046185.3, TTTY14, LINC01526, LINC02523, LINC00592, and C5orf66) were identified as prognostic biomarkers with disease free survival. These thirteen lncRNA biomarkers were combined to construct a prognostic signature for disease free survival. The C-indexes of the current predictive signature in model cohort were 0.849 (95% CI 0.803–0.895), 0.859 (95% CI 0.813–0.905) and 0.888 (95% CI 0.842–0.934) for 1-year, 3-year and 5-year disease free survival respectively. Based on thirteen-lncRNA prognostic signature, patients in model cohort could be stratified into high risk group and low risk group with significant different disease free survival rate (hazard ratio [HR] = 7.355, 95% confidence interval [CI] 4.378–12.356). Good reproducibility of thirteen-lncRNA prognostic signature was confirmed in an external validation cohort (GSE62254) with HR 3.919 and 95% CI 2.817–5.453. Further analysis demonstrated that the prognostic significance of thirteen-lncRNA prognostic signature was independent of other clinical characteristics.

Conclusions

In conclusion, a simple noninvasive prognostic signature was established for preoperative prediction of disease free survival in GC patients. This prognostic signature might predict the individual mortality risk of disease free survival without pathological information and facilitate individual treatment decision-making.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0846-6) contains supplementary material, which is available to authorized users.

The discovery of a novel eight-mRNA-lncRNA signature predicting survival of hepatocellular carcinoma patients

Increasing evidence indicates that the expressions of messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs) undergo a frequent and aberrant change in carcinogenesis and cancer development. But some research was carried out on mRNA-lncRNA signatures for prediction of hepatocellular carcinoma (HCC) prognosis. We aimed to establish an mRNA-lncRNA signature to improve the ability to predict HCC patients' survival. The subjects from the cancer genome atlas (TCGA) data set were randomly divided into two parts: training data set (n = 246) and testing data set (n = 124). Using computational methods, we selected eight gene signatures (five mRNAs and three lncRNAs) to generate the risk score model, which were significantly correlated with overall survival of patients with HCC in both training and testing data set. The signature had the ability to classify the patients in training data set into a high-risk group and low-risk group with significantly different overall survival (hazard ratio = 4.157, 95% confidence interval = 2.648-6.526, P < 0.001). The prognostic value was further validated in testing data set and the entire data set. Further analysis revealed that this signature was independent of tumor stage. In addition, Gene Set Enrichment Analysis suggested that high risk score group was associated with cell proliferation and division related pathways. Finally, we developed a well-performed nomogram integrating the prognostic signature and other clinical information to predict 3- and 5-year overall survival. In conclusion, the prognostic mRNAs and lncRNAs identified in our study indicate their potential role in HCC biogenesis. The risk score model based on the mRNA-lncRNA may be an efficient classification tool to evaluate the prognosis of patients' with HCC.

Anatomical location-based nodal staging system is superior to the 7th edition of the American Joint Committee on Cancer staging system among patients with surgically resected, histologically low-grade gastric cancer: A single institutional experience

Background

A hybrid topographic and numeric lymph node (LN) staging system for gastric cancer, which was recently proposed by Japanese experts as a simple method with a prognostic predictive power comparable to the N staging of the American Joint Committee on Cancer (AJCC) Tumor-node-metastasis classification, has not yet been validated in other Asian countries. This study aimed to examine the prognostic predictability of the hybrid staging system with the current AJCC staging system in gastric cancer.

Methods

Overall, 400 patients with gastric cancer who underwent surgery at Changhua Christian Hospital from January 2007 to December 2017 were included in the study. Univariate and multivariate analyses were performed to identify prognostic factors for gastric cancer-related death. Homogeneity and discrimination abilities of the two staging systems were compared using likelihood ratio chi-square test, linear trend chi-square test, Harrell’s c-index, and bootstrap analysis.

Results

One-third of the LN-positive patients were reclassified into the new N and Stage system. The concordance rates of the two staging systems and the N staging between the two staging systems were 0.810 and 0.729, respectively. Harrell’s c-indices for the stage and N staging were higher in the 7^th AJCC staging system than the hybrid staging system (c-index for stage, 0.771 vs 0.764; c-index for nodal stage, 0.713 vs 0.705). Stratification of the patients according to the histological grade revealed that Harrell’s c-indices for the stage and N stage of the hybrid staging system were comparable with those of the 7^th AJCC staging system (c-index for AJCC stage vs hybrid stage, 0.800 vs 0.791; c-index for AJCC N stage vs hybrid N stage, 0.746 vs 0.734) among patients with histologically lower grade gastric cancer. The performance of the new nodal staging system was better than that of the 7^th AJCC staging system by likelihood ratio and linear trend tests and bootstrap analysis in the low-grade group.

Conclusions

The hybrid anatomical location-based classification may have better prognostic predictive ability than the 7^th AJCC staging system for LN metastasis of low-grade gastric cancer. Further studies involving different ethnic populations are necessary for the validation of the new staging system.

