A 50-year analysis of 562 gastric carcinoids: small tumor or larger problem?

Gastric neuroendocrine tumors: 20-Year experience in a reference center

Few studies have been published on the long-term outcomes of patients with gastric neuroendocrine tumors (gNETs). We analyzed their management over a two-decade period, focusing on endoscopic and clinical outcomes. Clinical, laboratory, endoscopic, surgical, and histopathological data from Types 1 and 3 gNETs histologically diagnosed between March 2000 and December 2021 at the European Institute of Oncology (IEO, Milan) were retrospectively collected. Sixty-nine patients were included (60 Type 1, 9 Type 3): 53 (77%) were treated endoscopically, 6 (9%) surgically, and 10 (14%) did not receive any treatment. Overall, 293 lesions were removed endoscopically: 74% by forceps, 20% by endoscopic mucosal resection (EMR), and 5% by endoscopic submucosal dissection (ESD). No differences were observed between EMR and ESD in terms of complete resection rate (p value = .50) and complications rate (p value = .084). The median follow-up period was 5.8 years (range: 0.3-20.5), during which no gNET-related deaths were observed. Metachronous gNETs developed in 60% of patients with Type 1 gNET. Six patients with lymph node metastases (LNM) were younger (p value = .006) and had larger lesions (p value <.001) than patients without LNM. Most Type 1 gNETs were successfully excised using forceps, with EMR and ESD being equally effective. The presence of incomplete resection was not associated with a worse prognosis, which remains excellent in this highly recurrent disease. Younger age and a size ≥10 mm were associated with an increased risk of LNM. CLINICAL TRIAL REGISTRATION: Project code UID 2854.

Understanding the increasing incidence of neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors (NETs) are a diverse group of tumors with origins from different primary sites such as gastro-entero-pancreatic, lung and endocrine tissue. Worldwide, their incidence has increased in recent decades. Advances in imaging and better clinical awareness are traditionally attributed to this trend; however, other factors such as genetic and environmental contributors are appreciated as well.

AREAS COVERED

The purpose of this article is to review the worldwide epidemiologic trends in incidence of NET through the decades and discuss the various factors potentially contributing to the observed changes in incidence trends.

EXPERT OPINION

Overall, the incidence of NET has increased across the globe over the last few decades. Although multiple genetics and environmental factors have been proposed, the majority of this increase in incidence is secondary to earlier detection. Future studies will help in more accurate assessments and an improved understanding of disease incidence among patients with different grades and differentiation.

Robotically assisted total gastrectomy for lymphadenopathy after long-term follow-up for multiple type 1 gastric neuroendocrine tumor (NET): a case report

BACKGROUND

Type 1 gastric neuroendrine tumor (NET) is usually associated with chronic atrophic gastritis and forms multiple lesions. While most cases of type 1 gastric NET are generally slowly growing, some develop regional lymph node metastases even after long-term dormancy.

CASE PRESENTATION

A 73-year-old male patient with a 32-year history of multiple gastric NET was being followed-up at the study center after endoscopic submucosal dissection (ESD) of a large gastric NET. A blood examination revealed high serum gastrin (> 3000 pg/ml). An endoscopic examination found atrophic mucosa and multiple, elevated lesions in the upper to lower stomach body. Computed tomography (CT) revealed regional lymphadenopathy in the greater omentum along the gastroepiploic artery. Robotically assisted total gastrectomy was performed with D2 lymphadenectomy and Roux-en-Y reconstruction. Pathological analysis revealed a large number of gastric NET (grade 1) with a maximum size of 4.5 mm invading the submucosal layer. A single lymph node metastasis was also detected pathologically at station #4d. The postoperative course was uneventful, and serum gastrin normalized postoperatively. At postoperative year 3, the patient has been doing well without any recurrences.

CONCLUSIONS

The present case of multiple gastric NET with a single regional lymph node metastasis at year 32 of follow-up was successfully treated with a robotically assisted total gastrectomy.

