Clinicopathological characteristics and prognostic analysis of Lauren classification in gastric adenocarcinoma in China

Clinical outcomes and biomarker exploration of first-line PD-1 inhibitors plus chemotherapy in patients with low PD-L1-expressing of gastric or gastroesophageal junction adenocarcinoma

BACKGROUND

The beneficial effects of first-line programmed death-1 (PD-1) inhibitors plus chemotherapy in patients with low programmed death-ligand 1 (PD-L1)-expressing advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma are controversial.

METHODS

We conducted a retrospective analysis of patients with G/GEJ adenocarcinoma who had undergone first-line treatment with PD-1 inhibitors plus chemotherapy between October 2017 and May 2022. The primary outcomes were objective response rate (ORR) and progression-free survival (PFS). SPSS software V27.0 was used for data analysis.

RESULTS

Of 345 enrolled patients, 290 had measurable lesions. The overall ORR was 59.3%. PD-L1 status was available in 171 patients, and 67.8% of them were considered as low PD-L1 expression level (combined positive score (CPS) < 5). Patients with PD-L1 CPS < 5 showed a lower response rate (51.1% vs 70.8%, P = 0.024) and a worse PFS (P = 0.009) compared to those with PD-L1 CPS ≥ 5. In the PD-L1 low-expression cohort, patients with non-diffuse type, GEJ cancer, synchronous metastasis, distant lymph node metastasis, liver metastasis, non-peritoneal metastasis, and HER2 positive were significantly associated with higher response rates to PD-1 inhibitors plus chemotherapy (P < 0.05). The presence of peritoneal metastasis (P = 0.028) and diffuse type (P = 0.046) were identified as independent predictors of poor PFS in multivariate analysis of the PD-L1 CPS < 5 subgroup. When evaluated for correlation with overall survival (OS) in the PD-L1 low-expression subgroup, peritoneal metastasis was found to be the only independent prognostic factor of an increased risk of death (hazard ratio: 2.31, 95% CI 1.09-4.90; P = 0.029).

CONCLUSIONS

PD-L1 CPS ≥ 5 is significantly associated with improved response and extended PFS in G/GEJ cancer patients treated with a combination of PD-1 inhibitors and chemotherapy. Specific subgroups within the low PD-L1-expressing population, such as those with non-diffuse-type tumors and without peritoneal metastases, may also benefit from immunotherapy combined with chemotherapy.

Unraveling metabolic characteristics and clinical implications in gastric cancer through single-cell resolution analysis

Background: Gastric cancer is a highly prevalent malignant neoplasm. Metabolic reprogramming is intricately linked to both tumorigenesis and cancer immune evasion. The advent of single-cell RNA sequencing technology provides a novel perspective for evaluating cellular metabolism. This study aims to comprehensively investigate the metabolic pathways of various cell types in tumor and normal samples at high resolution and delve into the intricate regulatory mechanisms governing the metabolic activity of malignant cells in gastric cancer. Methods: Utilizing single-cell RNA sequencing data from gastric cancer, we constructed metabolic landscape maps for different cell types in tumor and normal samples. Employing unsupervised clustering, we categorized malignant cells in tumor samples into high and low metabolic subclusters and further explored the characteristics of these subclusters. Results: Our research findings indicate that epithelial cells in tumor samples exhibit significantly higher activity in most KEGG metabolic pathways compared to other cell types. Unsupervised clustering, based on the scores of metabolic pathways, classified malignant cells into high and low metabolic subclusters. In the high metabolic subcluster, it demonstrated the potential to induce a stronger immune response, correlating with a relatively favorable prognosis. In the low metabolic subcluster, a subset of cells resembling cancer stem cells (CSCs) was identified, and its prognosis was less favorable. Furthermore, a set of risk genes associated with this subcluster was discovered. Conclusion: This study reveals the intricate regulatory mechanisms governing the metabolic activity of malignant cells in gastric cancer, offering new perspectives for improving prognosis and treatment strategies.

Comparison of survival between diffuse type and intestinal type early-onset gastric cancer patients: A large population-based study

Currently, little knowledge about the survival of early-onset gastric cancer and little evidence about the difference of survival based on Lauren type has been reported. In order to investigate the difference, we conducted a retrospective study using the Surveillance, Epidemiology, and End Results (SEER) database and compared it comprehensively. SEER database was used to extracted patients and multiple imputation was utilized to fill blank data. Multivariate cox regression analysis and competing risk model were used to identify the risk factors of survival. K-M survival curve and propensity score matching (PSM) was applied to compare the difference of survival of patients based on Lauren type. Totally, we extracted 3932 EOGC patients including 2086 diffused type and 1846 intestinal type. K-M survival curve showed patients aged 20 to 29 had worse survival compared to patients aged at 30 to 45 years. The survival of EOGC patients would be greatly improved after surgery. Multivariate cox regression analysis revealed diffused type was an independent risk factor, as well as T stage, lymph node metastasis, tumor size (>5 cm) and metastasis, while surgery treatment and examined lymph nodes were protective factors. Multivariate competing risk regression model also showed diffused type was risk factor. We performed PSM by matching 1433 diffused EOGC with 1433 intestinal EOGC patients, finding patients with diffused type had a poorer survival. our results revealed that compared to diffused type EOGC, intestinal type was characterized by a better survival. EOGC should be attached more attention by clinicians.

Predicting lymph node metastasis in colorectal cancer: An analysis of influencing factors to develop a risk model

BACKGROUND

Colorectal cancer (CRC) is a significant global health issue, and lymph node metastasis (LNM) is a crucial prognostic factor. Accurate prediction of LNM is essential for developing individualized treatment strategies for patients with CRC. However, the prediction of LNM is challenging and depends on various factors such as tumor histology, clinicopathological features, and molecular characteristics. The most reliable method to detect LNM is the histopathological examination of surgically resected specimens; however, this method is invasive, time-consuming, and subject to sampling errors and interobserver variability.

AIM

To analyze influencing factors and develop and validate a risk prediction model for LNM in CRC based on a large patient queue.

METHODS

This study retrospectively analyzed 300 patients who underwent CRC surgery at two Peking University Shenzhen hospitals between January and December 2021. A deep learning approach was used to extract features potentially associated with LNM from primary tumor histological images while a logistic regression model was employed to predict LNM in CRC using machine-learning-derived features and clinicopathological variables as predictors.

RESULTS

The prediction model constructed for LNM in CRC was based on a logistic regression framework that incorporated machine learning-extracted features and clinicopathological variables. The model achieved high accuracy (0.86), sensitivity (0.81), specificity (0.87), positive predictive value (0.66), negative predictive value (0.94), area under the curve for the receiver operating characteristic (0.91), and a low Brier score (0.10). The model showed good agreement between the observed and predicted probabilities of LNM across a range of risk thresholds, indicating good calibration and clinical utility.

CONCLUSION

The present study successfully developed and validated a potent and effective risk-prediction model for LNM in patients with CRC. This model utilizes machine-learning-derived features extracted from primary tumor histology and clinicopathological variables, demonstrating superior performance and clinical applicability compared to existing models. The study provides new insights into the potential of deep learning to extract valuable information from tumor histology, in turn, improving the prediction of LNM in CRC and facilitate risk stratification and decision-making in clinical practice.

Impact of positive microscopic resection margins (R1) after gastrectomy in diffuse-type gastric cancer

INTRODUCTION

Diffuse-type gastric cancer (DTGC) is associated with poor outcome. Surgical resection margin status (R) is an important prognostic factor, but its exact impact on DTGC patients remains unknown. The aim of this study was to assess the prognostic value of microscopically positive margins (R1) after gastrectomy on survival and tumour recurrence in DTGC patients.

METHODS

All consecutive DTGC patients from two tertiary centers who underwent curative oncologic gastrectomy from 2005 to 2018 were analyzed. The primary endpoint was overall survival (OS) for R0 versus R1 patients. Secondary endpoints included disease-free survival (DFS), recurrence patterns as well as the overall survival benefit of chemotherapy in this DTGC patient cohort.

RESULTS

Overall, 108 patients were analysed, 88 with R0 and 20 with R1 resection. Patients with negative lymph nodes and negative margins (pN0R0) had the best OS (median 102 months, 95% CI 1-207), whereas pN + R0 patients had better median OS than pN + R1 patients (36 months 95% CI 13-59, versus 7 months, 95% CI 1-13, p < 0.001). Similar findings were observed for DFS. Perioperative chemotherapy offered a median OS of 46 months (95% CI 24-68) versus 9 months (95% CI 1-25) after upfront surgery (p = 0.022). R1 patients presented more often early recurrence (< 12 postoperative months, 30% vs 8%, p = 0.002), however, no differences were observed in recurrence location.

CONCLUSION

DTGC patients with microscopically positive margins (R1) presented poorer OS and DFS, and early tumour recurrence in the present series. R0 resection should be obtained whenever possible, even if other adverse biological features are present.

