Gastric cancer in patients with type I gastric carcinoids

Gastric neuroendocrine neoplasms

Gastric neuroendocrine neoplasms (gNENs) display peculiar site-specific features among all NENs. Their incidence and prevalence have been rising in the past few decades. gNENs comprise gastric neuroendocrine carcinomas (gNECs) and gastric neuroendocrine tumours (gNETs), the latter further classified into three types. Type I anatype II gNETs are gastrin-dependent and develop in chronic atrophic gastritis and as part of Zollinger-Ellison syndrome within a multiple endocrine neoplasia type 1 syndrome (MEN1), respectively. Type III or sporadic gNETs develop in the absence of hypergastrinaemia and in the context of a near-normal or inflamed gastric mucosa. gNECs can also develop in the context of variable atrophic, relatively normal or inflamed gastric mucosa. Each gNEN type has different clinical characteristics and requires a different multidisciplinary approach in expert dedicated centres. Type I gNETs are managed mainly by endoscopy or surgery, whereas the treatment of type II gNETs largely depends on the management of the concomitant MEN1. Type III gNETs may require both locoregional approaches and systemic treatments; NECs are often metastatic and therefore require systemic treatment. Specific data regarding the systemic treatment of gNENs are lacking and are derived from the treatment of intestinal NETs and NECs. An enhanced understanding of molecular and clinical pathophysiology is needed to improve the management and outcomes of patients' gNETs.

Gastric neuroendocrine tumors in a BRCA2 germline mutation carrier: A case report

BACKGROUND

The molecular changes present in gastric neuroendocrine tumors (NETs) include a loss of heterozygosity or mutation of MEN1, CDKN1B gene mutation, P27 heterozygous mutation, and ATP4A gene missense mutation. We identified and are the first to report a case of type 1 histamine-producing enterochromaffin-like cell NETs (ECL-cell NETs) with a BRCA2 gene germline mutation.

CASE SUMMARY

The patient had a history of iron-deficient anemia for 5 years, and gastroscopic examination indicated multiple gastric tumors. Then, the patient underwent distal gastrectomy. Microscopically, multifocal tumor cells were found in the mucosa and submucosa; tumor cells were organoid and arranged in nests and cords, and the stroma was rich in sinusoids. The surrounding gastric mucosa showed atrophy with mild intestinal metaplasia or pseudopyloric gland metaplasia. Neuroendocrine cells could be seen with diffuse linear, nodular, and adenomatous hyperplasia. Immunohistochemically, the tumor cells diffusely expressed cytokeratin, chromogranin, synaptophysin, and CD56. Whole-genome high-throughput molecular sequencing revealed a pathogenic germline mutation in the BRCA2 gene, a heterozygous germline frameshift mutation in exon 11, c.6443_6444del (p.S2148Yfs*2). The final diagnosis was gastric type 1 ECL-cell NETs with a BRCA2 gene germline mutation, accompanied by autoimmune gastritis.

CONCLUSION

This is the first report of a case of type 1 gastric ECL-cell NETs with a pathogenic germline mutation of the BRCA2 gene. The findings of this report will expand the germline mutation spectrum of gastric NETs and increase the understanding of the molecular changes present in these tumors for their improved diagnosis in the future.

Chronic Treatment with Somatostatin Analogues in Recurrent Type 1 Gastric Neuroendocrine Tumors

Background: Type 1 gastric neuroendocrine tumors (GC-1) represent an uncommon subtype of neoplasms. Endoscopic resection has been proposed as the treatment of choice; active surveillance may be performed in those smaller than 1 cm, while gastric surgery may be performed for those with frequent recurrences. The antiproliferative effect of somatostatin analogues (SSA) is well known, and their action on GC-1s has been postulated as a chronic treatment to reduce recurrence. Methods: A two-centered, retrospective, observational study that included nine patients (55.6% women) diagnosed with GC-1, receiving long-term treatment with SSA, with a median follow-up from baseline of 22 months, was undertaken. Endoscopic follow-up, extension study, and analytical values of chromogranin A (Cg A) and gastrin were collected. Results: In total, 88.9% of patients presented partial or complete response. Treatment with SSA was the only independent factor with a trend to prevent tumor recurrence (Odds Ratio 0.054; p = 0.005). A nonsignificant tendency toward a decrease in CgA and gastrin was observed; lack of significance was probably related to concomitant treatment with proton pump inhibitors in some patients. Conclusions: Chronic treatment with SSA is a feasible option for recurrent GC-1s that are difficult to manage using endoscopy or gastrectomy. Randomized clinical trials to provide more scientific evidence are still needed.

