Early-onset gastric cancer: Learning lessons from the young

CTNND1 is involved in germline predisposition to early-onset gastric cancer by affecting cell-to-cell interactions

BACKGROUND

CDH1 and CTNNA1 remain as the main genes for hereditary gastric cancer. However, they only explain a small fraction of gastric cancer cases with suspected inherited basis. In this study, we aimed to identify new hereditary genes for early-onset gastric cancer patients (EOGC; < 50 years old).

METHODS

After germline exome sequencing in 20 EOGC patients and replication of relevant findings by gene-panel sequencing in an independent cohort of 152 patients, CTNND1 stood out as an interesting candidate gene, since its protein product (p120ctn) directly interacts with E-cadherin. We proceeded with functional characterization by generating two knockout CTNND1 cellular models by gene editing and introducing the detected genetic variants using a lentiviral delivery system. We assessed β-catenin and E-cadherin levels, cell detachment, as well as E-cadherin localization and cell-to-cell interaction by spheroid modeling.

RESULTS

Three CTNND1 germline variants [c.28_29delinsCT, p.(Ala10Leu); c.1105C > T, p.(Pro369Ser); c.1537A > G, p.(Asn513Asp)] were identified in our EOGC cohorts. Cells encoding CTNND1 variants displayed altered E-cadherin levels and intercellular interactions. In addition, the p.(Pro369Ser) variant, located in a key region in the E-cadherin/p120ctn binding domain, showed E-cadherin mislocalization.

CONCLUSIONS

Defects in CTNND1 could be involved in germline predisposition to gastric cancer by altering E-cadherin and, consequently, cell-to-cell interactions. In the present study, CTNND1 germline variants explained 2% (3/172) of the cases, although further studies in larger external cohorts are needed.

Current and Future Perspectives on the Management of Helicobacter pylori: A Narrative Review

The prevalence of Helicobacter pylori (H. pylori), a pathogen, has decreased globally in the last decade. To date, the management of H. pylori has focused on a reactive approach, whereby those diagnosed are treated with antimicrobials and acid suppression in combination. This review article provides an overview of the shift in the management of H. pylori from a reactive approach towards a proactive 'screen and treat' approach; the article reflects the current pharmacological landscape for H. pylori treatment by exploring similarities such as the first-line prescription of quadruple therapy in most countries and provides a summary table of the best practice guidance from Europe, Asia, and North America. It explores significant ongoing challenges in management, such as rising antimicrobial resistance rates, and explores a potential 'work smart' approach to antimicrobial susceptibility testing. We explore the role of registry databases in providing data on treatment efficacy and safety and how they can support a strategic approach to H. pylori treatment. We question if such a database's availability, update, and regular audit should serve as a key quality indicator in a population screening programme. Despite a call for vaccination against H. pylori and decades of research, not many have made it to a phase-three clinical trial. We explore the challenges that have complicated the development of such a vaccine, such as the genetic diversity of H. pylori, immunotolerance, and limitations of mouse models in research; we reflect on how these challenges are contributing to a low likelihood of having a vaccine in the short-medium term. Lastly, it explores the heterogeneity in research on probiotics and their role as an adjunct in the management of H. pylori.

Nomogram models for predicting overall and cancer-specific survival in early-onset gastric cancer patients: a population-based cohort study

To develop nomogram models for predicting the overall survival (OS) and cancer-specific survival (CSS) of early-onset gastric cancer (EOGC) patients. A total of 1077 EOGC patients from the Surveillance, Epidemiology, and End Results (SEER) database were included, and an additional 512 EOGC patients were recruited from the Fourth Hospital of Hebei Medical University, serving as an external test set. Univariate and multivariate Cox regression analyses were performed to identify independent prognostic factors. Based on these factors, two nomogram models were established, and web-based calculators were developed. These models were validated using receiver operating characteristics (ROC) curve analysis, calibration curves, and decision curve analysis (DCA). Multivariate analysis identified gender, histological type, stage, N stage, tumor size, surgery, primary site, and lung metastasis as independent prognostic factors for OS and CSS in EOGC patients. Calibration curves and DCA curves demonstrated that the two constructed nomogram models exhibited good performance. These nomogram models demonstrated superior performance compared to the 7th edition of the AJCC tumor-node-metastasis (TNM) classification (internal validation set: 1-year OS: 0.831 vs 0.793, P = 0.072; 1-year CSS: 0.842 vs 0.816, P = 0.190; 3-year OS: 0.892 vs 0.857, P = 0.039; 3-year CSS: 0.887 vs 0.848, P = 0.018; 5-year OS: 0.906 vs 0.880, P = 0.133; 5-year CSS: 0.900 vs 0.876, P = 0.109). In conclusion, this study developed two nomogram models: one for predicting OS and the other for CSS of EOGC patients, offering valuable assistance to clinicians.

The landscape of 8q24 cytoband in gastric cancer (Review)

Worldwide, gastric cancer (GC) is estimated to be the fifth most common type of cancer type in both sexes, ranking sixth for new cases, with >640,850 cases per year, and fourth in terms of mortality rate. Cancer presents numerical and structural alterations in chromosomes, often through gains and losses of regions. In GC, there are multiple genetic alterations, in which those located in cytoband 8q24 have been frequently described; essential genes are present in this cytoband, regulating the homeostasis of crucial biological processes, such as the MYC gene, which induces expression of selective genes to promote cell growth and proliferation. Conversely, DNA sequence variations can also occur when a single nucleotide in the genome sequence is altered, and this is termed a single nucleotide polymorphism (SNP). These alterations, which can serve as a biological marker, are present in at least 1% of the population and assist in identifying genes associated with GC. In the present review, 12 genes present in cytoband 8q24 related to GC (NSMCE2, PCAT1, CASC19, CASC8, CCAT2, PRNCR1, POU5F1B, PSCA, JRK, MYC, PVT1 and PTK2) are discussed. The PSCA gene was cited more frequently than others; it has four known SNPs associated with GC (rs2978980, rs2294008, rs2976392 and rs9297976). Thus, these SNPs should be further studied in different populations to determine their risk value in patients with GC.