Surgical Compliance and Outcomes in Gastric Cancer: a population-based cohort study

Background: Surgical resection is one of curative treatment for gastric cancer (GC), however, a set of patients show poor surgical compliance in the USA. We aimed to identify the risk factors associated with surgical compliance and investigate the difference in survival.

Methods: GC patients diagnosed between 1973 and 2014 were identified from the Surveillance Epidemiology and End Results (SEER) databases. Based on different surgical compliance and treatment regimen, patients were classified into three subgroups: surgical compliance group, surgical noncompliance group, and non-surgical group. Multivariable Logistic regression analysis was adopted to identify the factors related to surgical compliance; Multivariable Cox regression was used to investigate the prognostic factors. Overall survival (OS) and cancer-specific survival (CSS) were analyzed using the Kaplan-Meier estimator method.

Results: Of 79374 GC patients who were recommended for surgical therapy, 15201(19.2%) cases did not perform surgery. Poor compliance of surgery was related to old age, American Indian/Alaska Native race, poor grading/late staging, single/widowed status, lower socioeconomic status and earlier time of diagnosis. As expected, GC patients of surgical compliance group showed significantly more favorable survival than the other two groups (P<0.0001); notably, the outcome of surgical noncompliance group came close to that of non-surgical group.

Conclusion: GC patients of poor surgical compliance demonstrated adverse survival, which was comparable to that of non-surgical patients. The poor surgical compliance was associated with older age, American Indian/Alaska Native race, poor tissue differentiation/advanced stage of tumor, single/widowed status, lower socioeconomic status and earlier time of diagnosis.

Novel role of miR-133a-3p in repressing gastric cancer growth and metastasis via blocking autophagy-mediated glutaminolysis

BACKGROUND

Autophagy plays a crucial role in sustaining the homeostasis in various malignant diseases. It has also been reported to promote tumor development in multiple cancers. Glutaminolysis instead of Warburg Effect produce adequate ATP and provide nitrogen and carbon to replenish the TCA cycle which has been discovered to be a new energy source for tumor cells recently. By means of degrading intracellular particles including amino acids, nucleotides, fatty acids, sugars and aged organisms, autophagy can recycle the aforementioned particles into bioenergetics and biosynthesis pathways, finally favoring tumor cells. MicroRNA is a kind of noncoding RNA that regulates the targeting gene expression mostly at post-transcription level. Among these miRNAs, microRNA-133a-3p is reported to be a tumor suppressor in numerous cancers.

METHODS

We characterized the down-regulated expression level of microRNA-133a-3p in gastric cancer via TCGA database. Subsequently, we verified the tumor suppressor role of microRNA-133a-3p in gastric cancer cells through a series biological function assay. We used immunofluorescence and transmission electron microscope to observe the negative effect of microRNA-133a-3p on autophagy and used dual-luciferase report assay to identify the candidate gene GABARAPL1 of microRNA-133A-3p.Then we used high performance liquid phase mass spectrometry and seahorse analysis to detect whether miR-133a-3p could block the glutaminolysis metabolism through autophagy. At last, we confirmed the tumor suppressor role of microRNA-133a-3p in vivo on PDX mice model.

RESULTS

We demonstrated that microRNA-133a-3p overexpression could block the activation of autophagy to ruin the abnormal glutaminolysis and further inhibit the growth and metastasis of gastric cancer cells. We successfully proved gastric cancer cells can replenish glutaminolysis via autophagy and microRNA-133a-3p could block aforementioned pathway by targeting core autophagy participants GABARAPL1 and ATG13.We then verified the negative function of microRNA-133a-3p on autophagy-mediated glutaminolysis both in PDX model and human gastric cancer organoid model.

CONCLUSIONS

MicroRNA-133a-3p targets GABARAPL1 to block autophagy-mediated glutaminolysis, further repressing gastric cancer growth and metastasis.

Development and validation of a prognostic signature for preoperative prediction of overall survival in gastric cancer patients

Background

As a serious challenge for public health, the prognosis of gastric cancer patients is still poor. The current study aimed to develop and validate a prognostic signature to predict the overall survival of gastric cancer patients.

Patients and methods

The dataset in the present study was obtained from The Cancer Genome Atlas database. The present study finally included 343 gastric cancer patients with information on long non-coding RNA (lncRNA) expression and overall survival.