Usefulness of 68-Gallium PET in Type I Gastric Neuroendocrine Neoplasia: A Case Series

Background: Type I gastric neuroendocrine neoplasia (gNEN) is a rare and low-grade tumor in which the therapeutic strategy is almost always endoscopic. For this reason, the use of radiology or nuclear medicine imaging is not recommended by guidelines. Conversely, in a small number of cases, locoregional or distant metastases may develop, thus suggesting a role for imaging techniques. This retrospective study was performed to explore the usefulness of [68Ga]Ga-DOTA-SST PET/CT in the management of patients with T1gNENs. Patients and Method: Single-center retrospective analysis, in an ENETS Center of Excellence, of patients with type I gNEN who underwent [68Ga]Ga-DOTA-SST PET/CT. The indication for performing [68Ga]Ga-DOTA-SST PET/CT was generally based on the presence of at least one of the following criteria: (1) polyps > 10 mm; (2) endoscopic positive (R1) margin after previous endoscopic resection; and (3) Ki-67 > 3%. Results: A total of 120 patients with T1gNEN were evaluated. Overall, 15 out of 120 (13%) patients had performed [68Ga]Ga-DOTA-SST PET/CT. The median Ki-67 value was 6% (IQR 1−9): 9 out of 15 (60%) were G1 tumors, and 6 out of 15 (40%) were G2 tumors. Ninety-three percent of patients were treated by tumor endoscopic resection, whereas surgery was performed in two patients (13%) after incomplete endoscopic resection; the remaining patients (6.6%) received somatostatin analogs due to the presence of multiple recurrent tumors. Overall, [68Ga]Ga-DOTA-SST PET/CT was positive in 8 out of 15 patients (53%). Following the [68Ga]Ga-DOTA-SST PET/CT findings, the clinical management was modified in 6 out of 15 (40%) patients. Conclusion: [68Ga]Ga-DOTA-SST PET/CT can be useful in a restricted and selected group of patients with gastric neuroendocrine neoplasia with relevant risk factors to establish the most appropriate therapeutic strategy.

Autoimmune gastritis induces aberrant DNA methylation reflecting its carcinogenic potential

BACKGROUND

Autoimmune gastritis (AIG) is a chronic inflammatory condition in gastric mucosa and is associated with increased cancer risk, though not as high as that by Helicobacter pylori (H. pylori)-associated gastritis (HPG). Although aberrant DNA methylation is induced by HPG and the level correlates with the risk of gastric cancer, DNA methylation induction by AIG is unknown.

METHODS

Gastric mucosa samples from the corpus were collected from 12 people with AIG without H. pylori infection, 10 people with HPG, and eight healthy volunteers. Genome-wide DNA methylation analysis was conducted using Infinium Methylation EPIC array. Gene expression was analyzed by quantitative RT-PCR.

RESULTS

The AIG samples had extensive aberrant DNA methylation but presented unique methylation profiles against the HPG samples after correction of leucocyte fractions. Comparison between the AIG and HPG samples showed that AIG induced methylation, but less than HPG, in overall CpG sites and also in promoter CpG islands. Promoter CpG islands of tumor-suppressor genes in the pathway of cell cycle, cell adhesion, p53, and WNT were highly methylated in the AIG samples, but more so in the HPG samples. The expression levels of IL1B and IL8, secreted by macrophage, were significantly lower in the AIG samples than in the HPG samples, suggesting that a difference in inflammatory response affected the degree and patterns of aberrant DNA methylation.

CONCLUSIONS

AIG induced aberrant DNA methylation in gastric mucosa. However, the degree of DNA methylation was less than that by HPG, which reflected carcinogenic risk.

Selective Resection of Type 1 Gastric Neuroendocrine Neoplasms and the Risk of Progression in an Endoscopic Surveillance Programme

BACKGROUND

Current guidance for type 1 gastric neuroendocrine neoplasms (gNENs) recommends either resection of all visible lesions or selective resection of gNENs >10 mm. We adopt a selective strategy targeting lesions approaching 10 mm for endoscopic mucosal resection (EMR) and provide surveillance for smaller lesions.

OBJECTIVES

This study aimed to describe the incidence of type 1 gNENs requiring endoscopic/surgical resection and the risk of disease progression (both considered significant disease) on endoscopic surveillance. The secondary objective was to assess the risk factors for disease progression during surveillance and the incidence of gastric dysplasia/adenoma/adenocarcinoma.

