Hereditary diffuse gastric cancer: What the clinician should know

Managing CDH1 Cancer Risks in a Child: Complex Decision Making in a Family With Hereditary Diffuse Gastric Cancer

Germline pathogenic variants (PVs) in CDH1 cause hereditary diffuse gastric cancer. The management of CDH1 cases with a positive family history includes total prophylactic gastrectomy or intensive surveillance. In this study, we report a 16-year-old boy with intramucosal gastric signet ring cells in the setting of a germline CDH1 PV and a family history of early-onset gastric cancer. The approach to managing both the proband and their 9-year-old sister, who also had the CDH1 PV, presented a challenge to both clinicians and the family. Herein, we present the complexities of managing gastric cancer risk when a CDH1 PV is identified in childhood in the setting of a family history of early-onset gastric cancer.

The Regulation of Cyclins and Cyclin-Dependent Kinases in the Development of Gastric Cancer

Gastric cancer predominantly occurs in adenocarcinoma form and is characterized by uncontrolled growth and metastases of gastric epithelial cells. The growth of gastric cells is regulated by the action of several major cell cycle regulators including Cyclins and Cyclin-dependent kinases (CDKs), which act sequentially to modulate the life cycle of a living cell. It has been reported that inadequate or over-activity of these molecules leads to disturbances in cell cycle dynamics, which consequently results in gastric cancer development. Manny studies have reported the key roles of Cyclins and CDKs in the development and progression of the disease in either in vitro cell culture studies or in vivo models. We aimed to compile the evidence of molecules acting as regulators of both Cyclins and CDKs, i.e., upstream regulators either activating or inhibiting Cyclins and CDKs. The review entails an introduction to gastric cancer, along with an overview of the involvement of cell cycle regulation and focused on the regulation of various Cyclins and CDKs in gastric cancer. It can act as an extensive resource for developing new hypotheses for future studies.

The Role of CTNNA1 in Malignancies: An Updated Review

Catenin alpha 1 (CTNNA1), encoding α-catenin, is involved in several physiological activities, such as adherens junction synthesis and signal transduction. Recent studies have suggested additional functions for CTNNA1 malignancies. This review systematically summarizes the varying functions of CTNNA1 in different tumors and briefly describes the diverse pathways and mechanisms involved in different types of tumors. CTNNA1 is abnormally expressed in leukemia and solid tumor such as cancers of digestive system, genitourinary system and breast, and it's related to the occurrence, development, and prognosis of tumors. In addition, the possible physiological processes involving CTNNA1, such as methylation, miRNA interference, or regulatory axes, similar to those of CDH1, SETD2, and hsa-miR-30d-5p/GJA1 are also summarized here. The precise mechanism of CTNNA1 in most cancers remains uncertain; hence, additional pre-clinical studies of CTNNA1 are warranted for potential early tumor diagnosis, prognosis, and treatment.

CDH1 Gene Mutation Hereditary Diffuse Gastric Cancer Outcomes: Analysis of a Large Cohort, Systematic Review of Endoscopic Surveillance, and Secondary Cancer Risk Postulation

Simple Summary

Some patients carry a mutated copy of the CDH1 gene that can lead to a very rare form of hereditary gastric cancer called signet-ring cell adenocarcinoma (SRCC). SRCCs rarely form visible tumors prior to spreading. Hence, patients are recommended to have prophylactic gastrectomies at a young age. Many patients wish to avoid surgery and thus have regular checks with upper endoscopy with biopsies to rule out cancer. Further, these patients may also be at risk of other cancers beyond the already known breast cancer risks, but this is not known. In this study, we show that despite systematic biopsy protocols, many early cancers might be missed on endoscopy. Therefore, patients should not rely on endoscopy to delay surgery. These patients may also be at increased risk of colorectal SRCC, which has very poor survival outcomes. To confirm this, we need a central database that captures outcomes for this patient population.