Results

A prognostic model named Eleven-lncRNA signature was constructed according to the expression values of eleven prognostic lncRNA predictors identified by univariate and multivariate Cox regression model. According to time-dependent receiver operating characteristic curves, the Harrell's concordance indexes of Eleven-lncRNA signature were 0.764 (95% CI 0.720-0.808), 0.776 (95% CI 0.732-0.820), and 0.807 (95% CI 0.763-0.851) for 1-year overall survival, 3-year overall survival, and 5-year overall survival respectively in the model group. In the validation group, the Harrell's concordance indexes of Eleven-lncRNA signature were 0.748 (95% CI 0.704-0.792), 0.794 (95% CI 0.750-0.838), and 0.798 (95% CI 0.754-0.842) for 1-year overall survival, 3-year overall survival, and 5-year overall survival respectively. The gastric cancer patients (n=343) in the model group could be stratified into low-risk group (n=171) and high-risk group (n=172) according to the median of Eleven-lncRNA signature score. Kaplan-Meier survival curves showed that the mortality rate in the high-risk group was significantly poorer than that in the low-risk group (P<0.001).

Conclusion

The present study constructed and validated a prognostic model named Eleven-lncRNA signature for preoperative individual mortality risk prediction in gastric cancer patients. This Eleven-lncRNA signature can predict the individual mortality risk of gastric cancer patients and is helpful in improving clinical decision making regarding individualized treatment.

Assessment of the 8th edition of TNM staging system for gastric cancer: the results from the SEER and a single-institution database

AIM

To investigate whether the 8th edition of Tumor, Node, Metastasis (TNM) staging could properly evaluate the prognosis of gastric cancer patients.

METHODS

The prognostic performance between the 7th and 8th edition of TNM staging was compared and clinicopathologic features were analyzed.

RESULTS

The stage shifts in the 8th edition staging resulted in the increased numbers of stage IIIA patients and decreased numbers of stage IIB, stage IIIB and stage IIIC patients. Compared with the previous edition, the 8th edition of TNM staging provided a better prognostic stratification for stage III patients. However, whether it is reasonable to incorporate T4aN2, T4aN3a and T4bN3b into stage IIIA, stage IIIB and stage IIIC respectively, which still need further validation.

CONCLUSION

Despite the obvious superiority, several deficiencies may still exist in the new edition staging. To better provide prognostic information and therapeutic guidance for gastric cancer patients, the TNM staging system should be further improved in the future.

Correlations of TNM staging and lymph node metastasis of gastric cancer with MRI features and VEGF expression

OBJECTIVE

To investigate the correlations of expression of vascular endothelial growth factor (VEGF) in gastric cancer tissues of patients and magnetic resonance imaging (MRI) features with clinical tumor-node-metastasis (TNM) staging and lymph node metastasis, and to analyze the diagnostic value of MRI features for preoperative TNM staging and lymph node metastasis of patients with gastric cancer, and the roles of VEGF in tumor development and metastasis.

METHODS

A total of 120 gastric cancer patients treated in our hospital from May 2015 to July 2017 were selected as objects of study. The VEGF protein expressions in gastric cancer tissues of patients with different TNM staging and lymph node metastasis degrees were detected using immunohistochemical method, and the correlations of VEGF protein expression with TNM staging and lymph node metastasis were analyzed. Before operation, MRI was used to predict TNM staging and lymph node metastasis of all patients, and prediction results were compared with postoperative pathological diagnosis results. At the same time, the differences in lymph node apparent diffusion coefficient (ADC), long diameter and short diameter, relative ADC of primary lesion (rADCp) and relative ADC of muscle (rADCm) were compared and analyzed between lymph node metastasis group and non-lymph node metastasis group.

RESULTS

The VEGF expression in patients with stage-N3 gastric cancer was about 7 times that in patients with stage-N0 gastric cancer, and it was increased with the increased degree of lymph node metastasis (p< 0.01). The VEGF expression in patients with distant metastasis of tumor cells was significantly higher than that in patients without distant metastasis (p< 0.01). The expression of VEGF in stage-T4 gastric cancer was about 10 times that in stage-Tis cancer, and the larger the infiltration depth of tumor cells was, the higher the expression level of VEGF would be (p< 0.01). The VEGF expression in gastric cancer tissues was positively correlated with the infiltration depth, lymph node metastasis and distant metastasis of tumor cells. Moreover, the prediction results of MRI for TNM staging and lymph node metastasis before operation were compared with postoperative pathological results, and it was found that there was better consistency (Kappa = 0.739). ADC, rADCp and rADCm in gastric cancer patients without lymph node metastasis were significantly higher than those in patients with lymph node metastasis, but the short diameter and long diameter were obviously shorter than those in patients with lymph node metastasis, and the differences were statistically significant (p< 0.05).

