Gastric adenocarcinoma and proximal polyposis of the stomach: diagnosis and clinical perspectives

Risk of Esophageal and Gastric Cancer in Patients with Type 2 Diabetes Receiving Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs): A National Analysis

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are becoming more popular in managing type 2 diabetes mellitus (T2DM). Concerns linger over potential links to malignancies like pancreatic and thyroid cancers, requiring more research to clarify their safety profiles. Additionally, evidence suggests GLP-1 RAs may lower colorectal and pancreatic cancer risk, especially in obese and overweight individuals, indicating a protective effect beyond weight loss. Current studies leave a gap in comprehensively understanding cancer risks associated with GLP-1 RAs, which prompts further research to enhance our understanding of their overall safety.

METHODS

We queried the US Collaborative Network (63 health care organizations) of the TriNetX research database. Patients with T2DM were identified and divided into two cohorts: patients on GLP-1 RAs and patients not on GLP-1 RAs. We excluded tobacco use and alcohol use disorders, obese patients with a body mass index (BMI) of >25 kg/m2, and those with a family history of gastrointestinal malignancy, infectious mononucleosis, chronic gastritis, pernicious anemia, helicobacter pylori infection, or gastroesophageal reflux disease (GERD). We used a 1:1 propensity score matching (PSM) model using patients' baseline characteristics, medications, labs, and genetics. We compared the rate of gastric cancer and esophageal cancer at the seven-year mark.

RESULTS

A total of 2,748,431 patients with T2DM were identified. Of those, 6% (n = 167,077) were on a GLP-1 RA and 94% (n = 2,581,354) were not on a GLP-1 RA. After PSM, both cohorts included 146,277 patients. Patients with T2DM who were on a GLP-1 RA, compared to those who were not, had a statistically significant lower risk of both gastric cancer (0.05% vs. 0.13%, p < 0.0001) and esophageal cancer (0.04% vs. 0.13%, p < 0.0001) at the seven-year mark.

CONCLUSION

The use of GLP-1 RAs in patients with T2DM does not significantly increase the risk of gastric or esophageal cancer. This finding supports the continued use of GLP-1 analogues as a therapeutic option in managing T2DM, considering their well-established benefits and low risk of complications. Based on the study results, these medications may even have a protective effect against these malignancies.

A case of an unreported point mutation in promoter 1B of the adenomatous polyposis coli gene, which is responsible for gastric adenocarcinoma and proximal polyposis of the stomach

A 35-year-old woman of Asian descent with epigastralgia was referred to our hospital. Esophagogastroduodenoscopy revealed gastric cancer in the upper body and carpeting fundic gland polyposis in the fornix and body. Computed tomography revealed no metastases. Total colonoscopy and capsule endoscopy revealed no polyposis, except in the stomach. The patient was diagnosed with advanced gastric cancer and underwent open total gastrectomy. We speculated that her gastric cancer was a hereditary tumor due to its early onset and accompanying fundic gland polyposis. Germline multi-gene panel testing identified a single-nucleotide variant, c.-191 T > G, in exon 1B of the adenomatous polyposis coli gene, which can cause gastric adenocarcinoma and proximal polyposis of the stomach. To our knowledge, this is the first manuscript to report the variant (c.-191 T > G) in promoter 1B of the adenomatous polyposis coli gene, which is related to a predisposition to gastric adenocarcinoma and proximal polyposis of the stomach.

Hereditary Gastrointestinal Tumor Syndromes: When Risk Comes with Your Genes

Despite recent campaigns for screening and the latest advances in cancer therapy and molecular biology, gastrointestinal (GI) neoplasms remain among the most frequent and lethal human tumors. Most GI neoplasms are sporadic, but there are some well-known familial syndromes associated with a significant risk of developing both benign and malignant GI tumors. Although some of these entities were described more than a century ago based on clinical grounds, the increasing molecular information obtained with high-throughput techniques has shed light on the pathogenesis of several of them. The vast amount of information gained from next-generation sequencing has led to the identification of some high-risk genetic variants, although others remain to be discovered. The opportunity for genetic assessment and counseling in these families has dramatically changed the management of these syndromes, though it has also resulted in significant psychological distress for the affected patients, especially those with indeterminate variants. Herein, we aim to summarize the most relevant hereditary cancer syndromes involving the stomach and colon, with an emphasis on new molecular findings, novel entities, and recent changes in the management of these patients.