Evaluation of FAPI PET imaging in gastric cancer: a systematic review and meta-analysis

Purpose: Recent studies suggest that 68Ga-FAPI PET/CT demonstrated superiority over 18F-FDG PET/CT in the evaluation of various cancer types, especially in gastric cancer (GC). By comprehensively reviewing and analysing the differences between 68Ga-FAPI and 18F-FDG in GC, some evidence is provided to foster the broader clinical application of FAPI PET imaging. Methods: In this review, studies published up to July 3, 2023, that employed radionuclide labelled FAPI as a diagnostic radiotracer for PET in GC were analysed. These studies were sourced from both the PubMed and Web of Science databases. Our statistical analysis involved a bivariate meta-analysis of the diagnostic data and a meta-analysis of the quantitative metrics. These were performed using R language. Results: The meta-analysis included 14 studies, with 527 patients, of which 358 were diagnosed with GC. Overall, 68Ga-FAPI showed higher pooled sensitivity (0.84 [95% CI 0.67-0.94] vs. 0.46 [95% CI 0.32-0.60]), specificity (0.91 [95% CI 0.76-0.98] vs. 0.88 [95% CI 0.74-0.96]) and area under the curve (AUC) (0.92 [95% CI 0.77-0.98] vs. 0.52 [95% CI 0.38-0.86]) than 18F-FDG. The evidence showed superior pooled sensitivities of 68Ga-FAPI PET over 18F-FDG for primary tumours, local recurrence, lymph node metastases, distant metastases, and peritoneal metastases. Furthermore, 68Ga-FAPI PET provided higher maximum standardized uptake value (SUVmax) and tumour-to-background ratios (TBR). For bone metastases, while 68Ga-FAPI PET demonstrated slightly lower patient-based pooled sensitivity (0.93 vs. 1.00), it significantly outperformed 18F-FDG in the lesion-based analysis (0.95 vs. 0.65). However, SUVmax (mean difference [MD] 1.79 [95% CI -3.87-7.45]) and TBR (MD 5.01 [95% CI -0.78-10.80]) of bone metastases showed no significant difference between 68Ga-FAPI PET/CT and 18F-FDG PET/CT. Conclusion: Compared with 18F-FDG, 68Ga-FAPI PET imaging showed improved diagnostic accuracy in the evaluation of GC. It can be effectively applied to the early diagnosis, initial staging, and detection of recurrence/metastases of GC. 68Ga-FAPI may have the potential of replacing 18F-FDG in GC in future applications.

Gastric Intestinal Metaplasia: Challenges and the Opportunity for Precision Prevention

GIM is a persistent, premalignant lesion whereby gastric mucosa is replaced by metaplastic mucosa resembling intestinal tissue, arising in the setting of chronic inflammation, particularly in the context of Helicobacter pylori. While the overall rates of progression to gastric adenocarcinoma are low, estimated at from 0.25 to 2.5%, there are features that confer a much higher risk and warrant follow-up. In this review, we collate and summarise the current knowledge regarding the pathogenesis of GIM, and the clinical, endoscopic and histologic risk factors for cancer. We examine the current state-of-practice with regard to the diagnosis and management of GIM, which varies widely in the published guidelines and in practice. We consider the emerging evidence in population studies, artificial intelligence and molecular markers, which will guide future models of care. The ultimate goal is to increase the detection of early gastric dysplasia/neoplasia that can be cured while avoiding unnecessary surveillance in very low-risk individuals.

Preoperative prediction of Lauren classification in gastric cancer: a radiomics model based on dual-energy CT iodine map

OBJECTIVE

To investigate the value of a radiomics model based on dual-energy computed tomography (DECT) venous-phase iodine map (IM) and 120 kVp equivalent mixed images (MIX) in predicting the Lauren classification of gastric cancer.

METHODS

A retrospective analysis of 240 patients undergoing preoperative DECT and postoperative pathologically confirmed gastric cancer was done. Training sets (n = 168) and testing sets (n = 72) were randomly assigned with a ratio of 7:3. Patients are divided into intestinal and non-intestinal groups. Traditional features were analyzed by two radiologists, using logistic regression to determine independent predictors for building clinical models. Using the Radiomics software, radiomics features were extracted from the IM and MIX images. ICC and Boruta algorithm were used for dimensionality reduction, and a random forest algorithm was applied to construct the radiomics model. ROC and DCA were used to evaluate the model performance.

RESULTS

Gender and maximum tumor thickness were independent predictors of Lauren classification and were used to build a clinical model. Separately establish IM-radiomics (R-IM), mixed radiomics (R-MIX), and combined IM + MIX image radiomics (R-COMB) models. In the training set, each radiomics model performed better than the clinical model, and the R-COMB model showed the best prediction performance (AUC: 0.855). In the testing set also, the R-COMB model had better prediction performance than the clinical model (AUC: 0.802).

CONCLUSION

The R-COMB radiomics model based on DECT-IM and 120 kVp equivalent MIX images can effectively be used for preoperative noninvasive prediction of the Lauren classification of gastric cancer.

CRITICAL RELEVANCE STATEMENT

The radiomics model based on dual-energy CT can be used for Lauren classification prediction of preoperative gastric cancer and help clinicians formulate individualized treatment plans and assess prognosis.

Exploring the Genetic Diversity of Epstein-Barr Virus among Patients with Gastric Cancer in Southern Chile

The Epstein-Barr virus (EBV) has been associated with gastric cancer (GC), one of the deadliest malignancies in Chile and the world. Little is known about Chilean EBV strains. This study aims to investigate the frequency and genetic diversity of EBV in GC in patients in southern Chile. To evaluate the prevalence of EBV in GC patients from the Chilean population, we studied 54 GC samples using the gold standard detection method of EBV-encoded small RNA (EBER). The EBV-positive samples were subjected to amplification and sequencing of the Epstein-Barr virus nuclear protein 3A (EBNA3A) gene to evaluate the genetic diversity of EBV strains circulating in southern Chile. In total, 22.2% of the GC samples were EBV-positive and significantly associated with diffuse-type histology (p = 0.003). Phylogenetic analyses identified EBV-1 and EBV-2 in the GC samples, showing genetic diversity among Chilean isolates. This work provides important information for an epidemiological follow-up of the different EBV subtypes that may cause GC in southern Chile.

Prediction model based on radiomics and clinical features for preoperative lymphovascular invasion in gastric cancer patients

Background: We explored whether a model based on contrast-enhanced computed tomography radiomics features and clinicopathological factors can evaluate preoperative lymphovascular invasion (LVI) in patients with gastric cancer (GC) with Lauren classification. Methods: Based on clinical and radiomic characteristics, we established three models: Clinical + Arterial phase_Radcore, Clinical + Venous phase_Radcore and a combined model. The relationship between Lauren classification and LVI was analyzed using a histogram. Results: We retrospectively analyzed 495 patients with GC. The areas under the curve of the combined model were 0.8629 and 0.8343 in the training and testing datasets, respectively. The combined model showed a superior performance to the other models. Conclusion: CECT-based radiomics models can effectively predict preoperative LVI in GC patients with Lauren classification.

Prediction models for the survival in patients with intestinal-type gastric adenocarcinoma: a retrospective cohort study based on the SEER database

OBJECTIVE

To explore the influencing factors of survival in intestinal-type gastric adenocarcinoma (IGA) and set up prediction model for the prediction of survival of patients diagnosed with IGA.

DESIGN

A retrospective cohort study.

SETTING AND PARTICIPANTS

A total of 2232 patients with IGA who came from the Surveillance, Epidemiology, and End Results database.

PRIMARY AND SECONDARY OUTCOME MEASURES

Patients' overall survival (OS) rate and cancer-specific survival (CSS) at the end of follow-up.

RESULTS

Of the total population, 25.72% survived, 54.93% died of IGA and 19.35% died of other causes. The median survival time of patients was 25 months. The result showed that age, race, stage group, T stage, N stage, M stage, grade, tumour size, radiotherapy, number of lymph nodes removed and gastrectomy were independent prognostic factors of OS risk for patients with IGA; age, race, race, stage group, T stage, N stage, M stage, grade, radiotherapy and gastrectomy were associated with CSS risk for patients with IGA. In view of these prognostic factors, we developed two prediction models for predicting the OS and CSS risk for patients with IGA separately. For the developed OS-related prediction model, the C-index was 0.750 (95% CI: 0.740 to 0.760) in the training set, corresponding to 0.753 (95% CI: 0.736 to 0.770) in the testing set. Likewise, for the developed CSS-related prediction model, the C-index was 0.781 (95% CI: 0.770 to 0.793) in the training set, corresponding to 0.785 (95% CI: 0.766 to 0.803) in the testing set. The calibration curves of the training set and testing set revealed a good agreement between model predictions in the 1-year, 3-year and 5-year survival for patients with IGA and actual observations.

CONCLUSION

Combining demographic and clinicopathological features, two prediction models were developed to predict the risk of OS and CSS in patients with IGA, respectively. Both models have good predictive performance.

Integrative proteomic characterization of adenocarcinoma of esophagogastric junction

The incidence of adenocarcinoma of the esophagogastric junction (AEG) has been rapidly increasing in recent decades, but its molecular alterations and subtypes are still obscure. Here, we conduct proteomics and phosphoproteomics profiling of 103 AEG tumors with paired normal adjacent tissues (NATs), whole exome sequencing of 94 tumor-NAT pairs, and RNA sequencing in 83 tumor-NAT pairs. Our analysis reveals an extensively altered proteome and 252 potential druggable proteins in AEG tumors. We identify three proteomic subtypes with significant clinical and molecular differences. The S-II subtype signature protein, FBXO44, is demonstrated to promote tumor progression and metastasis in vitro and in vivo. Our comparative analyses reveal distinct genomic features in AEG subtypes. We find a specific decrease of fibroblasts in the S-III subtype. Further phosphoproteomic comparisons reveal different kinase-phosphosubstrate regulatory networks among AEG subtypes. Our proteogenomics dataset provides valuable resources for understanding molecular mechanisms and developing precision treatment strategies of AEG.

Development and validation of nomogram of peritoneal metastasis in gastric cancer based on simplified clinicopathological features and serum tumor markers

BACKGROUND

Peritoneal metastasis (PM) is not uncommon in patients with gastric cancer(GC), which affects clinical treatment decisions, but the relevant examination measures are not efficiently detected. Our goal was to develop a clinical radiomics nomogram to better predict peritoneal metastases.