Autoimmune gastritis and stomach cancer: assessing the risks

The purpose of this publication is to systematize available data on the risks of developing stomach cancer in patients with a chronic autoimmune gastritis with a demonstration of the clinical case of a patient with a chronic autoimmune gastritis and a neuroendocrine gastric tumor of the type 1. Discussion: the article discusses the risks of stomach cancer in patients with chronic autoimmune gastritis. A mechanism for the formation of a neuroendocrine gastric tumor of the type 1, associated with autoimmune gastritis, is given. A clinical example of a patient with a long history of dyspepsia, the presence of concomitant changes in the results of laboratory tests, describes an algorithm for diagnosis of autoimmune gastritis and associated neuroendocrine tumors. The risks of the development in patients with autoimmune gastritis of formidable complications as an adenocarcinoma of the stomach are considered. Conclusion: Chronic autoimmune gastritis is a precancerous diseases of the stomach, with the progressive atrophy of the gastric body mucosa, and associated with an increased risk of developing neuroendocrine gastric tumor of the type 1 and adenocarcinoma of the stomach. Patients with autoimmune gastritis need dynamic outpatient observation, with endoscopic control and assessment of the degree and stage of gastritis in OLGA system, with immunogistochemistry to evaluate the risks of stomach cancer and timely implementation of the necessary measures of carcinoprection.

Advanced gastric neuroendocrine tumor with hepatic metastasis - A case report

INTRODUCTION AND IMPORTANCE

Gastric neuroendocrine tumors (NETs) are rare neoplasms that originate from enterochromaffin cells in the gastric mucosa and pose a diagnostic dilemma due to their non-specific presentation.

CASE PRESENTATION

We present a 79-year-old woman, who came with complaints of abdominal pain associated with loss of pain and appetite. Although on the first look multiple differentials could be listed, upon complete evaluation she was diagnosed to have type III Gastric NET. Histopathology and immunohistochemistry allowed diagnostic confirmation of the disease along with strong clinical suspicion. The patient however succumbed to the illness due to advanced disease and lack of established protocol for its management.

CLINICAL DISCUSSION

The treatment of Gastric NETs primarily involves surgical resection of the tumor and is especially helpful in type I and II cases. For advanced metastatic type III NETs, lines of therapy have not been established although surgical resection can be done if the majority (∼90 %) of the tumor is resectable. Patients should be given a choice in decision making and newer drug therapies should always be considered.

CONCLUSION

Since gastric NETs are a rarer cause of abdominal pain, it can often be overlooked in favor of other, more common differentials. One should be aware of this disease and the newer diagnostic methods to have any sort of clinical suspicion when presented with such a scenario. The management of the condition although not been established, novel therapies should be considered if the tumor is not resectable.

The Morphologic Spectrum of Gastric Type 1 Enterochromaffin-Like Cell Neuroendocrine Tumors

Although most well-differentiated gastric neuroendocrine tumors (gNETs) arise from enterochromaffin-like (ECL) cells in patients with autoimmune metaplastic atrophic gastritis (AMAG), the morphologic spectrum of these type 1 ECL-cell gNETs is not well defined. The extent of metaplastic progression in the background mucosa of AMAG patients with gNETs is likewise unclear. Here we report the histomorphology of 226 gNETs, including 214 type 1 gNETs (78 cases from 50 AMAG patients) pooled from a population with high AMAG prevalence. Most type 1 gNETs were ≤1.0 cm, of low grade, and multifocal, consistent with the results of previous reports. However, a high proportion (70/214, 33%) displayed unusual gNET morphologies not previously appreciated in AMAG patients. Unlike other type 1 gNETs with conventional neuroendocrine tumor morphologies, unconventional type 1 gNETs displayed cribriform networks of atrophic cells embedded within myxoid matrix (secretory-cribriform variant, 59%), sheets of deceptively bland discohesive cells resembling inflammatory infiltrates (lymphoplasmacytoid variant, 31%), or wreath-like arrangements of columnar cells wrapped around collagenous cores (pseudopapillary variant, 14%). Another unusual feature was that unconventional gNETs grew laterally within the mucosa (50/70, 71%) and were only rarely sampled from the submucosa (3/70, 4%). These features also differed from the conspicuous radial nodules (99/135, 73%) and frequent submucosal involvement (57/135, 42%) observed for conventional gNETs (P < .0001). Irrespective of morphology, type 1 gNETs were nearly always detected at first AMAG diagnosis (45/50, 90%) and tended to persist thereafter (34/43, 79%), despite similar clinical symptoms and laboratory values between AMAG patients with gNETs and those without. However, unlike AMAG patients without gNETs (n = 50), the background mucosa in patients with gNETs (n = 50) had already progressed to the morphologic equivalent of end-stage metaplasia (P < .0001). This included diffuse loss of parietal cells (92% vs 52%), complete intestinal metaplasia (82% vs 40%), and pancreatic metaplasia (56% vs 6%). Thus, type 1 ECL-cell gNETs are morphologically heterogeneous with a high prevalence of unconventional gNET morphologies. They tend to present silently at first AMAG diagnosis as multifocal lesions that persist within fields of mature metaplasia.

