β-Catenin activation in fundic gland polyps, gastric cancer and colonic polyps in families afflicted by 'gastric adenocarcinoma and proximal polyposis of the stomach' (GAPPS)

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.

Gastric fundic gland polyposis and cancer development after eradication of Helicobacter pylori in patient with gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS)

A 44-year-old woman with gastric cancer (GC) and fundic gland polyposis (FGPs) was referred to our hospital for further diagnosis and treatment. She successfully underwent eradication therapy for Helicobacter pylori (HP) 6 years ago, but did not exhibit FGPs at that time. When she underwent an esophagogastroduodenoscopy 2, 4, and 5 years after the eradication of HP, her imaging results revealed the existence of FGPs which gradually increased in her gastric fundus and body. Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) was suspected and a mutational analysis was performed, revealing an APC promoter 1B variant c.-191T > C. A robotic total gastrectomy with lymphadenectomy was performed. Histopathological analysis of the surgical specimens revealed GC with no lymph node metastasis. GAPPS is characterized by GC and FGPs. However, our case shows different gastric phenotypes that are dependent on the status of HP infection.

Two families with gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): case reports and literature review

Background

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), a hereditary gastric polyposis syndrome that presents with fundic gastric polyposis, is associated with an increased risk of gastric adenocarcinoma. The four patterns of point mutation in the adenomatous polyposis coli (APC) promoter 1B region have been identified as the cause of GAPPS. GAPPS was first reported in 2012, and only 33 families with GAPPS have been reported worldwide to date. Therefore, the clinical management for GAPPS are still controversial. We herein report two unrelated GAPPS families with the same point mutation site.

Case Description

Total seven patients of two families had >100 carpeting polyps in the gastric body and fundus, and one of them (69-year-old female) had gastric adenocarcinoma. As a result of germline analysis, both families harbored a point mutation (c.-192A>G) in APC promoter 1B region, previously reported in only one family. Three of seven patients underwent total gastrectomy, and others were followed-up with regular esophagogastroduodenoscopy (EGD) and biopsy every 6 months. To summarize the reported cases, total 42 patients of 35 families have developed gastric adenocarcinoma.

Conclusions

This report may contribute to determining the appropriate guidelines for the clinical practice of GAPPS. When EGD reveals gastric polyposis localized to the gastric body and fundus, it is important to obtain a detailed family history and perform germline mutational analysis. And more, point mutation type of our family cases was a rare pattern, suggested that c.-192A>G pattern might be a pathogenic variant.

Attenuated Familial Adenomatous Polyposis

A 36-year-old man was diagnosed with multiple gastric polyps by esophagogastroduodenoscopy. Subsequent colonoscopy identified two tubular adenomas, and computed tomography revealed subcutaneous tumors. Based on these findings, we suspected that gastric polyposis was associated with the APC gene, either attenuated familial adenomatous polyposis (AFAP) or gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). A genetic analysis demonstrated that he had a frameshift variant at codon 1928 of APC, suggesting AFAP. In this era of less Helicobacter pylori infection and frequent use of proton pump inhibitors, diagnoses of AFAP and GAPPS should be considered in patients with prominent gastric fundic gland polyposis.

The comprehensive review of gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) from diagnosis and treatment

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) was first proposed by Wothley et al. in 2012 as a rare familial gastric cancer syndrome associated with an autosomal dominant form of inheritance. GAPPS is characterized by gastric basal gland polyposis from the hilum to the body of the stomach. Li et al. in 2016 showed that the cause of the disease is a point mutation in the promotor 1B region of the APC gene, and genetic testing was used to confirm the diagnosis. If the patient has already developed gastric cancer, treatment should be based on the usual treatment for gastric cancer. If no distant metastases exist, a good prognosis can be expected by performing a total gastrectomy. On the other hand, patients with distant metastasis have a poor prognosis. In the case of dysplasia, prophylactic total gastrectomy is recommended, but because it is highly invasive and postoperative postgastrectomy syndrome must be considered, the decision should be made with careful consideration of the patient's background. Therefore, there are no guidelines for screening for GAPPS, the timing of prophylactic total gastrectomy, or methods of endoscopic surveillance. Because GAPPS is a rare disease, its natural history is still unclear. Further case series are needed to elucidate the molecular biology and clinicopathological features of GAPPS and to establish clinical management, including diagnosis, treatment, and surveillance. In this review, we provide an overview of GAPPS, its clinical management, and its problems, which will be useful for the treatment of GAPPS.

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.

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.

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.

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.

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.

Clinical features of fundic gland polyps and their correlation with colorectal tumors

Fundic gland polyps (FGPs) are multiple, sessile polypoid bumps formed by the gastric mucosa of the fundus and body, which are the most common type of gastric polyps and generally tend to be benign. Studies have shown that patients with FGPs have a higher risk of developing colorectal tumors (adenoma and cancer) than the general population, but their correlation is still controversial. This article is aimed to review the clinical features of FGPs and their correlation with colorectal tumors.

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

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a recently described, rare gastric polyposis syndrome. It is characterized by extensive involvement of the fundus and body of the stomach with fundic gland polyps sparing the antrum and lesser curvature, an autosomal dominant inheritance pattern with incomplete penetrance, and a significant predisposition for the development of gastric adenocarcinoma. Due to the recent discovery of APC promotor IB mutations (c.-191T>C, c.-192A>G, and c.-195A>C), which reduce binding of the transcription factor Yin Yang 1 (YY1) and transcriptional activity of the promotor, as its underlying genetic perturbation, GAPPS has been added to the growing molecular class of APC-associated disorders. Recent reports on family members afflicted by gastric polyposis due to GAPPS have described the development of metastatic cancer or the presence of invasive gastric adenocarcinoma in total gastrectomy specimens after variable periods of endoscopic surveillance emphasizing the need for an improved understanding of the to-date poorly characterized natural history of the syndrome. There are, however, currently no guidelines on screening, timing of prophylactic gastrectomy, or endoscopic surveillance for GAPPS available. In this review, we summarize the clinical, pathological, and genetic aspects of GAPPS as well as management approaches to this rare cancer predisposition syndrome, highlighting the need for early recognition, a multidisciplinary approach, and the creation of prospective family registries and consensus guidelines in the near future.

Correlation between fundic gland polyps and colorectal neoplasms

AIM

To investigate the correlation between fundic gland polyps (FGPs) and colorectal neoplasms.

METHODS

Clinical data of patients who underwent both gastroduodenoscopy and colonoscopy during the period from May 2013 to May 2016 at the First Hospital of Jilin University were retrospectively analyzed. The patients were divided into either an FGPs group (243 cases) or a control group (n = 486). SPSS17.0 software was used for statistical analysis to assess the correlation between FGPs and colorectal neoplasms.

RESULTS

Colorectal neoplasms were detected in 19.8% (48/243) of patients with FGPs, while only in 8.8% (43/486) of the control group. The incidence of colorectal cancer was not significantly different (P = 0.67), while the incidence of colorectal adenoma was significantly different between the two groups (P < 0.001). Stratified analysis showed that the incidence of colorectal neoplasms in the FGPs group was higher than in the control group in females and in patients aged more than 50 years (P < 0.001 for both). Stratified analysis of different parts of colorectal neoplasms suggested that the incidence of colorectal neoplasms in patients who were female or aged over 50 years in the FGPs group was significantly higher than that in the control group, regardless of the proximal colon, distal colon or rectum (P < 0.05).

CONCLUSION

Patients with FGPs, especially females or those aged over 50, have a higher risk for colorectal neoplasms. Colonoscopy is necessary in this group of patients.