METHODS

A total of 3480 patients from 2 centers were divided into 1 training, 1 internal validation, and 1 external validation cohort(1949 in the internal training set, 704 in the validation set, and 827 in the external validation cohort) with clinicopathologically confirmed GC. We recruited 11 clinical factors, including age, sex, smoking status, tumor size, differentiation, Borrmann type, location, clinical T stage, and serum tumor markers (STMs) comprising carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 72-4 (CA72-4), and carcinoembryonic antigen (CEA), to develop the radiomics nomogram. For clinical predictive feature selection and the establishment of clinical models, statistical methods of analysis of variance (ANOVA), relief and recursive feature elimination (RFE) and logistic regression analysis were used. To develop combined predictive models, tumor diameter, type, and location, clinical T stage and STMs were finally selected. The discriminatory ability of the nomogram to predict PM was evaluated by the area under the receiver operating characteristic curve(AUC), and decision curve analysis (DCA) was conducted to evaluate the clinical usefulness of the nomogram.

RESULTS

The AUC of the clinical models was 0.762 in the training cohorts, 0.772 in the internal validation cohort, and 0.758 in the external validation cohort. However, when combined with STMs, the AUC was improved to 0.806, 0.839 and 0.801, respectively. DCA showed that the combined nomogram was of good clinical evaluation value to predict PM in GC.

CONCLUSIONS

The present study proposed a clinical nomogram with a combination of clinical risk factors and radiomics features that can potentially be applied in the individualized preoperative prediction of PM in GC patients.

Identification of a Two-Gene Signature and Establishment of a Prognostic Nomogram Predicting Overall Survival in Diffuse-Type Gastric Cancer

BACKGROUND

It is widely acknowledged that the molecular biological characteristics of diffuse-type gastric cancer are different from intestinal-type gastric cancer. Notwithstanding that significant progress in high-throughput sequencing technology has been made, there is a paucity of effective prognostic biomarkers for diffuse gastric cancer for clinical practice.

METHODS

We downloaded four GEO datasets (GSE22377, GSE38749, GSE47007 and GSE62254) to establish and validate a prognostic two-gene signature for diffuse gastric cancer. The TGCA-STAD dataset was used for external validation. The optimal gene signature was established by using Cox regression analysis. Receiver operating characteristic (ROC) methodology was used to find the best prognostic model. Gene set enrichment analysis was used to analyze the possible signaling pathways of the two genes (MEF2C and TRIM15).

RESULTS

A total of four differently expressed genes (DEGs) (two upregulated and two downregulated) were identified. After a comprehensive analysis, two DEGs (MEF2C and TRIM15) were utilized to construct a prognostic model. A prognostic prediction model was constructed according to T stage, N stage, M stage and the expression of MEF2C and TRIM15. The area under the time-dependent receiver operator characteristic was used to evaluate the performance of the prognosis model in the GSE62254 dataset.

CONCLUSIONS

We demonstrated that MEF2C and TRIM15 might be key genes. We also established a prognostic nomogram based on the two-gene signature that yielded a good performance for predicting overall survival in diffuse-type gastric cancer.

Whole-Exome Sequencing Among Chinese Patients With Hereditary Diffuse Gastric Cancer

IMPORTANCE

The E-cadherin gene, CDH1, and the α-E-catenin gene, CTNNA1, were previously identified as hereditary diffuse gastric cancer (HDGC) susceptibility genes, explaining 25% to 50% of HDGC cases. The genetic basis underlying disease susceptibility in the remaining 50% to 75% of patients with HDGC is still unknown.

OBJECTIVE

To assess the incidence rate of CDH1 germline alterations in HDGC, identify new susceptibility genes that can be used for screening of HDGC, and provide a genetic landscape for HDGC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study conducted retrospective whole-exome and targeted sequencing of 284 leukocyte samples and 186 paired tumor samples from Chinese patients with HDGC over a long follow-up period (median, 21.7 [range, 0.6-185.9] months). Among 10 431 patients diagnosed with gastric cancer between January 1, 2002, and August 31, 2018, 284 patients who met the criteria for HDGC were included. Data were analyzed from August 1 to 30, 2020.

MAIN OUTCOMES AND MEASURES

Incidence rate of CDH1 germline alterations, identification of new HDGC susceptibility genes, and genetic landscape of HDGC.

RESULTS

Among 284 Chinese patients, 161 (56.7%) were female, and the median age was 35 (range, 20-75) years. The frequency of CDH1 germline alterations was 2.8%, whereas the frequency of CDH1 somatic alterations was 25.3%. The genes with the highest incidence (>10%) of private germline alterations (including insertions and deletions) in the HDGC cohort were MUC4, ABCA13, ZNF469, FCGBP, IGFN1, RNF213, and SSPO, whereas previously reported germline alterations of CTNNA1, BRCA2, STK11, PRSS1, ATM, MSR1, PALB2, BRCA1, and RAD51C were observed at low frequencies (median, 4 [range, 1-12] cases). Furthermore, enrichment of the somatic variant signature of exposure to aflatoxin suggested potential interaction between genetics and environment in HDGC. Double-hit events in genes such as CACNA1D were observed, which suggested that these events might serve as important mechanisms for HDGC tumorigenesis. In addition, germline variants of FSIP2, HSPG2, and NCKAP5 and somatic alterations of FGFR3, ASPSCR1, CIC, DGCR8, and LZTR1 were associated with poor overall survival among patients with HDGC.

CONCLUSIONS AND RELEVANCE

This study provided a genetic landscape for HDGC. The study's findings challenged the previously reported high germline alteration rate of CDH1 in HDGC and identified new potential susceptibility genes. Analyses of variant signatures and double-hit events revealed potentially important mechanisms for HDGC tumorigenesis. Findings from the present study may provide helpful information for further investigations of HDGC.

A radiomics nomogram analysis based on CT images and clinical features for preoperative Lauren classification in gastric cancer

PURPOSE

To develop a combined radiomics nomogram based on computed tomography (CT) images and clinical features to preoperatively distinguish Lauren's diffuse-type gastric cancer (GC) from intestinal-type GC.

METHODS

Ninety-five patients with Lauren's intestinal or diffuse-type GC confirmed by postoperative pathology had their preoperative clinical information and dynamic contrast CT images retrospectively analyzed and were subdivided into training and test groups in a 7:3 ratio. To select the optimal features and construct the radiomic signatures, we extracted, filtered, and minimized the radiomic features from arterial phase (AP) and venous phase (VP) CT images. We constructed four models (clinical model, AP radiomics model, VP radiomics model, and radiomics-clinical model) to assess and compare their predictive performance between the intestinal- and diffuse-type GC. Receiver-operating characteristic (ROC) curve, area under the ROC curve (AUC), and the DeLong test were used for assessment and comparison. In this study, radiomic nomograms integrating combined radiomic signatures and clinical characteristics were developed.

RESULTS

Compared to the AP radiomics model, the VP radiomics model had better performance, with an AUC of 0.832 (95% confidence interval [CI], 0.735, 0.929) in the training cohort and 0.760 (95% CI 0.580, 0.940) in the test cohort. Among the combined models that assessed Lauren's type GC, the model including age and VP radiomics showed the best performance, with an AUC of 0.849 (95% CI 0.758, 0.940) in the training cohort and 0.793 (95% CI 0.629, 0.957) in the test cohort.

CONCLUSIONS

Nomogram incorporating radiomic signatures and clinical features effectively differentiated Lauren's diffuse-type from intestinal-type GC.

ARHGAP-RhoA signaling provokes homotypic adhesion-triggered cell death of metastasized diffuse-type gastric cancer

Genetic alteration of Rho GTPase-activating proteins (ARHGAP) and GTPase RhoA is a hallmark of diffuse-type gastric cancer and elucidating its biological significance is critical to comprehensively understanding this malignancy. Here, we report that gene fusions of ARHGAP6/ARHGAP26 are frequent genetic events in peritoneally-metastasized gastric and pancreatic cancer. From the malignant ascites of patients, we established gastric cancer cell lines that spontaneously gain hotspot RHOA mutations or four different ARHGAP6/ARHGAP26 fusions. These alterations critically downregulate RhoA-ROCK-MLC2 signaling, which elicits cell death. Omics and functional analyses revealed that the downstream signaling initiates actin stress fibers and reinforces intercellular junctions via several types of catenin. E-cadherin-centered homotypic adhesion followed by lysosomal membrane permeabilization is a pivotal mechanism in cell death. These findings support the tumor-suppressive nature of ARHGAP-RhoA signaling and might indicate a new avenue of drug discovery against this refractory cancer.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Synaptotagmin 11 scaffolds MKK7-JNK signaling process to promote stem-like molecular subtype gastric cancer oncogenesis

Background

Identifying biomarkers related to the diagnosis and treatment of gastric cancer (GC) has not made significant progress due to the heterogeneity of tumors. Genes involved in histological classification and genetic correlation studies are essential to develop an appropriate treatment for GC.

Methods

In vitro and in vivo lentiviral shRNA library screening was performed. The expression of Synaptotagmin (SYT11) in the tumor tissues of patients with GC was confirmed by performing Immunohistochemistry, and the correlation between the expression level and the patient’s survival rate was analyzed. Phospho-kinase array was performed to detect Jun N-terminal kinase (JNK) phosphorylation. SYT11, JNK, and MKK7 complex formation was confirmed by western blot and immunoprecipitation assays. We studied the effects of SYT11 on GC proliferation and metastasis, real-time cell image analysis, adhesion assay, invasion assay, spheroid formation, mouse xenograft assay, and liver metastasis.