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.

The central role of gastrin in gastric cancer

The prevalence of gastric cancer has markedly declined, but due to the high mortality rates associated with gastric cancer, it is still a serious disease. The preferred classification of gastric cancer is according to Lauren into either the intestinal type, which has a glandular growth pattern, or the diffuse type, which does not have glandular structures. Both types have been classified as adenocarcinomas, with the latter type based on periodic acid-Schiff (PAS) positivity presumed to reflect mucin. However, the presence of mucin in the diffuse type, in contrast to neuroendocrine/enterochromaffin-like (ECL) cell markers, has not been confirmed by immunohistochemistry and in situ hybridization. The ECL cells are probably prone to becoming cancerous because they do not express E-cadherin. Gastric cancer is unique in that a bacterium, Helicobacter pylori, is thought to be its main cause. H. pylori predisposes infected individuals to cancer only after having caused oxyntic atrophy leading to gastric hypoacidity and hypergastrinemia. No single H. pylori factor has been convincingly proved to be carcinogenic. It is probable that gastrin is the pathogenetic factor for gastric cancer due to H. pylori, autoimmune gastritis, and long-term prolonged inhibition of gastric acid secretion. Hypergastrinemia induces ECL cell hyperplasia, which develops into neuroendocrine tumors (NETs) and then into neuroendocrine carcinomas in rodents, a sequence that has also been described in humans. During carcinogenesis, the tumor cells lose specific traits, requiring that sensitive methods be used to recognize their origin. Gastric cancer occurrence may hopefully be prevented by H. pylori eradication at a young age, and by the reduced use of inhibitors of acid secretion and use of a gastrin antagonist in those with previous long-term H. pylori infection and those with autoimmune gastritis.

Biological and clinical implications of early-onset cancers: A unique subtype

In recent years, the incidence of cancers is continuously increasing in young adults. Early-onset cancer (EOC) is usually defined as patients with cancers under the age of 50, and may represent a unique subgroup due to its special disease features. Overall, EOCs often initiate at a young age, present as a better physical performance but high degree of malignancy. EOCs also share common epidemiological and hereditary risk factors. In this review, we discuss several representative EOCs which were well studied previously. By revealing their clinical and molecular similarities and differences, we consider the group of EOCs as a unique subtype compared to ordinary cancers. In consideration of EOC as a rising threat to human health, more researches on molecular mechanisms, and large-scale, prospective clinical trials should be carried out to further translate into improved outcomes.

Incorporating Immunotherapy in the Management of Gastric Cancer: Molecular and Clinical Implications

Simple Summary

Gastric cancer is one of the most common malignant tumours worldwide, with the fifth and third highest morbidity and mortality, respectively, of all cancers. Survival is limited, as most of the patients are diagnosed at an advanced stage, and are not suitable for surgery with a curative intent. Chemotherapy has only modestly improved patients’ outcomes and is mainly given with a palliative intent. Immunotherapy has improved overall survival of patients with gastric cancer, and has thus become a new standard of care in clinic. In this review we discuss the strong molecular rationale for the administration of immunotherapy in this disease and analyse the clinical data supporting its use.

Abstract

Gastric cancer has a median survival of 11 months, and this poor prognosis has not improved over the last 30 years. Recent pre-clinical data suggest that there is high tumour-related neoantigen expression in gastric cancer cells, suggesting that a clinical strategy that enhances the host’s immune system against cancer cells may be a successful approach to improve clinical outcomes. Additionally, there has been an increasing amount of translational evidence highlighting the relevance of PD-L1 expression in gastric cancer cells, indicating that PD-1/PD-L1 inhibitors may be useful. Several molecular subgroups of gastric cancer have been identified to respond with excellent outcomes to immunotherapy, including microsatellite instable tumours, tumours bearing a high tumour mutational burden, and tumours related to a chronic EBV infection. In gastric cancer, immunotherapy has produced durable responses in chemo-refractory patients; however, most recently there has been a lot of enthusiasm as several large-scale clinical trials highlight the improved survival noted from the incorporation of immunotherapy in the first line setting for advanced gastric cancer. Our review aims to discuss current pre-clinical and clinical data supporting the innovative role of immunotherapy in gastric cancer.

Multi‑institutional development and validation of a nomogram to predict prognosis of early-onset gastric cancer patients

Background

Early-onset gastric cancer (EOGC, ≤45 years old) is characterized with increasing incidence and more malignant phenotypes compared with late-onset gastric cancer, which exhibits remarkable immune cell infiltration and is potential immunotherapeutic population. Till now, restricted survival information of EOGC is available due to limited case numbers. This study established a novel nomogram to help evaluate cancer-specific survival (CSS) of EOGC patients who underwent gastrectomy, and may provide evidence for predicting patients’ survival.

Methods

We retrospectively enrolled a cohort containing 555 EOGC cases from five independent medical centers in China, among which 388 cases were randomly selected into a training set while the other 167 cases were assigned into the internal validation set. Asian or Pacific Islander (API) patients diagnosed with EOGC during 1975-2016 were retrieved from the SEER database (n=299) and utilized as the external validation cohort. Univariate and multivariate analyses were conducted to test prognostic significances of clinicopathological factors in the training set. Accordingly, two survival nomogram models were established and compared by concordance index (C-index), calibration curve, receiver operating characteristics (ROC) curves and decision curve analyses (DCA).