Abstract

Hereditary diffuse gastric cancer (HDGC) is a rare signet-ring cell adenocarcinoma (SRCC) linked to CDH1 (E-cadherin) inactivating germline mutations, and increasingly other gene mutations. Female CDH1 mutation carriers have additional risk of lobular breast cancer. Risk management includes prophylactic total gastrectomy (PTG). The utility of endoscopic surveillance is unclear, as early disease lacks macroscopic lesions. The current systematic biopsy protocols have unknown efficacy, and other secondary cancer risks are postulated. We conducted a retrospective study of consecutive asymptomatic HDGC patients undergoing PTG, detailing endoscopic, pathologic, and outcome results. A systematic review compared endoscopic biopsy foci detection via random sampling versus Cambridge Protocol against PTG findings. A population-level secondary-cancer-risk postulation among sporadic gastric SRCC patients was completed using the Surveillance, Epidemiology, and End Results database. Of 97 patients, 67 underwent PTG, with 25% having foci detection on random endoscopic biopsy despite 75% having foci on final pathology. There was no improvement in the endoscopic detection rate by Cambridge Protocol. The postulated hazard ratio among sporadic gastric SRCC patients for a secondary colorectal SRCC was three-fold higher, relative to conventional adenocarcinoma patients. Overall, HDGC patients should not rely on endoscopic surveillance to delay PTG, and may have secondary SRCC risks. A definitive determination of actual risk requires collaborative patient outcome data banking.

Secondary Prevention in Hereditary Breast and/or Ovarian Cancer Syndromes Other Than BRCA

BRCA1- and BRCA2-associated hereditary breast and ovarian cancer syndromes are among the best-known and most extensively studied hereditary cancer syndromes. Nevertheless, many patients who proved negative at BRCA genetic testing bring pathogenic mutations in other suppressor genes and oncogenes associated with hereditary breast and/or ovarian cancers. These genes include TP53 in Li-Fraumeni syndrome, PTEN in Cowden syndrome, mismatch repair (MMR) genes in Lynch syndrome, CDH1 in diffuse gastric cancer syndrome, STK11 in Peutz-Jeghers syndrome, and NF1 in neurofibromatosis type 1 syndrome. To these, several other genes can be added that act jointly with BRCA1 and BRCA2 in the double-strand break repair system, such as PALB2, ATM, CHEK2, NBN, BRIP1, RAD51C, and RAD51D. Management of primary and secondary cancer prevention in these hereditary cancer syndromes is crucial. In particular, secondary prevention by screening aims to discover precancerous lesions or cancers at their initial stages because early detection could allow for effective treatment and a full recovery. The present review aims to summarize the available literature and suggest proper screening strategies for hereditary breast and/or ovarian cancer syndromes other than BRCA.

Hereditary gastric cancer: Three rules to reduce missed diagnoses

Gastric cancer remains one of the most lethal cancers. The incidence and mortality rates are quite similar. The main reason for the high mortality is diagnosis at advanced stages of disease, when treatment options are poor. One of the supposed strategies to overcome late-stage diagnosis is identifying people at high risk with the aim of establishing rigorous clinical control, including routine endoscopy and biopsies. Hereditary gastric cancer (HGC) syndromes, though representing a sizeable group to monitor for prevention or, at least, for early diagnosis, are apparently extremely rare. The low rate of HGC diagnosis might be related to the low rates of suspicion, insufficient familiarity about clinical diagnosis criteria, and the supposed conditional necessity of a molecular diagnosis. In this review, we will discuss simple measures to increase HGC diagnosis by applying three rules that might provide an opportunity for precision care to benefit the families affected by this disease.

Influence of serum vitamin D level on Helicobacter pylori eradication: A multi-center, observational, prospective and cohort study

OBJECTIVES

This study was designed to test whether serum vitamin D levels affected Helicobacter pylori (H. pylori) infection and eradication rates.