Results

SYT11 is highly expressed in the stem-like molecular subtype of GC in transcriptome analysis of 527 patients with GC. Moreover, SYT11 is a potential prognostic biomarker for histologically classified diffuse-type GC. SYT11 functions as a scaffold protein, binding both MKK7 and JNK1 signaling molecules that play a role in JNK1 phosphorylation. In turn, JNK activation leads to a signaling cascade resulting in cJun activation and expression of downstream genes angiopoietin-like 2 (ANGPTL2), thrombospondin 4 (THBS4), Vimentin, and junctional adhesion molecule 3 (JAM3), which play a role in epithelial-mesenchymal transition (EMT). SNU484 cells infected with SYT11 shRNA (shSYT11) exhibited reduced spheroid formation, mouse tumor formation, and liver metastasis, suggesting a pro-oncogenic role of SYT11. Furthermore, SYT11-antisense oligonucleotide (ASO) displayed antitumor activity in our mouse xenograft model and was conferred an anti-proliferative effect in SNU484 and MKN1 cells.

Conclusion

SYT11 could be a potential therapeutic target as well as a prognostic biomarker in patients with diffuse-type GC, and SYT11-ASO could be used in therapeutic agent development for stem-like molecular subtype diffuse GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02420-3.

Clinicopathological differences, risk factors and prognostic scores for western patients with intestinal and diffuse-type gastric cancer

BACKGROUND

In the molecular era, the Laurén system is still a cost-effective and widely implemented classification for gastric cancer (GC) and it has been recently associated with clinical, histological and molecular features of these tumors. Despite recent advances in the understanding of the molecular biology of GC, there is a need to develop new prognostic tools for patient stratification in clinical practice. Thus, the identification of easily available prognostic factors in patients with intestinal and diffuse-type tumors can significantly improve risk assessment and patient stratification in GC.

AIM

To identify clinicopathological differences, risk factors, and to develop cost-effective prognostic scores for patients with intestinal and diffuse-type GC.

METHODS

Retrospective study of all patients undergoing surgery for GC at a tertiary referral center from 2001 to 2019. 286 cases met inclusion criteria (intestinal: 190, diffuse: 96). Clinical data and gross findings were collected. All specimens were reviewed by two independent pathologists and a detailed protocol for histologic evaluation was followed. Five tissue microarrays (TMAs) were constructed and sections of the TMA block were immunostained for HERCEPTEST, MSH2, MSH6, MLH1 and PMS2. Statistical analyses were performed and prognostic scores were developed based on hazard ratios.

RESULTS

Intestinal and diffuse-type GC showed different epidemiological, clinicopathological and prognostic features. Diffuse tumors were significantly associated with younger age, less symptomatology, flat morphology, deeper invasion, perineural infiltration, advanced stage at diagnosis, administration of adjuvant therapy and poorer prognosis. Intestinal lesions were fungoid or polypoid, showed necrosis, desmoplasia, microsatellite instability and HERCEPTEST positivity and were diagnosed at earlier stages. Tumor depth, desmoplasia, macroscopic type and lymph node involvement were independently related to the Laurén subtype. Furthermore, intestinal and diffuse GC were associated with different risk factors for progression and death. Vascular invasion, perineural infiltration and growth pattern were important prognostic factors in intestinal-type GC. On the contrary, tumor size and necrosis were significant prognosticators in diffuse-type GC. Our recurrence and cancer-specific death scores for patients with intestinal and diffuse-type GC showed an excellent patient stratification into three (diffuse GC) or four (intestinal) prognostic groups.

CONCLUSION

Our findings support that Laurén subtypes represent different clinicopathological and biological entities. The development of specific prognostic scores is a useful and cost-effective strategy to improve risk assessment in GC.

Efficacy of AS versus SOX regimen as first-line chemotherapy for gastric cancer patients with peritoneal metastasis: a real-world study

Background

To compare the prognosis of first-line systemic chemotherapy of AS (Albumin-bound paclitaxel and S-1) versus SOX (S-1 and oxaliplatin) regimen in Chinese gastric cancer patients with peritoneal metastasis.

Methods

This was a real-world study of gastric cancer patients with peritoneal metastasis who have been treated with AS or SOX regimen as first-line chemotherapy. Patients were matched by the method of propensity score matching (PSM). The primary and secondary endpoints were overall survival (OS) and progress-free survival (PFS).

Results

A total of 108 gastric cancer patients with peritoneal metastasis were enrolled after PSM analysis. There was no significant difference between AS and SOX regimen based on gender, age, ascites, treatment cycles, gastric cancer resection, received checkpoint inhibitors, and HER-2 expression after PSM analysis. The median OS (14.13 vs. 11.17 months, p = 0.0356) and median PFS (10.30 vs. 6.70 months, p = 0.0003) of patients who received AS regimen were longer than those treated by SOX regimen as first-line systemic chemotherapy. In sub-group analysis, the median OS and median PFS were longer for patients in AS regimen than SOX regimen in Lauren diffuse type. The occurrence of toxicity between the two groups was shown no significant difference.

Conclusions

The results verified that AS regimen was more effective than SOX chemotherapy in gastric cancer patients with peritoneal metastasis, especially in Lauren diffuse type.

Tumor Molecular Profiling in Hispanics: Moving Towards Precision Oncology and Health Equity

BACKGROUND

Tumor molecular profiling techniques, such as next-generation sequencing (NGS) to identify somatic genetic alterations, allow physicians to have a better understanding of the affected carcinogenic pathways and guide targeted therapy. The objective of our study was to characterize common somatic alterations and carcinogenic pathways among Puerto Rican Hispanics with solid tumors.

METHODS

We conducted a single-institution, retrospective study to characterize molecular tumor profiles using a 592-gene NGS platform. Actionable mutations with current or developing therapies targeting affected genes/pathways were highlighted.

RESULTS

Tumors from 50 Hispanic patients were evaluated using CARIS Life Science© NGS testing. The median age of our study population was 55 (range 21-84); 54% (n = 27) were males. The primary tumor sites were colorectal (n = 24), gastric (n = 5), breast (n = 4), and lung (n = 3). The most common genetic mutations identified were in TP53 (44%), APC (38%), and KRAS (32%); followed by alterations in EGFR (4%), HER2 (6%), and homologous recombinant deficiency genes (BRCA2, 6%). Genetic alterations were found in multiple signaling pathways particularly in the cell cycle control pathway, MAPK and Wnt/β-Catenin signaling pathways. Targetable biomarkers were identified in 27/50 (54.0%) of tumors.

DISCUSSION

Molecular profiling techniques, such as next-generation sequencing, have substantially expanded access to alterations in the cancer genome. Our findings demonstrated important actionable mutations in most of the tumors evaluated and support the integration of somatic mutation profiling in the evaluation of Hispanic cancer patients with advanced cancer to help guide therapeutic options.

Genome-Scale Metabolic Model Analysis of Metabolic Differences between Lauren Diffuse and Intestinal Subtypes in Gastric Cancer

Gastric cancer (GC) is one of the most lethal cancers worldwide; it has a high mortality rate, particularly in East Asia. Recently, genetic events (e.g., mutations and copy number alterations) and molecular signaling associated with histologically different GC subtypes (diffuse and intestinal) have been elucidated. However, metabolic differences among the histological GC subtypes have not been studied systematically. In this study, we utilized transcriptome-based genome-scale metabolic models (GEMs) to identify differential metabolic pathways between Lauren diffuse and intestinal subtypes. We found that diverse metabolic pathways, including cholesterol homeostasis, xenobiotic metabolism, fatty acid metabolism, the MTORC1 pathway, and glycolysis, were dysregulated between the diffuse and intestinal subtypes. Our study provides an overview of the metabolic differences between the two subtypes, possibly leading to an understanding of metabolism in GC heterogeneity.

The risk of diffuse-type gastric cancer following diagnosis with gastric precancerous lesions: a systematic review and meta-analysis

PURPOSE

Gastric cancers are classified as diffuse-type (DTGC) or intestinal-type (ITGC). DTGCs have distinct clinical and histopathologic features, and carry a worse overall prognosis compared to ITGCs. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known precursors to ITGC. It is unknown if AG and IM increase risk for DTGC.

METHODS

We performed a systematic review to identify studies reporting on the association of AG/IM and DTGC. We extracted the odds ratio (OR) of the association from studies, and performed pool analysis. Subgroup analysis was performed on studies reporting histologic severity (using operative link systems) to assess if histologic severity of AG/IM was associated with higher risk.

RESULTS

We identified six case-control and eight cohort studies for inclusion. Both AG (pooled OR = 1.9, 95% CI 1.5 to 2.4, p < 0.001) and IM (pooled OR = 2.3, 95% CI 1.9 to 2.9, p < 0.001) demonstrated an association with DTGC. High AG severity was associated with increased risk for DTGC compared to low AG severity (OR = 1.7, 95% CI 1.2 to 2.3, p = 0.002). Similarly, high IM severity was associated with increased risk compared to low IM severity (OR = 1.9, 95% CI 1.3 to 2.7, p = 0.001).

CONCLUSION

Both AG and IM are associated with DTGC. Increasing histologic severity of both AG and IM increases risk for DTGC. There may exist a common pathway between ITGC and some DTGCs mediated through mucosal precursor lesions. These data may inform future strategies of cancer risk attenuation and control.

CT-based radiomics nomograms for preoperative prediction of diffuse-type and signet ring cell gastric cancer: a multicenter development and validation cohort

BACKGROUND

The prevalence of diffuse-type gastric cancer (GC), especially signet ring cell carcinoma (SRCC), has shown an upward trend in the past decades. This study aimed to develop computed tomography (CT) based radiomics nomograms to distinguish diffuse-type and SRCC GC preoperatively.

