Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

A real-world study on the characteristics of autoimmune gastritis: A single-center retrospective cohort in China

BACKGROUND AND AIM

Autoimmune gastritis (AIG) was previously considered a rare disease in China, and its clinical characteristics were not fully understood. This study aimed to demonstrate the characteristics of AIG in China and evaluate gastric oxyntic mucosal atrophy using a modified AIG-atrophic staging.

METHODS

This was a single-center retrospective observational real-world study. The diagnosis of AIG was based on pathological results combined with parietal cell antibody (PCA) and intrinsic factor antibody (IFA) results, and endoscopic findings.

RESULTS

A total of 745 patients were enrolled, the median age at diagnosis was 58 years old, and 69.9 % were female. The symptoms of AIG patients were nonspecific, and about 2/5 of the cases were asymptomatic. The proportions of cases from modified AIG-atrophic stage 1 to 4 were 0.8 %, 14.1 %, 73.8 %, and 11.3 %, respectively. Approximately 1/5 had autoimmune thyroiditis (AITD). Near 1/2 had one or more comorbidities: iron-deficiency anemia (IDA), pernicious anemia (PA), neuropathy, gastric hyperplastic polyps (GHP), gastric intraepithelial neoplasia (GIN), type 1 gastric neuroendocrine tumors (g-NET), or gastric adenocarcinoma (GAC). There was a high risk of type 1 g-NET (7.0 %) and GAC (9.1 %) in AIG patients.

CONCLUSIONS

AIG is not rare in China, and its early diagnosis is challenging, accompanied by a high risk of GAC. The modified four-stage AIG-atrophic staging can effectively represent the extent of oxyntic mucosal atrophy and the progression in AIG.

TPOAb indicates neuroendocrine tumor in autoimmune gastritis: A retrospective study of 91 patients

BACKGROUND

The association between serological indexes and occurrence of complications in patients with autoimmune gastritis (AIG) remains unclear.

METHODS

91 patients with AIG were recruited and their clinical information were collected. The differences between serological indexes and complications of AIG were analyzed. And potential biomarker for early prediction and diagnosis of AIG with complications was explored.

RESULTS

AIG patients in our study was 58.12 ± 11.68 years old, containing 31 males and 60 females. G17 was elevated in 49 of 52; PGI/II decreased in 43/49; GPA positive in 48/61; Anemia presented 28 in 80; Vitamin B12 deficiency occurred 23 in 58. Neuroendocrine tumor (NET) was the most common complication in AIG patients, accounting for 27/91. The second was polyps, making up for 14/91. There is also 9/91 of gastric mucosa neoplasia happened in AIG. No significant difference of G7, PGI, PGII, PGI/II and VB12 in AIG was found in different gastric mucosal lesions (P > 0.05). However, AIG patients with TPOAb positive had a higher risk in the occurrence of NET simultaneously (P = 0.0212). Those AIG with NET patients exhibited a significantly higher TPOAb level (P = 0.0078). ROC curve suggested that TPOAb can predict the existence of NET in AIG (AUC = 0.7410, P < 0.05).

CONCLUSION

We found that TPOAb can serve as a predictive biomarker of NET in AIG. This accessible test is helpful for endoscopy specialists to pay attention to gastric mucosal lesions in TPOAb-positive AIG patients, improving early diagnosis and intervention of comorbidities ability.

Autoimmune gastritis diagnosed due to recurrent gastric neuroendocrine tumor: a case report

As digestive endoscopy becomes more prevalent, an increasing number of autoimmune gastritis (AIG) cases have been diagnosed, which has contributed to a growing body of research on AIG. We report the case of a patient with AIG who was diagnosed due to receiving endoscopic surgery after discovering a gastric neuroendocrine tumor (GNET) during gastroscopy twice within 3 years. The patient was admitted to our hospital for endoscopic submucosal dissection (ESD) due to GNET recurrence discovered during gastroscopy. The patient had previously undergone ESD due to a GNET discovered during gastroscopy 3 years ago. Recent repeat gastroscopy revealed severe mucosal atrophy in the gastric body and fundus, an ulcer in the gastric antral, and two mucosal bulges in the gastric body. Pathology indicated Grade 2 (G2)-GNET, and ESD was performed again. The patient also had iron deficiency anemia and thyroid dysfunction, elevated gastrin, and decreased pepsinogen I (PG I) and PG I/II. Hence, AIG was diagnosed. Recurrent GNET cases, especially those with concurrent anemia and abnormal thyroid function, may experience AIG. In addition to symptomatic treatment, the clinician must evaluate the patient's overall condition.

