Carcinoid tumors of the stomach

Gallbladder Neuroendocrine Neoplasms in Dogs and Humans

Gallbladder neuroendocrine neoplasms (GB NENs) are among the rarest cancers reported in humans and dogs. This review provides a detailed review of the canine GB NEN literature and an interspecies comparison of demographics, clinical pathophysiology, pathobiology, and therapeutic response of GB NENs. The aim of this work is to explore the relevance of dogs as a spontaneous model for human GB NENs.

Clinicopathological characteristics of gastric neuroendocrine neoplasms: A comprehensive analysis

OBJECTIVE

This study aimed to explore the clinicopathological characteristics and prognostic implications of gastric neuroendocrine neoplasms (g-NENs).

METHODS

A retrospective enrollment of 142 patients diagnosed with g-NENs was conducted at Zhejiang Cancer Hospital between January 1, 2007 and December 31, 2021. The study compared essential clinicopathological features and survival rates. Additionally, the prognosis of gastric neuroendocrine carcinomas/mixed neuroendocrine-non-neuroendocrine neoplasms (g-NEC/MiNEN) were contrasted with those of gastric adenocarcinoma (GAC) and signet ring cell carcinoma (SRCC).

RESULTS

The study comprised a total of 142 g-NENs cases, with a male-to-female ratio of approximately 2:1. The 5-year survival rates for g-NEC and g-MiNEN were 26.7% and 35.2%, respectively. Corresponding 5-year survival rates for G1 and G2 were observed at 100% and 80.0%, respectively. g-NEC/MiNEN showed a significantly worse prognosis compared to g-NET (p < 0.001). g-NEC/MiNEN exhibited a poor prognosis compared to GAC (p < 0.001), and within poorly differentiated GAC, g-NEC/MiNEN demonstrated a worse prognosis (p = 0.007). Additionally, patients receiving postoperative adjuvant therapy exhibited notably prolonged overall survival (OS) in the case of g-NEC/MiNEN (p = 0.010).

CONCLUSION

In short, the prognosis of g-NEC/MiNEN was worse than that of g-NET, GAC and poorly differentiated GAC, but this group benefit from postoperative adjuvant therapy.

Resistant gastroenteropancreatic neuroendocrine tumors: a definition and guideline to medical and surgical management

Gastroenteropancreatic neuroendocrine tumors (NETs), also historically known as carcinoids, are tumors derived of hormone-secreting enteroendocrine cells. Carcinoids may be found in the esophagus, stomach, small intestine, appendix, colon, rectum, or pancreas. The biologic behavior of carcinoids differs based on their location, with gastric and appendiceal NETs among the least aggressive and small intestinal and pancreatic NETs among the most aggressive. Ultimately, however, biologic behavior is most heavily influenced by tumor grade. The incidence of NETs has increased by 6.4 times over the past 40 years. Surgery remains the mainstay for management of most carcinoids. Medical management, however, is a useful adjunct and/or definitive therapy in patients with symptomatic functional carcinoids, in patients with unresectable or incompletely resected carcinoids, in some cases of recurrent carcinoid, and in postoperative patients to prevent recurrence. Functional tumors with persistent symptoms or progressive metastatic carcinoids despite therapy are called "resistant" tumors. In patients with unresectable disease and/or carcinoid syndrome, an array of medical therapies is available, mainly including somatostatin analogues, molecular-targeted therapy, and peptide receptor radionuclide therapy. Active research is ongoing to identify additional targeted therapies for patients with resistant carcinoids.

Therapeutic Challenges for Gastric Neuroendocrine Neoplasms: Take It or Leave It?

Background and Objectives: Gastric neuroendocrine neoplasms (gNENs) represent rare but increasingly recognized tumors. They are distinguished into three main clinical types (type-1, type-2, and type-3) according to gastrin level and at histological evaluation in well-differentiated G1, G2, or G3 lesions, as well as poorly-differentiated lesions. Small type-1 and type-2 neoplasms with low proliferation indices demonstrated excellent survival without progression during an extended follow-up period, and for these reasons, active endoscopic observation or endoscopic resection are feasible options. On the other hand, surgery is the treatment of choice for more aggressive type-3, G3, or infiltrating neoplasms. The present study aims to comprehensively review and compare the available therapeutic strategies for gNENs. Materials and Methods: A computerized literature search was performed using relevant keywords to identify all of the pertinent articles with particular attention to gNEN endoscopic treatment. Results: In recent years, different endoscopic resective techniques (such as endoscopic mucosal dissection, modified endoscopic mucosal resection, and endoscopic full-thickness resection) have been developed, showing a high rate of complete resection for advanced and more aggressive lesions. Conclusions: Overall, gNENs represent a heterogeneous group of lesions with varying behavior which require personalized management. The non-operative approach for small type-1 gNENs seems to be feasible and should be promoted. A step-up approach with minimally invasive endoscopic therapies might be proposed, particularly for type-1 gNEN. On the other hand, it is important to recognize the negative prognostic factors in order to identify those rare cases requiring more aggressive approaches. A possible therapeutic algorithm for localized gNEN management is provided.

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.

RUNDC3A regulates SNAP25-mediated chemotherapy resistance by binding AKT in gastric neuroendocrine carcinoma (GNEC)

Gastric neuroendocrine carcinoma (GNEC) is a common type of neuroendocrine carcinoma (NEC) with a poor prognosis and limited therapeutic options. The underlying mechanisms of chemoresistance in patients with GNEC and those with NEC are largely unknown, and thus, reliable biomarkers and therapeutic targets that could improve treatment outcomes in patients with NECs are lacking. The aim of this study was to identify specific targets and investigate their roles in GNEC progression and treatment resistance. Differentially expressed genes (DEGs) were identified in GNEC specimens and were further analysed by focusing on their roles in chemoresistance. Gene Ontology (GO) and pathway enrichment analyses of GNEC DEGs revealed that synapse-related function was the most prominent cellular function perturbed in GNEC. SNAP25 was identified as the target gene involved in most of the enriched pathways. In vitro and in vivo experiments showed that SNAP25 plays a role in proliferation and chemoresistance in GNEC cell lines. AKT has been identified as a downstream target, and SNAP25 binds to AKT protein and promotes AKT protein half-life. Further analysis of other types of NEC as well as small cell lung cancer, which resembles NEC on a molecular level, has identified RUNDC3A as an upstream molecule that regulates SNAP25 expression and the associated phenotypes that could enhance chemoresistance in NECs. Our results show that SNAP25 expression in GNEC is mediated by RUNDC3A and promotes GNEC progression and chemoresistance via posttranslational modification of AKT. Thus, our results suggest that the RUNDC3A/SNAP25/Akt axis could be a potential therapeutic target in GNEC.

Long-term surgical outcomes of gastric neuroendocrine carcinoma and mixed neuroendocrine-non-neuroendocrine neoplasms

Background

Neuroendocrine carcinoma (NEC) and mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) are extremely rare subtypes of gastric cancer. MiNEN is a mix of carcinomatous components and neuroendocrine neoplasm in the same lesion. NEC and MiNEN have a poor prognosis, are difficult to diagnose, and have no established treatment. Herein, we assessed the clinicopathological characteristics and long-term surgical outcomes of gastric NEC and MiNEN patients in our hospital.

Methods

We retrospectively assessed 1538 patients pathologically diagnosed with gastric cancer and who underwent curative surgical resection at our institution between January 1999 and October 2021. Of these patients, 25 (1.6%) were pathologically diagnosed with neuroendocrine neoplasms. From these 25 patients, we retrospectively analyzed the clinicopathological characteristics and surgical outcomes of 13 (0.8%) patients pathologically diagnosed with NEC or MiNEN.

Results

The NEC and MiNEN patients consisted of 11 men and 2 women [mean age, 74 (62–84) years]. The preoperative histological diagnoses were NEC (n = 4) and adenocarcinoma (n = 9). The final pathological diagnoses were large cell neuroendocrine carcinoma (LCNEC; n = 7) and MiNEN (n = 6). Total gastrectomy was the most common surgical procedure (9/13, 69.2%), followed by distal gastrectomy (3/13, 23.1%) and proximal gastrectomy (1/13, 7.7%). Immunohistochemical staining showed 8 CD56-positive patients. All 13 patients were positive for chromogranin A and synaptophysin. The mean Ki-67 value was 64.8 (0–95)%, and the mean mitotic score was 107.9 (0–400). Nine patients survived without recurrence postresection. The median postresection overall survival time was 68.7 (8.0–129) months. The 5-year survival rate was 0.75 ([95% CI] 0.408–0.912).