CONCLUSION

The VEGF protein expression in gastric cancer tissues is positively correlated with TNM staging and lymph node metastasis in patients. The preoperative prediction results of MRI are well consistent with postoperative pathological results, and MRI features are correlated with lymph node metastasis in patients, which has an important guiding significance for the diagnosis and treatment of gastric cancer.

miR-671-5p inhibits gastric cancer cell proliferation and promotes cell apoptosis by targeting URGCP

Various studies have demonstrated that microRNA (miRNA) serves an important role in the development of gastric cancer. However, the expression level, clinical significance and the biological function of miRNA in gastric cancer remain largely unknown. The present study investigated the exact roles of miR-671-5p in gastric cancer, confirmed its target and explored its mechanism. Initially, the low expression levels of miR-671-5p in gastric cancer cells were confirmed by reverse transcription-quantitative polymerase chain reaction. TargetScan and MiRanda databases were utilized to forecast the target genes of miR-671-5p, and the prediction was verified by dual-luciferase reporter assay and western blot analysis. Cell Counting Kit-8 was used for cell proliferation detection. An annexin V-fluorescein isothiocyanate kit was used for cell apoptosis determination. Western blot analysis was adopted to measure the protein expression levels in different groups. The results of the present study revealed that there were lower expression levels of miR-671-5p in gastric cancer cells than in normal gastric cells. Upregulator of cell proliferation (URGCP) is a direct target of miR-671-5p and it may be negatively regulated by miR-671-5p. miR-671-5p mimics induced reduction of MKN28 cell proliferation. miR-671-5p mimics caused upregulation of MKN28 cell apoptosis. In addition, western blotting results indicated that the ratio of B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein was significantly decreased in the miR-671-5p mimic group compared with the negative control group (P<0.01). These results suggested that miR-671-5p had a protective role in gastric cancer through inhibiting gastric cancer cell proliferation and promoting cell apoptosis by targeting URGCP. Therefore, miR-671-5p may be an effective therapeutic target for gastric cancer.

Gastric cancer with breast metastasis: Clinical features and prognostic factors

Metastatic spread of gastric carcinoma to the breast is rare. In previous decades, reports on this subject were minimal and primarily limited to case reports. At present, little is known on the clinicopathological features and prognosis of this condition, and breast metastasis remains a challenging clinical problem. A total of 54 cases of breast metastasis from gastric cancer were collected from databases between January 1960 and December 2016. The present study included 3 cases of gastric cancer with breast metastasis from Renji hospital and 51 additional cases from previous studies. The clinicopathological features of patients, including epidemiology, symptoms, macroscopic presentation, pathological diagnosis, imaging, treatment and overall survival time, were analyzed. The median survival time was 8.6 months. All but one of the patients were female, and the median age at diagnosis of breast metastasis was 43 years old (age range, 22–72 years). A majority of patients presented with Borrmann class III disease, signet ring cell carcinoma, T4 tumor types, lymph node involvement, initial stage IV gastric cancer, primary lesions in the gastric antrum, left breast metastasis and palpable breast nodules. The median interval between the primary gastric carcinoma diagnosis and presentation of breast metastasis was 1.25 months (range, 0–72 months). The expression of the estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2 and gross cystic disease fluid protein-15 was negative in the patients with breast metastases. In univariate analysis, age, gastric tumor size, gastric lymph node involvement and breast metastasis histology were significantly associated with overall survival (OS) time (P=0.001, 0.039, 0.034 and <0.001, respectively). Therapeutically, gastric surgery and chemotherapy were not associated with OS (P=0.959 and 0.290, respectively). In further multivariate analysis, the time between occurrence (P=0.017), age (P=0.009), histology (P=0.045) and breast metastasis localization (P=0.043) were independent indicators of OS time. Although breast metastasis from gastric cancer is rare, physicians should be vigilant when patients with a history of gastric cancer present with newly developed mammary symptoms and signs.

Superiority of the 8th edition of the TNM staging system for predicting overall survival in gastric cancer: Comparative analysis of the 7th and 8th editions in a monoinstitutional cohort

The present study was performed to evaluate the predictive capacity of the 8th edition vs. the 7th edition of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system for overall survival (OS) of patients with gastric cancer. Data of eligible patients with gastric cancer in our institution between June 2004 and June 2014 were retrospectively reviewed. A total of 1,506 patients were followed up to July 2016, among whom 1,484 patients with complete stage information were included in the TNM staging analysis. A total of 339 (22.8%) patients presented stage migration, including 325 (21.9%) migrating to a lower tier and 14 (0.9%) to a higher tier. All patients with stage migration to a lower tier were in stage III, including 177 (54.5%) patients migrating from stage IIIB to IIIA, and 148 (45.5%) from stage IIIC to IIIB. Patients migrating from IIIB to IIIA yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIA. Similarly, patients migrating from IIIC to IIIB yielded a median OS time and 5-year OS rate closer to those remaining in stage IIIB. The 7th edition of the staging system exhibited prognostic discrepancy in discriminating stage IIIA from IIIB on survival curves, which was improved in the 8th edition. The 8th edition had a better predictive capability of survival, as evidenced by a smaller value of -2log likelihood in the Cox proportional regression model (7th edition 4738.859 vs. 8th edition 4736.683). Therefore, the present study demonstrated that the 8th edition of the AJCC TNM staging system is superior to the 7th edition in predicting the OS of patients with gastric cancer.