METHODS

A total of 693 GC patients from two centers were retrospectively analyzed and divided into training, internal validation and external validation cohorts. Radiomics features were extracted from CT images, and the Lauren radiomics model was established with a support vector machine (SVM) classifier to identify diffuse-type GC. The Lauren radiomics nomogram integrating radiomics features score (Rad-score) and clinicopathological characteristics were developed and evaluated regarding prediction ability. Further, the SRCC radiomics nomogram designed to identify SRCC from diffuse-type GC was developed and evaluated following the same procedures.

RESULTS

Multivariate analysis revealed that Rad-scores was significantly associated with diffuse-type GC and SRCC (p < 0.001). The Lauren radiomics nomogram showed promising prediction performance with an area under the curve (AUC) of 0.895 (95%CI, 0.957-0.932), 0.841 (95%CI, 0.781-0.901) and 0.893 (95%CI, 0.831-0.955) in each cohort. The SRCC radiomics nomogram also showed good discrimination, with AUC of 0.905 (95%CI,0.866-0.944), 0.845 (95%CI, 0.775-0.915) and 0.918 (95%CI, 0.842-0.994) in each cohort. The radiomics nomograms showed great model fitness and clinical usefulness by calibration curve and decision curve analysis.

CONCLUSION

Our CT-based radiomics nomograms had the ability to identify the diffuse-type and SRCC GC, providing a non-invasive, efficient and preoperative diagnosis method. They may help guide preoperative clinical decision-making and benefit GC patients in the future.

Pattern of lymph node metastases in gastric cancer: a side-study of the multicenter LOGICA-trial

BACKGROUND

The relation between gastric cancer characteristics and lymph node (LN) metastatic patterns is not fully clear, especially following neoadjuvant chemotherapy (NAC). This study analyzed nodal metastatic patterns.

METHODS

Individual LN stations were analyzed for all patients from the LOGICA-trial, a Dutch multicenter randomized trial comparing laparoscopic versus open D2-gastrectomy for gastric cancer. The pattern of metastases per LN station was related to tumor location, cT-stage, Lauren classification and NAC.

RESULTS

Between 2015-2018, 212 patients underwent D2-gastrectomy, of whom 158 (75%) received NAC. LN metastases were present in 120 patients (57%). Proximal tumors metastasized predominantly to proximal LN stations (no. 1, 2, 7 and 9; p < 0.05), and distal tumors to distal LN stations (no. 5, 6 and 8; OR > 1, p > 0.05). However, distal tumors also metastasized to proximal LN stations, and vice versa. Despite NAC, each LN station (no. 1-9, 11 and 12a) showed metastases, regardless of tumor location, cT-stage, histological subtype and NAC treatment, including station 12a for cT1N0-tumors. LN metastases were present more frequently in diffuse versus intestinal tumors (66% versus 52%; p = 0,048), but not for cT3-4- versus cT1-2-stage (59% versus 51%; p = 0.259). However, the pattern of LN metastases was similar for these subgroups.

CONCLUSIONS

The extent of lymphadenectomy cannot be reduced after NAC for gastric cancer. Although the pattern of LN metastases is related to tumor location, all LN stations contained metastases regardless of tumor location, cT-stage (including cT1N0-tumors), histological subtype, or NAC treatment. Therefore, D2-lymphadenectomy should be routinely performed during gastrectomy in Western patients.

Higher Lymph Node Metastasis Rate and Poorer Prognosis of Intestinal-Type Gastric Cancer Compared to Diffuse-Type Gastric Cancer in Early-Onset Early-Stage Gastric Cancer: A Retrospective Study

Background: The incidence of early-onset gastric cancer (GC) that was diagnosed at <50 years is increasing, but there is a knowledge gap on early-onset early-stage GC (EEGC) that was defined as early-onset GC limited to the mucosa or submucosa. Therefore, we comprehensively analysed the clinical features based on Lauren type.

Methods: Logistic and Cox analyses were used to investigate risk factors for lymph node metastasis (LNM) and prognosis, respectively. Propensity score matching (PSM) was used to adjust confounding factors. Protein mass spectrometry analysis was used to explore the molecular mechanism of LNM.

Result: Our study included 581 patients with EEGC from the Surveillance, Epidemiology, and End Results (SEER) database and 226 patients with EEGC from our own centre. We identified intestinal type, T1b stage, and tumour size (>3 cm) as risk factors for LNM using SEER and our own data. We also found that the prognosis of patients with intestinal-type EEGC was poorer than patients with diffuse-type EEGC, and T1b stage and positive LNM were hazard factors for survival. After analysing the expression of proteins between positive and negative LNM in the intestinal or diffuse type, we found no similar proteins between these groups. The differentially expressed genes (DEGs) in the intestinal type functioned as epithelial cell signalling in Helicobacter pylori. The DEGs in the diffuse type functioned in the tricarboxylic acid cycle (TCA cycle) and oxidative phosphorylation.

Conclusion: For EEGC, our study was the first report to demonstrate that the intestinal type was a risk factor for LNM and survival compared to the diffuse type, and the oncogenic expression promoting the occurrence of LNM was different. These findings suggest that clinicians should pay more attention to intestinal-type EEGC than diffuse-type EEGC.

Peripheral Cytokine Levels as a Prognostic Indicator in Gastric Cancer: A Review of Existing Literature

Although strong connections exist between the carcinogenesis of gastric cancer and chronic inflammation, gastric cancer is unique in that the chronic gastritis which frequently precedes carcinogenesis is strongly associated with H. pylori infection. The interplay between H. pylori virulence factors and host immune cells is complex but culminates in the activation of inflammatory pathways and transcription factors such as NF-κB, STAT3, and AP-1, all of which upregulate cytokine production. Due to the key role of cytokines in modulating the immune response against tumour cells as well as possibly stimulating tumour growth and proliferation, different patterns of cytokine secretion may be associated with varying patient outcomes. In relation to gastric cancer, interleukin-6, 8, 10, 17A, TNF, and IFN-γ may have pro-tumour properties, although interleukin-10, TNF, and IFN-γ may have anti-tumour effects. However, due to the lack of studies investigating patient outcomes, only a link between higher interleukin-6 levels and poorer prognosis has been demonstrated. Further investigations which link peripheral cytokine levels to patient prognosis may elucidate important pathological mechanisms in gastric cancer which adversely impact patient survival and allow treatments targeting these processes to be developed.

One stomach, two subtypes of carcinoma-the differences between distal and proximal gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract, posing a significant risk to human health. Over the past 10 years, the pathological characteristics and the prognosis of GC have been determined based on the locations of the tumors that were then classified into two types-proximal and distal GC. This review focuses on the differences in epidemiology, etiology, cell source, pathological characteristics, gene expression, molecular markers, manifestations, treatment, prognosis, and prevention between proximal and distal GC to provide guidance and a basis for clinical diagnosis and treatment.

Proteomic Signatures of Diffuse and Intestinal Subtypes of Gastric Cancer

Gastric cancer is a leading cause of death from cancer globally. Gastric cancer is classified into intestinal, diffuse and indeterminate subtypes based on histology according to the Laurén classification. The intestinal and diffuse subtypes, although different in histology, demographics and outcomes, are still treated in the same fashion. This study was designed to discover proteomic signatures of diffuse and intestinal subtypes. Mass spectrometry-based proteomics using tandem mass tags (TMT)-based multiplexed analysis was used to identify proteins in tumor tissues from patients with diffuse or intestinal gastric cancer with adjacent normal tissue control. A total of 7448 or 4846 proteins were identified from intestinal or diffuse subtype, respectively. This quantitative mass spectrometric analysis defined a proteomic signature of differential expression across the two subtypes, which included gremlin1 (GREM1), bcl-2-associated athanogene 2 (BAG2), olfactomedin 4 (OLFM4), thyroid hormone receptor interacting protein 6 (TRIP6) and melanoma-associated antigen 9 (MAGE-A9) proteins. Although GREM1, BAG2, OLFM4, TRIP6 and MAGE-A9 have all been previously implicated in tumor progression and metastasis, they have not been linked to intestinal or diffuse subtypes of gastric cancer. Using immunohistochemical labelling of a tissue microarray comprising of 124 cases of gastric cancer, we validated the proteomic signature obtained by mass spectrometry in the discovery cohort. Our findings should help investigate the pathogenesis of these gastric cancer subtypes and potentially lead to strategies for early diagnosis and treatment.

Poor oral hygiene behavior is associated with an increased risk of gastric cancer: A population-based case-control study in China

BACKGROUND

Poor oral health may be a significant risk factor for gastric cancer (GC); however, previous results are not consistent. Here, we investigated the effect of oral health on GC and effect modification by other factors.

METHODS

We conducted a population-based case-control study in Taixing, China. Participants aged between 40 and 85 years and who had lived in Taixing for at least 5 years were included. The GC cases were confirmed by endoscopy and pathological diagnosis, and the controls were randomly selected using the frequency-matching method. Unconditional logistic regression models were used to derive odds ratios (ORs) and 95% confidence intervals (CIs) of oral health for GC risk after adjusting for confounders and risk factors.

RESULTS

Overall, 901 GC cases and 1972 controls were included. Tooth loss was not significantly associated with an increased risk of GC (yes vs. no, OR = 1.08, 95% CI 0.88 to 1.33). Compared with toothbrushing at least twice per day, toothbrushing once per day or less was associated with an increased risk of GC (OR = 2.39, 95% CI 1.94 to 2.94), and was more pronounced in esophagogastric junction cancer and intestinal-type GC. There was no significant interaction between the indicators of oral health and age, sex, tobacco smoking, alcohol drinking, and Helicobacter pylori seropositivity.

CONCLUSION

Poor oral hygiene behavior is associated with an increased risk of GC, and this positive association is consistent across all GC subgroups classified by anatomy and histology. Further studies are needed to explore the possible mechanisms behind this association.