Results

The 5-year CSS rate of training cohort was 61.3% with a median survival time as 97.2 months. High consistency was observed on calibration curves in all three cohorts. Preferred nomogram was selected due to its better performance on ROC and DCA results. Accordingly, a novel predicative risk model was introduced to better stratify high-risk EOGC patients with low-risk patients. In brief, the 5-year CSS rates for low-risk groups were 92.9% in training set, 83.1% in internal validation set, 89.9% in combined NQSQS cohort, and 85.3% in SEER-API cohort. In contrast, the 5-year CSS rates decreased to 38.5%, 44.3%, 40.5%, and 36.9% in the high-risk groups of the four cohorts above, respectively. The significant survival difference between high-risk group (HRG) and low-risk group (LRG) indicated the precise accuracy of our risk model. Furthermore, the risk model was validated in patients with different TNM stages, respectively. Finally, an EOGC web-based survival calculator was established with public access, which can help predict prognosis.

Conclusions

Our data provided a precise nomogram on predicting CSS of EOGC patients with potential clinical applicability.

Immunogenetics of gastrointestinal cancers: A systematic review and retrospective survey of inborn errors of immunity in humans

BACKGROUND AND AIM

Humans with inborn errors of immunity (IEI), or primary immunodeficiencies, may be associated with a potential risk factor for early-onset gastrointestinal (GI) cancer.

METHODS

We systematically reviewed all cases with clinical diagnoses of both an IEI and a GI cancer in three databases (MEDLINE, SCOPUS, and EMBASE). In total, 76 publications satisfying our inclusion criteria were identified, and data for 149 cases were analyzed. We also searched our institutional cancer registry for such cases.

RESULTS

We identified 149 patients with both an IEI and a GI cancer, 95 presented gastric cancer, 13 small bowel cancer, 35 colorectal cancer, and 6 had an unspecified cancer or cancer at another site. Gastric and colon adenocarcinomas were the most common. For both gastric and colorectal cancers, age at onset was significantly earlier in patients with IEIs than in the general population, based on the SEER database. Common variable immunodeficiency (CVID) was the most common IEI associated with gastrointestinal cancer. About 12% of patients had molecular genetic diagnoses, the three most frequently implicated genes being ATM, CARMIL2, and CTLA4. Impaired humoral immunity and Epstein-Barr virus (EBV) infection were frequently reported as factors potentially underlying early-onset GI cancers in patients with IEIs. We identified one patient with CVID and early-onset gastric adenocarcinoma, recurrent diarrhea, and gastrointestinal CMV infection from a retrospective survey.

CONCLUSION

Patients with IEIs should be considered at risk of early-onset GI cancers and should therefore undergo cancer screening at an earlier age.

Comparison of treatment strategies and survival of early-onset gastric cancer: a population-based study

Treatments for early-onset gastric cancer (EOGC) patients are rarely included in clinical trials, resulting in an unclear impact on survival. This study aimed to investigate the treatment patterns of EOGC patients and their impact on survival. Based on the Surveillance, Epidemiology, and End Results database, we conducted a retrospective analysis of 1639 EOGC patients (< 50 years) diagnosed between 2010 and 2018. Patients with larger tumours, distant metastasis, and AJCC TNM stage in IV were prone to receive nonsurgical treatment. Patients treated with surgery alone had a better prognosis than those receiving SROC or SCRT or nonsurgical treatment. However, analyses stratified by histological type, tumour size and TNM stage showed that patients did not benefit more from SROC and SCRT than from surgery alone. Similar results were observed in the stratified Cox regression risk analysis. Patients who received nonsurgical treatment had the highest risk of overall death [hazard ratio (HR) = 2.443, 95% confidence interval (CI) 1.865–3.200, P < 0.001]. This study indicated that additional radiotherapy, chemotherapy or chemoradiotherapy did not provide a coordinated survival benefit to EOGC patients.

Copy number alterations and epithelial‑mesenchymal transition genes in diffuse and intestinal gastric cancers in Mexican patients

Gastric cancer (GC) is a common malignancy with the highest mortality rate among diseases of the digestive system, worldwide. The present study of GC alterations is crucial to the understanding of tumor biology and the establishment of important aspects of cancer prognosis and treatment response. In the present study, DNA from Mexican patients with diffuse GC (DGC), intestinal GC (IGC) or non‑atrophic gastritis (NAG; control) was purified and whole‑genome analysis was performed with high‑density arrays. Shared and unique copy number alterations (CNA) were identified between the different tissues involving key genes and signaling pathways associated with cancer. This led to the molecular distinction and identification of the most relevant molecular functions to be identified. A more detailed bioinformatics analysis of epithelial‑mesenchymal transition (EMT) genes revealed that the altered network associated with chromosomal alterations included 11 genes that were shared between DGC, IGC and NAG, as well as 19 DGC‑ and 7 IGC‑exclusive genes. Furthermore, the main molecular functions included adhesion, angiogenesis, migration, metastasis, morphogenesis, proliferation and survival. The present study provided the first whole‑genome high‑density array analysis in Mexican patients with GC and revealed shared and exclusive CNA‑associated genes in DGC and IGC. In addition, a bioinformatics‑predicted network was generated, focusing on CNA‑altered genes associated with EMT and the hallmarks of cancer, as well as precancerous alterations that may lead to GC. Molecular signatures of diffuse and intestinal GC, predicted bioinformatically, involve common and distinct CNA‑EMT genes related to the hallmarks of cancer that are potential candidates for screening biomarkers of GC, including early stages.

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.

Global Incidence and Mortality of Gastric Cancer, 1980-2018

IMPORTANCE

Gastric cancer is one of the most common cancers, with a high mortality-to-incidence ratio. It is uncertain whether developed nations may encounter an increasing burden of gastric cancer in young adults, as occurs for other cancers.