Clinical characteristics and prognostic significance of galectins for patients with gastric cancer: A meta-analysis

OBJECTIVE

To explore the relationships between the expression level of different galectins and its prognostic value for patients with gastric cancer.

METHODS

The PubMed, EMbase, the Cochrane Library and Web of Science databases were systematically searched. All the eligible studies were included according to the inclusion and exclusion criteria. All the relevant data was extracted by two independent researchers. The quality assessment was conducted according to the evaluation of the quality of prognosis study which published by Harden in 2006. The STATA 12.0 software was used to perform a meta-analysis.

RESULTS

All of 8 retrospective case-controlled studies involving 2093 patients with gastric cancer were included in this study. The results of meta-analysis presented that the elevated galectin-1 which is related to the poor overall survival (HR = 1.85, 95% CI: 1.33-2.58; P < 0.001) may predicted a larger tumor size (OR = 2.20, 95% CI: 1.35-3.35; P = 0.001) and was positively associated with the higher expression of VEGF (OR = 1.44, 95% CI: 1.14-1.82; P = 0.002). Moreover, the decreased galectin-3 (HR = 0.49, 95% CI: 0.36-0.67; P < 0.001), galectin-8 (HR = 0.49, 95% CI: 0.36-0.67; P < 0.001) and galectin-9 (HR = 0.78, 95% CI: 0.66-0.92; P = 0.003) were also significantly associated with poorer prognosis. Our meta-analysis also showed that lower expression of galectin-3 was also related to lymphatic vessel invasion (OR = 0.48, 95% CI: 0.26-0.89; P = 0.018), worse TNM stages (OR = 0.47, 95% CI: 0.32-0.40; P < 0.001), deeper invasive depth (OR = 0.33, 95% CI: 0.21-0.51; P < 0.001) and poorer differentiation grade (OR = 0.10, 95% CI: 0.04-0.25; P < 0.001).

CONCLUSIONS

High expression of galectin-1 or low expression of galectin-3, -8 and -9 were significantly related to a poorer prognosis for patients with gastric cancer. The expression level of galectins was associated with clinical characteristics and were potential independent prognostic predictor for GC patients.

Validation of the American Joint Commission on Cancer (8th edition) changes for patients with stage III gastric cancer: survival analysis of a large series from a Specialized Eastern Center

The 8th edition of the TNM was released in 2016 and included major revisions, especially for stage III. We aimed to compare the prognostic value of the 7th and 8th editions of the AJCC TNM classification for stage III gastric cancer. Clinical data from 1557 patients operated on for stage III gastric cancer according to the 7th edition between 2007 and 2014 were analyzed and compared using the 7th and 8th TNM classifications. A proposed staging system was established, and the three systems were compared in terms of prognostic performance. The stage shifted for 669 (42.96%) patients. It shifted from IIIA to IIIB (one patient, 0.06%), IIIB to IIIA (230 patients, 14.8%), IIIB to IIIC (94 patients, 6.0%), and IIIC to IIIB (344 patients, 22.1%). However, the new AJCC subgroupings did not prove distinctive for survival levels between T3N3aM0 (stage IIIB) and T3N3bM0 (stage IIIC) or between T4aN3aM0 (stage IIIB) and T4aN3bM0 (stage IIIC) when <30 lymph nodes (LNs) were resected. The performance of the 8th edition (c-index, 0.614; 95% confidence interval [CI], 0.596-0.633) revealed no relevant improvement compared to the 7th edition (c-index, 0.624; 95% CI, 0.605-0.643). The proposed staging system generated the best prognostic stratification. The 8th TNM edition may not provide better accuracy in predicting the prognosis of stage III gastric cancer. The proposed staging system, comprised of a combination of the number of LNs harvested and the 7th and 8th AJCC classifications, may improve predictive capacities for stage III gastric cancer.

Validation of the 8th Edition of the AJCC TNM Staging System for Gastric Cancer using the National Cancer Database

BACKGROUND

The 8th edition AJCC gastric cancer staging manual was refined using Japanese and Korean data from the International Gastric Cancer Association (IGCA). This study evaluated the eighth edition's validity for U.S.

POPULATIONS

METHODS

National Cancer Database (NCDB) was used to obtain data on gastric cancer patients diagnosed from 2004 to 2008 who underwent surgery and to examine differences in stage grouping and survival between AJCC 7th and 8th editions. Discrimination of models derived from NCDB and IGCA data was compared.