From Lauren's diffuse gastric cancer to WHO's poorly cohesive carcinoma. Clinicopathological and prognostic characteristics

INTRODUCTION

since Lauren classified gastric cancer into intestinal-type adenocarcinoma and diffuse gastric carcinoma back in 1965, countless categorizations have been published that attempt to elucidate the clinicopathological and prognostic differences between histological subtypes.

OBJECTIVE

a retrospective study was performed of gastric cancer cases managed in a third-level site over ten years in order to compare subtypes between the most widely used classifications (Lauren and World Health Organization [WHO]).

METHODS

a comparative study of the most relevant clinicopathological characteristics and a multivariate survival analysis were performed.

RESULTS

significant differences exist between histological subtypes in terms of age, gender, location, extension, stage and treatment received. A univariate overall survival analysis revealed better survival rates for intestinal-type adenocarcinoma as compared to diffuse carcinoma (hazard ratio [HR]: 1.405 [1.024-1.927]) according to the Lauren's classification. Furthermore, there was a better prognosis of mucinous carcinoma (HR: 0.378 [0.164-0.868]), though failing to prove a poorer prognosis of poorly cohesive (HR: 1.242 [0.878-1.757]) and signet cell (HR: 1.354 [0.792-2.314]) carcinomas, according to the WHO classification. In the multivariate overall survival analysis, the following poor prognosis factors were identified: male gender, local infiltration (T), nodal invasion (N) and received adjuvant therapy.

CONCLUSION

although the various histological subtypes show significant clinicopathological differences, further studies are needed to compare them and clarify the prognostic relevance of each one.

Sp1-Induced FNBP1 Drives Rigorous 3D Cell Motility in EMT-Type Gastric Cancer Cells

Cancer is heterogeneous among patients, requiring a thorough understanding of molecular subtypes and the establishment of therapeutic strategies based on its behavior. Gastric cancer (GC) is adenocarcinoma with marked heterogeneity leading to different prognoses. As an effort, we previously identified a stem-like subtype, which is prone to metastasis, with the worst prognosis. Here, we propose FNBP1 as a key to high-level cell motility, present only in aggressive GC cells. FNBP1 is also up-regulated in both the GS subtype from the TCGA project and the EMT subtype from the ACRG study, which include high portions of diffuse histologic type. Ablation of FNBP1 in the EMT-type GC cell line brought changes in the cell periphery in transcriptomic analysis. Indeed, loss of FNBP1 resulted in the loss of invasive ability, especially in a three-dimensional culture system. Live imaging indicated active movement of actin in FNBP1-overexpressed cells cultured in an extracellular matrix dome. To find the transcription factor which drives FNBP1 expression in an EMT-type GC cell line, the FNBP1 promoter region and DNA binding motifs were analyzed. Interestingly, the Sp1 motif was abundant in the promoter, and pharmacological inhibition and knockdown of Sp1 down-regulated FNBP1 promoter activity and the transcription level, respectively. Taken together, our results propose Sp1-driven FNBP1 as a key molecule explaining aggressiveness in EMT-type GC cells.

[Factors affecting survival prognosis of advanced gastric cancer and establishment of a nomogram predictive model]

OBJECTIVE

To explore the factors affecting the survival of patients with advanced gastric cancer and establish a reliable predictive model of the patients' survival outcomes.

OBJECTIVE

We retrospectively collected the clinical data from patients with advanced gastric cancer treated in our department between January, 2015 and December, 2019. Univariate survival analysis was carried out using Kaplan-Meier method followed by multivariate Cox regression analysis to identify the factors associated with the survival outcomes of the patients. The R package was used to generate the survival rates, and a nomogram was established based on the results of multivariate analysis. The calibration curves and C-index were calculated to determine the predictive and discriminatory power of the model. The performance of the nomogram model for predicting the survival outcomes of the patients was evaluated using receiver- operating characteristic (ROC) curve analysis and decision curve analysis (DCA).

OBJECTIVE

Univariate analysis showed that the number of metastatic sites, the number of treatment lines received, disease control rate (DCR) and progression-free survival (PFS) time following first-line treatment, and surgical treatment in first-line treatment were significantly correlated with the survival time of the patients (P < 0.05). Multivariate Cox regression analysis showed that surgical treatment, number of treatment lines, PFS time following first-line treatment and peritoneal metastasis, as independent prognostic factors, were significantly correlated with the patients' survival (P < 0.05). The C-index of the nomogram was 0.785 (95%CI: 0.744-0.826) for overall survival of the patients. The calibration curves showed that the actual survival rate of the patients was consistent with the predicted survival rate. The time-dependent AUC and DCA demonstrated that the nomogram had a good performance for predicting the survival outcomes of patients with advanced gastric cancer.

OBJECTIVE

Peritoneal metastasis is associated with s shorter overall survival time of patients with advanced gastric cancer, while a PFS time following first-line treatment of more than 7.0 months and third-line and posterior-line treatments are related with a longer survival time. Systematic treatment including elective surgery can improve the survival outcomes of the patients. The nomogram we established provides a reliable prognostic model for evaluating the prognosis of patients with advanced gastric cancer.

Diagnostic and therapeutic potencies of miR-18a-5p in mixed-type gastric adenocarcinoma

Mixed-type gastric adenocarcinoma (by Lauren Classification) has poor clinical outcomes with few targeted treatment options. The primary objective of this study was to find the prognostic factors, accurate treatment approaches, and effective postoperative adjuvant therapy strategies for patients with mixed-type gastric adenocarcinoma (GA). A microRNA sequencing data set and the corresponding clinical parameters of patients with gastric cancer were obtained from The Cancer Genome Atlas. Differentially expressed microRNAs (DEMs) of diffuse- and intestinal-type GA were, respectively, determined. Kaplan-Meier and log-rank tests were subsequently carried out to evaluate the prognostic relevance of each DEM. To study the common factors between diffuse- and intestinal-type GA, a pathway enrichment analysis was performed on the target genes of identified DEMs using the PANTHER database. After data preprocessing, we analyzed a total of 230 samples from 210 patients with GA. Eighty-six DEMs in diffuse-type GA samples and 59 DEMs in intestinal-type GA samples were, respectively, identified (p  2.0). The Kaplan-Meier survival method further screened out six prognosis-related DEMs for diffuse-type GA and seven prognosis-related DEMs for intestinal-type GA (p < 0.05). MiR-18a-5p was found to be the only common prognosis-related DEM between diffuse- and intestinal-type GA. The common signaling pathways further revealed that target genes of miR-18a-5p are involved in mixed-type GA progression. This study suggests that miR-18a-5p acts as a potential target for treatment, and common signal pathways provide a rich basis to seek reliable and effective molecular targets for the diagnosis, clinical treatment, and postoperative adjuvant therapy strategy of mixed-type GA.

Bioinformatics analysis identifies biomarkers associated with poor prognosis in diffuse‑type gastric cancer

Gastric cancer (GC) is one of the most common malignancies of the digestive system. In diffuse‑type GC, differentiation is relatively poor, and the probability of distant metastasis and lymph node metastasis is high, resulting in poor clinical prognosis. The purpose of this study was to identify specific genes that can predict the prognosis of different types of GC. Differentially expressed genes (DEGs) were screened in the GSE62254 dataset obtained from the Gene Expression Omnibus using the 'limma' and 'survival' R packages. A total of 355 survival‑related DEGs were selected according to specific screening criteria, of which 293 were associated with diffuse‑type GC and 62 with intestinal‑type GC. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used for functional annotation and pathway enrichment analysis of DEGs. Using protein‑protein interaction networks and Cytoscape software, three hub genes were identified in diffuse‑type GC‑associated DEGs, including angiotensinogen (AGT), C‑X‑C motif chemokine ligand 12 (CXCL12) and adrenoceptor β2 (ADRB2). Immunohistochemical staining and reverse transcription‑quantitative PCR revealed that the expression levels of the three genes in diffuse‑type GC samples were upregulated compared with in intestinal‑type GC samples. Kaplan Meier analysis indicated that a higher expression levels of these three hub genes were associated with a poorer prognosis of diffuse‑type GC. In summary, the present findings suggested that AGT, CXCL12 and ADRB2 might contribute to the progression of diffuse‑type GC, and could serve as potential biomarkers or therapeutic targets for this disease.

Preoperative prediction for lauren type of gastric cancer: A radiomics nomogram analysis based on CT images and clinical features

PURPOSE

To investigate feasibility of predicting Lauren type of gastric cancer based on CT radiomics nomogram before operation.

MATERIALS AND METHODS

The clinical data and pre-treatment CT images of 300 gastric cancer patients with Lauren intestinal or diffuse type confirmed by postoperative pathology were retrospectively analyzed, who were randomly divided into training set and testing set with a ratio of 2:1. Clinical features were compared between the two Lauren types in the training set and testing set, respectively. Gastric tumors on CT images were manually segmented using ITK-SNAP software, and radiomic features of the segmented tumors were extracted, filtered and minimized using the least absolute shrinkage and selection operator (LASSO) regression to select optimal features and develop radiomics signature. A nomogram was constructed with radiomic features and clinical characteristics to predict Lauren type of gastric cancer. Clinical model, radiomics signature model, and the nomogram model were compared using the receiver operating characteristic (ROC) curve analysis with area under the curve (AUC). The calibration curve was used to test the agreement between prediction probability and actual clinical findings, and the decision curve was performed to assess the clinical usage of the nomogram model.