Occurrence and characteristics of endoscopic gastric polyps in patients with autoimmune gastritis (AGAPE study): A multicentric cross-sectional study

BACKGROUND

Autoimmune gastritis (AIG) leads to increased gastrin (G) levels due to hypo-achlorhydria, providing proliferative stimuli on the gastric mucosa.

AIMS

To evaluate the incidence and characteristics of gastric polyps in AIG patients across six tertiary centers in Italy.

METHODS

A multicentric, cross-sectional study enrolled patients with AIG diagnosed from January 2000 to June 2023, who underwent at least one endoscopy. Data on demographics, clinical history, biochemical profiles, and endoscopic and histopathological findings were systematically collected.

RESULTS

Among 612 AIG patients followed for a median of 4 years, 222 (36.3 %) developed at least one gastric polyp. Of these, 214 were non-endocrine lesions detected in 162 patients, including 151 inflammatory (70.5 %), 29 adenomatous (13.6 %), 18 fundic gland polyps (8.4 %), 13 adenocarcinomas (6.1 %), and one MALT lymphoma. Additionally, 108 patients had gastric neuroendocrine neoplasms (gNENs), with 48 also having non-endocrine polyps. Older age and higher gastrin and chromogranin A levels were associated with polyp occurrence. No differences in OLGA/OLGIM stages or Helicobacter pylori status were noted among patients with and without lesions.

CONCLUSION

This large multicentric study underscores the substantial occurrence of gastric polyps in AIG patients, including notable rates of gNENs and adenocarcinomas, emphasizing the importance of proactive endoscopic surveillance and histopathological examination for effective management.

A systematic review of gastritis as an immune-related adverse event in clinical interventions

Immune checkpoint inhibitors (ICIs) are crucial in cancer treatment, and the associated immune-related adverse events (irAEs) have garnered significant attention, yet reports on associated immune related gastritis are limited. The diagnosis of immune related gastritis remains predominantly exclusionary, meanwhile its management diverges significantly from that of conventional gastritis. Current guidelines lack standardized grading criteria, and substantial data from large-scale, tertiary clinical studies are absent, therefore we conducted a systematic review of Medline, Web of Science, and Embase databases, identifying 31 articles from 2017 to December 31, 2023, involving 258 patients. Clinical manifestations included epigastric pain (53.1%), mucosal erythema (56.1%), and lymphocyte infiltration (48.6%). Corticosteroid therapy was common (94.7%), with 86.7% experiencing post-treatment improvement. 80% of patients can be diagnosed through endoscopy and pathology, while the remaining 20% may require PET-CT. Hormonal therapy is favored but diverges from standard management. Accurate diagnosis is crucial in managing immune related gastritis effectively.

Distinguishing Features of Autoimmune Gastritis Depending on Previous Helicobacter pylori Infection or Positivity to Anti-Parietal Cell Antibodies: Results From the Autoimmune gastRitis Italian netwOrk Study grOup (ARIOSO)

INTRODUCTION

To describe the clinical features and the risk of developing gastric tumors in patients with autoimmune gastritis (AIG).

METHODS

This was a retrospective, longitudinal, multicenter study conducted at 8 Italian tertiary referral centers. We retrieved clinical data from all histologically proven patients with AIG. Differences between Helicobacter pylori -exposed vs H. pylori -naive and anti-parietal cell antibody (PCA)-positive vs PCA-negative patients were investigated. The rate of gastric adenocarcinoma and type 1 gastric neuroendocrine neoplasm (gNEN) was assessed. A multivariable model for factors associated with gNEN was fitted.

RESULTS

A total of 1,598 patients with AIG (median age 58 years, interquartile range 46-68; F:M ratio 2.7:1) were included. H. pylori -naive patients were more likely to have a first-degree family history of AIG (14.7% vs 8.9%; P = 0.012), type 1 diabetes mellitus (4.9% vs 2.3%; P = 0.025), and pernicious anemia (30.9% vs 21.1%; P = 0.003). PCA-positive patients had significantly more associated autoimmune diseases (59.0% vs 42.9%; P < 0.001) and were more likely to have been diagnosed by a case-finding strategy (15.3% vs 2.6%; P < 0.001). Overall, 15 cases (0.9%) of gastric adenocarcinoma and 153 cases (9.6%) of gNEN occurred, with a global rate of 0.12 (95% confidence interval [CI] 0.07-0.20) and 1.22 (95% CI 1.03-1.42) per 100 person/year, respectively. Having a vitamin B12/iron deficiency manifestation at AIG diagnosis was associated with a 16.44 (95% CI 9.94-27.20 P < 0.001) hazard ratio of gNEN.