RESULTS

Of 12,041 patients, median age was 65, 57.6% were male, median lymph nodes retrieved was 2 (0-76), 30.9% underwent distal/partial gastrectomy, and 49.8% received no adjuvant treatment. The 8th edition differed in that T1-T3 disease was upstaged with N3b, T4aN3a was downstaged from IIIC to IIIB, and T4bN0 and T4aN2 were downstaged from IIIB to IIIA. These changes resulted in increased patients in IIIA (1436 in the 7th edition to 2310 in the 8th) and IIIB (1737-1896) and decreased in IIIC (2100-1067). This also resulted in lower median survival for IIIA (28.7-25.0 months), IIIB (19.6-17.4), IIIC (13.7-11.8). The concordance index for the 8th edition applied to NCDB data was 0.719 [95% confidence interval (CI) 0.703-0.734), which is comparable to that for the 8th edition developed from IGCA data (0.775, 95% CI 0.770-0.780) and the 7th edition applied to NCDB data (0.720, 95% CI 0.704-0.735).

CONCLUSIONS

The 8th edition is valid for U.S. populations, showing clear separation of data with preservation of group order.

Differentially Expressed lncRNAs in Gastric Cancer Patients: A Potential Biomarker for Gastric Cancer Prognosis

Current studies indicate that long non-coding RNAs (lncRNAs) are frequently aberrantly expressed in cancers and implicated with prognosis in gastric cancer (GC). We intended to generate a multi-lncRNA signature to improve prognostic prediction of GC. By analyzing ten paired GC and adjacent normal mucosa tissues, 339 differentially expressed lncRNAs were identified as the candidate prognostic biomarkers in GC. Then we used LASSO Cox regression method to build a 12-lncRNA signature and validated it in another independent GEO dataset. An innovative 12-lncRNA signature was established, and it was significantly associated with the disease free survival (DFS) in the training dataset. By applying the 12-lncRNA signature, the training cohort patients could be categorized into high-risk or low-risk subgroup with significantly different DFS (HR = 4.52, 95%CI= 2.49-8.20, P < 0.0001). Similar results were obtained in another independent GEO dataset (HR=1.58, 95%CI=1.05 - 2.38, P=0.0270). Further analysis showed that the prognostic value of this 12-lncRNA signature was independent of AJCC stage and postoperative chemotherapy. Receiver operating characteristic (ROC) analysis showed that the area under receiver operating characteristic curve (AUC) of combined model reached 0.869. Additionally, a well-performed nomogram was constructed for clinicians. Moreover, single-sample gene-set enrichment analysis (ssGSEA) showed that a group of pathways related to drug resistance and cancer metastasis significantly enriched in the high risk patients. A useful innovative 12-lncRNA signature was established for prognostic evaluation of GC. It might complement clinicopathological features and facilitate personalized management of GC.

DIMT1 overexpression correlates with progression and prognosis in gastric carcinoma

We investigated the expression of dimethyladenosine transferase 1 homolog (DIMT1) in human gastric carcinoma (GC) tissues, pericarcinoma histologically normal tissues, and normal gastric tissues and explored its clinical significance. Immunohistochemistry staining was used to detect the expression of DIMT1, and the findings were compared with clinicopathological features of patients with GC. The result also was ascertained by Western blotting. The Kaplan-Meier method and log-rank test were used to compare the overall survival rate and time in the DIMT1 low-level and high-level expression groups. Immunohistochemical staining indicated that the expression of DIMT1 in GC tissues (65/75; 86.7%) was significantly more common (P<.001) than that in pericarcinoma histologically normal tissues (14/75; 18.7%) and normal gastric tissues (2/12; 16.7%). High expression of DIMT1 correlated closely with differentiation (P=.023), invasion (P=.042), lymph node metastasis (P=.008), distant metastasis (P=.006), and TNM stage (P=.013). Western blotting showed that DIMT1 expression correlated positively with TNM stage and implied that more advanced TNM stage was accompanied by higher expression of DIMT1 (P<.001). Kaplan-Meier survival analysis showed that high DIMT1 expression correlated significantly (P<.001) with a poor prognosis. Our data suggest that DIMT1 is a useful molecular biomarker to predict tumor progression and prognosis in patients with GC.

Prognostic Discrepancy of the 6th and 7th UICC N Classification for Lymph Node Staging in Gastric Cancer Patients after Curative Resection

BACKGROUND

The validity of N classification of the 7th edition of the American Joint Committee on Cancer/Union Internationale contre le Cancer (AJCC/UICC) tumor-node-metastasis (TNM) staging system is still under debate. The purpose of this study was to evaluate the prognostic efficacy of the 7th edition of the AJCC/UICC TNM staging system (focusing on N stage), in comparison with the 6th edition, at a single Eastern institution.

METHODS

We analyzed 1,435 patients with gastric cancer who underwent curative resection performed from September 1998 to August 2003 at the Memorial Jin-Pok Kim Korea Gastric Cancer Center. We analyzed the survival rate of the patients according to the AJCC/UICC 6th and 7th editions, and compared each stage, focusing on N stage.

RESULTS

Significant differences in the 5-year survival rates were observed between the 6th and the 7th AJCC/UICC staging system. In the 6th edition staging system, the Kaplan-Meier curves discriminated each N stage significantly. In contrast, there was no difference in terms of survival curves for N stage according to the 7th edition, especially between N1 and N2: the Kaplan-Meier plots of survival curves between N1 (77.0%) and N2 (78.1%) stages overlapped significantly (p < 0.05).