Consideration of a Novel Surgical Approach in the Management of Gastric Adenocarcinoma and Proximal Polyposis Syndrome

Investigators at MSKCC highlight a novel surgical approach to manage GAPPS.

Upper Gastrointestinal Cancers and the Role of Genetic Testing

Beyond the few established hereditary cancer syndromes with an upper gastrointestinal cancer component, there is increasing recognition of the contribution of novel pathogenic germline variants (gPVs) to upper gastrointestinal carcinogenesis. The detection of gPVs has potential implications for novel treatment approaches of the index cancer patient as well as long-term implications for surveillance and risk-reducing measures for cancer survivors and far-reaching implications for the patients' family. With widespread availability of multigene panel testing, new associations may be identified with germline-somatic integration being critical to determining true causality of novel gPVs. Comprehensive cancer care should incorporate both somatic and germline testing.

Updated European guidelines for clinical management of familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), gastric adenocarcinoma, proximal polyposis of the stomach (GAPPS) and other rare adenomatous polyposis syndromes: a joint EHTG-ESCP revision

BACKGROUND

Hereditary adenomatous polyposis syndromes, including familial adenomatous polyposis and other rare adenomatous polyposis syndromes, increase the lifetime risk of colorectal and other cancers.

METHODS

A team of 38 experts convened to update the 2008 European recommendations for the clinical management of patients with adenomatous polyposis syndromes. Additionally, other rare monogenic adenomatous polyposis syndromes were reviewed and added. Eighty-nine clinically relevant questions were answered after a systematic review of the existing literature with grading of the evidence according to Grading of Recommendations, Assessment, Development, and Evaluation methodology. Two levels of consensus were identified: consensus threshold (≥67% of voting guideline committee members voting either 'Strongly agree' or 'Agree' during the Delphi rounds) and high threshold (consensus ≥ 80%).

RESULTS

One hundred and forty statements reached a high level of consensus concerning the management of hereditary adenomatous polyposis syndromes.

CONCLUSION

These updated guidelines provide current, comprehensive, and evidence-based practical recommendations for the management of surveillance and treatment of familial adenomatous polyposis patients, encompassing additionally MUTYH-associated polyposis, gastric adenocarcinoma and proximal polyposis of the stomach and other recently identified polyposis syndromes based on pathogenic variants in other genes than APC or MUTYH. Due to the rarity of these diseases, patients should be managed at specialized centres.

Endoscopy in pediatric polyposis syndromes: why, when and how

Single or multiple polyps are frequently encountered during colonoscopy among children and adolescents and may be indicative of hereditary polyposis syndrome (HPS). The management of children with single or multiple polyps is guided by the number of polyps, their distribution and the histological findings. Children with HPS carry a high risk of complications, including intestinal and extra-intestinal malignancies. The goals of surveillance in pediatric HPS are to treat symptoms, monitor the burden of polyps and prevent short- and long-term complications. Therefore, the management of children with HPS is based on therapeutic endoscopy. The strategy of therapeutic endoscopy is a careful assessment and characterization of the polyps and performing polypectomies using advanced endoscopic techniques. A multidisciplinary approach, comprising clinical, interventional endoscopy, cancer surveillance and support of familial and emotional aspects is essential in the management of children with HPS.

NCAD v1.0: a database for non-coding variant annotation and interpretation

The application of whole genome sequencing is expanding in clinical diagnostics across various genetic disorders, and the significance of non-coding variants in penetrant diseases is increasingly being demonstrated. Therefore, it is urgent to improve the diagnostic yield by exploring the pathogenic mechanisms of variants in non-coding regions. However, the interpretation of non-coding variants remains a significant challenge, due to the complex functional regulatory mechanisms of non-coding regions and the current limitations of available databases and tools. Hence, we develop the non-coding variant annotation database (NCAD, http://www.ncawdb.net/), encompassing comprehensive insights into 665,679,194 variants, regulatory elements, and element interaction details. Integrating data from 96 sources, spanning both GRCh37 and GRCh38 versions, NCAD v1.0 provides vital information to support the genetic diagnosis of non-coding variants, including allele frequencies of 12 diverse populations, with a particular focus on the population frequency information for 230,235,698 variants in 20,964 Chinese individuals. Moreover, it offers prediction scores for variant functionality, five categories of regulatory elements, and four types of non-coding RNAs. With its rich data and comprehensive coverage, NCAD serves as a valuable platform, empowering researchers and clinicians with profound insights into non-coding regulatory mechanisms while facilitating the interpretation of non-coding variants.