METHODS

We collected consecutive patients with type 1 gNENs and obtained demographic and clinical data through the electronic patient record.

RESULTS

In our cohort of 57 patients, 12 patients had EMR at index gastroscopy; 7 patients had surgery (4: large/multiple gNENs and 3: nodal metastases) (5.2% [3/57] risk of nodal metastases); and a patient with nodal and liver metastases (1.8% [1/57] risk of distant metastases). The prevalence of gastric adenocarcinoma in our study was 3.5% with an incidence rate of 9.59 per 1,000 persons per year. For patients undergoing surveillance, 29.5% (13/44) of patients progressed requiring resection. Serum gastrin was significantly higher in patients who progressed to resection (p value = 0.023).

CONCLUSION

We concluded that up to a third of patients with type 1 gNENs have significant disease requiring resection. Hence, endoscopic surveillance and resect strategy would benefit patients.

Towards Understanding of Gastric Cancer Based upon Physiological Role of Gastrin and ECL Cells

Simple Summary

Generally, we know that cancers represent genetic changes in tumour cells, but we most often do not know the causes of cancers or how they develop. Our knowledge of the regulation of gastric acid secretion is well known, with the gastric hormone gastrin maintaining gastric acidity by stimulation of the enterochromaffin-like (ECL) cell to release histamine, which subsequently augments acid secretion. Furthermore, it seems to be a general principle that stimulation of function (which, for the ECL cell, is release of histamine) in a parallel way stimulates the proliferation of the same cell. Long-term hyperstimulation of cell division predisposes to genetic changes and, thus, development of tumours. All conditions with reduced gastric acidity result in an increased risk of gastric tumours due to elevated gastrin in order to restore gastric acidity. It is probable that Helicobacter pylori infection (the most important cause of gastric cancer), as well as drugs inhibiting gastric acid secretion induce gastric cancer in the long-term, due to an elevation of gastrin caused by reduced gastric acidity. Gastric carcinomas have been shown to express ECL cell markers, further strengthening this relationship.

Abstract

The stomach is an ideal organ to study because the gastric juice kills most of the swallowed microbes and, thus, creates rather similar milieu among individuals. Combined with a rather easy access to gastric juice, gastric physiology was among the first areas to be studied. During the last century, a rather complete understanding of the regulation of gastric acidity was obtained, establishing the central role of gastrin and the histamine producing enterochromaffin-like (ECL) cell. Similarly, the close connection between regulation of function and proliferation became evident, and, furthermore, that chronic overstimulation of a cell with the ability to proliferate, results in tumour formation. The ECL cell has long been acknowledged to give rise to neuroendocrine tumours (NETs), but not to play any role in carcinogenesis of gastric adenocarcinomas. However, when examining human gastric adenocarcinomas with the best methods presently available (immunohistochemistry with increased sensitivity and in-situ hybridization), it became clear that many of these cancers expressed neuroendocrine markers, suggesting that some of these tumours were of neuroendocrine, and more specifically, ECL cell origin. Thus, the ECL cell and its main regulator, gastrin, are central in human gastric carcinogenesis, which make new possibilities in prevention, prophylaxis, and treatment of this cancer.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Autoimmune metaplastic atrophic gastritis and association with neuroendocrine tumors of the stomach

Autoimmune metaplastic atrophic gastritis (AMAG) previously called type A chronic gastritis is an immune-mediated chronic inflammatory disease characterized by the immune-mediated destruction of gastric parietal cells in the fundus and body of the stomach. AMAG is an uncommon disease that often presents with hematological manifestations and may lead to the development of gastric carcinoids. AMAG can be reliably diagnosed by antibody assays, functional serology, and histology. The understanding of the disease process is essential for the detection and management of hematological complications and gastric lesions. The prevalence of AMAG is on the rise and subsequently gastric carcinoids. However, this association is not well recognized in clinical practice, and management and diagnosis of AMAG and gastric carcinoids remain suboptimal. In the current review, we will discuss the pathophysiology, diagnosis and management of AMAG. A special focus is given to the association between AMAG and gastric carcinoids. We will also review the management options of type 1 gastric carcinoids.