RESULTS

In clinical features, Lauren type of gastric cancer relate to age and CT-N stage of patients (all p < 0.05). Radiomics signature was developed with the retained 10 radiomic features. The nomogram was constructed with the 2 clinical features and radiomics signature. Among 3 prediction models, performance of the nomogram was the best in predicting Lauren type of gastric cancer, with the respective AUC, accuracy, sensitivity and specificity of 0.864, 78.0%, 90.0%, 70.0%in the testing set. In addition, the calibration curve showed a good agreement between prediction probability and actual clinical findings (p > 0.05).

CONCLUSION

The nomogram combining radiomics signature and clinical features is a useful tool with the increased value to predict Lauren type of gastric cancer.

Descriptive Analysis of Patients with Gastric Tumors Referred to the Largest Emergency Hospital in Oltenia Region-Romania, Between 2015-2020

Gastric cancer represents the third most frequent cause of death worldwide, with the treatment being impaired also by the fact that patients present in the late stages of disease progression. We have aimed here to evaluate the main clinical and pathological features of all recorded cases of gastric tumor patients presented between January 2015 and December 2020 within the Emergency County Hospital of Craiova. Our retrospective analysis identified a total number of 745 cases, and showed a relative homogenous distribution of the age of the patients / year, with the peak age at presentation of 70-80 years old, and with males having a slightly higher prevalence compared to females. There was no correlation of the number of hospitalization days with the localization of the tumor, but the patients in the age group 60-70 years of age tended to show longer hospitalization times compared to the rest of the age groups. Also, pyloric/ antral tumors tended to present at younger ages compared to other localizations, and interestingly, these patients also represented most of the casuistry. Altogether, the distribution of gastric cancer patients' features did not change significantly in the last 5 years despite treatment advances (especially chemo-and radiotherapy), and the advanced stage of presentation call for a more aggressive detection and increased awareness of the population for this frequent pathology.

Transcriptome Analysis and the Prognostic Role of NUDC in Diffuse and Intestinal Gastric Cancer

INTRODUCTION

There have been few studies about gene differences between patients with diffuse-type gastric cancer and those with intestinal-type gastric cancer. The aim of this study was to compare the transcriptomes of signet ring cell gastric cancer (worst prognosis in diffuse-type) and well-differentiated gastric cancer (best prognosis in intestinal-type); NUDC was identified, and its prognostic role was studied.

MATERIALS AND METHODS

We performed next-generation sequencing with 5 well-differentiated gastric cancers and 3 of signet ring cell gastric cancer surgical samples. We performed gene enrichment and functional annotation analysis using the Database for Annotation, Visualization and Integrated Discovery bioinformatics resources. Immunohistochemistry was used to validate NUDC expression.

RESULTS

Overall, 900 genes showed significantly higher expression, 644 genes showed lower expression in signet ring cell gastric cancer than in well-differentiated gastric cancers, and there was a large difference in adhesion, vascular development, and cell-to-cell junction components between the 2 subtypes. We performed variant analysis and found 52 variants and 30 cancer driver genes, including NUDC. We analyzed NUDC expression in gastric cancer tissue and its relationship with prognosis. Cox proportional hazard analysis identified T stage, N stage, and NUDC expression as independent risk factors for survival (P < 0.05). The overall survival of the NUDC-positive group was significantly higher (53.2 ± 0.92 months) than that of the NUDC-negative group (44.6 ± 3.7 months) (P = 0.001) in Kaplan-Meier survival analysis.

CONCLUSION

We found 30 cancer driver gene candidates and found that the NUDC-positive group showed significantly better survival than the NUDC-negative group via variant analysis.

Single-cell dissection of intratumoral heterogeneity and lineage diversity in metastatic gastric adenocarcinoma

Intratumoral heterogeneity (ITH) is a fundamental property of cancer; however, the origins of ITH remain poorly understood. We performed single-cell transcriptome profiling of peritoneal carcinomatosis (PC) from 15 patients with gastric adenocarcinoma (GAC), constructed a map of 45,048 PC cells, profiled the transcriptome states of tumor cell populations, incisively explored ITH of malignant PC cells and identified significant correlates with patient survival. The links between tumor cell lineage/state compositions and ITH were illustrated at transcriptomic, genotypic, molecular and phenotypic levels. We uncovered the diversity in tumor cell lineage/state compositions in PC specimens and defined it as a key contributor to ITH. Single-cell analysis of ITH classified PC specimens into two subtypes that were prognostically independent of clinical variables, and a 12-gene prognostic signature was derived and validated in multiple large-scale GAC cohorts. The prognostic signature appears fundamental to GAC carcinogenesis and progression and could be practical for patient stratification.

Towards Personalization in the Curative Treatment of Gastric Cancer

Gastric cancer is the fifth most common cancer worldwide and has a high mortality rate. In the last decades, treatment strategy has shifted from an exclusive surgical approach to a multidisciplinary strategy. Treatment options for patients with resectable gastric cancer as recommended by different worldwide guidelines, include perioperative chemotherapy, pre- or postoperative chemoradiotherapy and postoperative chemotherapy. Although gastric cancer is a heterogeneous disease with respect to patient-, tumor-, and molecular characteristics, the current standard of care is still according to a one-size-fits-all approach. In this review, we discuss the background of the different treatment strategies in resectable gastric cancer including the current standard, the specific role of radiotherapy, and describe the current areas of research and potential strategies for personalization of therapy.

Intratumoral and peritumoral radiomics analysis for preoperative Lauren classification in gastric cancer

Background

Preoperative prediction of the Lauren classification in gastric cancer (GC) is very important to the choice of therapy, the evaluation of prognosis, and the improvement of quality of life. However, there is not yet radiomics analysis concerning the prediction of Lauren classification straightly. In this study, a radiomic nomogram was developed to preoperatively differentiate Lauren diffuse type from intestinal type in GC.

Methods

A total of 539 GC patients were enrolled in this study and later randomly allocated to two cohorts at a 7:3 ratio for training and validation. Two sets of radiomic features were derived from tumor regions and peritumor regions on venous phase computed tomography (CT) images, respectively. With the least absolute shrinkage and selection operator logistic regression, a combined radiomic signature was constructed. Also, a tumor-based model and a peripheral ring-based model were built for comparison. Afterwards, a radiomic nomogram integrating the combined radiomic signature and clinical characteristics was developed. All the models were evaluated regarding classification ability and clinical usefulness.

Results

The combined radiomic signature achieved an area under receiver operating characteristic curve (AUC) of 0.715 (95% confidence interval [CI], 0.663–0.767) in the training cohort and 0.714 (95% CI, 0.636–0.792) in the validation cohort. The radiomic nomogram incorporating the combined radiomic signature, age, CT T stage, and CT N stage outperformed the other models with a training AUC of 0.745 (95% CI, 0.696–0.795) and a validation AUC of 0.758 (95% CI, 0.685–0.831). The significantly improved sensitivity of radiomic nomogram (0.765 and 0.793) indicated better identification of diffuse type GC patients. Further, calibration curves and decision curves demonstrated its great model fitness and clinical usefulness.

Conclusions

The radiomic nomogram involving the combined radiomic signature and clinical characteristics holds potential in differentiating Lauren diffuse type from intestinal type for reasonable clinical treatment strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-020-00358-3.

Hypergastrinemia is associated with an increased risk of gastric adenocarcinoma with proximal location: A prospective population-based nested case-control study

The incidence of proximal gastric adenocarcinoma is increasing among younger adults. Rodent models have shown that hypergastrinemia causes carcinogenesis in the proximal stomach. The aim of our study was therefore to assess if hypergastrinemia was associated with an increased risk of developing gastric adenocarcinoma also in humans. A prospective population‐based nested case‐control study within the Nord‐Trøndelag Health Study (HUNT) cohort, Norway, was used to assess this association. Serum was collected from 78 962 participants in 1995 to 1997 and 2006 to 2008. In the cohort, 181 incident gastric adenocarcinoma cases were identified from the Norwegian Cancer and Patient Registries through 2015 and matched with 359 controls. The risk of gastric adenocarcinoma was compared between participants with prediagnostic hypergastrinemia (>60 pmol/L) and normal serum gastrin (≤60 pmol/L). Logistic regression provided odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for body mass index, tobacco smoking and comorbidity. Hypergastrinemia was associated with increased risk of gastric adenocarcinoma overall (OR 2.2, 95% CI 1.4‐3.4) and in particular for gastric adenocarcinoma with proximal location (OR 6.1, 95% CI 2.7‐13.8), but not with gastric adenocarcinoma with distal location (OR 1.7, 95% CI 0.9‐3.4). Moreover, hypergastrinemia was associated with an increased risk of gastric adenocarcinoma of intestinal histological type (OR 3.8, 95% CI 1.8‐7.9), but not for diffuse histological type (OR 1.6, 95% CI 0.7‐3.7). In conclusion, hypergastrinemia was associated with an increased risk of proximal and intestinal type gastric adenocarcinoma.

What's new?

The incidence of proximal gastric adenocarcinoma has been reported to increase among younger adults in Western countries. Rodent models have shown that serum gastrin levels above the normal range cause carcinogenesis in the proximal stomach. In this first prospective population‐based study on the association between hypergastrinemia and gastric adenocarcinoma, the risk of gastric adenocarcinoma in the proximal stomach, but not in the distal stomach, was markedly increased in hypergastrinemic individuals. The finding supports the hypothesis that hypergastrinemia mediates the development of gastric adenocarcinoma in the proximal stomach, where mucosal proliferation is stimulated by gastrin.