Gastric Cancer: A Practical Review on Management of Individuals with Hereditary or Familial Risk for Gastric Cancer

Gastric adenocarcinoma is one of the most frequent and deadly cancers worldwide. However, its incidence is variable, being higher in eastern countries where screening the general population is recommended. On the other hand, in low to intermediate-risk countries, screening the general population may not be cost-effective, and therefore, it is necessary to be aware of high-risk populations that may benefit from adequate screening and surveillance. It is not always easy to identify these individuals, leading to a late diagnosis of gastric adenocarcinoma. In this review, the authors intend to summarize the data required to identify the population at risk of sporadic or familial gastric adenocarcinoma and the beginning of screening and its surveillance, with the final aim of increasing early detection of gastric adenocarcinoma and decreasing morbimortality. The authors highlight the importance to be aware of the several hereditary syndromes and MAPS recommendations and apply screen and surveillance protocols. The high-risk syndromes to gastric adenocarcinoma are gastric adenocarcinoma and proximal polyposis of the stomach, hereditary diffuse gastric cancer, and familial intestinal gastric cancer.

Hereditary Gastric Cancer: Single-Gene or Multigene Panel Testing? A Mono-Institutional Experience

Gastric cancer (GC) has long been a 'Cinderella' among hereditary cancers. Until recently, single-gene testing (SGT) was the only approach to identify high-risk individuals. With the spread of multigene panel testing (MGPT), a debate arose on the involvement of other genes, particularly those pertaining to homologous recombination (HR) repair. We report our mono-institutional experience in genetic counseling and SGT for 54 GC patients, with the detection of nine pathogenic variants (PVs) (9/54:16.7%). Seven out of fifty (14%) patients who underwent SGT for unknown mutations were carriers of a PV in CDH1 (n = 3), BRCA2 (n = 2), BRCA1 (n = 1), and MSH2 (n = 1), while one patient (2%) carried two variants of unknown significance (VUSs). CDH1 and MSH2 emerged as genes involved in early-onset diffuse and later-onset intestinal GCs, respectively. We additionally conducted MGPT on 37 patients, identifying five PVs (13.5%), including three (3/5:60%) in an HR gene (BRCA2, ATM, RAD51D) and at least one VUS in 13 patients (35.1%). Comparing PV carriers and non-carriers, we observed a statistically significant difference in PVs between patients with and without family history of GC (p-value: 0.045) or Lynch-related tumors (p-value: 0.036). Genetic counseling remains central to GC risk assessment. MGPT appeared advantageous in patients with unspecific phenotypes, although it led to challenging results.

Early-Onset GI Cancers: Rising Trends, Genetic Risks, Novel Strategies, and Special Considerations

Cancers in young adults (commonly described as early-onset [EO] cancer) represent a group of malignancies that have unique and challenging biology and genetic, treatment, social, and psychological implications. Even more concerning is a rising trend of EO cancers in multiple tumor types. Research and investigation in EO cancers will help elucidate mechanisms of carcinogenesis, differences in biology and response to treatment, and the need for multidisciplinary care to ensure comprehensive treatment and support for young patients.

Cancer Progress and Priorities: Gastric Cancer

Gastric cancer, the fifth leading cause of cancer worldwide, is estimated to be responsible for approximately 1.4% of all new cancers and 1.8% of all cancer-related deaths in the United States. Despite declining incidence rates and improved survival rates, however, gastric cancer continues to disproportionately affect racial and ethnic minorities and individuals of lower socioeconomic status at higher rates than the general population. To improve outcomes globally and address disparities within the United States, continued improvements are needed in risk factor modification and biomarker development and to improve access to existing preventative measures such as genetic testing and H. pylori eradication testing, in addition to expanding upon current clinical guidelines for premalignant disease to address gaps in endoscopic surveillance and early detection.

Pediatric Gastric Adenocarcinoma Presenting As Hip Pain

The third most lethal cancer in the world is gastric adenocarcinoma, which is uncommon in children. Patients with gastric adenocarcinoma typically experience vomiting, abdominal pain, anemia, and weight loss. We present a case of a 14.5-year-old male with gastric adenocarcinoma that manifested as left hip pain, epigastric pain, dysphagia, weight loss, and melena. Physical exam revealed cachexia, jaundice, a palpable epigastric mass, palpable liver edge, and left hip tenderness. Laboratory tests showed microcytic anemia, increase in carcinoembryonic antigen (CEA), and abnormal liver function test. Endoscopy revealed a cardial mass extending to the esophagus involving the gastroesophageal junction (GEJ). The gastric mass biopsy was consistent with invasive, moderately-differentiated gastric adenocarcinoma, which confirmed the diagnosis of gastric adenocarcinoma. Furthermore, a bone isotope scan revealed mildly hypervascular active bone pathology within the left proximal femur implying possible metastasis. Computed tomography scans and barium swallow were also helpful in supporting the diagnosis. Our case report emphasizes that gastric adenocarcinoma should be encompassed in the differential diagnosis of pediatric patients with hip pain.