Synchronous Early Gastric Cancer/Neuroendocrine Tumor Associated with Autoimmune Gastritis Completely Resected with Endoscopic Submucosal Dissection

Synchronous early gastric cancer/neuroendocrine tumor (NET) associated with autoimmune gastritis is rare, and its endoscopic and pathological features remain poorly described. Screening esophagogastroduodenoscopy performed on a 71-year-old man revealed a whitish, superficial elevated lesion and a submucosal tumor with redness that appeared slightly centrally depressed. Endoscopic submucosal dissection (ESD) allowed these lesions to be resected with negative margins, and they were diagnosed as tubular adenocarcinoma, well-differentiated type (tub1), pT1a (M) and NET G1, pT1b (SM). To our knowledge, this is the first report describing the endoscopic and pathological findings of synchronous early gastric cancer/NET that was amenable to complete resection with ESD.

Gastric neuroendocrine neoplasias: manifestations and comparative outcomes

Although gastric neuroendocrine neoplasias (gNEN) are an orphan disease, their incidence is rising. The heterogeneous clinical course powers the ongoing discussion of the most appropriate classification system and management. Prognostic relevance of proposed classifications was retrospectively analysed in 142 patients from a single tertiary referral centre. Baseline, management and survival data were acquired for statistical analyses. The distribution according to the clinicopathological typification was gNEN-1 (n = 86/60.6%), gNEN-2 (n = 7/4.9%), gNEN-3 (n = 24/16.9%) and gNEN-4 (n = 25/17.6%), while hypergastrinemia-associated gNEN-1 and -2 were all low-grade tumours (NET-G1/2), formerly termed sporadic gNEN-3 could be subdivided into gNEN-3 with grade 1 or 2 and gNEN-4 with grade 3 (NEC-G3). During follow-up 36 patients died (25%). The mean overall survival (OS) of all gNEN was 14.2 years. The OS differed statistically significant across all subgroups with either classification system. According to UICC 2017 TNM classification, OS differed for early and advanced stages, while WHO grading indicated poorer prognosis for NEC-G3. Cox regression analysis confirmed the independent prognostic validity of either classification system for survival. Particularly careful analysis of the clinical course of gNEN-1 (ECLomas, gastric carcinoids) confirmed their mostly benign, but recurrent and extremely slowly progressive behaviour with low risk of metastasis (7%) and an efficient long-term control by repetitive endoscopic procedures. Our study provides evidence for the validity of current classifications focusing on typing, grading and staging. These are crucial tools for risk stratification, especially to differentiate gNEN-1 as well as sporadic gNET and gNEC (gNEN-3 vs -4).

Gastric cancer and gastrin: on the interaction of Helicobacter pylori gastritis and acid inhibitory induced hypergastrinemia

Gastric cancer, a disease with a reduced frequency for decades, now appears to be on the rise again in young Americans. The epidemiology of gastric cancer differs between tumors in the cardia and those of the more distal parts of the stomach. The tumors are divided into the intestinal type showing glandular growth pattern and the diffuse type with a different pattern. The latter often expresses neuroendocrine and more specifically ECL-cell markers suggesting that they originate from the ECL cell, the target cell for the antral hormone, gastrin. Helicobacter pylori gastritis is accepted as the major cause of gastric cancer, but only after having induced oxyntic atrophy which reduces gastric acid secretion and thus induces hypoacidity leading to hypergastrinemia. Long-term hypergastrinemia is known to induce malignant neoplasia in the stomach of animals as well as man. Recently treatment with proton pump inhibitor after Helicobacter pylori eradication in patients with gastroesophageal reflux disease, has been reported to predispose to gastric cancer. Since profound acid inhibition is a well-known cause of gastric neoplasia, it is to be expected that Helicobacter pylori infection and profound acid inhibition has an additive or possibly potentiating effect on the development of gastric cancer.

Neuroendocrine Gastroenteropancreatic Tumors: Where Are We?

AIMS

Neuroendocrine gastroenteropancreatic tumors are infrequently found neoplasms. Our objective was to analyze the survival rates for all sites that they occur in by studying different variables.

MATERIALS AND METHODS

A retrospective study was carried out using records for a 7-year period from January 1, 2008 to December 31, 2014 on neuroendocrine gastroenteropancreatic tumors patients diagnosed at the Pontevedra-Salnés Hospital Complex. The variables used were as follows: age at diagnosis, tumor size, presence or absence of metastases at diagnosis, cell proliferation index, Ki-67 of each tumor, treatments received, postdiagnosis survival time, existence or not of tumor progression, and time from diagnosis to progression and from diagnosis to mortality. In relation to treatments, the information recorded was whether the treatment was endoscopic, surgical, or pharmacological.