Conclusion

The surgical treatment outcomes of NEC and MiNEN patients were relatively favorable. Although evidence concerning the effectiveness of surgery alone is meager, radical resection as part of multidisciplinary treatment including chemotherapy can potentially improve prognosis.

Expression alteration and dysfunction of ion channels/transporters in the parietal cells induces gastric diffused mucosal injury

Gastric mucosal injuries include focal and diffused injuries, which do and do not change the cell differentiation pattern. Parietal cells loss is related to the occurrence of gastric mucosal diffused injury, with two phenotypes of spasmolytic polypeptide-expressing metaplasia and neuroendocrine cell hyperplasia, which is the basis of gastric cancer and gastric neuroendocrine tumor respectively. Multiple ion channels and transporters are located and expressed in the parietal cells, which is not only regulate the gastric acid-base homeostasis, but also regulate the growth and development of parietal cells. Therefore, alteration and dysregulation of ion channels and transporters in the parietal cells impairs the morphology and physiological functions of stomach, resulted in gastric diffused mucosal damage. In this review, multiple ion channels and transporters in parietal cells, including K⁺ channels, aquaporins, Cl^- channels, Na⁺/H⁺ transporters, and Cl^-/HCO₃^- transporters are described, and their roles in gastric diffused mucosal injury are discussed. We hope to drive researcher's attention to focus on the role of ion channels/transporters loss in the parietal cells induced gastric diffused mucosal injury.

Gastric neuroendocrine neoplasms and precursor lesions: Case reports and literature review

RATIONALE

Gastric neuroendocrine neoplasms (g-NENs) represent a distinctive group of gastric tumors, stratified into different prognostic categories according to different histological characteristics, put forth in the 2018 World Health Organization classification system. The clinical presentations, as well as pathological features, represent important data in establishing the type of the tumor, in estimating the tumor behavior, and in selecting the best therapeutic strategy. In our case series we presented different clinical scenarios that may be encountered in practice regarding gastric NENs. We performed a literature review and discussed diagnostic strategy, current classification system, precursor lesions, and therapeutic options in g-NENs.

PATIENT CONCERNS

The first patient was a 41-year-old female with weight loss, persistent dyspeptic complaints and a history of pernicious anemia. In the second clinical case a 61-year-old man was admitted with heartburn, abdominal pain, diarrhea and mild iron deficiency anemia. The third patient was a 56-year-old male with a history of neoplasia, admitted for weight loss, dyspeptic complaints, and liver metastases.

DIAGNOSIS

All the 3 patients underwent upper endoscopy with targeted biopsies. Histopathological and laboratory evaluation, together with imagistic evaluation (abdominal ultrasound, endoscopic ultrasound, and magnetic resonance imaging) allowed the distinction between 3 different types of gastric tumors: type 1 enterochromaffin-like-cell G1 NET, type 2 enterochromaffin-like-cell G2 NET, and type 3 G2 NET with liver metastases.

INTERVENTIONS

Endoscopic polypectomy of the largest lesion was performed in patient with type 1 g-NET and autoimmune chronic atrophic gastritis, followed by regular endoscopic surveillance with biopsies. In type 2 g-NET associated with pancreatic gastrinoma, pancreaticoduodenectomy with total gastrectomy were performed. In type 3 g-NET, detected in metastatic stage, oncologic therapy was performed.

OUTCOMES

The patients follow-up was selected according to tumor behavior, from regular endoscopic surveillance to oncology follow-up. The prognosis was good in case 1, whilst poorer outcomes were associated with more aggressive tumors in case 2 and case 3.

LESSONS

g-NENs are rare tumors with distinct clinical and histological features. Our case series emphasized the role of close collaboration between clinician and pathologist, as well as the importance of a detailed pathology report.

Management of Other Gastric and Duodenal Neuroendocrine Tumors

Gastric and duodenal neuroendocrine tumors (NETs) are increasing in incidence as a result of increased detection and awareness of neuroendocrine tumors as distinct tumor types. The three types of gastric NETs and duodenal NETs have different etiologies and tumor-specific factors, such as grade, location, and hormone-production, and the clinical settings influence management. Options for treatment include removal by local endoscopic resection and surgical resection. Medical therapy is used to treat the inciting condition or as systemic therapy in advanced disease. Although the overall prognosis for most is good, higher grade tumors behave aggressively and have reduced survival.

Comparison of Endoscopic Techniques in the Management of Type I Gastric Neuroendocrine Neoplasia: A Systematic Review

BACKGROUND

Endoscopic resection is considered the treatment of choice for type I gastric neuroendocrine neoplasia (gNEN) given its indolent behaviour; however, the favoured endoscopic technique to remove these tumours is not well established.

AIMS

This systematic review is aimed at investigating the best endoscopic management for type I gNEN.

METHODS

PubMed Central/Medline and Scopus were systematically searched for records up to August 31, 2020.

RESULTS

After screening the 675 retrieved records, 6 studies were selected for the final analysis. The main endoscopic resection techniques described were endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Overall, 112 gNENs were removed by EMR and 77 by ESD. Both techniques showed similar results for complete and en bloc resection (97.4% and 98.7%; 92.3% and 96.3% with ESD and EMR, respectively). ESD was associated with a higher rate of complications than EMR (11.7% vs. 5.4%), but this difference was not statistically significant (p = 0.17). The rates of recurrence during follow-up were 18.2% and 11.5% for EMR and ESD, respectively.

CONCLUSIONS

To date, there are no sufficient data showing superiority of a given endoscopic technique over others. Both ESD and EMR seem to be effective in the management of type I gNEN, with a relatively low rate of recurrence.

Duodenal, ampullary, and pancreatic neuroendocrine tumors: Oncologic outcomes are driven by tumor biology and tissue of origin

BACKGROUND

Periampullary neuroendocrine tumors (NETs) arise from the duodenum, ampulla, and periampullary pancreas. Duodenal and ampullary NETs are rare and may have distinct biologic behavior from pancreatic NETs (P-NETs). We examined the outcomes of these entities.

METHODS

An institutional database was queried for patients undergoing resection for pancreatic head, duodenal, or ampullary NETs from 2000 to 2018. Patients with MEN1 syndrome or follow up less than 12 months were excluded.

RESULTS

Three hundred and ten patients were identified. Tumor locations were ampulla (n = 15), duodenum (n = 35) and pancreas (n = 260). Median follow-up and recurrence-free survival (RFS) were 60.9 (interquartile range [IQR]: 34.8-99.3) and 171.7 (IQR: 84.0-NR) months. Clinicopathologic data and survival outcomes were similar for duodenal and ampullary NETs (RFS: p = .347 and overall survival [OS]: p = .246) and were combined into an intestinal subtype (IS) group. There were no differences in OS or RFS when comparing IS-NET and P-NET. On multivariate analysis, tissue of origin was not associated with risk of recurrence. The current American Joint Committee on Cancer staging guidelines, which account for origin tissue, were predictive of outcomes for all subtypes.

CONCLUSION

Tissue of origin does not appear to impact long-term outcomes when comparing IS-NETs and P-NETs. The AJCC staging system offers good discriminatory capacity in the context of the tissue type.

Effect of sarcopenia on short- and long-term outcomes in patients with gastric neuroendocrine neoplasms after radical gastrectomy: results from a large, two-institution series

BACKGROUND

The relationship between sarcopenia and the prognoses of patients with gastric neuroendocrine neoplasms (g-NENs) is unclear. This study was designed to explore the effects of sarcopenia on short-term and long-term outcomes of patients with g-NENs after radical gastrectomy.

METHODS

This study retrospectively collected data from 138 patients with g-NENs after radical gastrectomy. The skeletal muscle index (SMI) diagnostic threshold for sarcopenia was determined using X-tile software. Cox regression analyses were performed to determine the independent risk factors for 3-year overall survival (OS) and 3-year recurrence-free survival (RFS).

RESULTS

In this study, 59 patients (42.8%) were diagnosed with sarcopenia. Among patients in the sarcopenia group and nonsarcopenia group, the incidences of total postoperative complications were 33.9 and 30.4%, incidences of serious postoperative complications were 0 and 3.7%, incidences of postoperative surgical complications were 13.6 and 15.2%, and incidences of postoperative systemic complications were 20.3 and 15.2%, respectively (all p > 0.05). The 3-year OS and RFS rates were significantly worse in the sarcopenia group than in the nonsarcopenia group (OS: 42.37% vs 65.82%, p = 0.004; RFS: 52.54% vs 68.35%, p = 0.036). The multivariate analysis revealed a relation between sarcopenia and the long-term prognoses of patients with g-NENs. A stratified analysis based on the pathological type revealed that the Kaplan-Meier curve was only significantly different in patients with gastric mixed adenoneuroendocrine carcinoma (gMANEC) (OS: 40.00% vs 71.79%, p = 0.007; RFS: 51.43% vs 74.36%, p = 0.026); furthermore, the multivariate analysis identified sarcopenia as an independent risk factor for patients with gMANEC (p < 0.05).