Genetic Predisposition to Colorectal Cancer: How Many and Which Genes to Test?

Colorectal cancer is one of the most common tumors, and genetic predisposition is one of the key risk factors in the development of this malignancy. Lynch syndrome and familial adenomatous polyposis are the best-known genetic diseases associated with hereditary colorectal cancer. However, some other genetic disorders confer an increased risk of colorectal cancer, such as Li-Fraumeni syndrome (TP53 gene), MUTYH-associated polyposis (MUTYH gene), Peutz-Jeghers syndrome (STK11 gene), Cowden syndrome (PTEN gene), and juvenile polyposis syndrome (BMPR1A and SMAD4 genes). Moreover, the recent advances in molecular techniques, in particular Next-Generation Sequencing, have led to the identification of many new genes involved in the predisposition to colorectal cancers, such as RPS20, POLE, POLD1, AXIN2, NTHL1, MSH3, RNF43 and GREM1. In this review, we summarized the past and more recent findings in the field of cancer predisposition genes, with insights into the role of the encoded proteins and into the associated genetic disorders. Furthermore, we discussed the possible clinical utility of genetic testing in terms of prevention protocols and therapeutic approaches.

Early Prophylactic Gastrectomy for the Management of Gastric Adenomatous Proximal Polyposis Syndrome (GAPPS)

Background

Gastric adenomatous proximal polyposis syndrome (GAPPS) is a recently described, rare, autosomal dominant condition characterized by the extensive involvement of the proximal stomach with hundreds of heterogeneous fundic gland polyps with antral and duodenal sparing. GAPPS is caused by a point mutation of the APC gene promoter 1B and is associated with a risk of malignant transformation, distant metastasis, and death. There are no surveillance, screening, or treatment guidelines for managing GAPPS. The few reported cases have been variably managed with endoscopic surveillance or prophylactic gastrectomy. However, there is no consensus on the optimal management approach.

Summary

In this case series, we review the relevant literature on GAPPS and present two siblings who underwent early prophylactic total gastrectomies with good outcomes.

Conclusion

Due to the poor correlation between the endoscopic findings on sampled polyps and the risk of harboring invasive gastric cancer, patients with GAPPS should be strongly considered for early prophylactic total gastrectomies in the absence of prohibitive comorbidities.

Endoscopic Surveillance in Patients with the Highest Risk of Gastric Cancer: Challenges and Solutions

Gastric cancer is one of the most significant causes of cancer-related morbidity and mortality worldwide. Recognized modifiable risk factors include Helicobacter pylori infection, geographic location, select dietary factors, tobacco use and alcohol consumption. In addition, multiple hereditary cancer predisposition syndromes are associated with significantly elevated gastric cancer risk. Endoscopic surveillance in hereditary gastric cancer predisposition syndromes has the potential to identify gastric cancer at earlier and more treatable stages, as well as to prevent development of gastric cancer through identification of precancerous lesions. However, much uncertainty remains regarding use of endoscopic surveillance in hereditary gastric cancer predisposition syndromes, including whether or not it should be routinely performed, the surveillance interval and age of initiation, cost-effectiveness, and whether surveillance ultimately improves survival from gastric cancer for these high-risk individuals. In this review, we outline the hereditary gastric cancer predisposition syndromes associated with the highest gastric cancer risks. Additionally, we cover current evidence and guidelines addressing hereditary gastric cancer risk and surveillance in these syndromes, along with current challenges and limitations that emphasize a need for continued research in this field.

Molecular pathogenesis and emerging targets of gastric adenocarcinoma

Gastric adenocarcinoma (GC) is a devastating disease and is the third leading cause of cancer deaths worldwide. This heterogeneous disease has several different classification systems that consider histological appearance and genomic alterations. Understanding the etiology of GC, including infection, hereditary conditions, and environmental factors, is of particular importance and is discussed in this review. To improve survival in GC, we also must improve our therapeutic strategies. Here, we discuss new targets that warrant further exploration.