CONCLUSION

Although the 7th UICC staging system is a more detailed and sophisticated system in the T category, there was no prognostic significance between the pN1 and pN2 stages according to our data. Therefore, we suggest establishing a new UICC staging system taking into consideration the application of the N stage.

Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.

METHODS

We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.

RESULTS

A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.

CONCLUSIONS

Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

Ongoing problems concerning 7th TNM Staging System and Proposals for 8th TNM Staging System of Gastric Cancer

Because of different prognosis of gastric cancer patients with the same T and N stages, the impossibility of N3 staging in patients with fewer than 15 removed lymph nodes, and the presence of stage migration phenomenon, the 6^th edition TNM Staging System for gastric cancer was updated to the 7^th edition TNM staging system in 2009. Despite some opposing views, the superiority of the 7^th edition TNM staging system compared to the 6^th has been demonstrated in many studies. However, there are doubts about the 7^th edition that it will reduce the stage migration phenomenon. The most important problem about the 7^th TNM staging system is regarding subgroups N3a and N3b. The separation of N3 stage as N3a and N3b does not contribute to the TNM staging system. In conclusion, separate usage of N3a and N3b subgroups in the TNM staging system should be considered in the creation phase of the 8^th edition.

Validation of the 7th AJCC/UICC staging system for gastric cancer and a proposal for a new TNM system based on a prognostic score: a retrospective multicenter study

Purpose

We validate the 7th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system for gastric cancer and propose a new staging system that reflects the prognostic significances of each of T and N category.

Methods

Data from 5,957 patients who underwent curative gastrectomies from 2000 to 2007 at 4 university hospitals in Daegu Metropolitan city in Korea were analyzed for the validation of the 7th AJCC/UICC staging system for gastric cancer. The hazard ratios of the respective T and N categories were estimated and converted to weightings and summated to make prognostic score (P-score). Homogeneity and stage grouping were determined according to the P-scores.

Results

In the 7th AJCC/UICC staging system for gastric cancer, poor discrimination was noted between stages IIB and IIIA (P = 0.152). In addition, heterogeneity in stage IIB (P = 0.021) and a small gap in 5-year survival rates (1.7%) between stages IA and IB were noted. A new proposed staging system was generated on the basis of P-scores and demonstrated more discrimination between stages and more homogeneity within stages. The new staging system reflects the different prognostic impacts of N3a and N3b.

Conclusion

Several controversial issues of the 7th AJCC/UICC staging system for gastric cancer were reconfirmed in the present analysis. The TNM system based on P-score appears to be more scientifically accurate than the 7th AJCC/UICC staging system for gastric cancer.

Prognostic value of microRNA-126 and CRK expression in gastric cancer

Background

MicroRNA (miR)-126, acting as a tumor suppressor, has been reported to inhibit the invasion of gastric cancer cells in part by targeting v-crk sarcoma virus CT10 oncogene homologue (CRK). The aim of this study was to investigate the clinical significance of miR-126/CRK axis in gastric cancer.

Methods

miR-126 and CRK mRNA expression levels were detected by real-time quantitative reverse transcription polymerase chain reaction in 220 self-pairs of gastric cancer and adjacent noncancerous tissues.

Results

Expression levels of miR-126 and CRK mRNA in gastric cancer tissues were, respectively, lower and higher than those in adjacent noncancerous tissues (both P<0.001). Low miR-126 expression and high CRK expression, alone or in combination, were all significantly associated with positive lymph node and distant metastases and advanced TNM stage of human gastric cancer (all P<0.05). We also found that the overall survival rates of the patients with low miR-126 expression and high CRK expression were, respectively, shorter than those with high miR-126 expression and low CRK expression. Interestingly, miR-126-low/CRK-high expression was associated with a significantly worse overall survival of all miR-126/CRK groups (P<0.001). Moreover, multivariate analysis identified miR-126 and/or CRK expression as independent prognostic factors for patients with gastric cancer. Notably, the prognostic relevance of miR-126 and/or CRK expression was more obvious in the subgroup of patients with TNM stage IV.

Conclusion

Dysregulation of miR-126/CRK axis may promote the malignant progression of human gastric cancer. miR-126 and CRK combined expression may serve as an independent predictor of overall survival in patients with advanced gastric cancer.

A long non-coding RNA signature to improve prognosis prediction of gastric cancer

BACKGROUND

Increasing evidence suggests long non-coding RNAs (lncRNAs) are frequently aberrantly expressed in cancers, however, few related lncRNA signatures have been established for prediction of cancer prognosis. We aimed at developing alncRNA signature to improve prognosis prediction of gastric cancer (GC).

