Laparoscopic Prophylactic Total Gastrectomy for Hereditary Diffuse Gastric Cancer in CDH1 Mutation Carriers

Germline CDH1 variants in hereditary diffuse gastric cancer syndrome with focus on younger women

PURPOSE

The objective of this study was to determine the male and female frequency of diffuse gastric cancer (DGC), the age at diagnosis, and the country of origin in a selected population with germline CDH1 variants from families with the hereditary diffuse gastric cancer (HDGC) syndrome.

METHODS

Relevant literature dating from 1998 to 2021 was systematically searched for data on CDH1 gene. The Wilcoxon rank sum test and the Chi-square test were used to estimate if the difference observed between patients with gastric cancer (GC) and unaffected individuals was significant.

RESULTS

We identified 80 families fulfilling the established clinical criteria for HDGC CDH1 genetic screening. There were more women than men with DGC and germline CDH1 variant (65.5%). Stratifying the age at diagnosis, we identified an association between DGC, positive CDH1 screening and young women (≤ 40 years) (p = 0.015). The mean age at diagnosis was 39.6 ys for women and 42.5 ys for men. There was an association between CDH1 carrier status and DGC (p = 0.021).

CONCLUSIONS

Young women carrying germline CDH1 variants with DGC are comparatively frequent in the HDGC syndrome, and potentially at higher risk to develop DGC particularly in low-incidence areas for GC.

Pioneering use of genetic analysis for CDH1 to identify candidates for prophylactic total gastrectomy to prevent hereditary diffuse gastric cancer

Worldwide, gastric cancer results in significant morbidity and mortality. Ten per cent of patients with gastric cancer have a strong family history of the disease. CDH1 (E-cadherin) has been identified as a key gene whose mutation leads to hereditary diffuse gastric cancer. We overviewed 33 articles with prophylactic total gastrectomy and assessed the outcomes and benefits. Families with mutations in CDH1 may benefit from early prophylactic total gastrectomy. Dr Mark Duncan has applied his experience as a high-volume gastric cancer surgeon to treat not only individual patients, but several generations of patients within a family. This use of prophylactic total gastrectomy is well tolerated by patients and prevents the future development of gastric cancer.

Early stage gastric adenocarcinoma: clinical and molecular landscapes

Gastric adenocarcinoma, even when diagnosed at an early (localized) disease stage, poses a major health-care burden with cure rates that remain unsatisfactorily low, particularly in Western countries. This lack of progress reflects, among other aspects, the impracticality of early diagnosis, considerable variations in therapeutic approaches that is partly based on regional preferences, and the ingrained heterogeneity of gastric adenocarcinoma cells and their associated tumour microenvironment (TME). Clinical trials have long applied empirical interventions with the assumption that all early stage gastric adenocarcinomas are alike. Despite certain successes, the shortcomings of these approaches can potentially be overcome by targeting the specific molecular subsets of gastric adenocarcinomas identified by genomic and/or multi-omics analyses, including microsatellite instability-high, Epstein-Barr virus-induced, DNA damage repair-deficient, HER2-positive and PD-L1-high subtypes. Future approaches, including the availability of sophisticated vaccines, novel antibody technologies, agents targeting TME components (including fibroblasts, macrophages, cytokines or chemokines, and T cells) and novel immune checkpoint inhibitors, supported by improved tissue-based and blood-based diagnostic assays, seem promising. In this Review, we highlight current knowledge of the molecular and cellular biology of gastric adenocarcinomas, summarize the current approaches to clinical management of the disease, and consider the role of novel management and/or treatment strategies.

CDH1 mutations recurrence and global clustering in genetically tested families with hereditary diffuse gastric cancer syndrome: results from a systematic study

The global distribution of germline CDH1 mutations in hereditary diffuse gastric cancer families, is highly heterogenous. The aim of this study was to determine if there is any geographic clustering of CDH1 mutations in families with the hereditary diffuse gastric cancer syndrome. Data from 1998 to 2021 were collected systematically according to the PRISMA guidelines. 571 germline CDH1 mutations were recorded worldwide, with 387 (67.8%) of them reported in 108 families. The largest clusters of CDH1 mutations were identified in central Europe, north America, northern Europe, New Zealand (Māori), and south America. A high penetrance risk for GC development was observed for c.1008G > T in New Zealand (Māori), c.1565 + 2insT in northern Europe, c.1901C > T in Portugal, and c.1003C > T in the USA. Our observations are consistent with a specific local clustering of some recurrent CDH1 mutations within specific countries.

An Immunity-Associated lncRNA Signature for Predicting Prognosis in Gastric Adenocarcinoma

Background

Gastric adenocarcinoma (GAD) is one of the most common tumors in the world and the prognosis is still very poor.

Objective

We sought to identify reliable prognostic biomarkers for the progression of GAD and the sensitivity to drug therapy.

Method

The RNA sequencing data of GAD was downloaded from the Cancer Genome Atlas (TCGA) database and used for analysis. Differentially expressed, immune-related lncRNA (DEIRlncRNA) was characterized by differential analysis and correlation analysis. Univariate Cox regression analysis was used to identify DEIRlncRNA associated with prognosis. Least absolute shrinkage and selection operator (LASSO) regression analysis allowed us to determine a signature composed of eight IRlncRNAs. Based on this signature, we further performed gene set enrichment analysis (GSEA) and somatic mutation analysis to evaluate the ability of this signature to predict prognosis.

Results

In total, 72 immune-related lncRNAs (DEIRlncRNAs) with prognostic value were identified. These lncRNAs were used to construct a model containing eight immune-related lncRNAs (8-IRlncRNAs). Based on this risk model, we divided GAD patients into high-risk and low-risk groups. The analysis showed that the prognosis of the two groups was different and that the high-risk group had worse overall survival (OS). Immune cell infiltration analysis showed that the proportion of memory B cells increased in the high-risk group while the proportion of macrophages M1, T cells, CD4 memory-activated cells, and T cell follicular helpers decreased. GSEA results showed that 8-IRlncRNA was significantly enriched in tumorigenesis pathways such as myc. The results of somatic mutation analysis showed that the CDH1 gene was significantly mutated in the high-risk group.

Conclusion

A prognostic signature of 8-IRlncRNAs in GAD was established and this signature was able to predict the prognosis of GAD patients.