Clinical outcomes of gastroduodenal neuroendocrine tumors according to their WHO grade: A single-institutional retrospective analysis

The management of gastroduodenal neuroendocrine tumor (NET) has been controversial between radical surgical resection and local excision including endoscopic resection. A gastroduodenal NET grade (G), measured by their mitotic rate and Ki67 proliferation index, is important to predict prognosis. In this study, we aimed to compare the clinical outcomes of gastroduodenal NET according to grades in order to identify poor prognostic factors of gastroduodenal NETs. Fifty-four gastroduodenal NETs diagnosed between December 2008 and December 2020 in a tertiary referral hospital were retrospectively reviewed. The clinical outcomes of gastroduodenal NETs, according to tumor grades and factors associated with NET G2-3, were analyzed. A total of 52 gastroduodenal NET patients was enrolled. The mean follow-up period was 56.2 ± 40.1 months. The mean size of gastric and duodenal NET was 7.9 ± 11.0 mm and 9.8 ± 7.6 mm, respectively. During the study period, 72.7% (16/22) of gastric NETs and 83.3% (25/30) of duodenal NETS were G1. All G1 gastroduodenal NETs showed no lymph node or distant metastasis during the study periods. All G3 gastroduodenal NETs showed metastasis (one lymph node metastasis and 3 hepatic metastases). Among metastatic NETs, the smallest tumor size was a 13 mm gastric G3 NET. Factors associated with G2-3 NETs were larger tumor size, mucosal ulceration, proper muscle or deeper invasion, and lymphovascular invasion. A small-sized gastroduodenal NET confined to submucosa without surface ulceration may be suitable for endoscopic resection. After local resection of a gastroduodenal NET (G1) without lymphovascular and muscle proper invasion, follow-up examination without radical surgical resection can be recommended. G3 NETs may be treated by radical surgical resection, regardless of tumor size.

Parietal Cell Dysfunction: A Rare Cause of Gastric Neuroendocrine Neoplasm with Achlorhydria and Extreme Hypergastrinemia

A 69-year-old woman with multiple neuroendocrine neoplasms (NENs) was referred to our hospital. Although she had extreme hypergastrinemia (11,675 pg/mL), no findings that indicated types I to III gastric NENs were found. Although gastric corpus atrophy was suspected on conventional white-light imaging, findings on magnifying endoscopy with narrow-band imaging indicated no severe atrophy. A biopsy from the background fundic gland mucosa revealed no atrophic changes, parietal cells with vacuolated cytoplasm and negative findings for H⁺K⁺-ATPase. Thus, this case was diagnosed as multiple NENs with parietal cell dysfunction. Neither progression nor metastasis has been confirmed during two-year follow-up.

Defining prognostic parameters of well-differentiated gastric neuroendocrine tumors based on metastatic potential: a two-center experience

Background: Gastric neuroendocrine tumors [gNETs] are heterogeneous tumors and we are still unable to predict the behavior of these tumors. We aim to define the prognostic parameters of well-differentiated gNETs based on metastatic potential and to evaluate the current classification systems. Patients and methods: We retrospectively retrieved 44 well differentiated gNET cases who underwent radical surgery between 2000-2015 at two tertiary-care centers. Results: Among the 44 well-differentiated gNET patients, 17 (38%) patients had metastatic disease to lymph nodes and/or distant sites, while 27 (62%) were confined to the stomach. Higher risk of metastasis was observed with increasing tumor size, grade, depth of invasion and with type-3 and solitary tumors. 30 (68%) patients had type-1 gNET and 14 (32%) had type-3 gNET. Majority of the type-1 cases (76,6%) were Grade 1 [G1] and type-3 cases (78,5%) were Grade 3 [G3]. Type-1 subgroup had no G3 tumor, and type-3 had no G1. Grade 2 [G2] tumors were more controversial, with metastatic and non-metastatic cases. G2 cases with a >10% Ki67 expression or type-3, had a worse prognosis. Although most of the type-1 gNETs had an indolent course, 6 of 30 (20%) patients had metastatic disease. Metastasizing type-1 gNETs were >10 mm in diameter or extended to/beyond the submucosa. Conclusion: Regarding our results, tumor type, grade, size, focality and depth of invasion are the prognostic parameters for gNETs, based on metastatic potential. Besides these parameters, a two-tiered grading system with a 10% Ki-67 proliferation index cut-off value could be considered for right treatment choice.