METHODS

Using a lncRNA-mining approach, we performed lncRNA expression profiling in large GC cohorts from Gene Expression Ominus (GEO), including GSE62254 data set (N = 300) and GSE15459 data set (N = 192). We established a set of 24-lncRNAs that were significantly associated with the disease free survival (DFS) in the test series.

RESULTS

Based on this 24-lncRNA signature, the test series patients could be classified into high-risk or low-risk subgroup with significantly different DFS (HR = 1.19, 95 % CI = 1.13-1.25, P < 0.0001). The prognostic value of this 24-lncRNA signature was confirmed in the internal validation series and another external validation series, respectively. Further analysis revealed that the prognostic value of this signature was independent of lymph node ratio (LNR) and postoperative chemotherapy. Gene set enrichment analysis (GSEA) indicated that high risk score group was associated with several cancer recurrence and metastasis associated pathways.

CONCLUSIONS

The identification of the prognostic lncRNAs indicates the potential roles of lncRNAs in GC biogenesis. Our results may provide an efficient classification tool for clinical prognosis evaluation of GC.

Meta-analysis: The diagnostic efficacy of chromoendoscopy for early gastric cancer and premalignant gastric lesions

BACKGROUND AND AIM

Chromoendoscopy (CE) is widely used in the diagnosis of early gastric cancer (EGC) and premalignant gastric lesions (PGLs). We conducted a meta-analysis to evaluate the diagnostic efficacy of CE for EGC and PGLs.

METHODS

We searched PubMed/MEDLINE, EMBASE, and the Cochrane library to identify all eligible studies according to inclusion and exclusion standards. Publication bias was tested using Funnel plots and Egger's test. The possible sources of the heterogeneity were explored by performing a meta-regression analysis. Heterogeneity was assessed by the Q test and I(2) statistic.

RESULTS

Ten studies met the inclusion standards, including a total of 699 patients and 902 lesions. The pooled sensitivity, specificity, and area under the curve of CE were 0.90 (95% confidence interval, 0.87-0.92), 0.82 (95% confidence interval, 0.79-0.86), and 0.9464, respectively. In subgroup analysis of diagnostic accuracy, CE showed higher accuracy versus standard white light endoscopy for EGC (P = 0.005) and PGLs (P = 0.001).

CONCLUSION

Chromoendoscopy seems to have a high diagnostic efficacy and improve the detection of EGC and PGLs compared with standard white light endoscopy.

Surgical management of advanced gastric cancer: An evolving issue

Worldwide, gastric cancer represents the fifth most common cancer and the third leading cause of cancer deaths. Although the overall 5-year survival for resectable disease was more than 70% in Japan due to the implementation of screening programs resulting in detection of disease at earlier stages, in Western countries more than two thirds of gastric cancers are usually diagnosed in advanced stages reporting a 5-year survival rate of only 25.7%. Anyway surgical resection with extended lymph node dissection remains the only curative therapy for non-metastatic advanced gastric cancer, while neoadjuvant and adjuvant chemotherapies can improve the outcomes aimed at the reduction of recurrence and extension of survival. High-quality research and advances in technologies have contributed to well define the oncological outcomes and have stimulated many clinical studies testing multimodality managements in the advanced disease setting. This review article aims to outline and discuss open issues in current surgical management of advanced gastric cancer.

A comparison of endoscopic submucosal dissection (ESD) and radical surgery for early gastric cancer: a retrospective study

Background

Endoscopic submucosal dissection (ESD) has become one of the mainstays of treatment for early gastric cancer (EGC). Radical surgery is also a classical treatment method for EGC. There have been no systematic clinical studies of the curative effects and adverse events associated with ESD vs. radical surgery for EGC. This study investigated the therapeutic efficacy and safety of ESD and radical surgery for EGC.

Methods

Twenty-nine patients with EGC underwent ESD, and 59 underwent radical surgery at Weihai Municipal Hospital. The pathological characteristics, postoperative outcomes, hospital course, morbidity and mortality were retrospectively compared between the two groups.

Results

The oncological clearance was 93.1 % (27/29) in the ESD group. Postoperative delayed haemorrhage occurred in two patients. The hospital stay ranged from 10 to 23 days, and the average stay was 14.3 ± 3.7 days. The patients were followed-up for 1 to 5 years, with a mean follow-up of 26.9 ± 8.5 months. Regular endoscopic examinations showed that the wound had healed with no cancer recurrence in all of the patients. In the radical surgery group, the oncological clearance was 100 % (59/59). The hospital stay ranged from 11 to 55 days, and the average stay was 21.7 ± 9.3 days. The patients were followed-up for 1 to 3.7 years, with a mean follow-up of 22.3 ± 9.4 months. Nine patients developed complications, including acute postoperative adhesive ileus (1/59) and symptomatic residual gastritis (3/59). These complications were improved by an additional operation, drainage, gastrointestinal decompression and comprehensive therapy.

Conclusions

ESD achieved similar efficacy and had many advantages compared with radical surgery for the treatment of EGC.