DISCUSSION

The "pure" AIG pattern has typical features of an autoimmune disease and seems to be unrelated to H. pylori . In a tertiary referral setting, the risk of developing overt gastric adenocarcinoma is low, while patients with vitamin B12 deficiency complications at onset may benefit from a more intense endoscopic follow-up for early gNEN detection.

Gastric Neuroendocrine Tumors and Pernicious Anemia: A Case Report and Literature Review

Gastrointestinal neuroendocrine tumors (GI-NETs) are rare neoplasms, with the gastric (stomach) subtype (G-NETs) representing a significant clinical focus. Type 1 G-NETs are particularly noteworthy due to their relationship with autoimmune atrophic gastritis (AAG) and pernicious anemia (PA), conditions that impact vitamin B12 absorption. This report presents the case of a patient with a type 1 G-NET identified at the initial diagnosis of PA, demonstrating the connection between these conditions. In the literature review, we discuss the general mechanisms underlying PA, including its etiology, pathogenesis, clinical presentations, and diagnostic approaches. Emphasis is placed on the importance of recognizing and diagnosing this condition early, given the treatable nature of the associated gastric neuroendocrine dysregulation. Additionally, the report examines the broad spectrum of G-NETs, with a special emphasis on the characteristics of type 1 tumors. By considering recent developments in the field, we provide an overview of the current understanding of G-NET epidemiology, classification, clinical features, diagnosis, and management strategies.

Autoimmune gastritis studies and gastric cancer: True renaissance or bibliometric illusion

A bibliometric analysis of studies dedicated to autoimmune gastritis (AIG) recently published demonstrated a noteworthy surge in publications over the last three years. This can be explained by numerous publications from different regions of the world reporting the results of several studies that stimulated reassessment of our view of AIG as a precancerous condition. Follow-up studies and retrospective analyses showed that the risk of gastric cancer (GC) in AIG patients is much lower than expected if the patients ever being infected with Helicobacter pylori (H. pylori) were excluded. The low prevalence of precancerous lesions, such as the incomplete type of intestinal metaplasia, may explain the low risk of GC in AIG patients because the spasmolytic polypeptide-expressing metaplasia commonly observed in AIG does not involve clonal reprogramming of the gastric gland and can be considered as an adaptive change rather than a true precancerous lesion. However, changes in gastric secretion due to the progression of gastric atrophy during the course of AIG cause changes in the gastric mic-robiome, stimulating the growth of bacterial species such as streptococci, which may promote the development of precancerous lesions and GC. Thus, Streptococcus anginosus exhibited a robust proinflammatory response and induced the gastritis-atrophy-metaplasia-dysplasia sequence in mice, reproducing the well-established process for carcinogenesis associated with H. pylori. Prospective studies in H. pylori-naïve patients evaluating gastric microbiome changes during the long-term course of AIG might provide an explanation for the enigmatic increase in GC incidence in the last decades in younger cohorts, which has been reported in economically developed countries.

Laparoscopic total gastrectomy for multiple type І gastric neuroendocrine tumours: a case report

Background. The gastric neuroendocrine tumours (G-NETs), arising from neuroendocrine cells within the stomach. Type I lesions are associated with chronic atrophic gastritis (CAG). Multiple G-NETs are rare. Purpose – of our report is to describe a rare case of multiple Type-I G-NETs. Material and methods. During routine gastroscopy in a 44-year-old female with history of CAG and anaemia, multiple (15–20) polyps of size 2–9 mm were found. Multiple biopsies were obtained. Histopathological examination with haematoxylin and eosin staining described these lesions as undifferentiated cancer. Repeated gastroscopy was done. The three biggest polyps (5–9 mm) were removed by snare polypectomy. Repeated histopathological examination was specific for G-NET. The neoplasm presented Ki-67 proliferation index of < 3%; Cytokeratin 18, Chromogranin A, Synaptophysin, INSM1 were positive in neoplasm cells. Laparoscopic total gastrectomy was done. The operative time was 255 min, and the blood loss was 50 ml. Histopathological examination of a surgical specimen revealed multiple, Grade 1 G-NET (fig. 1–3). All lesions are limited to the mucosa and submucosa of the stomach, the longest size of the largest tumour lesion is 5 mm, what corresponds to pT1(m). No signs of lymphovascular or perineural invasion were found (L0 V0 Pn0). 18 regional lymph nodes were examined, no metastases were detected (0/18, pN0). Edges of resections of the esophagus and duodenum without signs of tumour growth (R0). Outside of tumours, there were signs of chronic inflammation of the stomach mucosa, with intestinal metaplasia and mixed glandular atrophy, there are also foci of nodular hyperplasia of neuroendocrine cells. Conclusion. We reported a rare case of multiple type-I G-NETs (pT1N0M0) with pernicious anaemia due to autoimmune CAG. Laparoscopic total gastrectomy is a method of choice in treatment of such patients.