ENETS standardized (synoptic) reporting for endoscopy in neuroendocrine tumors

Despite efforts from various endoscopy societies, reporting in the field of endoscopy remains extremely heterogeneous. Harmonisation of clinical practice in endoscopy has been highlighted by application of many clinical practice guidelines and standards pertaining to the endoscopic procedures and reporting are underlined. The aim of the proposed "standardised reporting" is to (1) facilitate recognition of gastrointestinal neuroendocrine neoplasms (NEN) on initial endoscopy, (2) to enable interdisciplinary decision making for treatment by a multidisciplinary team, (3) to provide a basis for a standardised endoscopic follow-up which allows detection of recurrence or progression reliably, (4) to make endoscopic reports on NEN comparable between different units, and (5) to allow research collaboration between NEN centres in terms of consistency of their endoscopic data. The ultimate goal is to improve disease management, patient outcome and reduce the diagnostic burden on the side of the patient by ensuring the highest possible diagnostic accuracy and validity of endoscopic exams and possibly interventions.

Gastric Neuroendocrine Tumor Mimicking Gastrointestinal Stromal Tumor: A Case Report

Gastric neuroendocrine tumors (NETs) are rare lesions that arise from enterochromaffin-like cells of the gastric mucosa. Gastric NETs are classified into 3 types of NETs and poorly differentiated neuroendocrine cancers. Most gastric NETs usually present as hemispherical, yellowish, polypoid lesions with a central depression and often as subepithelial tumors (SETs) because they are confined within the submucosal layer. Here, we report a case of gastric NET presenting as SET mimicking a gastrointestinal stromal tumor (GIST). Endoscopy revealed a 2.3-cm-sized SET with intact surface mucosa, and endoscopic ultrasonography showed a homogeneous hypoechoic lesion with a well-circumscribed margin. Typical features of gastric NET, such as yellowish mucosal changes or central ulceration, were not observed. GIST was suspected, and a laparoscopic wedge resection was performed. The final diagnosis was gastric NET with grade 2 differentiation.

Clinical Outcomes of Endoscopic Treatment for Type 1 Gastric Neuroendocrine Tumor

BACKGROUND

Although the rate of early detection and endoscopic treatment of gastric neuroendocrine tumors (NETs) is steadily increasing, there are insufficient studies on the long-term outcomes of endoscopic treatment. Therefore, we aimed to investigate the clinical features and long-term outcomes of endoscopic treatment for type 1 gastric NETs.

METHODS

Subjects who underwent endoscopic treatment for gastric NETs between March 1997 and December 2015 were included. Clinical features and endoscopic treatment outcomes were retrospectively investigated by reviewing medical records.

RESULTS

In total, 125 subjects underwent endoscopic treatment including forceps biopsy (n = 21), argon plasma coagulation (n = 1), endoscopic mucosal resection (EMR, n = 62), and endoscopic submucosal dissection (ESD, n = 41). In total, 103 patients with 114 lesions, who underwent EMR or ESD, were analyzed to evaluate endoscopic and oncologic outcomes. The rates of en bloc resection in the EMR and ESD groups were 91.5% and 97.7%, respectively. Complete resection rates were significantly higher in the ESD group than in the EMR group; it was also higher in < 1-cm small-sized lesions than in 1-2-cm large-sized lesions. Adverse events were similar between the two groups. During a median follow-up period of 63 months, local recurrence rates were 6.5% and 2.4% in the EMR and ESD groups, respectively, and the disease-free survival rate did not differ significantly between the groups.