CONCLUSIONS

Sarcopenia is not related to the short-term prognoses of patients with g-NENs. Sarcopenia is an independent risk factor for patients with gMANEC after radical surgery.

Exploration of gastric neuroendocrine carcinoma (GNEC) specific signaling pathways involved in chemoresistance via transcriptome and in vitro analysis

Gastric neuroendocrine carcinoma (GNEC) is rare cancer detected in the stomach. Previously, we demonstrated that the poorer prognosis of GNEC patients compared with gastric adenocarcinoma (GAC) patients was probably due to the lack of response to chemotherapy. Thus, it is crucial to study the specific GNEC gene expression pattern and investigate chemoresistance mechanism of GNEC. The transcriptome of GNEC patients was compared with that of GAC patients using RNA-seq. The KEGG analysis was employed to explore the specific differential expression gene function enrichment pattern. In addition, the transcriptomes of two GNEC cell lines, ECC10 and ECC12, were also compared with those of two GAC cell lines, MGC-803 and AGS, using RNA-seq. Comparing patient samples and cell lines transcriptome data, we try to uncover the potential targets and pathways which may affect the chemoresistance of GNEC. By combing all transcriptome data, we identified 22 key genes that were specifically up-regulated in GNEC. This panel of genes probably involves in the chemoresistance of GNEC. From our current experimental data, NeuroD1, one of the 22 genes, is associated with the prognosis of GNEC patients. Knockdown of NeuroD1 enhanced the sensitivity to irinotecan of GNEC cell lines. Our research sheds light in identifying a panel of novel therapeutic target specifically for GNEC clinical treatment which has not been reported before.

The NETest liquid biopsy is diagnostic for gastric neuroendocrine tumors: observations on the blood-based identification of microscopic and macroscopic residual diseaseOK

Background

NETest, a novel multi-gene liquid biopsy has utility in neuroendocrine tumor (NET) diagnosis and identification of residual disease. We independently assessed utility of the NETest to diagnose gastric neuroendocrine neoplasms (GNENs) and identify micro- and macroscopic residual disease.

Methods

Cohorts comprised histologically confirmed GNENs at biopsy, n = 46; GNETs Type 1: 42 (32 NET G1, 10 NET G2), a GNET Type 3: 1 well-differentiated NET G3, neuroendocrine carcinomas (NECs) (n = 3), and controls (n = 63). Disease status at sampling was assessed by gastroscopy, histology (resection margin [R] positivity of polypectomy or biopsy), EUS, CT or MRI, and/or ⁶⁸Ga-DOTA-TATE PET/CT. Groups included image- (gastroscopy, EUS, and anatomical and/or functional imaging) positive or image negative disease. NETest assay by PCR (spotted plates, normal cut-off: 20). Data: mean ± SD.

Results

Disease extent: Image-negative (n = 30) (21 R0, 9 R1); Image-positive, n = 16.

Diagnosis: NETest was increased in GNETs (23 ± 11) vs. controls (7 ± 4, p < 0.0001). In histology-positive, the NETest accuracy was 100% (25/25).

Microscopic disease: In image-negative but R1, NETest was elevated in 100% (9/9; 28 ± 9). Levels were elevated vs. controls (7 ± 4, p < 0.0001), or R0 (16 ± 11, p = 0.02). Eight of 21 R0, exhibited positive NETest.

Macroscopic disease: Gastric lesions were multiple: 38%, single: 62%, submucosal: 13%, or ulcerated: 13%. Lesions size was ≤5 mm (50%), > 5–9.9 mm (17%), 10–19.9 mm (17%), ≥20 mm (17%) [≥10 mm: 34%). The NETest accuracy was 100% (16/16). Levels (28 ± 7) were higher than controls (7 ± 4, p < 0.0001) or R0 (16 ± 11, p = 0.002) but not to R1 (28 ± 9, p = 0.5).

Conclusions

NETest is diagnostic for gastric NETs. Elevated levels identify both microscopic and macroscopic residual disease. In histology/image-negative disease, elevated NETest may reflect early evidence of increased neuroendocrine gene expression of hypergastrinemia-induced neoplastic transformation of enterochromaffin-like (ECL) cells to tumor status. A sensitive liquid biopsy has utility in the management and surveillance of gastric NET disease.

Development and Validation of Prognostic Nomograms for Patients with Duodenal Neuroendocrine Neoplasms

Background

This study was designed to predict prognosis of patients with primary duodenal neuroendocrine neoplasms (D-NENs) by developing nomograms.

Material/Methods

Patients diagnosed with D-NENs between 1988 and 2015 were queried from the SEER database and a total of 965 appropriate cases were randomly separated into the training and validation sets. Kaplan-Meier analysis was used to generated survival curves, and the difference among the groups was assessed by the log-rank test. Independent prognostic indicators were acquired by Cox regression analysis, and were used to develop predictive overall survival (OS) and cancer-specific survival (CSS) nomograms. Harrell’s concordance index (C-index), area under the curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the efficacy of nomograms. Tumor stage was regarded as a benchmark in predicting prognostic compared with the nomograms built in this study.

Results

The C-index was 0.739 (0.690–0.788) and 0.859 (0.802–0.916) for OS and CSS nomograms, respectively. Calibration curves exhibited obvious consistency between the nomograms and the actual observations. In addition, C-index, AUC, and DCA were better than tumor stage in the evaluative performance of nomograms.

Conclusions

The nomograms were able to predict the 1-, 5-, and 10-year OS and CSS for D-NENs patients. The good performance of these nomograms suggest that they can be used for evaluating the prognosis of patients with D-NENs and can facilitate individualized treatment in clinical practice.

Narrow band imaging characteristics of gastric polypoid lesions: a single-center prospective pilot study

INTRODUCTION

Gastric polypoid lesions (GPL) are endoscopic findings whose histological nature is difficult to determine with white-light endoscopy. Hyperplastic polyps (HP), type-1 gastric carcinoids (T1-GC) and adenomas are the most frequent GPL needing different management. Narrow-band imaging (NBI) has high accuracy for gastric malignant lesions but few studies assessed whether GPL display specific NBI characteristics. We aimed to investigate the endoscopic NBI appearances of GPL.

MATERIALS AND METHODS

During gastroscopies, images of GPL were recorded, and lesions were removed for histological evaluation. Two endoscopists blindly reviewed the digital images and registered the endoscopic NBI appearances on a specific check-list. GPL were categorized in HP, adenomas and T1-GC using histology as gold standard.

RESULTS

Overall 52 GPL, observed in 40 patients [F55%; age 63 (36-85) years], were included: 29 (55.8%) HP; 18 (34.6%) T1-GC; 5 (9.6%) adenomas. The median size was seven (2-35) mm. A regular circular mucosal pattern was more frequently observed in HP and T1-GC compared to adenomas (P < 0.001). T1-GC showed a central erosion in 77.8% (P < 0.001 versus HP) with a clear demarcation line in 33.3%. Adenomas had tubule-villous mucosal pattern in 80% (P = 0.01 versus other lesions).

CONCLUSION

NBI analysis of the mucosal pattern seems to be effective to endoscopically discriminate between adenomas and HP while the main characteristic of T1-GC seems to be the presence of a central erosion, sometimes with demarcation line. The endoscopic NBI characterization of GPL may contribute to optimize the management of these lesions.

[Gastric neuroendocrine tumors]

Gastrointestinal neuroendocrine tumors are rare neoplasms. Currently, incidence of gastric neuroendocrine tumors (gNETs) is being significantly increased. There are 3 groups of gNETs: types I, II and III. Each type has important features regarding clinical picture, prognosis and treatment strategy. Type I is the most common (70-80%) and associated with chronic atrophic gastritis including autoimmune gastritis and Helicobacter associated atrophic gastritis. Type II (5-6%) is associated with multiple endocrine neoplasia type I and Zollinger-Ellison syndrome (MEN I - ZES). Both types are characterized by hypergastrinemia and small tumor dimension. These neoplasms are multiple and mostly benign. On the contrary, NETs type III (10-15%) is not associated with hypergastrinemia and represented by single large neoplasms. Tumors are malignant as a rule. Therefore, surgical resection and chemotherapy are preferred for these tumors. Endoscopic surgery followed by observation is acceptable for almost all NETS type I and II. At the same time, this approach is advisable only for small and highly differentiated neoplasms type III.