OBJECTIVES

To evaluate the incidence and mortality of gastric cancer and compare the global incidence trends between younger (<40 years) and older (≥40 years) populations.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study analyzed data from global and national cancer registries, including data from 1980 to 2018, with at least 15 calendar years of incidence and mortality data. Data on age-standardized incidence and mortality rates of gastric cancer among 48 countries were retrieved from the Surveillance, Epidemiology, and End Results Program, the National Cancer Institute, the Nordic Cancer Registries, and the World Health Organization Mortality Database. The 10-year incidence trend of gastric cancer was assessed by age and sex. The 2018 GLOBOCAN database was used for reporting the global incidence and mortality of gastric cancer, the most recent data available at the time of analysis. Analyses were performed between January 10, 2020, and March 20, 2020.

MAIN OUTCOMES AND MEASURES

The average annual percent change (AAPC) of the incidence and mortality trends as evaluated by joinpoint regression analysis.

RESULTS

A total of 1 033 701 new cases of gastric cancer and 782 685 related deaths were reported in 2018. Overall, the incidence of gastric cancer decreased in 29 countries, and mortality decreased in 41 countries. The age-standardized incidence of gastric cancer decreased from a range of 2.6 to 59.1 in 1980 to a range of 2.5 to 56.8 in 2018 per 100 000 persons. The overall age-standardized mortality rate changed from a range of 1.3 to 25.8 in 1980 to a range of 1.5 to 18.5 in 2018 per 100 000 persons, but increasing mortality was observed in Thailand (female: AAPC, 5.30; 95% CI, 4.38-6.23; P < .001; male: AAPC, 3.92; 95% CI, 2.14-5.74; P < .001). The incidence of gastric cancer decreased in most regions among individuals 40 years or older and increased in populations younger than 40 years in several countries, including Sweden (male: AAPC, 13.92; 95% CI, 7.16-21.11; P = .001), Ecuador (female: AAPC, 6.05; 95% CI, 1.40-10.92; P = .02), and the UK (male: AAPC, 4.27; 95% CI, 0.15-8.55; P = .04; female: AAPC, 3.60; 95% CI, 3.59-3.61; P < .001).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, an increasing incidence of gastric cancer was observed in younger individuals in some countries, highlighting the need for more preventive strategies in younger populations. Future research should explore the reasons for these epidemiologic trends.

Clinical, Molecular and Genetic Characteristics of Early Onset Gastric Cancer: Analysis of a Large Multicenter Study

Gastric adenocarcinoma (GC) is a common tumor with high morbidity and mortality. Only 7% of patients with GC are diagnosed before age 50 (early onset gastric cancer (EOGC)), and their characteristics have been poorly described. We aimed to describe clinical, molecular, and genetic characteristics of EOGC. A total of 309 patients with EOGC were retrospectively studied in four Spanish centers. Personal information, family history, and tumor information were registered. Germinal genetic analysis was performed in patients who met current criteria of a hereditary syndrome at the time of diagnosis. The median age at diagnosis was 44 years. The majority (73.3%) of tumors were diffuse, and 78.3% were diagnosed in an advanced stage. Familial aggregation of GC was present in 18/117 (15.4%) cases, and 5/117 (4.3%) met criteria for familial GC. MMR-IHC was performed in 126/309 (40.7%) tumors: 4/126 (3.1%) had loss of expression in MLH1/PMS2, without an associated germline mutation. Sixteen germline genetic analyses were performed, detecting a pathogenic variant in four (25%) cases: one in BRCA2, one in TP53, and two in CDH1. Most EOGC are diffuse and diagnosed in an advanced stage. In these patients, DNA MMR system deficiency is uncommon. Although familial aggregation was observed in only 15% of cases, a germline mutation was found in 25% of patients tested with clinical criteria. This demonstrates that EOGC has a marked genetic heterogeneity, reinforcing the importance of an accurate genetic counseling and enhancing the emerging use of multigene panels.

Identification of New Genes Involved in Germline Predisposition to Early-Onset Gastric Cancer

The genetic cause for several families with gastric cancer (GC) aggregation is unclear, with marked relevance in early-onset patients. We aimed to identify new candidate genes involved in GC germline predisposition. Whole-exome sequencing (WES) of germline samples was performed in 20 early-onset GC patients without previous germline mutation identified. WES was also performed in nine tumor samples to analyze the somatic profile using SigProfilerExtractor tool. Sequencing germline data were filtered to select those variants with plausible pathogenicity, rare frequency and previously involved in cancer. Then, a manual filtering was performed to prioritize genes according to current knowledge and function. These genetic variants were prevalidated with Integrative Genomics Viewer 2.8.2 (IGV). Subsequently, a further selection step was carried out according to function and information obtained from tumor samples. After IGV and selection step, 58 genetic variants in 52 different candidate genes were validated by Sanger sequencing. Among them, APC, FAT4, CTNND1 and TLR2 seem to be the most promising genes because of their role in hereditary cancer syndromes, tumor suppression, cell adhesion and Helicobacter pylori recognition, respectively. These encouraging results represent the open door to the identification of new genes involved in GC germline predisposition.

Comparison of metastasis between early-onset and late-onset gastric signet ring cell carcinoma

Background

There is little knowledge to date about the distant metastasis of early-onset gastric signet ring cell carcinoma (SRCC) or the difference in metastasis based on age. Therefore, we conducted a comprehensive retrospective study using the Surveillance, Epidemiology, and End Results (SEER) database and data from our hospital.

Methods

Patients were collected from the SEER database and our hospital. Univariate and multivariate logistic regression analyses and propensity score matching (PSM) were used to identify risk factors for metastasis. K-M survival curves were generated to analyse patient survival.

Results

In total, we retrieved 2052 EOGC patients diagnosed with SRCC from the SEER database and included 403 patients from our hospital. K-M survival curves showed that late-onset SRCC patients had worse survival than early-onset patients but that late-onset SRCC patients were less likely to have distant metastasis, as validated by SEER data (OR = 0.462, 95%CI, 0.272–0.787; P = 0.004) and our data (OR = 0.301, 95%CI, 0.135–0.672; P = 0.003). Multivariate logistic regression and PSM analysis revealed that age of 45 or younger was an independent risk factor for distant metastasis.