CONCLUSION

Endoscopic treatment for type 1 gastric NETs less than 2 cm in diameter and confined to mucosal and submucosal layers could be an effective and safe treatment strategy based on the favorable long-term outcome.

AGA Clinical Practice Update on the Diagnosis and Management of Atrophic Gastritis: Expert Review

DESCRIPTION

The purpose of this Clinical Practice Update Expert Review is to provide clinicians with guidance on the diagnosis and management of atrophic gastritis, a common preneoplastic condition of the stomach, with a primary focus on atrophic gastritis due to chronic Helicobacter pylori infection-the most common etiology-or due to autoimmunity. To date, clinical guidance for best practices related to the diagnosis and management of atrophic gastritis remains very limited in the United States, which leads to poor recognition of this preneoplastic condition and suboptimal risk stratification. In addition, there is heterogeneity in the definitions of atrophic gastritis, autoimmune gastritis, pernicious anemia, and gastric neoplasia in the literature, which has led to confusion in clinical practice and research. Accordingly, the primary objective of this Clinical Practice Update is to provide clinicians with a framework for the diagnosis and management of atrophic gastritis. By focusing on atrophic gastritis, this Clinical Practice Update is intended to complement the 2020 American Gastroenterological Association Institute guidelines on the management of gastric intestinal metaplasia. These recent guidelines did not specifically discuss the diagnosis and management of atrophic gastritis. Providers should recognize, however, that a diagnosis of intestinal metaplasia on gastric histopathology implies the diagnosis of atrophic gastritis because intestinal metaplasia occurs in underlying atrophic mucosa, although this is often not distinctly noted on histopathologic reports. Nevertheless, atrophic gastritis represents an important stage with distinct histopathologic alterations in the multistep cascade of gastric cancer pathogenesis.

METHODS

The Best Practice Advice statements presented herein were developed from a combination of available evidence from published literature and consensus-based expert opinion. No formal rating of the strength or quality of the evidence was carried out. These statements are meant to provide practical advice to clinicians practicing in the United States. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Atrophic gastritis is defined as the loss of gastric glands, with or without metaplasia, in the setting of chronic inflammation mainly due to Helicobacter pylori infection or autoimmunity. Regardless of the etiology, the diagnosis of atrophic gastritis should be confirmed by histopathology. BEST PRACTICE ADVICE 2: Providers should be aware that the presence of intestinal metaplasia on gastric histology almost invariably implies the diagnosis of atrophic gastritis. There should be a coordinated effort between gastroenterologists and pathologists to improve the consistency of documenting the extent and severity of atrophic gastritis, particularly if marked atrophy is present. BEST PRACTICE ADVICE 3: Providers should recognize typical endoscopic features of atrophic gastritis, which include pale appearance of gastric mucosa, increased visibility of vasculature due to thinning of the gastric mucosa, and loss of gastric folds, and, if with concomitant intestinal metaplasia, light blue crests and white opaque fields. Because these mucosal changes are often subtle, techniques to optimize evaluation of the gastric mucosa should be performed. BEST PRACTICE ADVICE 4: When endoscopic features of atrophic gastritis are present, providers should assess the extent endoscopically. Providers should obtain biopsies from the suspected atrophic/metaplastic areas for histopathological confirmation and risk stratification; at a minimum, biopsies from the body and antrum/incisura should be obtained and placed in separately labeled jars. Targeted biopsies should additionally be obtained from any other mucosal abnormalities. BEST PRACTICE ADVICE 5: In patients with histology compatible with autoimmune gastritis, providers should consider checking antiparietal cell antibodies and anti-intrinsic factor antibodies to assist with the diagnosis. Providers should also evaluate for anemia due to vitamin B-12 and iron deficiencies. BEST PRACTICE ADVICE 6: All individuals with atrophic gastritis should be assessed for H pylori infection. If positive, treatment of H pylori should be administered and successful eradication should be confirmed using nonserological testing modalities. BEST PRACTICE ADVICE 7: The optimal endoscopic surveillance interval for patients with atrophic gastritis is not well-defined and should be decided based on individual risk assessment and shared decision making. A surveillance endoscopy every 3 years should be considered in individuals with advanced atrophic gastritis, defined based on anatomic extent and histologic grade. BEST PRACTICE ADVICE 8: The optimal surveillance interval for individuals with autoimmune gastritis is unclear. Interval endoscopic surveillance should be considered based on individualized assessment and shared decision making. BEST PRACTICE ADVICE 9: Providers should recognize pernicious anemia as a late-stage manifestation of autoimmune gastritis that is characterized by vitamin B-12 deficiency and macrocytic anemia. Patients with a new diagnosis of pernicious anemia who have not had a recent endoscopy should undergo endoscopy with topographical biopsies to confirm corpus-predominant atrophic gastritis for risk stratification and to rule out prevalent gastric neoplasia, including neuroendocrine tumors. BEST PRACTICE ADVICE 10: Individuals with autoimmune gastritis should be screened for type 1 gastric neuroendocrine tumors with upper endoscopy. Small neuroendocrine tumors should be removed endoscopically, followed by surveillance endoscopy every 1-2 years, depending on the burden of neuroendocrine tumors. BEST PRACTICE ADVICE 11: Providers should evaluate for iron and vitamin B-12 deficiencies in patients with atrophic gastritis irrespective of etiology, especially if corpus-predominant. Likewise, in patients with unexplained iron or vitamin B-12 deficiency, atrophic gastritis should be considered in the differential diagnosis and appropriate diagnostic evaluation pursued. BEST PRACTICE ADVICE 12: In patients with autoimmune gastritis, providers should recognize that concomitant autoimmune disorders, particularly autoimmune thyroid disease, are common. Screening for autoimmune thyroid disease should be performed.