METHODS

A multicenter observational prospective cohort study was conducted. A total of 496 H. pylori- positive (H. pylori+ ) and 257 H. pylori-negative (H. pylori- ) patients were enrolled from four hospitals in China. Baseline serum vitamin D levels were measured and a 13 C-urea breath test (UBT) was performed for all the participants. The H. pylori+ patients were divided into two subgroups based on their serum vitamin D levels (<10 or ≥10 ng/mL). A second 13 C-UBT was performed between 4 and 8 weeks after 14-day bismuth-containing quadruple eradication therapies. Factors potentially affecting H. pylori eradication were determined using a questionnaire survey.

RESULTS

Serum vitamin D levels were significantly lower in the H. pylori+ group than in the H. pylori- group ([17.0 ± 6.9] ng/mL vs [19.2 ± 8.0] ng/mL, P = 0.000). H. pylori eradication rate significantly differed between patients with serum vitamin D levels of <10 ng/mL and ≥10 ng/mL (71.7% vs 87.3%, P = 0.005). A multivariate analysis showed that having serum vitamin D level ≥10 ng/mL was an independent risk factor for a successful H. pylori eradication (odds ratio 0.381, 95% confidence interval 0.183-0.791, P = 0.010).

CONCLUSIONS

Serum vitamin D level may affect H. pylori infection and its eradication. Randomized controlled trials are needed to find out whether vitamin D supplements may increase the H. pylori eradication rate.

The role of endoscopy in the management of hereditary diffuse gastric cancer syndrome

Hereditary diffuse gastric cancer (HDGC) syndrome is an inherited cancer risk syndrome associated with pathogenic germline CDH1 variants. Given the high risk for developing diffuse gastric cancer, CDH1 carriers are recommended to undergo prophylactic total gastrectomy for cancer risk reduction. Current guidelines recommend upper endoscopy in CDH1 carriers prior to surgery and then annually for individuals deferring prophylactic total gastrectomy. Management of individuals from HDGC families without CDH1 pathogenic variants remains less clear, and management of families with CDH1 pathogenic variants in the absence of a family history of gastric cancer is particularly problematic at present. Despite adherence to surveillance protocols, endoscopic detection of cancer foci in HDGC is suboptimal and imperfect for facilitating decision-making. Alternative endoscopic modalities, such as chromoendoscopy, endoscopic ultrasound, and other non-white light methods have been utilized, but are of limited utility to further improve cancer detection and risk stratification in HDGC. Herein, we review what is known and what remains unclear about endoscopic surveillance for HDGC, among individuals with and without germline CDH1 pathogenic variants. Ultimately, the use of endoscopy in the management of HDGC remains a challenging arena, but one in which further research to improve surveillance is crucial.

Contemporary paradigm for the evaluation and treatment of hereditary gastric cancer

Gastric cancer is the third leading cause of cancer mortality worldwide. Survival is linked to stage at diagnosis and tolerance to surgery and adjuvant therapy. The emergence of sophisticated methods to identify patients at high risk for the development of gastric cancer has given us an opportunity to eliminate a lethal disease in an identifiable patient population. Guidelines and recommendations have been established and prophylactic total gastrectomy is considered the most effective treatment. However, this requires substantial physical and emotional investment. It is imperative that patients and families are supported by genetic counseling, ongoing surveillance, and survivorship studies.

Multiple infections by EBV, HCMV and Helicobacter pylori are highly frequent in patients with chronic gastritis and gastric cancer from Southwest Mexico: An observational study