Response and relapse rates after treatment with long-acting somatostatin analogs in multifocal or recurrent type-1 gastric carcinoids: A systematic review and meta-analysis

BACKGROUND

Type-1 gastric neuroendocrine tumors represent a recurring disease and long-acting somatostatin analogs can inhibit both gastrin release and endocrine cell proliferation. The efficacy and timing of this treatment are still unclear. We performed a systematic review of the literature to clarify the role of somatostatin analog treatment in type-1 gastric neuroendocrine tumors.

METHODS

A computerized literature search was performed using relevant keywords to identify all the pertinent articles published in the last 15 years.

RESULTS

Eight studies were included in this systematic review on somatostatin analogs in type-1 gastric neuroendocrine tumors. A complete response rate ranged from 25-100%. When only the six prospective studies were considered, no significant heterogeneity was observed, and the pooled cumulative complete response rate was 84.5% (confidence interval 73.8-92.8). Three studies evaluated the type-1 gastric neuroendocrine tumor recurrence, with a cumulative relapse rate of 30.2% (confidence interval 13.1-50.6) after 34 months.

CONCLUSION

Somatostatin analogs, namely lanreotide and octreotide, have an excellent response rate, with a good safety profile in selected type-1 gastric neuroendocrine tumors, which cannot be safely managed by endoscopic follow-up or resection due to multiple or frequently recurring disease. After therapy discontinuation, the cumulative relapse rate observed after a median 34-month follow-up was relatively high (30.2%).

Duodenal neuroendocrine tumors: Impact of tumor size and total number of lymph nodes examined

BACKGROUND

The current study sought to investigate the impact of tumor size and total number of LN examined (TNLE) on the incidence of lymph node metastasis (LNM) among patients with duodenal neuroendocrine tumor (dNET).

METHODS

Patients who underwent curative resection for dNETs between 1997-2016 were identified from 8 high-volume US centers. Risk factors associated with overall survival and LNM were identified and the optimal cut-off of TNLE relative to LNM was determined.

RESULTS

Among 162 patients who underwent resection of dNETs, median patient age was 59 (interquartile range [IQR], 51-68) years and median tumor size was 1.2 cm (IQR, 0.7-2.0 cm); a total of 101 (62.3%) patients underwent a concomitant LND at the time of surgery. Utilization of lymphadenectomy (LND) increased relative to tumor size (≤1 cm:52.2% vs 1-2 cm:61.4% vs >2 cm:93.8%; P < .05). Similarly, the incidence of LNM increased with dNET size (≤1 cm: 40.0% vs 1-2 cm:65.7% vs >2 cm:80.0%; P < .05). TNLE ≥ 8 had the highest discriminatory power relative to the incidence of LNM (area under the curve = 0.676). On multivariable analysis, while LNM was not associated with prognosis (hazard ratio [HR] = 0.9; 95% confidence intervals [95%CI], 0.4-2.3), G2/G3 tumor grade was (HR = 1.5; 95%CI, 1.0-2.1).

CONCLUSIONS

While the incidence of LNM directly correlated with tumor size, patients with dNETs ≤ 1 cm had a 40% incidence of LNM. Regional lymphadenectomy of a least 8 LN was needed to stage patients accurately.

Gastric Endocrine Carcinoma: A New Look at a Rare Tumor From Cases in Japan

Objective:

We evaluated the clinicopathologic factors associated with gastric neuroendocrine carcinoma (NEC) in patients who underwent surgical resection. Gastric NEC is rare, accounting for only about 0.6% of all malignant gastric tumors. Neither its pathogenesis nor its treatment has been fully established.

Methods:

We assessed 10 patients with gastric NEC who underwent surgical resection in our hospital between September 2007 and June 2019.

Results:

The patients consisted of 9 men and 1 woman, aged 63 to 78 years. The tumors were localized in the upper region (n = 5), middle region (n = 3), and lower region (n = 2). The macroscopic types were evaluated as 0-IIc (n = 3), 1 (n = 3), 2 (n = 1), 3 (n = 2), and 4 (n = 1). The stages were ascertained as IA (n = 3), IIB (n = 3), IIIA (n = 2), IIIB (n = 1), and IIIC (n = 1). Radical resection was performed in all the patients. After surgery, relapse-free survival was achieved in 6 patients. The mean postoperative survival time was 63.5 months. On immunostaining, 6 patients were positive for CD56, and all were positive synaptophysin and chromogranin A. Of the 10 patients, standard-type adenocarcinoma was concomitantly present in 6.

Conclusions:

Some patients with surgically resected gastric NEC survived over a long period, suggesting the usefulness of radical resection. In future studies, the pathogenesis of gastric NEC should be fully clarified, and therapeutic strategies must be further developed.

Prognostic factors for survival after curative resection of gastric mixed adenoneuroendocrine carcinoma: a series of 80 patients

BACKGROUND

To assess the prognostic factors and investigate the optimal treatment of gastric mixed adenoneuroendocrine tumors.

METHODS

We retrospectively analyzed clinical data from 80 patients with gastric mixed adenoneuroendocrine carcinoma that received radical resection in our department from January 2007 to December 2016. Risk factors for relapse and survival were analyzed using a multivariate Cox proportional hazards regression model. Gastric mixed adenoneuroendocrine carcinoma was divided into neuroendocrine carcinoma and adenocarcinoma based on the predominant type in the tumor.

RESULTS

The 3-year overall survival was 40% in the neuroendocrine carcinoma group and 75% in the adenocarcinoma group (P = 0.006). The neuroendocrine carcinoma (NEC)-dominant tumors and a Ki-67-positive index ≥60% were independent risk factors for worse overall survival. The 3-year recurrence-free survival was 33% in the neuroendocrine carcinoma group and 68% in the adenocarcinoma group. NEC-dominant tumors and a Ki-67-positive index ≥60% were independent risk factors for gastric mixed adenoneuroendocrine carcinoma recurrence. Patients in the adenocarcinoma group that received adjuvant chemotherapy exhibited significantly better overall survival than patients that did not receive chemotherapy (median survival time 43 months vs. 13 months, P = 0.026).

CONCLUSION

The NEC-dominant tumors and a Ki-67-positive index ≥60% were significantly associated with worse survival and a higher recurrence rate for gastric mixed adenoneuroendocrine carcinoma patients. Patients in the adenocarcinoma group may benefit from gastric adenocarcinoma treatments.

Gastric Carcinoids

Gastric carcinoids, formally named gastric neuroendocrine neoplasms (NENs), are derived from enterochromaffin-like cells of the stomach and are increasingly diagnosed. A majority are designated as type I (related to autoimmune gastritis) and type II (related to gastrinoma) neoplasms that develop secondary to gastrin hypersecretion. Types I and II gastric carcinoids are mostly small-sized (1-2 cm), multiple, low-malignancy potential lesions mainly confined to the gastric mucosa/submucosa. These lesions have an indolent course and low metastatic potential. In contrast, type III gastric carcinoids are single, larger-sized (>2 cm), non-gastrin-related lesions that infiltrate the muscular layers associated with local and distant metastases.

Gastrin-induced miR-222 promotes gastric tumor development by suppressing p27kip1

Background and Aims

Elevated circulating concentrations of the hormone gastrin contribute to the development of gastric adenocarcinoma and types-1 and 2 gastric neuroendocrine tumors (NETs). MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate proteins which in turn influence various biological processes. We hypothesised that gastrin induces the expression of specific gastric miRNAs within CCK2 receptor (CCK2R) expressing cells and that these mediate functionally important actions of gastrin.

Results

Gastrin increased miR-222 expression in AGS_GR cells, with maximum changes observed at 10 nM G17 for 24 h. Signalling occurred via CCK2R and the PKC and PI3K pathways. miR-222 expression was increased in the serum and gastric corpus mucosa of hypergastrinemic INS-GAS mice and hypergastrinemic patients with autoimmune atrophic gastritis and type 1 gastric NETs; it decreased in patients following treatment with the CCK2R antagonist netazepide (YF476). Gastrin-induced miR-222 overexpression resulted in reduced expression and cytoplasmic mislocalisation of p27^kip1, which in turn caused actin remodelling and increased migration in AGS_GR cells.

Materials and Methods

miRNA PCR arrays were used to identify changes in miRNA expression following G17 treatment of human gastric adenocarcinoma cells stably transfected with CCK2R (AGS_GR). miR-222 was further investigated using primer assays and samples from hypergastrinemic mice and humans. Chemically synthesised mimics and inhibitors were used to assess cellular phenotypical changes associated with miR-222 dysregulation.

Conclusions

These data indicate a novel mechanism contributing to gastrin-associated gastric tumor development. miR-222 may also be a promising biomarker for monitoring gastrin induced premalignant changes in the stomach.