The clinicopathological characteristics and genetic alterations of gastric cancer patients according to the Lauren classification

ObjectiveThe Lauren classification is an important histological classification of gastric cancer (GC) with different biological behaviors between histological types.BackgroundTo date, there are few reports on the genetic alterations and survival differences between different histological types according to the Lauren classification.MethodsIn total, 433 GC patients undergoing surgery were enrolled. The clinicopathological features, prognoses, and genetic alterations of the different Lauren types were compared.ResultsDiffuse-type GC was associated with a younger age, female predominance, more Borrmann type 3 and 4 tumors, more advanced pathological tumor (T) and node (N) categories, more tumor recurrences (especially peritoneal recurrence), and worse 5-year overall survival and disease-free survival rates than intestinal-type GC and mixed-type GC. Regarding genetic alterations, mixed-type GC was associated with more TP53 mutations than intestinal-type GC and diffuse-type GC. Multivariate analysis demonstrated the following independent prognostic factors: age, Lauren classification, and pathological T and N categories. Regarding mixed-type GC, diffuse-type major tumors were associated with more lymphovascular invasion, a more advanced N category and TNM stage, and fewer PI3K/AKT pathway mutations than intestinal-type major tumors.ConclusionsDiffuse-type GC had unfavorable clinicopathological features and a worse prognosis than intestinal-type GC. For mixed-type GC, the clinicopathological features and genetic alterations were different between intestinal-type major tumors and diffuse-type major tumors.

Machine Learning-Based Computational Models Derived From Large-Scale Radiographic-Radiomic Images Can Help Predict Adverse Histopathological Status of Gastric Cancer

INTRODUCTION

Adverse histopathological status (AHS) decreases outcomes of gastric cancer (GC). With the lack of a single factor with great reliability to preoperatively predict AHS, we developed a computational approach by integrating large-scale imaging factors, especially radiomic features at contrast-enhanced computed tomography, to predict AHS and clinical outcomes of patients with GC.

METHODS

Five hundred fifty-four patients with GC (370 training and 184 test) undergoing gastrectomy were retrospectively included. Six radiomic scores (R-scores) related to pT stage, pN stage, Lauren & Borrmann (L&B) classification, World Health Organization grade, lymphatic vascular infiltration, and an overall histopathologic score (H-score) were, respectively, built from 7,000+ radiomic features. R-scores and radiographic factors were then integrated into prediction models to assess AHS. The developed AHS-based Cox model was compared with the American Joint Committee on Cancer (AJCC) eighth stage model for predicting survival outcomes.

RESULTS

Radiomics related to tumor gray-level intensity, size, and inhomogeneity were top-ranked features for AHS. R-scores constructed from those features reflected significant difference between AHS-absent and AHS-present groups (P < 0.001). Regression analysis identified 5 independent predictors for pT and pN stages, 2 predictors for Lauren & Borrmann classification, World Health Organization grade, and lymphatic vascular infiltration, and 3 predictors for H-score, respectively. Area under the curve of models using those predictors was training/test 0.93/0.94, 0.85/0.83, 0.63/0.59, 0.66/0.63, 0.71/0.69, and 0.84/0.77, respectively. The AHS-based Cox model produced higher area under the curve than the eighth AJCC staging model for predicting survival outcomes. Furthermore, adding AHS-based scores to the eighth AJCC staging model enabled better net benefits for disease outcome stratification.

DISCUSSION

The developed computational approach demonstrates good performance for successfully decoding AHS of GC and preoperatively predicting disease clinical outcomes.

HOXC9 overexpression is associated with gastric cancer progression and a prognostic marker for poor survival in gastric cancer patients

BACKGROUND

As a member of the homeobox family, HOXC9 is overexpressed in several malignant tumors and may be regarded as a biomarker for prognostic evaluation. However, the expression pattern and prognostic significance of HOXC9 in gastric cancer have not been detailedly studied.

METHODS

HOXC9 mRNA expression difference in normal tissues and gastric cancer tissues were investigated using RT-PCR, and immunohistochemistry was used to analyze HOXC9 protein expression in precancerous lesions and gastric cancer at different stages, and its clinicopathological characteristics and survival were statistically tested.

RESULTS

Compared to the normal gastric mucosa tissues, the expression levels of HOXC9 mRNA in the human gastric cancer tissues were significantly higher. HOXC9 protein levels of gastric cancer were obviously higher than that in other noncancerous tissues (P < 0.001). Positive expression of HOXC9 was associated with tumor size (P = 0.036), lymphatic invasion (P = 0.001), depth of invasion (P < 0.001), lymph-node metastasis (P < 0.001), and higher stage disease (P < 0.001). Furthermore, Kaplan-Meier survival curves showed that HOXC9 expression is inversely correlated with both disease-specific and disease-free 5 year survival of patients with gastric cancer (P < 0.001 for both). Strikingly, our multivariate Cox regression analysis revealed that HOXC9 expression was an independent poor prognostic factor in gastric cancer (P < 0.05).

CONCLUSIONS

HOXC9 expression was observed in a subset of patients with gastric cancer and was associated with an unfavorable prognosis. As well as being a new prognostic indicator, HOXC9 protein could be a useful marker for early diagnosis.

Epstein-Barr virus infection and genome polymorphisms on gastric remnant carcinoma: a meta-analysis

Background

Previous studies reported that Epstein–Barr virus (EBV) may play a causal role in the pathogenesis of gastric remnant carcinoma (GRC). However, there was still some controversy.

Methods

Articles published until July 15, 2020, in PubMed, MEDLINE, Embase and CNKI databases were selected. According to the inclusion criteria, corresponding data of included articles were abstracted and used for statistical analysis.

Results

Thirteen papers were finally enrolled, nine of which showed the result that the risk of EBV infection rate in the GRC was higher than conventional gastric carcinoma (OR = 5.22, 95% CI 3.89–7.00). In addition, we found that EBV associated GRC (EBVaGRC) had higher rate of Billroth-II (OR = 3.80, 95% CI 1.90–7.57), carcinoma in anastomotic site (OR = 2.41, 95% CI 1.27–4.56) and diffuse type (Lauren classification) (OR = 1.97, 95% CI 1.04–3.73),while sex, initial diagnosis and lymphocytic infiltration were calculated no statistical difference. By genetic polymorphism analysis, “V-val” subtype of EBNA1 (OR = 21.84, 95% CI 11.92–31.76) and “C” subtype of BamHI-W1/I1 (OR = 7.07, 95% CI 1.47–34.03) were observed to be highly expressed in EBVaGRC.

Conclusion

EBV infection rate in the GRC was higher. Further analysis showed that Billroth-II, carcinoma in anastomotic site and diffuse type (Lauren classification) were associated to EBVaGRC. Through analysis of EBV genome polymorphisms, we thought that “V-val” subtype of EBNA1 and “C” subtype of BamHI-W1/I1 may become predictor of EBVaGRC.

High Level of Legumain Was Correlated With Worse Prognosis and Peritoneal Metastasis in Gastric Cancer Patients

Background: Accumulating evidence has demonstrated that legumain (LGMN) is abnormally expressed in several malignancies and functions as an oncogene. However, the association between LGMN and gastric cancer (GC) has not yet been fully elucidated. In this study, we performed a comprehensive analysis of the role of LGMN in clinicopathologic characteristics and survival of GC patients.

Methods: The study had two patient cohorts, The Cancer Genome Atlas (TCGA) cohort and the Zhongshan Hospital cohort, both of which were used to analyze the role of LGMN in GC samples. The relationship between LGMN and clinicopathologic characteristics was determined by the Chi-square test and logistic regression analysis. The Kaplan–Meier method and Cox proportional hazards regression analysis were conducted to investigate the prognostic role of LGMN in GC patients. Moreover, a nomogram was constructed based on the factors that were independently associated with peritoneal metastasis. Finally, the gene set enrichment analysis (GSEA) was conducted to explore the underlying pathways through which LGMN was involved in GC progression.

Results: The mRNA and protein levels of LGMN were significantly upregulated in GC tissues, especially for diffuse-type GC. High level of LGMN was independently associated with poor prognosis in both TCGA and Zhongshan cohorts. Further analysis showed that increased protein level of LGMN was related to peritoneal metastasis in GC patients. In a nomogram model, the LGMN expression could help predict the possibility of peritoneal metastasis in GC patients. LGMN was a strong determinant for prediction of peritoneal metastasis. GC patients with high LGMN expression tended to have worse survival together with more frequent diffuse-type tumors and increased risk of peritoneal metastasis. The GSEA results showed that focal adhesion, ecm receptor interaction, cell adhesion molecules cams, TGF-β signaling pathway, JAK-STAT signaling pathway, gap junction, etc. were differentially enriched in the phenotype with high LGMN expression.

Conclusion: LGMN was an independent prognostic factor for OS in GC patients. Increased expression of LGMN was significantly associated with peritoneal metastasis. The nomogram based on LGMN might guide the clinical decisions for patients with GC.

Gastric carcinoma: Insights into risk factors, methods of diagnosis, possible lines of management, and the role of primary care

Gastric carcinoma represents the second most common type of malignancy that contributes to cancer-related mortality worldwide. However, the geographic incidence of gastric carcinoma had changed over the last few decades, possibly due to increased hygiene, increased awareness of the importance of healthy nutrition, and increased rates of eradication of Helicobacter pylori infection. Gastric carcinoma consists of two pathological variants, intestinal and diffuse. Early cases of gastric carcinoma may be asymptomatic. However, advanced cases may present with significant weight loss, dysphagia, abdominal pain, vomiting, and even severe upper gastrointestinal bleeding. Patients at high risk of developing gastric carcinoma should be adequately screened at primary healthcare centers for early detection and effective management. Lines of treatment vary according to the stage of the disease but surgical resection of the tumor with regional lymphadenectomy remains the gold standard of therapy. This review sheds light on gastric carcinoma given the recent trends regarding its prevalence, risk factors, types, clinical picture, methods of diagnosis, possible lines of management, and the role of primary care.