The chronic inflammation and damage to the gastric epithelium induced by Helicobacter pylori (H. pylori) are the main risk factors for gastric cancer development. Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) induce chronic inflammation and have been found in gastric tumors. The objectives this observational study were to determine the frequency of multiple infections by Helicobacter pylori, Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) and to relate the infection by EBV and HCMV with H. pylori vacA/cagA genotypes in patients with chronic gastritis or gastric cancer. DNA from H. pylori, EBV and HCMV was detected by PCR in biopsies from 106 Mexican patients with chronic gastritis and 32 from gastric cancer. The cagA status and the vacA genotypes of H. pylori were determined by PCR. In chronic gastritis and gastric cancer EBV was found in 69.8% and 87.5%, HCMV in 52.8% and 53.1%, and H. pylori in 48.1% and 40.6%, respectively. In chronic gastritis, 53% of H. pylori patients were EBV and 33% were both EBV/HCMV; in gastric cancer, 92.3% of H. pylori-infected individuals were EBV and 46.1% were EVB/HCMV. All the intestinal- and mixed-type tumors and the 83.3% of diffuse-type tumors were EBV. No significant differences were found between single infections or coinfections with the diagnosis or the cancer type. The H. pylori genotypes were not related to EBV or HCMV infection. The frequency of dual infections by H. pylori, EBV and HCMV is higher in patients from southwest Mexico than other populations. It is likely that these pathogens act synergistically to induce inflammation and gastric cancer.

Fifth Chinese National Consensus Report on the management of Helicobacter pylori infection

BACKGROUND

Since the 'Fourth Chinese National Consensus Report on the management of H. pylori infection' was published in 2012, three important consensuses (Kyoto global consensus report on H. pylori gastritis, The Toronto Consensus for the Treatment of H. pylori Infection in Adults and Management of H. pylori infection-the Maastricht V/Florence Consensus Report) have been published regarding the management of H. pylori infection.

MATERIALS AND METHODS

A Delphi method was adopted to develop the consensus of relevant 'statements'. First, the established 'statements' were sent to experts via email. Second, after undergoing two rounds of consultation, the initial statements were discussed face to face and revised in the conference item by item on 16 December 2016. Finally, 21 core members of conferees participated in the final vote of statements. Voting for each statement was performed using an electronic system with levels of agreements shown on the screen in real time.

RESULTS

Consensus contents contained a total of 48 "statements" and related 6 parts, including indications for H. pylori eradication, diagnosis, treatment, H. pylori and gastric cancer, H. pylori infection in special populations, H. pylori and gastrointestinal microbiota.

CONCLUSIONS

Recommendations are provided on the basis of the best available evidence.

Comparative study of endoscopic surveillance in hereditary diffuse gastric cancer according to CDH1 mutation status

BACKGROUND AND AIMS

Hereditary diffuse gastric cancer (HDGC) accounts for 1% of gastric cancer cases. For patients with a germline CDH1 mutation, risk-reducing gastrectomy is recommended. However, for those delaying surgery or for families with no causative mutation identified, regular endoscopy is advised. This study aimed to determine the yield of signet ring cell carcinoma (SRCC) foci in individuals with a CDH1 pathogenic variant compared with those without and how this varies with successive endoscopies.

METHODS

Patients fulfilling HDGC criteria were recruited to a prospective longitudinal cohort study. Endoscopy was performed according to a strict protocol with visual inspection followed by focal lesion and random biopsy sampling to detect foci of SRCC. Survival analysis determined progression to finding of SRCC according to CDH1 mutation status. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and 36-item Short Form Health Survey questionnaires assessed quality of life before surveillance and each endoscopy.

RESULTS

Eighty-five individuals fulfilling HDGC criteria underwent 201 endoscopies; 54 (63.5%) tested positive for CDH1 mutation. SRCC yield was 61.1% in CDH1 mutation carriers compared with 9.7% in noncarriers, and mutation-positive patients had a 10-fold risk of SRCC on endoscopy compared with those with no mutation detected (P < .0005). Yield of SRCC decreased substantially with subsequent endoscopies. Surveillance was associated with improved psychological health.

CONCLUSIONS

SRCC foci are prevalent in CDH1 mutation carriers and can be detected at endoscopy using a standardized, multiple biopsy sampling protocol. Decreasing yield over time suggests that the frequency of endoscopy might be reduced. For patients with no CDH1 pathogenic variant detected, the cost-to-benefit ratio needs to be assessed in view of the low yield.