Gastric Neuroendocrine Tumors: Reappraisal of Type in Predicting Outcome

BACKGROUND

Type I gastric neuroendocrine tumors (GNETs) are typically managed either expectantly or endoscopically. In contrast, locoregional surgery has been recommended for patients with type III GNETs because of the risk of metastasis. This study aimed to identify predictors of outcome independent of type in a contemporary cohort of GNET patients.

METHODS

A single-institution retrospective cohort study of 121 patients with a pathologic diagnosis of primary GNET between January 2009 and June 2019 was performed. GNETs were designated as type 1 (n = 74) if atrophic gastritis was present, or as type III (n = 47) in the absence of atrophic gastritis. Demographic, clinical, and histopathologic factors were examined using Kaplan-Meier and multivariable Cox regression to assess the impact of various factors on recurrence and overall survival.

RESULTS

Median follow-up for the entire cohort was 62.7 months. While there was no difference in OS in patients with different GNET types (p = 0.10), higher tumor grade (p = 0.02) and presence of nodal or distant metastases (p = 0.02) predicted worse survival on multivariable analysis. Among type III GNET patients, those with small (< 0.5 cm), grade 1 lesions ("low-risk") were less likely to develop metastases (0% versus 33%, p < 0.01) and more likely to survive (100% versus 67%, p < 0.01) at 5 years.

CONCLUSIONS

Size and tumor grade predict recurrence and survival in patients with GNETs irrespective of type. Small, low-grade type III GNETs are associated with minimal risk of progression and may be managed accordingly.

Risk factors for lymph node metastasis in gastric neuroendocrine tumor: a retrospective study

Background

Lymph node metastasis (LNM) plays a vital role in the determination of clinical outcomes in patients with gastric neuroendocrine tumor (G-NET). Preoperative identification of LNM is helpful for intraoperative lymphadenectomy. This study aims to investigate risk factors for LNM in patients with G-NET.

Methods

We performed a retrospective study involving 37 patients in non-LNM group and 82 patients in LNM group. Data of demographics, preoperative lab results, clinical–pathological results, surgical management, and postoperative situation were compared between groups. Significant parameters were subsequently entered into logistic regression for further analysis.

Results

Patients in LNM group exhibited older age (p = 0.011), lower preoperative albumin (ALB) (p = 0.003), higher carcinoembryonic antigen (CEA) (p = 0.020), higher International normalized ratio (p = 0.034), longer thrombin time (p = 0.018), different tumor location (p = 0.005), higher chromogranin A positive rate (p = 0.045), and higher Ki-67 expression level (p = 0.002). Logistic regression revealed ALB (p = 0.043), CEA (p = 0.032), tumor location (p = 0.013) and Ki-67 (p = 0.041) were independent risk factors for LNM in G-NET patients.

Conclusions

ALB, CEA, tumor location, and Ki-67 expression level correlate with the risk of LNM in patients with G-NET.