Autoimmune Gastritis and Hypochlorhydria: Known Concepts from a New Perspective

Autoimmune atrophic gastritis is an immune-mediated disease resulting in autoimmune destruction of the specialized acid-producing gastric parietal cells. As a consequence, in autoimmune atrophic gastritis, gastric acid secretion is irreversibly impaired, and the resulting hypochlorhydria leads to the main clinical manifestations and is linked, directly or indirectly, to the long-term neoplastic complications of this disease. In the last few years, autoimmune atrophic gastritis has gained growing interest leading to the acquisition of new knowledge on different aspects of this disorder. Although reliable serological biomarkers are available and gastrointestinal endoscopy techniques have substantially evolved, the diagnosis of autoimmune atrophic gastritis is still affected by a considerable delay and relies on histopathological assessment of gastric biopsies. One of the reasons for the diagnostic delay is that the clinical presentations of autoimmune atrophic gastritis giving rise to clinical suspicion are very different, ranging from hematological to neurological-psychiatric up to gastrointestinal and less commonly to gynecological-obstetric symptoms or signs. Therefore, patients with autoimmune atrophic gastritis often seek advice from physicians of other medical specialties than gastroenterologists, thus underlining the need for increased awareness of this disease in a broad medical and scientific community.

Causal inference between pernicious anemia and cancers: a bidirectional two-sample mendelian randomization analysis

BACKGROUND

Observational study investigated the association between pernicious anemia (PA) and cancers. However, with the exception of gastric cancer, the results are mostly contradictory. The purpose of this study was to investigate the potential causal relationship between PA and cancers through bidirectional two-sample Mendelian randomized (MR) analysis.

METHODS

The European sample FinnGen project provided the genetic summary data for PA and 20 site-specific cancers. This bidirectional two-sample MR design mainly used the inverse variance weighting (IVW) method to evaluate the causal relationship between PA and cancer risk. Benjamini-Hochberg correction was performed to reduce the bias caused by multiple tests.

RESULTS

Our study shows that there was a causal relationship between PA and gastric cancer, prostate cancer, testicular cancer and malignant melanoma of skin, and there was a reverse causal relationship between prostate cancer or gastric cancer and PA (P < 0.05). After Benjamini-Hochberg correction test, there was still a causal correlation between PA and gastric or prostate cancer (P' < 0.05), while there was only an implied causal association between PA and testicular cancer and malignant melanoma of skin (P'> 0.05). There was still a reverse causal relationship between gastric cancer and PA (P'< 0.05), while prostate cancer shows an implied reverse causal relationship(P'> 0.05). In addition, MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy.

CONCLUSIONS

PA may be genetically associated with testicular cancer, prostate cancer, gastric cancer, and malignant melanoma of skin.

Differential Diagnoses and Management Approaches for Gastric Polyposis

Multiple gastric polyps are observed in various polyposis syndromes and conditions associated with polypoid lesion development in the stomach. Polyposis syndromes often occur concurrently with specific malignant tumors and can manifest at any point in an individual’s lifespan, thus explaining the diversity in surveillance methods. Furthermore, genetic counseling and surveillance are essential not only for the patients themselves but also for their blood relatives. Therefore, the accurate diagnosis and appropriate surveillance of multiple gastric polyps are crucial for improving patient outcomes. This review aims to provide essential information on such lesions along with representative endoscopic images of familial adenomatous polyposis, Peutz-Jeghers syndrome, Cowden syndrome, Cronkhite-Canada syndrome, juvenile polyposis syndrome, gastric adenocarcinoma and proximal polyposis of the stomach, neuroendocrine tumors in autoimmune gastritis, proton pump inhibitor-related gastric mucosal changes, and multiple submucosal heterotopic glands. We wish for this review to serve as a valuable resource for endoscopists seeking to deepen their comprehension of gastric polyposis.