Germline mutations in hereditary diffuse gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Among which, about 1%-3% of gastric cancer patients were characterized by inherited gastric cancer predisposition syndromes, knowing as hereditary diffuse gastric cancer (HDGC). Studies reported that CDH1 germline mutations are the main cause of HDGC. With the help of rapid development of genetic testing technologies and data analysis tools, more and more researchers focus on seeking candidate susceptibility genes for hereditary cancer syndromes. In addition, National Comprehensive Cancer Network (NCCN) guidelines recommend that the patients of HDGC carrying CDH1 mutations should undergo prophylactic gastrectomy or routine endoscopic surveillances. Therefore, genetic counseling plays a key role in helping individuals with pathogenic mutations make appropriate risk management plans. Moreover, experienced and professional genetic counselors as well as a systematic multidisciplinary team (MDT) are also required to facilitate the development of genetic counseling and benefit pathogenic mutation carriers who are in need of regular and standardized risk management solutions. In this review, we provided an overview about the germline mutations of several genes identified in HDGC, suggesting that these genes may potentially act as susceptibility genes for this malignant cancer syndrome. Furthermore, we introduced information for prevention, diagnosis and risk management of HDGC. Investigations on key factors that may have effect on risk management decision-making and genetic data collection of more cancer syndrome family pedigrees are required for the development of HDGC therapeutic strategies.

Imaging and Screening of Hereditary Cancer Syndromes

There is a wide spectrum of mendelian disorders that predispose patients to an increased risk of benign as well as malignant tumors. Hereditary cancer syndromes are characterized by the early onset of diverse, frequently advanced malignancies in specific organ systems in multiple family members, posing significant challenges to diagnosis and management. A better understanding of the genetic abnormalities and pathophysiology that underlie these disorders has led to contemporary paradigms to screen, allowing early diagnosis, and has improved targeted therapies to aid in management. This article reviews select hereditary cancer syndromes with an emphasis on imaging-based screening and surveillance strategies.

Gastric cancer in a teenager: a case report

Background Gastric cancer occurs mainly in older patients, with a peak incidence over 60 years of age. It is relatively rare among younger individuals. However, the frequency of gastric cancer in young patients appears to be on the rise worldwide. Case presentation We report the case of a 19-year-old female soldier who, after a considerable diagnostic delay, was diagnosed with gastric adenocarcinoma. She is one of the youngest gastric adenocarcinoma patients ever reported in Israel. Conclusion This case should serve as a reminder that gastric carcinoma is a possible diagnosis even in young patients. It also highlights the critical importance of obtaining a thorough medical history in the process of clinical decision making.

Promoter hypermethylation of MGMT gene may contribute to the pathogenesis of gastric cancer: A PRISMA-compliant meta-analysis

BECKGROUND

The association of MGMT (O-methyguanine deoxyribonucleic acid methyltransferase) promoter hypermethylation with gastric cancer (GC) risk has been studied extensively, but the results remained unclear. Here, we performed a meta-analysis to evaluate whether promoter hypermethylation of the MGMT gene contributed to gastric pathogenesis.

METHODS

Relevant studies were identified by retrieving the PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases. The Newcastle-Ottawa Scale was applied to assess methodological quality of the included studies. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to evaluate the association of MGMT promoter hypermethylation with gastric pathogenesis. Moreover, STATA 12.0 software was used to summarize the extracted data in this meta-analysis.

RESULTS

Seventeen studies, comprising 1736 cases and 1291 controls, were included in this meta-analysis. The frequency of MGMT promoter hypermethylation in the GC group (32.97%) was significantly higher than those in the control group (18.00%) (OR = 2.83, CI = 1.93-4.15, P < .05). When stratified by cancer subtype, the results indicated that the frequency of MGMT promoter hypermethylation was significantly higher in gastric adenocarcinoma than in control group (OR = 3.47, CI = 1.06-11.35, P < .05). In addition, MGMT promoter hypermethylation significantly promoted distant metastasis and lymph node (LN) metastasis of gastric tumor (for distant metastasis, OR = 4.22, CI = 2.42-7.37, P < .05; for LN metastasis, OR = 1.56, CI = 1.14-2.13, P < .05). A significant association between MGMT promoter hypermethylation and TNM-stage was also found in the present meta-analysis (OR = 2.70, CI = 1.79-4.08, P < .05).