Familial and hereditary gastric cancer, an overview

There are three major hereditable syndromes that affect primarily the stomach: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) and familial intestinal gastric cancer (FIGC). HDGC is caused by germline mutations in CDH1 gene that occur in 10-40% of HDGC families and, in a minority of cases, by mutations in CTNNA1 gene. GAPPS is caused by germline mutations in the promoter 1B of APC gene, and the genetic cause of FIGC is not fully elucidated. Gastric cancer can also be observed as part of other inherited cancer disorders, namely in familial adenomatous polyposis, MUTYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Lynch syndrome, Li-Fraumeni syndrome, Cowden syndrome, and hereditary breast and ovarian cancer syndrome. In this article, the state of the art of familial gastric cancer regarding the clinical, molecular and pathology features is reviewed, as well as the practical aspects for a correct diagnosis and clinical management.

Four cases of gastric adenocarcinoma and proximal polyposis of the stomach treated by robotic total gastrectomy

Background

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare disease and characterized by a unique point mutation in the promoter 1B region of the adenomatous polyposis coli (APC) gene. There are two aims in surgery for GAPPS; the first is prophylactic gastrectomy, and the second is excising concurrent cancer. We performed robotic total gastrectomy (RTG) for four cases of GAPPS.

Case presentation

Case 1 was a woman in her 40 s whose sister had died from gastric cancer. Mutational analysis revealed mutation of APC exon 1B. We performed prophylactic gastrectomy. Case 2 was a woman in her 30 s who had a mutation of APC exon 1B, and preoperative biopsy revealed suspected adenocarcinoma. Case 3 was a woman in her 40 s who was diagnosed with gastric cancer with multiple polyps in the stomach and a mutation of APC exon 1B. Case 4 was a woman in her 20 s in whom biopsy revealed low-grade dysplasia of a raised lesion. She had a mutation in APC exon 1B. We performed RTG with D1 + lymphadenectomy in all patients, and there were no intraoperative complications.

Conclusions

Patients with GAPPS are mainly followed regularly with repeat biopsy, and tumors are detected in an early stage. As the safety of robotic surgery for the early gastric cancer is reported, RTG is an option for these patients. This is the first report of RTG for GAPPS patients.

Early experience with total robotic D2 gastrectomy in a low incidence region: surgical perspectives

Background

Few European centers have reported on robotic gastrectomy for malignancy. We report our early experience with curative-intent total robotic gastrectomy.

Materials and methods

The Intuitive Surgery Da Vinci Surgical System Xi 4 armed robot was used. Routine D2 lymphadenectomy was applied.

Results

Some 27 patients with adenocarcinoma (n = 18), hereditary cancer susceptibility (n = 8) and premalignancy (n = 1) were allocated to robotic gastrectomy, three were excluded due to inoperability during surgery. Median (range) age was 66 (18–87) years, 14 (58.3%) were females and body mass index was 25.5 (22.1–33.5) kg/m². Total gastrectomy was performed in 19 (79.2%) and subtotal in five (20.8%) patients. One (4.2%) procedure was converted to laparotomy. Procedural time was 273 (195–427) minutes. Three (12.5%) patients were reoperated within 30 days, one (4.2%) died. Serious complications (Clavien Dindo IIIb or more) occurred in three (12.5%) patients. Postoperative hospital stay was 10 (6–43) days. Fourteen of 16 (87.5%) patients with adenocarcinoma/premalignancy received radical resections. The median number of harvested lymph nodes was 20 (11–34). Eleven (73.3%) patients with adenocarcinoma had T3/T4 tumors and 6 (40%) had TNM stage III or more.

Conclusion

Total robotic D2 gastrectomy appears feasible and safe during early introduction in a low incidence region.

Filling in the "GAPPS": an unusual presentation of a child with gastric adenocarcinoma and proximal polyposis of the stomach

Gastric Adenocarcinoma and Proximal Polyposis of the Stomach (GAPPS) is a very rare gastric polyposis syndrome characterized by numerous polyps of the gastric fundus and body. We present the unusual case of a 10-year-old Polish-American male with history of eosinophilic esophagitis, who was found to have multiple fundic gland polyps (FGP) with low grade dysplasia on esophagogastroduodenoscopy. Subsequent evaluation including genetic testing confirmed the diagnosis of GAPPS, and after exhaustive multidisciplinary consultation the decision was made to proceed with prophylactic total gastrectomy given the markedly increased risk of gastric adenocarcinoma in GAPPS patients. To our knowledge, this represents the youngest patient diagnosed with GAPPS and the youngest patient who has undergone prophylactic gastrectomy for this disease at age 8 and 10 years, respectively. The pathophysiology, presentation, and treatment of GAPPS in a pediatric patient are discussed.