Conclusion

Our study showed that distant metastasis was more common in early-onset SRCC than in late-onset SRCC. However, further studies are needed to explore the potential aetiologic basis for this disparity.

Gastric Cancer: Epidemiology, Risk Factors, Classification, Genomic Characteristics and Treatment Strategies

Gastric cancer (GC) is one of the most common malignancies worldwide and it is the fourth leading cause of cancer-related death. GC is a multifactorial disease, where both environmental and genetic factors can have an impact on its occurrence and development. The incidence rate of GC rises progressively with age; the median age at diagnosis is 70 years. However, approximately 10% of gastric carcinomas are detected at the age of 45 or younger. Early-onset gastric cancer is a good model to study genetic alterations related to the carcinogenesis process, as young patients are less exposed to environmental carcinogens. Carcinogenesis is a multistage disease process specified by the progressive development of mutations and epigenetic alterations in the expression of various genes, which are responsible for the occurrence of the disease.

Gastric cancer in young patients: a separate entity with aggressive features and poor prognosis

PURPOSE

To investigate the clinicopathological features and survival outcomes between young and old patients with gastric cancer (GC), and further determine the role of young age in the prognosis of GC.

METHODS

Patients with stage I-III gastric adenocarcinomas undergoing curative surgery were enrolled, divided into young (aged 18-49 years, YG), middle-aged (50-59 years, MG), and old (≥ 60 years, OG) groups. Exclusion criteria were neoadjuvant therapy and history of malignant tumors. Clinicopathological features, overall survival (OS), disease-free survival (DFS), and recurrence patterns were compared among three groups.

RESULTS

1131 patients were finally included, with 270, 314, and 547 cases in the YG, MG, and OG, respectively. Compared to others, YG had higher proportion of female, middle-third gastric cancer, poor differentiation, N3b stage, and adjuvant chemotherapy. YG demonstrated poorer 5-year OS than MG (62.4% vs. 70.8%, P = 0.019), but better than OG (62.4% vs. 58.7%, P = 0.031). YG also suffered inferior 5-year DFS (75.2% vs. 82.8%, P = 0.040) compared with MG, and higher incidence of peritoneal recurrence than MG (15.1% vs. 5.2%, P < 0.001) and OG (15.1% vs. 4.1%, P < 0.001). Multivariate analysis identified young age as the independent prognostic factor for OS [hazard ratio (HR) = 1.347, 95% CI 1.018-1.781, P = 0.037], DFS (HR = 1.601, 95% CI 1.079-2.376, P = 0.019), and peritoneal recurrence (HR = 2.936, 95% CI 1.505-5.726, P = 0.002).

CONCLUSIONS

Young GC patients demonstrated aggressive features with poor prognosis and enhanced management may be warranted for this subgroup.

Clinicopathologic Features, Survival Outcome, and Prognostic Factors in Gastric Cancer Patients 18-40 Years of Age

Purpose: Whether young patients with gastric cancer (GC) had a distinct prognostic outcome from older patients remains controversial. The objective of this study was to investigate the clinicopathologic characteristics and prognostic factors of young GC patients and evaluate the survival outcome in comparison to their older counterparts. Methods: We retrospectively reviewed clinicopathologic and survival data of 2022 patients who underwent curative resection for GC. All patients were divided into the young patient group (18-40 years) and older patient group (>40 years) according to the patient age. Clinicopathologic characteristics and prognostic factors of young GC patients were analyzed, and the survival difference between the two groups was compared. Results: The incidence of GC in the patients 18-40 years of age was 8.1% (164/2022). The young patient group had different clinicopathologic features from the older group, including a significant female predominance, a larger number of retrieved lymph nodes, a higher proportion of undifferentiated histology type, and middle or lower 1/3 GC. However, the survival outcome of young patients was similar to that of their older counterparts (5-year disease free survival [DFS]: 47.0% vs. 44.0%, p = 0.247), even when comparison based on the TNM stage was made. Deeper tumor invasion (T3-T4 stage, hazard ratios [HR]: 5.791, 95% confidence intervals [CIs]: 2.908-11.533, p < 0.001), lymph node metastasis (HR: 2.500, 95% CIs: 1.308-4.781, p = 0.006), and lymphovascular invasion (HR: 2.191, 95% CIs: 1.306-3.677, p = 0.003) were independent prognostic factors for young GC patients. Conclusions: Young age (18-40 years) was not associated with poorer survival outcome in GC patients. However, early diagnosis and curative resection with adequate lymphadenectomy will still be necessary for improving the survival outcome of young GC patients.

Development and validation of prognostic nomogram for young patients with gastric cancer

Background

This study was to establish nomogram models for prognostic evaluation of early-onset gastric cancer (EOGC) in both overall survival (OS) and cancer-specific survival (CSS).

Methods

EOGC patients from 2004 to 2015 were retrieved from the surveillance, epidemiology and end results (SEER) and further randomly assigned to training and validation sets. Univariate and multivariate cox analysis was used to screen out significant variables for construction of nomogram. Nomogram models were assessed by concordance index (C-index), calibration plot, receiver operating characteristics (ROCs) curve and decision curve analysis (DCA).

Results

A total of 549 EOGC were selected in this process. OS nomogram was constructed based on tumor size and tumor site. CSS nomogram was constructed based on tumor size, SEER stage and tumor site. In training set, C-index for the OS nomogram was 0.688 [95% confidence intervals (95% CI): 0.629-0.747], CSS nomogram 0.785 (95% CI: 0.735-0.835). In the external validation, the C-index for the OS nomogram was 0.633 (95% CI: 0.579-0.687), while for the CSS nomogram 0.733 (95% CI: 0.686-0.780). High quality of calibration plots both in OS and OS nomogram models was noticed. Nomograms displayed a comparable result to tumor-node-metastasis (TNM) stage and SEER stage for EOGC based on DCA.