SSAT State-of-the-Art Conference: Current Surgical Management of Gastric Tumors

INTRODUCTION

The current era of gastric surgery is marked by low morbidity and mortality rates, innovative strategies to approach resections with a minimally invasive fashion or hyperthermic intraperitoneal chemotherapy (HIPEC), as well as improved understanding of the biology of sporadic and hereditary stromal, neuroendocrine, and epithelial malignancies.

METHODS

In 2017, the Society for Surgery of the Alimentary Tract convened a State-of-the-Art Conference on Current Surgical Management of Gastric Tumors with both international experts and emerging leaders in the field of gastric surgery.

RESULTS

Martin D. McCarter, MD of the University of Colorado discussed the current management of gastric gastrointestinal stromal tumors (GIST). Kaitlyn J. Kelly, MD of the University of California, San Diego discussed the management of gastric carcinoid tumors. Jeffrey A. Norton of Stanford University discussed recent advances in the management of gastric adenocarcinoma including a focus on hereditary diffuse gastric cancer (HDGC). Joseph Kim, MD of Stony Brook University discussed a systematic approach to minimally invasive gastrectomy for cancer. Joyce Wong, MD of Pennsylvania State University discussed the role for cytoreductive surgery (CRS) and HIPEC for gastric adenocarcinoma.

CONCLUSIONS

This review provides gastrointestinal surgeons with a concise update on the current surgical management of gastric tumors.

Insights into gastric neuroendocrine tumors burden

Type 1 gastric neuroendocrine tumors (gNETs) are usually small lesions, restricted to mucosal and sub-mucosal layers of corpus and fundus, with low aggressive behavior, for the majority of cases. Nevertheless, some cases present aggressive behavior. The increasing incidence of gNETs brings together a new relevant problem: how to identify potentially aggressive type 1 gNETs. The challenging problem seems to be finding out signs or features able to predict potentially aggressive cases, allowing a tailored approach, since the involved societies dedicated to provide guidelines for management of these neoplasms apparently failed in producing staging systems able to accurately predict prognosis of these tumors. Additionally, it is also important to try to find out explanations for increasing incidence, as well as to identify potential targets aiming to reach better control of this neoplasia. Here, we discuss potential pathways implicated in aggressive behavior, as well as new strategies to improve clinical management of these tumors.

Follow-up of patients with ECL cell-derived tumours

OBJECTIVES

To review the presentation, treatment and outcome of patients with type 1 gastric carcinoid tumours.

MATERIAL AND METHODS

We retrospectively reviewed medical records and re-evaluated histopathological specimens of 26 patients with type 1 gastric carcinoids treated at a single tertiary referral centre from 1993 to 2013, with median time of follow-up 52.5 months (IQR 90.8).

RESULTS

Seven patients (27%) had single tumours and 19 patients (73%) multiple tumours at the time of diagnosis. The median number of tumours and median diameter of largest tumour were 2.5 (IQR 3.2) and 6.0 mm (IQR 9.5) respectively. Median serum gastrin was 321.0 pmol/l (IQR 604.0) and median serum chromogranin A 7.7 nmol/l (IQR 5.3). Three patients had metastatic disease at the time of diagnosis and two developed metastases during follow-up. Patients with metastatic disease had larger primary tumours than the others (20.0 mm (IQR 28.5) vs. 5.0 mm (IQR 5.5), p = 0.04). There was a positive correlation between age and tumour size (r = 0.44, p = 0.03) and between serum chromogranin A and serum gastrin at diagnosis (r = 0.76, p = 0.001). Patients were either treated with surgery (n = 8 (31%)), a long-acting somatostatin analogue and/or gastrin receptor antagonist (n = 10 (39%)) for a period of time, or were observed without treatment (n = 8 (31%) with close endoscopic follow up.

CONCLUSIONS

Although gastric carcinoids have an overall good prognosis, a significant proportion develops metastatic disease. As partial and total gastrectomy is associated with major side effects, treatment with long-acting a somatostatin analogue or gastrin antagonist should be considered.

Surgical treatment and prognosis of gastric neuroendocrine neoplasms: a single-center experience

Background

Gastric neuroendocrine neoplasms (G-NENs) are uncommon, and data on their management is limited. We here investigated the clinicopathological characteristics, surgical and survival outcomes in G-NENs among Chinese. Moreover, we will discuss their prognostic value.

Methods

From existing databases of the West China Hospital, we retrospectively identified 135 consecutive patients who were surgically treated and pathologically diagnosed as G-NENs from January 2009 to August 2015.

Results

This entire cohort comprised 98 males and 37 females, with a median age of 60 years. Twenty-five patients underwent endoscopic resection, while 110 patients underwent open/laparoscopic surgery. Thirty-nine patients had neuroendocrine tumor G1 (NET G1), seven patients had neuroendocrine tumor G2 (NET G2), 69 patients had neuroendocrine carcinoma G3 (NEC G3) and 20 patients had mixed adenoneuroendocrine carcinoma (MANEC). The median survival was not achieved for both NET G1 and NET G2 versus 19 months (range 3–48) for NEC G3 and 10.5 months (range 3–45) for MANEC. The 3-year survival rates for stage I, II, III, and IV were 91.1 %, 78.6 %, 51.1 % and 11.8 %, respectively (P < 0.001). As for the prognostic analysis, both surgical margin and the newly updated World Health Organization (WHO) classification were independent predictors of overall survival (OS).

Conclusions

G-NENs are a kind of rare tumors, and patients with NET G3 and MANEC have unfavorable prognosis even surgically treated. Moreover, surgical margin and the new 2010 WHO criteria are closely associated with OS for G-NENs.

Sporadic Gastric Well-Differentiated Neuroendocrine Tumors Have a Higher Ki-67 Proliferative Index

Well-differentiated neuroendocrine tumor (WDNET) of the stomach can arise in three distinct clinical settings: (1) in association with autoimmune atrophic gastritis, (2) in association with multiple neuroendocrine neoplasia type I (MEN I) or Zollinger-Ellison syndrome (ZES), or (3) sporadic. The Ki-67 proliferative index (PI) in gastric WDNETs in these three distinct clinical settings has not been evaluated in detail. Forty-five gastric WNETs underwent polypectomy (n = 4), endoscopic mucosal resection (n = 12), and surgical resection (n = 29) between 1994 and 2015 were included. H&E slides from each case were reviewed, and Ki-67 immunostain was performed on one representative tumor block. Ki-67 PI was determined by quantitative Aperio image analysis software in areas of strongest nuclear labeling ("hot spots"), and correlated with underlying clinical and pathological features. Twenty-one patients were male and 24 female with a median age of 57 years (range, 30-80 years). Tumors were classified as type I (n = 17), type II (n = 6), and type III (n = 22) WDNETs. Types II and III showed more advanced TNM stage compared to type I (p = 0.02, overall). WHO grade based on Ki-67 PI was higher in type III WDNETs [grade 1 (G1), n = 3; grade 2 (G2), n = 15; and grade 3 (G3), n = 4] than in type I WDNETs [G1, n = 5; G2, n = 12] and in type II WDNETs [G1, n = 2; G2, n = 4] (p = 0.050, overall). Ki-67 PI was significantly higher in type III WDNETs (mean ± SD = 13.0 ± 13.3 %) than in non-sporadic (type I and II) WDNETs (mean ± SD = 5.3 ± 3.3 %; p = 0.015). There was no difference in Ki-67 PI between type I WDNETs (mean ± SD = 5.2 ± 3.5 %) and type II WDNETs (mean ± SD = 5.6 ± 3.1%; p = 0.817). Higher Ki-67 PI was associated with higher tumor T stage (p = 0.003) and also tended to be associated with lymph node metastasis (p = 0.071). In the Kaplan-Meier survival analysis, type I was associated with a significantly longer disease-free survival (DFS) time compared to type II (p = 0.018) or III (0.010). Also, the WHO G3 group had a significantly shorter DFS time than the WHO G1 (p = 0.020) or G2 (p = 0.007) group. Gastric WDNET is a heterogeneous disease entity encompassing three clinical subtypes-type I, type II, and type III-having their own distinct clinicopathologic characteristics and prognosis. Our results showed that sporadic (type III) WDNET had a significantly higher Ki-67 PI than non-sporadic cases (type I or II); increased PI was associated with higher tumor stage. We also described four type III cases of morphologically WD gastric NET with WHO grade 3 on the basis of Ki-67 PI.

Giant type III well-differentiated neuroendocrine tumor of the stomach: A case report

INTRODUCTION

We describe a case of a large type III neuroendocrine tumor of the stomach. Management and current literature are reviewed.