Prophylactic laparoscopic total gastrectomy for gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): the first report in Asia

A 41-year-old woman was admitted to our hospital for epigastralgia. She had been admitted to another hospital for fundic gland polyposis (FGP) without any symptoms, and no malignancy had been noted in her previous endoscopy. However, a biopsy performed at our hospital revealed adenocarcinoma, and computed tomography (CT) revealed multiple liver and peritoneal metastases. We clinically suspected gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) and indicated genetic testing. The point mutation in exon 1B of APC was revealed. She was diagnosed with GAPPS with multiple liver metastases and underwent systemic chemotherapy. She has two older brothers who also have FGP. The same genomic mutation was observed in both brothers and their mother, and they were also diagnosed with GAPPS. The brothers underwent prophylactic laparoscopic total gastrectomy with D1 lymph-node dissection.

Genetic Syndromes Associated with Gastric Cancer

Although environmental factors such as Helicobacter pylori, tobacco, and diet are major contributors to the development of gastric cancer (GC) worldwide, it is estimated that up to 5% to 10% of GC cases are due to an underlying hereditary susceptibility caused by germline pathogenic variants. Hereditary diffuse gastric cancer (HDGC) caused by germline pathogenic variants in the CDH1 gene is the principal familial GC syndrome. However, other well-established hereditary gastrointestinal syndromes have been associated with an increased risk of GC. In this review, we will discuss the latest insights and advances in our understanding of GC associated with Lynch syndrome (LS), familial adenomatous polyposis (FAP), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), Li-Fraumeni syndrome (LFS), Peutz-Jeghers syndrome (PJS), and juvenile polyposis syndrome (JPS). We will also discuss the emergence of new associations of the homologous recombination pathway genes (BRCA1, BRCA2) with GC.

Gastric cancer genetic predisposition and clinical presentations: Established heritable causes and potential candidate genes

Tumour risk syndromes (TRS) are characterized by an increased risk of early-onset cancers in a familial context. High cancer risk is mostly driven by loss-of-function variants in a single cancer-associated gene. Presently, predisposition to diffuse gastric cancer (DGC) is explained by CDH1 and CTNNA1 pathogenic and likely pathogenic variants (P/LP), causing Hereditary Diffuse Gastric Cancer (HDGC); while APC promoter 1B single nucleotide variants predispose to Gastric Adenocarcinoma and Proximal Polyposis of the Stomach (GAPPS). Familial Intestinal Gastric Cancer (FIGC), recognized as a GC-predisposing disease, remains understudied and genetically unsolved. GC can also occur in the spectrum of other TRS. Identification of heritable causes allows defining diagnostic testing criteria, helps to clinically classify GC families into the appropriate TRS, and allows performing pre-symptomatic testing identifying at-risk individuals for downstream surveillance, risk reduction and/or treatment. However, most of HDGC, some GAPPS, and most FIGC patients/families remain unsolved, expecting a heritable factor to be discovered. The missing heritability in GC-associated tumour risk syndromes (GC-TRS) is likely explained not by a single major gene, but by a diversity of genes, some, predisposing to other TRS. This would gain support if GC-enriched small families or apparently isolated early-onset GC cases were hiding a family history compatible with another TRS. Herein, we revisited current knowledge on GC-TRS, and searched in the literature for individuals/families bearing P/LP variants predisposing for other TRS, but whose probands display a clinical presentation and/or family history also fitting GC-TRS criteria. We found 27 families with family history compatible with HDGC or FIGC, harbouring 28 P/LP variants in 16 TRS-associated genes, mainly associated with DNA repair. PALB2 or BRCA2 were the most frequently mutated candidate genes in individuals with family history compatible with HDGC and FIGC, respectively. Consolidation of PALB2 and BRCA2 as HDGC- or FIGC-associated genes, respectively, holds promise and worth additional research. This analysis further highlighted the influence, that proband's choice and small or unreported family history have, for a correct TRS diagnosis, genetic screening, and disease management. In this review, we provide a rational for identification of particularly relevant candidate genes in GC-TRS.