Conclusions

The nomogram models provided an insightful and applicable tool to evaluate the prognosis of EOGC both in OS and CSS.

More attention should be paid to adult gastric cancer patients younger than 35 years old: extremely poor prognosis was found

Purpose: Several studies have reported controversial results about prognosis of gastric cancer in young age patients. The difference may partially result from variable definitions of young age. The aim of this study was to find out the relation between age and prognosis of gastric cancer patients, and to analyze the clinicopathological features and prognostic factors in young gastric cancer patients.

Methods: Data queried for this analysis included GC patients from the Surveillance, Epidemiology, and End Results Program database from 1973 to 2014. Gastric cancer patients (N=79,505) diagnosed with an age≥18 were included. By combining patients with similar prognosis, we figured out 3 cutoff values of age, 35 years old, 65 years old and 75 years old. We divided patients into 4 groups: young age patients: 18-34 years; middle-age patients: 35-64 years; elderly patients: 65-74 years; extremely elderly patients: >74 years. GC patients from Sun Yat-sen University Cancer Center (SYSUCC) were used as external validation data.

Results: The clinicopathological features of young age gastric cancer patients included: poor-differentiated, diffuse type of cancer, and advanced stage at diagnosis. The median survival of patients <35 years old was significantly lower than middle-age patients (35-64 years) and elderly patients (65-74 years) (12 months vs. 15 and 16 months, respectively, both p <0.001). Location of tumor, ethnicity, tumor size, surgery and TNM stage were independent prognostic factors by multivariate analysis in young patients. The poor prognosis for young patients remained valid in the SYSUCC database.

Conclusions: Our results demonstrated that gastric cancer patients <35 years old had an extremely poor prognosis. Early detection of gastric cancer is of paramount importance in young age people.

The Endoscopic and Clinicopathological Characteristics of Early-onset Gastric Cancer in Vietnamese Patients

Aim: To assess the endoscopic and clinicopathological features of early-onset gastric cancer (EOGC) in Vietnamese, a population with intermediate risk of gastric cancer. Patients and methods: Consecutive patients diagnosed with gastric adenocarcinoma were prospectively recruited. The demographic, clinical data in each patient were collected. The location and macroscopic type of all gastric lesions suspected to be malignant were reported according to the Japanese classification. The histologic tumor type of gastric cancer (GC) was classified according to the Lauren classification. Helicobacter pylori (H. pylori) infection were diagnosed by rapid urease test and urinary H. pylori antibody test. The infection was diagnosed when at least one of the two tests was positive. Results: The rate of EOGC (i.e. ≤ 40 years of age) was 16.3% (23/141). The median age of patients with EOGC was 35 (range 28 – 40) years and the male-to-female was 1:1.09. Compared to the older group (i.e. ≥ 50 years of age), the rates of positive family history, H. pylori infection and alarm features in the EOGC group were not significantly different (0.0% vs. 5.4%, p = 0.581; 73.9% vs. 66.3%, p = 0.620; and 60.8% vs. 79.3%, p = 0.100; respectively). The EOGC group had significantly higher rate of tumor extending to entire stomach (21.7% vs. 3.4%, p = 0.003); but the rate of diffuse-type GC between the two groups were not significantly different (87.0% vs. 71.7%, p = 0.181). Conclusions: Vietnamese patients with EOGC had higher rate of tumor extending to entire stomach compared to the older group. But the family history of GC, H. pylori infection and the pathological characteristics were not significantly different between the two groups. Environmental factors which play important roles in the development of EOGC in Vietnam should be investigated in future study.

Evaluation of GWAS-Identified Genetic Variants for Gastric Cancer Survival

BACKGROUNDS

Genome-wide association studies (GWASs) have identified several gastric cancer (GC) susceptibility loci in Asians, but their effects on disease outcome are still unknown. This study aimed to investigate whether these GWAS-identified genetic variants could serve as robust prognostic biomarkers for GC.

METHODS

A multistage clinical cohort, including a total of 2432 GC patients in the Chinese population, was used to identify the association between GWAS-identified risk variants and overall survival of GC. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed by Cox regression analysis, and the log-rank P was calculated by the log-rank test with the Kaplan-Meier method.

RESULTS

We found that rs2274223 A>G in PLCE1 was associated with increased GC survival in both training set (P = .011), which was independently replicated in validation set 1 (P = .045), but not in validation set 2. The area under the curve (AUC) from receiver-operator characteristic (ROC) curve showed this clinical relevance with onset age-dependence, especially in the subgroup of early-onset cases. Moreover, a significant improvement in overall survival prediction was identified when the rs2274223 genetic effect was included in the estimation; this result was also supported by the prognostic nomogram. In addition, patients with lower expression of PLCE1 showed benefits via longer survival, potentially due to the functional effect of rs2274223.

INTERPRETATION

This preliminary study suggests that a GWAS-identified genetic variant in PLCE1 may serve as a potential biomarker for GC survival. Additional replication with larger samples size is warranted to further investigation.