CONCLUSION

The results of this meta-analysis suggested that MGMT gene-promoter hypermethylation was significantly associated with an increased risk of GC, especially in Asians. Furthermore, MGMT gene-promoter hypermethylation might be correlated with the distant metastasis and LN metastasis of GC.

Linear-Stapled Side-to-Side Esophagojejunostomy with Hand-Sewn Closure of the Common Enterotomy After Prophylactic and Therapeutic Total Gastrectomy

After total gastrectomy, anastomosis-related complications such as leak or stricture can be highly morbid. Between July 2005 and December 2015, a linear-stapled side-to-side esophagojejunostomy with hand-sewn closure of the common enterotomy (modified Orringer technique) was used for Roux-en-Y reconstruction after prophylactic total gastrectomy in 22 germline CDH1 mutation carriers and after therapeutic total gastrectomy in 18 patients diagnosed with gastric adenocarcinoma. All operations were performed by the same surgeon. No patient in either cohort developed a clinically evident anastomotic leak, one patient (2.5%) developed a contained radiographic leak that healed without intervention, and one patient (2.5%) developed an anastomotic stricture treated by endoscopic dilatation 7 months after operation. These rates were lower than radiographic leak and stricture rates in a comparison group of 32 patients who received a completely hand-sewn esophagojejunostomy (6.3 and 3.1%, respectively). Here, we describe how to perform the linear-stapled esophagojejunostomy anastomosis.

Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.

Prophylactic Total Gastrectomy for Hereditary Diffuse Gastric Cancer

Germline mutations in the CDH1 gene that produces E-cadherin have been implicated in the development of early-onset diffuse gastric cancer, termed hereditary diffuse gastric cancer. The mean age of gastric cancer diagnosis in affected individuals is 37 years. By age 80, CDH1 mutation carriers who fulfill the clinical criteria for hereditary diffuse gastric cancer have an estimated lifetime risk of gastric cancer development of 67% for men and 83% for women. Data suggest that endoscopic surveillance for mutation carriers is largely ineffective. Prophylactic total gastrectomy between the ages of 18 and 40 years is recommended in carriers of germline-truncating E-cadherin mutations.

MicroRNAs in hereditary diffuse gastric cancer

In 2012, gastric cancer (GC) was the third cause of mortality due to cancer in men and women. In Central and South America, high mortality rates have been reported. A total of 95% of tumors developed in the stomach are of epithelial origin; thus, these are denominated adenocarcinomas of the stomach. Diverse classification systems have been established, among which two types of GC based on histological type and growth pattern have been described as follows: Intestinal (IGC) and diffuse (DGC). Approximately 1-3% of GC cases are associated with heredity. Hereditary-DGC (HDGC), with 80% penetrance, is an autosomal-type, dominant syndrome in which 40% of cases are carriers of diverse mutations of the CDH1 gene, which encodes for the cadherin protein. By contrast, microRNA are non-encoded, single-chain RNA molecules. These molecules regulate the majority of cellular functions at the post-transcriptional level. However, analysis of these interactions by means of Systems Biology has allowed the understanding of complex and heterogeneous diseases, such as cancer. These molecules are ubiquitous; however, their expression can be specific in different tissues either temporarily or permanently, depending on the stage of the cell. Due to the participation of microRNA in the processes of cellular proliferation, cell cycle control, apoptosis, differentiation and metabolism, these have been indicated to have a role in the development of cancerous processes, finding specific patterns of expression in different neoplasms, including GC, in which the microRNA expression profile is different in samples of non-cancerous versus cancerous tissues. A difference has been observed in the expression patterns of DGC and IGC. However, the role of microRNA in HDGC has not yet been established. The present study reviews the investigations that describe the participation of microRNA in the regulation of genes CDH1, RHOA, CTNNA1, INSR and TGF-β in different neoplasms, such as HDGC.