Gastric Adenocarcinoma and Proximal Polyposis of the Stomach in a Hispanic Pediatric Patient With APC Gene Variant c.-191T>G

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare gastric polyposis syndrome defined by numerous polyps (>100) in the fundus and body of the stomach with sparing of the lesser curvature and antrum. GAPPS is linked to a variant in the promoter 1B region of the APC gene. These variants carry a high risk of developing gastric adenocarcinoma, which can occur at an early age. We report a case of GAPPS discovered in a 16-year-old Hispanic girl after endoscopy detected extensive fundic gland polyposis. Genetic testing revealed a promoter 1B point mutation of the APC gene, variant c.-191T>G. Although similar variants have been reported (i.e., c.-191T>C, c.-195A>C, c.-192A>G) in association with GAPPS, variant c.-191T>G has not nor has GAPPS ever been described in a Hispanic individual before.

Inherited Predisposition to Gastric Cancer

Approximately 10% of patients with gastric cancer show familial aggregation and up to 3% are related to an inherited cancer syndrome. There are multiple germline pathogenic variants and cancer syndromes associated with an increased risk of gastric cancer. Appropriate assessment of familial and genetic risk may allow a personalized approach to gastric cancer prevention through screening and risk-reducing surgeries. The ability to better identify carriers with pathogenic genetic variants associated with gastric cancer before a diagnosis of cancer requires effective genetic risk assessment and testing, followed by optimal screening and surveillance recommendations to further reduce the morbidity and mortality.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2020 for the Clinical Practice of Hereditary Colorectal Cancer

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

ACG Clinical Report and Recommendations on Transition of Care in Children and Adolescents With Hereditary Polyposis Syndromes

Transition of care (TOC) in adolescents and young adults (AYAs) with chronic gastrointestinal disorders has received increased attention, especially in those with inflammatory bowel disease. AYAs with hereditary polyposis syndromes are a heterogeneous group of patients with overlapping and complex medical needs. These patients are particularly vulnerable because of the risk of loss of continuity of care and subsequent poor disease outcomes. The Pediatric Committee of the American College of Gastroenterology commissioned a report with recommendations on TOC in AYAs with hereditary polyposis syndromes. This report aims at achieving best practice by both pediatric and adult gastroenterologists despite the paucity of published evidence in this population reflected in the included PRISMA report. Therefore, the group extrapolated findings from the literature related to other chronic gastrointestinal disorders, and a high degree of expert consensus was scored for all recommendations. The report addresses TOC through identifying shared domains followed by specific recommendations in disease management, including models of care, providers and patient and socioeconomic factors relevant to TOC. Areas of strong emphasis include the need for early planning, flexibility in the transition process to maintain continuity during major surgical procedures, patient and family psychological readiness, liaison among team members addressing transition, and changing insurance coverage in this population.

Genetic Gastric Cancer Risk Syndromes

Purpose of review

Gastric cancer is a leading cause of cancer death in the world. Between 1% and 3% of cases are associated with specific genetic cancer risk syndromes. The purpose of this article is to review the latest insights, as well as gaps in knowledge, regarding some of the most common hereditary gastric cancer syndromes: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), Lynch syndrome, the adenomatous polyposis syndromes, and the hamartomatous polyposis syndromes.

Recent findings

Patients carrying pathogenic variants in CDH1, but not meeting clinical criteria for HDGC, are increasingly being identified thanks to multigene panel testing; their absence from previous analyses overestimated gastric cancer penetrance. GAPPS is a recently described hereditary gastric cancer syndrome associated with specific point mutations in the promoter 1B region of the APC gene.

Summary

Risk of gastric cancer is highest among carriers of pathogenic variants in CDH1, with cumulative incidences approximately 40% and 30% for men and women, respectively. Mutations associated with Lynch syndrome and adenomatous polyposis syndromes confer greatest risk for gastric cancer in East Asian populations. Risk of gastric cancer in GAPPS and hamartomatous polyposis syndromes is difficult to estimate due to their rarity, but mutation status likely determines risk. Future research is needed to more precisely define risk of gastric cancer in these syndromes, so strategies for screening and prophylactic gastrectomy can be optimized.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) - A Helicobacter-opposite point

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare familial gastric cancer syndrome with an autosomal dominant pattern of inheritance. It is characterised by fundic gland polyposis of the gastric body and is associated with a significant risk of gastric adenocarcinoma. Unlike sporadic gastric cancer, Helicobacter pylori is usually absent in patients with GAPPS. This opposite-point finding has so far not been fully clarified. Prophylactic total gastrectomy is indicated in all cases of GAPPS with fundic gland polyposis and the presence of any dysplasia. If no dysplasia is found at histology, prophylactic gastrectomy is suggested at between 30 and 35 years of age, or at five years earlier than the age at which the youngest family member developed gastric cancer. Different phenotypes of GAPPS demand an individual approach to particular family members.