Risk prediction for early-onset gastric carcinoma: a case-control study of polygenic gastric cancer in Han Chinese with hereditary background

Recent genomewide studies have identified several germline variations associated with gastric cancer. The aim of the present study was to identify, in a Chinese Han population, the individual and combined effects of those single nucleotide polymorphisms (SNPs) that increase the risk of early-onset gastric cancer. We conducted a case-control study comprising 116 patients with gastric cancer as well as 102 sex- and age-matched controls and confirmed that the SNPs MUC1 (mucin 1) rs9841504 and ZBTB20 (zinc finger and BTB domain containing 20) rs4072037 were associated with an increased gastric cancer risk. Of the 116 patients diagnosed with cancer, 65 had at least 1 direct lineal relative with carcinoma of the digestive system or breast/ovarian cancer. These 65 had another 4 SNPs associated with gastric cancer susceptibility: PSCA (prostate stem cell antigen) rs2294008, PLCE1 (phospholipase C epsilon 1) rs2274223, PTGER4/PRKAA1 (prostaglandin E receptor 4/protein kinase AMP-activated catalytic subunit alpha 1) rs13361707, and TYMS (thymidylate synthetase) rs2790. However, each of these low-penetrance susceptibility polymorphisms alone is not considered influential enough to predict the absolute risk of early-onset gastric cancer. Thus we decided to study different combinations of polygenes as they affected for our population. Those subjects with both the risk alleles MUC1 rs9841504 and ZBTB20 rs4072037 had a greater than 3-fold increased risk of gastric cancer. Also those with a hereditary background including the risk alleles PLCE1 rs2274223 and PTGER4/PRKAA1 rs13361707 were 3 times more susceptible to cardia cancer than those without. These findings show that the study of combined polymorphisms, instead of single low-penetrance variations in susceptibility, may lead to a high-risk classification for a specific population.

Baseline characteristics, survival and direct costs associated to treatment of gastric cancer patients at the National Oncology Institute of Panama from 2012 to 2015: a hospital-based observational study

OBJECTIVES

Comprehensive epidemiological and economic studies of gastric cancer (GC) in Panama are limited. This study aims to evaluate the association between socioeconomic and clinical variables with survival, describe the survival outcomes according to clinical stage and estimate the direct costs associated to GC care in a Panamanian population with GC.

DESIGN AND SETTING

A retrospective observational study was conducted at the leading public institution for cancer treatment in Panama.

PARTICIPANTS

Data were obtained from 611 records of patients diagnosed with gastric adenocarcinoma (codes C16.0-C16.9 of the International Classification of Diseases 10th revision), identified between 1 January 2012 and 31 December 2015.

METHODS

Cox proportional hazards models were used to calculate HRs with 95%  CI to examine associations between the variables and survival. Kaplan-Meier curves were used to assess overall and stage-specific survival. Direct costs (based on 2015 US$) were calculated per patient using standard costs provided by the institution for hospital admission (occupied bed-days), radiotherapy, surgery and chemotherapy, yielding total and overall mean costs (OMC). A comparison of OMC between groups (sex, social security status, clinical stage) was performed applying the bootstrap method with a t-test of unequal variances.

RESULTS

An increased risk of dying was observed for patients without social security coverage (HR: 2.02; 95% CI 1.16 to 3.53), overlapping tumours (HR: 1.50; 95% CI 1.02 to 2.22), poorly differentiated tumours (HR: 2.27; 95% CI 1.22 to 4.22) and stage IV disease (HR: 5.54; 95% CI 3.38 to 9.08) (adjusted models). Overall 1-year survival rate was 41%. The estimated OMC of GC care per patient was 4259 US$. No statistically significant differences were found in OMC between groups.

CONCLUSIONS

Socioeconomic disparities influence GC outcomes and healthcare utilisation. Policies addressing healthcare disparities related to GC are needed, as well as in-depth studies evaluating barriers of access to GC-related services.

Frequent occurrence of gastric cancer in Asian kindreds with Li-Fraumeni syndrome

Type of cancer and age of onset in individuals with inherited aberrations in the tumour suppressor gene TP53 are variable, possibly influenced by genetic modifiers and different environmental exposure. Since 2009, the modified Chompret criteria (MCC) have been used to identify individuals for TP53 mutation screening. Using the TP53 mutation database maintained by the International Agency for Research on Cancer (IARC), we investigated if the MCC, mainly developed for a Caucasian population, was also applicable in Asia. We identified several differences in Asian families compared with similar Caucasian cohorts, suggesting that identification and management of Li-Fraumeni syndrome in Asia do not completely mirror that of North America and Western Europe. Early gastric cancer (<40 years) may be considered a new addition to the MCC especially for Asian families.

Clinical characteristics and outcomes for gastric cancer patients aged 18-30 years

BACKGROUND

There is little known about the clinicopathological features and the predictors of survival in extremely young adult patients aged 18-30 years. The aim of this study was to identify clinicopathological features and clinical outcomes for the overall population and for a resectable subgroup of gastric cancer patients aged 18-30 years.

METHODS

From January 2004 to December 2010, 207 patients aged between 18 and 30 years old were diagnosed with gastric cancer and treated at the Asan Medical Center. Clinical findings, histopathological parameters and outcomes were reviewed retrospectively. Patients were further divided into 2 groups according to tumor resectability and then clinicopathological factors that affect tumor resectability and clinical outcomes were analyzed.

RESULTS

Clinicopathological characteristics of study population showed a predominance of females, undifferentiated tumors, diffuse-type cancers, and advanced gastric cancer. The overall resectability rate was 70.0 % and the median follow-up period was significantly longer in the resectable tumor group (P < 0.001). Significant prognostic predictors for overall survival in overall patients were higher CEA levels (P = 0.016), larger tumor size (P < 0.001), unresectability (P = 0.006), and presence of lymphovascular invasion (P = 0.012) in a multivariate analysis. Significant prognostic factors for overall survival in patients with resectable disease included larger tumor size (>4 cm), lymphovascular invasion and higher CEA level in the multivariate analysis.

CONCLUSIONS

Gastric adenocarcinomas in young adult patients aged 18-30 years have unique clinicopathological features. Early detection in a resectable state and subsequent complete resection could increase survival period in young patients with gastric cancer.

Identification and characterization of CDH1 germline variants in sporadic gastric cancer patients and in individuals at risk of gastric cancer

Objective

To screen and characterize germline variants for E-cadherin (CDH1) in non-hereditary gastric cancer (GC) patients and in subjects at risk of GC.