PRESENTATION OF CASE

A 37year old female presented with upper gastrointestinal bleed and epigastric pain. Further workup demonstrated a large ulcerated gastric mass near the GE junction. Computer tomography scan and endoscopic ultrasound showed a 10cm mass with no evidence of distant disease. Fine needle aspiration pathology was consistent with a well differentiated neuroendocrine tumor (Ki67 index<2%), with elevated levels of chromogranin A and serotonin levels but normal gastrin. The patient underwent an uneventful total gastrectomy. Final pathology analysis reported a higher KI67 index (7.54%) and a final pathology of grade 2 type III, T3 N3, neuroendocrine tumor of the stomach. The chromogranin levels normalized and no recurrent disease has been detected in one year follow up.

DISCUSSION

Gastric neuroendocrine tumors are extremely rare, accounting for 4% of all neuroendocrine tumors of the body and 1% of all neoplasms of the stomach. Based on histomorphologic characteristics and pathogenesis, gastric neuroendocrine tumors are classified into four types with differing prognosis and behavior. Current literature describes type 3 gastric neuroendocrine tumors as larger than 2cm. However, there is no precedent in the literature for a tumor of this size.

CONCLUSION

The incidence of gastric neuroendocrine tumors has been increasing during the last decade, underscoring the need to improve our understanding of their biology and behavior. When identified histologically, patient outcomes depend on appropriate determination of tumor biology and subsequent choice of treatment.

Gastric neuroendocrine neoplasms and proton pump inhibitors: fact or coincidence?

OBJECTIVE

Reporting on three cases of gastric neuroendocrine tumors (g-NETs) in patients taking long-term proton pump inhibitors (PPIs). These tumors are not classifiable considering current criteria. g-NETs are currently grouped as: types 1 and 2, related to hypergastrinemia due to chronic atrophic gastritis and Zollinger-Ellison syndrome respectively, and type 3, normogastrinemic and more aggressive. Although the g-NETs onset in patients taking PPIs is biologically plausible, only a few cases have been reported so far.

MATERIALS AND METHODS

From January 2005 to July 2014, 31 g-NETs were referred to our Unit: 24 (77%), one (3%) and three (10%) resulted types 1, 2 and 3, respectively. Three cases (10%) did not meet the current classification criteria.

RESULTS

The three patients were administered long-term PPIs for gastro-esophageal reflux disease. Patient 1: a 78-year-old man, with a 4-mm well-differentiated g-NET (Ki-67<1%) and marked hypergastrinemia. Patient 2: a 58-year-old man affected by a 6-mm well-differentiated (Ki-67 = 4%) g-NET, with normal gastrin levels. Patients 3: a 67-year-old woman with an 18-mm well-differentiated g-NET (Ki-67 <2%), with mild hypergastrinemia. In the three patients, histology and pertinent blood tests excluded chronic atrophic gastritis, Helicobacter pylori infection or Zollinger-Ellison syndrome. The first two patients underwent endoscopic polypectomy; in the third case total gastrectomy was performed. Further clinical, endoscopic and imaging follow-up did not show any g-NET recurrence.

CONCLUSIONS

The present data point to the existence and epidemiological relevance of g-NETs associated with PPIs intake. These neoplasms are not included in the current classification, thus their treatment and follow-up have not been established.

Endoscopic appearances of polypoid type 1 gastric microcarcinoids by narrow-band imaging: a case series in a referral center

OBJECTIVE

Narrow-band imaging (NBI) has been associated with high accuracy for the identification of gastric malignant lesions. This study aimed to investigate for the first time the endoscopic NBI appearances of type 1 gastric carcinoids in a consecutive series of patients with atrophic gastritis.

METHODS

Seven consecutive patients (five women, median age 61 years) with atrophic gastritis and polypoid type 1 gastric carcinoids were included. After white-light examination, gastric antrum and body were examined by NBI for the examination of polyps and lesions. Digital images of polyps from recorded videos were extracted and reviewed for NBI features.

RESULTS

Fifteen polypoid type 1 gastric microcarcinoids (median size 3 mm) were detected in the seven patients; four patients had synchronous lesions. Nine (60%) lesions showed a tubulovillous and six lesions (40%) showed an irregular mucosal pattern; a regular circular pattern was never observed. A light-blue crest was observed on six (40%) lesions. The vascular pattern was irregular in eight (53.3%) microcarcinoids. All six type 1 gastric carcinoids with an irregular mucosal pattern showed an irregular vascular pattern without light-blue crest. Of the nine carcinoids with a tubulovillous mucosal pattern, two had an irregular and seven had a regular vascular pattern.

CONCLUSION

Polypoid type 1 gastric microcarcinoids always show an abnormal NBI mucosal surface pattern, but no specific features to distinguish them from other intraepithelial lesions such as intestinal metaplasia, adenomas, or low-grade and high-grade dysplasia are observed. Thus, target biopsies to diagnose the pathological nature of the lesion are advocated.

Republished: gastric neuroendocrine neoplasms and related precursor lesions

Gastric neuroendocrine neoplasms (NENs) are a heterogeneous group of tumours showing different clinicopathological features and behaviour, implying a wide spectrum of therapeutic options. They are currently classified using the 2010 WHO classification of digestive neuroendocrine neoplasms into G1-neuroendocrine tumours (NETs), G2-NETs, neuroendocrine carcinomas (NECs) and mixed adenoneuroendocrine carcinomas (MANECs). However, most gastric NENs are composed of ECL-cells (ECL-cell NETs) that can be preceded by ECL-cell hyperplastic and dysplastic lesions, whose oncologic potential has not yet been completely elucidated. ECL-cell NETs differ considerably in terms of prognosis depending on the proliferative status and clinicopathological background. The integration of both aspects in the diagnostic pathway may help to better classify tumours in different prognostic categories, especially when diagnosing them in small bioptic specimens. NECs are all poorly differentiated, highly aggressive carcinomas, while MANECs can show different morphological features that are directly associated with different prognoses. Precursor lesions of such carcinomas are not entirely understood. In this review, the clinicopathological features of gastric NENs and related precursor lesions will be described to give the reader a comprehensive overview on this topic.

Urticaria as initial finding of a patient with carcinoid tumor

BACKGROUND

Typical carcinoid syndrome is characterized by flushing, abdominal pain and diarrhea and occurs in <10 % of carcinoid tumor patients. Very rarely, initial signs include skin manifestations. Our purpose is to highlight cutaneous manifestations in the diagnosis and assessment of a patient with atypical manifestation of type I gastric carcinoid tumor.

CASE PRESENTATION

A 50-year-old woman presented with anemia, chronic urticaria and angioedema. Urticaria was triggered principally by seafood and appeared in the first hour after. Urticaria Activity Score 7 was 24, and quality of life (CU-Q2oL) was 3.61. P. Laboratory findings showed anemia, diminished iron, ferritin, and vitamin B12, with increased gastrin and anti-parietal cell antibody levels. 15 gastric carcinoids 5 mm in diameter were observed in the greater curvature of the stomach during gastric endoscopy and confirmed by biopsy, suggesting that this patient had type I gastric carcinoids. Four additional tumors were found in the small intestine upon examination via video capsule. Endoscopic argon plasma therapy was performed. The patient experienced definitive improvement in quality of life and urticaria activity score.

CONCLUSION

This patient, whose principal symptoms were anemia, urticaria and angioedema, was found to have atypical carcinoid syndrome, with tumors located in the stomach. Allergists, immunologists, internists and primary care physicians should consider the possibility of neuroendocrine malignancies, specifically type I carcinoid tumors, when evaluating patients with urticaria, and consider screening patients with chronic urticaria for elevated anti-parietal cell antibody levels.

Cancer Risk After Pernicious Anemia in the US Elderly Population

BACKGROUND & AIMS

Pernicious anemia, a result of autoimmune gastritis, is the most common cause of vitamin B12 deficiency, affecting 2% to 5% of the elderly population. Treatment with vitamin B12 cures the anemia, but not the gastritis. Findings from small studies have indicated that patients with pernicious anemia could have an increased risk of cancer.

METHODS

We performed a population-based, case-control study of individuals in the Surveillance, Epidemiology, and End Results-Medicare database, comparing 1,138,390 cancer cases (age, 66-99 y) with 100,000 matched individuals without cancer (controls). Individuals with pernicious anemia were identified based on their medical claims within the year before selection for the study. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression, and models were adjusted for sex, age, and calendar year of diagnosis and selection.