[Pathohistology of polyps of the gastrointestinal tract]

Polyps of the gastrointestinal tract encompass a variety of epithelial and non-epithelial tumour-like conditions. The most common polyps are epithelial lesions. In the upper gastrointestinal tract, reactive inflammatory changes and hyperplastic polyps dominate, whereas true neoplastic polyps, like adenomas, are much more common in the colorectum. In addition to neoplasias such as adenomas, non-neoplastic polyps such as hyperplastic polyps of the stomach may also be associated with an increased risk of malignancy. The risk of malignancy is determined by the histological subtype of polyp, as well as the size, presence and degree of dysplasia. The term "dysplasia" has been reintroduced for adenomas in the current 2019 World Health Organization (WHO) classification and replaces "intraepithelial neoplasia". A further change is the term "sessile serrated lesion" with and without dysplasia, which was formerly known as sessile serrated adenoma.

Recent advances in the pathology of heritable gastric cancer syndromes

Despite the relative rarity of hereditary gastric cancer syndromes, the prompt recognition of their specific clinical features and histopathological characteristics is pivotal in offering patients the most appropriate treatment. In this article, we address the three major inherited syndromes that primarily affect the stomach: hereditary diffuse gastric cancer (HDGC), caused by germline variants in CDH1 and CTNNA1; gastric adenocarcinoma and proximal polyposis of the stomach, caused by germline mutations in promoter 1B of APC; and familial intestinal gastric cancer, which has a poorly defined genetic cause. The main focus will be on HDGC, in light of the recent publication of updated clinical practice guidelines and emerging concepts regarding HDGC histopathology. In particular, we describe the broad morphological spectrum of HDGC lesions, stressing the importance of recognising indolent and aggressive phenotypes. Moreover, we discuss the increased risk of gastric (pre)malignancies developing in patients with other well-defined hereditary cancer syndromes, such as familial adenomatous polyposis, Lynch syndrome, Peutz-Jeghers syndrome, juvenile polyposis, Li-Fraumeni syndrome, and hereditary breast and ovarian cancer syndrome.

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.

Hereditary Polyposis Syndromes

PURPOSE OF REVIEW

Colorectal cancer (CRC) is the third most common cancer in the USA and inherited cancer syndromes are responsible for approximately 3-5% of all CRCs. Genetic testing costs have plummeted in recent years; however, awareness and referral of high-risk patients for testing is still very low. We review the salient clinical features, genetics, and management of well-defined gastrointestinal (GI) hereditary polyposis syndromes including familial adenomatous polyposis, MUTYH-associated polyposis, and the hamartomatous polyposis syndromes.

RECENT FINDINGS

Comprehensive endoscopic surveillance has the potential to prevent the development of GI cancer and to identify early-stage cancer; newer developments like high-definition endoscopes, chromoendoscopy, and the use of cap-assisted endoscopy have shown promise for enhanced lesion detection rates. Several chemoprevention trials have yielded promising results but safety and efficacy data for long-term use is still awaited. Several new polyposis genes have also been identified in the recent years. Multiple societies have recently published updated surveillance guidelines to aid clinicians in the detection and management of patients with hereditary GI polyposis syndromes. Although these syndromes are rare, it is crucial for the clinicians to recognize these in a timely manner, for the appropriate management plans for both the patient and their at risk family members.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Long noncoding RNA LINC00337 promote gastric cancer proliferation through repressing p21 mediated by EZH2

Gastric cancer is one of the most common human malignancies. Some long noncoding RNA (lncRNA) has been validated to be oncogene in gastric cancer. In this research, we found that LINC00337 was up-regulated in the gastric cancer cells and tissue specimens. Clinically, the ectopic LINC00337 overexpression indicates the poor clinical outcome. The functional experiments illustrated that LINC00337 silencing repressed the proliferation, invasion and tumor growth in vitro and in vivo. The mechanical experiments showed that LINC00337 epigenetically repressed the p21 via EZH2-mediated inhibition. Overall, this finding suggests that LINC00337 acts as the oncogene to promote gastric cancer cells proliferation through epigenetically repressing p21 mediated by EZH2, providing a new insight for gastric cancer.