Methods

59 GCs, 59 first degree relatives (FDRs) of GC, 20 autoimmune metaplastic atrophic gastritis (AMAGs) and 52 blood donors (BDs) were analyzed for CDH1 by direct sequencing, structural modelling and bioinformatics. Functional impact on splicing was assessed for intronic mutations. E-cadherin/β-catenin immunohistochemical staining and E-cadherin mRNA quantification using RT-PCR were performed.

Results

In GCs, 4 missense variants (p.G274S; p.A298T; p.T470I; p.A592T), 1 mutation in the 5′UTR (−71C>G) and 1 mutation in the intronic IVS12 (c.1937-13T>C) region were found. First pathogenic effect of p.A298T mutation was predicted by protein 3D modelling. The novel p.G274S mutation showed a no clear functional significance. Moreover, first, intronic IVS12 (c.1937-13T>C) mutation was demonstrated to lead to an aberrant CDH1 transcript with exon 11 deletion. This mutation was found in 2 GCs and in 1 BD. In FDRs, we identified 4 variants: the polymorphic (p.A592T) and 3 mutations in untranslated regions with unidentified functional role except for the 5′UTR (−54G>C) that had been found to decrease CDH1 transcription. In AMAGs, we detected 2 alterations: 1 missense (p.A592T) and 1 novel variant (IVS1 (c.48+7C>T)) without effect on CDH1 splicing. Several silent and polymorphic substitutions were found in all the groups studied.

Conclusions

Overall our study improves upon the current characterization of CDH1 mutations and their functional role in GC and in individuals at risk of GC. Mutations found in untranslated regions and data on splicing effects deserve a particular attention like associated with a reduced E-cadherin amount. The utility of CDH1 screening, in addition to the identification of other risk factors, could be useful for the early detection of GC in subjects at risk (i.e. FDRs and AMAGs), and warrants further study.

First-degree relatives of early-onset gastric cancer patients show a high risk for gastric cancer: phenotype and genotype profile

First-degree relatives (FDR) of early-onset gastric cancer (EOGC) is presumed to be a population with a distinct molecular and phenotypic profile, regarding the prevalence of gastric premalignant conditions and the association with Helicobacter pylori infection and host proinflammatory gene polymorphisms. A case-control study was conducted with FDR of EOGC patients (n = 103) and age and gender matched controls (n = 101; ranging from spouses to neighbors and dyspeptics). Upper endoscopy was performed, Operative Link on Gastritis Assessment (OLGA) system used for staging and H. pylori (cagA and vacA) and host IL1B-511, IL1RN intron2 VNTR and IFNGR1-56 genotyping. Seventy percent of cases showed atrophy, while 19 % presented with high-stage gastritis (OLGA stage III or IV) (p < 0.001); gastric dysplasia was present in seven cases (vs none in controls) (p = 0.007). In cases, H. pylori was present in 82 % (vs 62 % in controls; p = 0.004) with vacA s1 and vacA m1 + strains significantly associated with the presence of atrophy; individuals homozygous for IL1B-511*T present a significantly higher risk for dysplasia. An increased global prevalence of IFNGR1-56*T/*T polymorphism (37 % in cases vs 24 % in controls; p = 0.03) was observed with no association with atrophic changes or dysplasia. All trends observed were kept when comparing FDR of EOGC with spouses, neighbors, or dyspeptic controls. We demonstrated that FDR of EOGC patients have an increased prevalence of high-risk OLGA stages and dysplasia that seem to be associated with high virulence H. pylori strains and pro-inflammatory host genotypes, including a possible population-specific risk marker. FDR of EOGC patients may merit specific management through endoscopic and histopathological adequate assessment of gastric mucosa and surveillance.

Analysis of clinicopathologic characteristics and prognosis of gastric cancer in young and older patients

BACKGROUND

The worldwide incidence of gastric cancer is gradually declining, however it remains the fourth highest in cancer incidence and the second leading cause of cancer death. Gastric cancer in young people is a disturbing problem and the routine screening does not include people less than 35 years. The clinicopathological features of gastric carcinoma are said to differ between young and elderly patients and it is thought that the prognosis of this disease is worse for younger patients. It is also suggested that the diagnosis is usually made later or have a more aggressive behaviour. Although, others report that tumor staging and prognosis for young patients is similar to older patients and depends on whether the patients undergo a curative resection. All these data need more investigation and studies. Although Portugal has a high incidence of gastric cancer, no studies have yet been performed comparing the clinicopathologic features and prognosis of young and elderly patients with gastric cancer.

AIMS

This study intend to assess whether the clinicopathological features and prognosis of gastric cancer in young patients (YGC) is similar to older ones (OGC).

METHODS

Between 2000 and 2005, 406 patients with histological diagnosis of primary gastric cancer, treated in the Departments of Surgery and Oncology at the Centro Hospitalar of Vila Nova de Gaia / Espinho, were regularly followed at least for five years after surgery. These were reviewed retrospectively. Several variables were analyzed in young patients and compared with the elder ones. We used the chi-square and Fisher to evaluate the statistical association between categorical variables and t-test for numeric variables. Survival was estimated by the Kaplan-Meier method and used the log-rank test to assess differences in survival among different subgroups of patients. The criteria for statistical significance was p < 0.05. Data analysis was performed using the SPSS 18.

RESULTS AND CONCLUSIONS

With regard to resectability, 78 % of the tumors were resected in the group of younger patients, the surgery more frequently achieved was total gastrectomy with anastomosis in Y of Roux. In the elder group, about 62 % of the tumors were resected and BII gastrectomy was the most frequent surgery. The diffuse adenocarcinoma was the most frequent histological type in younger patients, whereas in older patients was intestinal adenocarcinoma. With regard to the stage in the first group there was a predominance of stages: IA and IV (26.1 %) in the second: IV (25.8 %). The survival for stage III e IV was significantly worst in YGC compared with OGC.