RESULTS

Compared with controls, we found individuals with pernicious anemia to be at increased risk for noncardia gastric adenocarcinoma (OR, 2.18; 95% CI, 1.94-2.45) and gastric carcinoid tumors (OR, 11.43; 95% CI, 8.90-14.69). In addition, people with pernicious anemia have an increased risk of developing tonsilar cancer (OR, 2.00; 95% CI, 1.40-2.85), hypopharyngeal cancer (OR, 1.92; 95% CI, 1.35-2.73), esophageal squamous cell carcinoma (OR, 2.12; 95% CI, 1.76-2.55), small intestinal cancer (OR, 1.63; 95% CI, 1.32-2.02), liver cancer (OR, 1.49; 95% CI, 1.28- 1.73), myeloma (OR, 1.55; 95% CI, 1.37-1.75), acute myeloid leukemia (OR, 1.68; 95% CI, 1.46-1.93), and myelodysplastic syndrome (OR, 2.87; 95% CI, 2.53-3.26). People with pernicious anemia have a lower risk of rectal cancer than the general population (OR, 0.82; 95% CI, 0.74- 0.92).

CONCLUSIONS

In a population-based, case-control study of individuals in the Surveillance, Epidemiology, and End Results-Medicare database, we found individuals with pernicious anemia to have significantly increased risks of gastric carcinoid tumors, adenocarcinomas, and other cancers located throughout the body.

Occurrence of gastric cancer and carcinoids in atrophic gastritis during prospective long-term follow up

OBJECTIVE

Atrophic gastritis (AG) is a risk condition for gastric cancer and type I gastric carcinoids. Recent studies assessing the overall risk of gastric cancer and carcinoids in AG at long-term follow up are lacking. This study aimed to investigate in a prospective cohort of AG patients the occurrence of gastric cancer and carcinoids at long-term follow up.

METHODS

A total of 200 AG patients from a prospective cohort (67% female, median age 55 years) with a follow up of 7.5 (range: 4-23.4) years were included. Inclusion criteria were presence of AG and at least one follow-up gastroscopy with biopsies at ≥4 years after AG diagnosis. Follow-up gastroscopies at 4-year intervals were performed.

RESULTS

Overall, 22 gastric neoplastic lesions were detected (crude incidence 11%). Gastric cancer was diagnosed in four patients at a median follow up of 7.2 years (crude incidence 2%). Eleven type I gastric carcinoids were detected at a median follow up of 5.1 years (crude incidence of 5.5%). In seven patients, six low-grade and one high-grade dysplasia were found. The annual incidence rate person-year were 0.25% (95% confidence interval [CI]: 0.067-0.63%), 0.43% (95% CI: 0.17-0.89%), and 0.68% (95% CI: 0.34-1.21%) for gastric cancer, dysplasia, and type I-gastric carcinoids, respectively. The incidence rates of gastric cancer and carcinoids were not different (p = 0.07).

CONCLUSION

This study shows an annual incidence rate of 1.36% person-year for gastric neoplastic lesions in AG patients at long-term follow up. AG patients are similarly exposed to gastric cancer and type I gastric carcinoids.

Gastric cancer in patients with type I gastric carcinoids

BACKGROUND

Atrophic body gastritis (ABG) is associated with both type I gastric carcinoids (T1-GCs) and intestinal-type gastric cancer. The occurrence of gastric cancer in ABG patients with type I gastric carcinoids has not yet been described.

AIM

To describe the occurrence at follow-up of gastric cancer in ABG patients with type I gastric carcinoid in a retrospective case series in a single tertiary referral center.

METHODS

Between 1994 and 2012, 17 new cases of T1-GCs were diagnosed among a cohort of ABG patients in a single tertiary referral center for ABG. The clinical charts of these 17 T1-GC patients were retrospectively evaluated for the occurrence of gastric cancer at follow-up (median 4.2 years, range 0.5-13).

RESULTS

In 4 (23.5 %)/17 T1-GCs patients (3 females, age 40-78 years), gastric cancer occurred (median follow-up 5.9 years, range 5.1-13). Three cases were intestinal-type adenocarcinomas and one a signet-ring cell diffuse gastric cancer, localized in three cases in the antrum. In two patients, it was detected on random biopsies during follow-up gastroscopy; in the other two, gastroscopy was performed because of new symptoms. All patients with gastric cancer had associated autoimmune features (pernicious anemia, autoimmune thyroid disease and a spared antrum) compared to 77, 46 and 54 % of those without gastric cancer, although statistical significance was not reached.

CONCLUSIONS

This case series shows that in patients with T1-GCs, gastric cancer may frequently occur at long-term follow-up. Thus, these patients should be monitored by a long-term surveillance program, including an accurate bioptic sampling of the antral mucosa.

Gastric neuroendocrine tumors: prevalence in Europe, USA, and Japan, and rationale for treatment with a gastrin/CCK2 receptor antagonist

OBJECTIVE

Gastric carcinoids (neuroendocrine tumors) arise from enterochromaffin-like cells in the gastric mucosa. Most are caused by hypergastrinemia. The objectives were to determine if their prevalence in Europe, USA and Japan meets the criteria for an orphan disease and to justify treatment with a gastrin/CCK2 receptor antagonist.

METHODS

We obtained data from European and USA cancer registries, and searched PubMed.

RESULTS

Prevalence per 10,000 population obtained from cancer registries was: median 0.32 (range 0.09-0.92) for Europe; and 0.17 for the USA, equivalent to 4812 for the whole population. A PubMed search for gastric carcinoids yielded prevalence for Japan only, which was 0.05 per 10,000 population, equivalent to 665 for the entire population. A further search for gastric carcinoids in patients with pernicious anemia (PA) or autoimmune chronic atrophic gastritis (CAG), two presentations of about 80% of gastric carcinoids, produced prevalence rates of 5.2-11%. Prevalence of PA itself was 0.12-1.9%. Data on CAG epidemiology were sparse.

CONCLUSION

Prevalence of gastric carcinoids varied widely. All sources probably underestimate prevalence. However, prevalence was below the limits required for recognition by drug regulatory authorities as an orphan disease: 5 per 10,000 population of Europe; 200,000 for the whole population of the USA; and 50,000 for the whole population of Japan. Because gastric carcinoids are an orphan disease, and nonclinical and healthy volunteer studies support treatment with netazepide, a gastrin/CCK2 antagonist, netazepide has been designated an orphan medicinal product in Europe and the USA for development as targeted treatment for gastric carcinoids.

Management and disease outcome of type I gastric neuroendocrine tumors: the Mount Sinai experience

BACKGROUND AND AIM

The incidence of gastric neuroendocrine tumors (NETs) has increased tenfold since the 1970s. Our aim was to describe the clinicopathologic profile, management, and outcomes of type I gastric NETs at The Mount Sinai Hospital.

METHODS

From existing databases of the Mount Sinai Division of Gastrointestinal Pathology and the Carcinoid Cancer Foundation, we identified 56 patients with type I gastric NETs seen at The Mount Sinai Hospital from 1993 to 2012. We generated a comprehensive dataset encompassing demographic, clinical, endoscopic, and pathologic factors. Survival information was determined from medical records and the Social Security Death Index. Tumor-node-metastasis staging was conducted, and tumors were graded based on mitotic counts and Ki67 index.

RESULTS

Median NET size was 3.0 mm; 55.8 % displayed multifocal disease. Stages I, II, III, and IV disease were observed in 83.8, 10.8, 5.4, and 0 %, respectively. Tumors were either low (69.7 %) or intermediate (30.3 %) grade. Furthermore, 3.6 % of patients developed gastric dysplasia, and 5.5 % had gastric adenocarcinoma. Patients underwent endoscopy every 15 months, while 28.6 % underwent polypectomy, 32.7 % somatostatin therapy, and 46.4 % surgical resection. 5- and 10-year disease-specific survival was 100 %.

CONCLUSIONS

Most patients received annual endoscopic surveillance, with a minority undergoing surgical resection, though outcomes remained excellent independent of therapeutic approach. We identified a very low but real rate of loco-regional spread, despite the generally indolent behavior of type I gastric NETs. Several patients demonstrated concurrent dysplasia or adenocarcinoma, underscoring the efficacy of regular endoscopic management not only for gastric NETs, but also for dysplasia and adenocarcinoma.

Gastric carcinoid tumor in a 14-year old girl

Gastric carcinoid tumors (GCT) are rare lesions that constitute 2.6-8.7% of all gastrointestinal carcinoids, mostly affect middle-aged females but the incidence in children is unknown. We present a 14-year-old girl, with GCT. She was treated with recombinant human growth hormone (GH) for complete GH deficiency, and endoscopy was performed to identify iron-deficiency anemia. Upper gastrointestinal endoscopy revealed a gastric polyp, and biopsies were compatible with GCT.