RESULTS

Ninety-three neuroendocrine tumors made up a ratio of 4.42 cases per 100,000 inhabitants per annum. The median patient follow-up time was 44 months. The overall 5-year survival rate for patients who were followed up for a minimum of 60 months (49 patients) was 65.3%. The progression-free survival was 75.6% for 41 patients who were followed up for a minimum of 60 months. The survival rate for patients receiving endoscopic treatment was 100%, as there was no patient mortality recorded for those treated by endoscopic resection during the follow-up period.

CONCLUSION

Pancreatic neuroendocrine tumors may be managed conservatively in elderly patients by either monitoring them with imaging studies or treating them with somatostatin analogs. In the case of digestive tract tumors (stomach, duodenum, and rectum) that meet the criteria for endoscopic resection, this is a reliable and safe technique in the long term.

Cost of detecting gastric neoplasia by surveillance endoscopy in atrophic gastritis in Italy: A low risk country

BACKGROUND

Atrophic gastritis (AG) is at increased risk of gastric neoplasia, thus surveillance gastroscopy has been proposed.

AIMS

To assess cost of detecting gastric neoplasias by surveillance endoscopy according to identified risk factors in Italy.

METHODS

Post-hoc analysis of a cohort study including 200 AG-patients from Italy followed up for a mean of 7.5 (4-23.4) years was done. Considered risk factors were: age >50years, extensive atrophy, pernicious anaemia, OLGA-OLGIM scores 3-4 at diagnosis. The number of 4-year-surveillance endoscopies needed to be performed to detect one gastric neoplasia (NNS) was calculated.

RESULTS

In 19 patients neoplasias (4 gastric cancers, 8 type 1 gastric carcinoids, 7 dysplasias) were detected at the 361 surveillance gastroscopies, corresponding to NNS of 19 and a cost per gastric neoplastic lesion of €2945. By restricting surveillance to pernicious anaemia patients, reduction of NNS and cost per neoplasia to 13.8 and €2139 may be obtained still detecting 74% of neoplasias. By limiting the surveillance to pernicious anaemia patients and OLGA 3-4, 5 (26.3%) neoplasias would have been detected with a corresponding NNS of 5.4 and a cost per lesion of €837.

CONCLUSION

Risk factors may allow an efficient allocation of financial and medical resources for endoscopic surveillance in AG in a low risk country.

Thyro-gastric autoimmunity in patients with differentiated thyroid cancer: a prospective study

Thyro-gastric autoimmunity has not been previously evaluated in patients with differentiated thyroid cancer (DTC), although its long-term complications may be relevant for the management of DTC patients. We assessed the prevalence of gastric autoimmunity and autoimmune gastritis (AG) in patients with Hashimoto's thyroiditis (HT) and concomitant DTC. Prevalence of parietal cell antibody (PCA) positivity, iron deficiency anemia (IDA), and pernicious anemia (PA) were prospectively assessed in 150 DTC patients referred for radioiodine ablation after total thyroidectomy. Patients were classified as HT (n = 31) and non-HT (n = 119) based on a combination of serological, ultrasonographic, and histological findings. Patients with PCA positivity were subsequently addressed to endoscopy for confirmation of atrophy body gastritis, required for the diagnosis of AG. For all the variables under study, a comparison between groups was made using Fisher's exact test and appropriate parametric and non-parametric tests. PCA positivity was significantly more prevalent in HT than in non-HT patients (12.9 vs 1.6 %, p = 0.017). After Hp eradication, a reversal of PCA positivity was observed in 3/4 patients in the HT group. IDA and PA did not differ significantly between groups. In the HT group, only one patient had endoscopical confirmation of mild gastric corporal atrophy. Gastric autoimmunity shows higher prevalence in patients with DTC and concomitant HT than in patients with DTC alone; however, in most cases, PCA positivity was associated with Hp infection. Furthermore, although previous reports found up to one-third of patients with HT to have associated AG, in our cohort AG was extremely rare.

Pernicious anemia. From past to present

Pernicious anemia is currently the most common cause of vitamin B12 deficiency in Western countries. The histological lesion upon which this condition is based is autoimmune chronic atrophic gastritis. The destruction of parietal cells causes a deficiency in intrinsic factor, an essential protein for vitamin B12 absorption in the terminal ileum. Advances in the last two decades have reopened the debate on a disease that seemed to have been forgotten due to its apparent simplicity. The new role of H. pylori, the value of parietal cell antibodies and intrinsic factor antibodies, the true usefulness of serum vitamin B12 levels, the risk of adenocarcinoma and gastric carcinoids and oral vitamin B12 treatment are just some of the current issues analyzed in depth in this review.