Gastric neuroendocrine neoplasms and related precursor lesions

Gastric neuroendocrine neoplasms (NENs) are a heterogeneous group of tumours showing different clinicopathological features and behaviour, implying a wide spectrum of therapeutic options. They are currently classified using the 2010 WHO classification of digestive neuroendocrine neoplasms into G1-neuroendocrine tumours (NETs), G2-NETs, neuroendocrine carcinomas (NECs) and mixed adenoneuroendocrine carcinomas (MANECs). However, most gastric NENs are composed of ECL-cells (ECL-cell NETs) that can be preceded by ECL-cell hyperplastic and dysplastic lesions, whose oncologic potential has not yet been completely elucidated. ECL-cell NETs differ considerably in terms of prognosis depending on the proliferative status and clinicopathological background. The integration of both aspects in the diagnostic pathway may help to better classify tumours in different prognostic categories, especially when diagnosing them in small bioptic specimens. NECs are all poorly differentiated, highly aggressive carcinomas, while MANECs can show different morphological features that are directly associated with different prognoses. Precursor lesions of such carcinomas are not entirely understood. In this review, the clinicopathological features of gastric NENs and related precursor lesions will be described to give the reader a comprehensive overview on this topic.

Review article: the investigation and management of gastric neuroendocrine tumours

BACKGROUND

Gastric carcinoids (GCs) or neuroendocrine tumours (NETs) are increasingly identified at endoscopy, and account for 0.6-2% of all gastric polyps identified. The SEER database in the US has demonstrated a rising incidence of gastric NETs amongst all NETs; from 2.2% between 1950 and 1969 to 6.0% between 2000 and 2007.

AIM

To review the literature and assist clinicians in managing patients with GCs.

METHODS

A literature search was conducted through MEDLINE using search terms: gastric, carcinoid, neuroendocrine tumour, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles.

RESULTS

There are three types of GCs with important epidemiological, pathophysiological, histological and endoscopic differences that affect prognosis and management. Type 1 and 2 GCs develop in the context of hypergastrinaemia that originates from achlorhydria in atrophic gastritis and a gastrinoma, respectively. Type 3 GCs occur sporadically and independent of gastrin. The histological type, grade and Ki67 index are used to determine prognosis and direct clinical management. Type 1 GCs >1 cm in size and type 2 GCs should be assessed for invasion beyond the submucosa with EUS prior to endoscopic resection with EMR or ESD. Type 3 GCs should be managed as per recommendations for gastric adenocarcinoma. The treatment of advanced disease is multimodal.

CONCLUSIONS

Patients with gastric carcinoids should be discussed in a specialist neuroendocrine tumour multidisciplinary meeting to ensure all treatment options are explored in localised and advanced disease. Areas of controversy exist that need further research.

Neuroendocrine carcinoma of the stomach-a case report

Neuroendocrine carcinomas of stomach have been considered a rare neoplasm. The present case concerns with a 69 year old male, who presented with vague abdominal discomfort and history of malena. Upper alimentary tract endoscopy showed an ulcero-proliferative growth in the antrum. Computed tomography abdomen revealed thickening of the gastric antrum, a subtotal gastrectomy was performed after correction of anemia. Microscopic evaluation revealed a neuroendocrine neoplasm. Immunohistochemically positive for Chromogranin A and Synaptophysin.A diagnosis of Neuroendocrine carcinoma of the stomach was given based on recent WHO classification of Neuroendocrine carcinoma of the stomach and on mitotic index with reference to grading scale.

Gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Studying menin and its complex interrelationship with gastrin may provide insight into tumor biology at the clinical level and in terms of basic cell biology (eg, the role of the epigenome in neuroendocrine cell proliferation), and lead to potential consideration of other targets that are known candidates for molecular-based therapies in other adenocarcinomas.

Correlation between a short-term intravenous octreotide suppression test and response to antrectomy in patients with type-1 gastric neuroendocrine tumours

BACKGROUND

Type-1 gastric neuroendocrine tumours (NETs) arise in some patients with chronic hypergastrinaemia secondary to autoimmune atrophic gastritis. Patients with small tumours are usually managed conservatively, because their prognosis is very good. However, larger tumours may require surgical intervention. Many type-1 gastric NETs regress following antrectomy because this removes the source of hypergastrinaemia. However, some tumours do not regress following antrectomy and additional surgery may be required. An octreotide suppression test has been previously suggested as a means to assess whether type-1 gastric NETs are likely to regress following antrectomy.

AIM

To prospectively examine the role of a short-term intravenous octreotide suppression test in predicting type-1 gastric NET regression in five patients who subsequently underwent antrectomy.

MATERIALS AND METHODS

Serum gastrin concentrations and gastric corpus and tumour histidine decarboxylase mRNA abundances were assessed in patients with type-1 gastric NETs before and 72 h after the administration of 25 µg/h intravenous octreotide. Gastric tumour response was assessed endoscopically following subsequent antrectomy.

RESULTS

All patients showed significant decreases in serum gastrin concentrations as well as corpus and tumour biopsy histidine decarboxylase mRNA abundance following octreotide infusion. All patients also showed resolution of hypergastrinaemia following subsequent antrectomy. However, tumour regression was only observed in four of the five patients. One patient had a persistent tumour 3 years after antrectomy and required additional surgical resection.

CONCLUSION

A positive octreotide suppression test result does not always predict response to antrectomy in patients with type-1 gastric NETs. Assessment of gastric mucosal responses to a gastrin/CCK-2 receptor antagonist may therefore also be helpful.

Management of gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Mainly due to better diagnostics and awareness of this tumor, the observed incidence has increased more than tenfold over the last 30 years. Small (<15-20 mm) localized type I and II lesions that are slowly proliferating (Ki67<2%) can usually be managed conservatively with endoscopic surveillance. Reducing hypergastrinemia by surgical removal of an underlying gastrinoma is important in inhibiting growth and induce reduction of type II lesions, while the specific gastrin receptor antagonist YF476 or gastrin antibodies may become useful for both type I and II lesions. Infiltrating and metastasized tumors and type III lesions require a more aggressive approach with surgical resection and consideration of modalities such as somatostatin analogs, cytotoxics, and peptide receptor targeted treatment.

Gastric and duodenal neuroendocrine tumours

Gastric neuroendocrine neoplasms (NENs) are increasing in frequency and have a varied spectrum with regard to histology, clinicopathologic background, stage, and prognosis. They are usually discovered incidentally, are for the most part benign and are associated with hypergastrinaemia (secondary either to chronic atrophic gastritis or rarely Zollinger-Ellison syndrome; types 1 and 2, respectively) or more rarely sporadic type 3. Applications of recent staging and grading systems - namely using Ki-67 proliferative indices - (from ENETS and WHO 2010) can be particularly helpful in further categorising these tumours. The natural history of Type 1 gastric carcinoids is generally (>95%) favourable and simple surveillance is usually recommended for small (<1 cm) T1 tumours, with local (endoscopic or surgical) resection for larger lesions. Other potential therapies such as somatostatin analogues and gastrin receptor antagonists may offer newer therapeutic possibilities. Rarely, gastric NENs have a malignant course and this is usually confined to Type 2 and especially Type 3 tumours; the latter mimic the biological course of gastric adenocarcinoma and require radical oncological therapies. Most duodenal NENs, apart from gastrinomas (that are not dealt with here) are sporadic and non functional. They are also increasing in frequency probably due to incidental discovery at endoscopy or imaging for other reasons and this may account for their overall good prognosis. Peri-ampullary and ampullary NENs may have a more aggressive outcome and should be carefully appraised and treated (often with surgical resection).

Ultrastructure of ECL cells in Mastomys after long-term treatment with H2 receptor antagonist loxtidine

Gastric ECL-cell hyperplasia and carcinoids (ECLoma) develop after 1 year in rats treated with omeprazole or 2 months in Mastomys treated with loxtidine. The aim of this study was to examine the ultrastructure of ECL cells in Mastomys after loxtidine treatment with an attempt to evaluate whether an impairment of autophagy was involved in the tumorigenesis. Mastomys were given loxtidine for 8 or 27 weeks. Morphological analysis of ECL cells showed that (1) cell size was not increased after 8 or 27 weeks; (2) secretory vesicles, a hallmark feature of welldifferentiated ECL cells, were unchanged after 8 weeks but reduced after 27 weeks; (3) granules were reduced after 8 or 27 weeks; (4) microvesicles were unchanged after the treatment; and (5) vacuoles and lipofuscin bodies were found occasionally after 8 weeks but not at 27 weeks. In addition, the appearance of ECL-cell ultrastructure differed between loxtidine-treated Mastomys and rats treated with omeprazole or subjected to antrectomy, but was similar between Mastomys treated with loxtidine for 27 weeks and mice deficient in CCK(2) receptor. We suggest that the ultrastructure of ECL cells in Mastomys after long-term treatment with loxtidine displayed an impaired formation of vacuoles and lipofuscin bodies, markers of the autophagic pathway.