Gastric neuroendocrine tumours from long-term proton pump inhibitor users are indolent tumours with good prognosis

AIMS

Proton pump inhibitors (PPIs) are among the most widely used medications in the United States. Most PPI users have persistent hypergastrinaemia during treatment. However, gastric neuroendocrine tumours diagnosed in long-term PPI users are rarely reported. Their clinicopathological features and prognosis are not characterised. It remains unclear whether or not they can be classified as Type III sporadic tumours.

METHODS AND RESULTS

We retrospectively characterised 66 gastric neuroendocrine tumours from patients without atrophic gastritis and gastrinoma from two tertiary care medical centres, including 38 tumours in patients who had used PPIs for at least 1 year and 28 tumours from patients without long-term PPI use (control group, Type III tumours). Compared to controls, tumours from long-term PPI users tended to be in the pT1-2 category (98% versus 79%, P = 0.09) and less often invaded the serosa (3% versus 18%, P = 0.08) or lymphovascular spaces (11% versus 32%, P = 0.06). Using Kaplan-Meier analysis, long-term PPI users had significantly longer overall survival than controls (P = 0.035). While three control patients developed distant metastasis and seven died, long-term PPI users were without distant metastasis (P = 0.06) or death (P = 0.002) during follow-up. However, five long-term PPI users developed additional gastric neuroendocrine tumour(s), while none of the controls did (P = 0.07).

CONCLUSIONS

Our results show that gastric neuroendocrine tumours of long-term PPI users are probably less aggressive compared to Type III sporadic tumours and have an indolent disease course. Our findings support the classification of gastric neuroendocrine tumours in long-term PPI users as a separate subtype.

Systematic review: management of localised low-grade upper gastrointestinal neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours (NETs) of the stomach and duodenum are rare, but are increasing in incidence. Optimal management of localised, low-grade gastric and duodenal NETs remains controversial.

AIMS

To systematically review recent literature that has evaluated the management of localised low-grade gastric and duodenal NETs.

METHODS

A systematic literature search was conducted. Articles were screened and eligible articles fully assessed. Additional articles were identified through the included articles' reference lists.

RESULTS

Several relevant retrospective case series were identified, but there was considerable heterogeneity between studies and they reported a variety of parameters. Type I gastric NETs had an excellent prognosis and conservative management approaches such as endoscopic surveillance/resection were appropriate in most cases. Many type III gastric NETs were low grade and appeared to have a better prognosis than has previously been appreciated. Endoscopic rather than surgical resection was therefore effective in some patients who had small, low-grade tumours. Duodenal NETs were more heterogenous. Endoscopic resection was generally safe and effective in patients who had small, low-grade, nonfunctional, non-ampullary tumours. However, some patients, especially those with larger or ampullary duodenal NETs, required surgical resection.

CONCLUSIONS

Most type I gastric NETs behave indolently and surgical resection is only rarely indicated. Some type III gastric and duodenal NETs have a worse prognosis, but selected patients who have small, localised, nonfunctional, low-grade tumours are adequately and safely treated by endoscopic resection. Due to the complexity of this area, a multidisciplinary approach to management is strongly recommended.

[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%).

Recurrence and metastatic potential in Type 1 gastric neuroendocrine neoplasms

BACKGROUND

The aim of our study was to assess clinico-pathological and biochemical parameters of Type 1 Gastric Neuroendocrine Neoplasms (GNEN1) with respect to tumours propensity for recurrence and metastasis.

METHODS

Hospital charts of GNEN1 patients were reviewed at a single tertiary referral centre.

RESULTS

We included 114 consecutive patients (74 women; age at baseline 54.5 ± 12.7 years [mean ± SD]) with GNEN1. All tumours (n = 114) were well differentiated; Grade 1 (G1) accounted for 56 patients (49%), whereas 46 (40%) were Grade 2 (G2) and 12 (11%) of unknown Grade. Overall follow-up encompassed 45.3 ± 46 (mean ± SD) months in 84 patients who were subjected to annual surveillance; 44 (52%) developed recurrence in the stomach during follow-up with 22 experiencing multiple recurrences; three (2.6%) presented with metastases in locoregional lymph nodes (n = 3) and/or the liver (n = 2); No metastasis or death was reported during follow-up. Median recurrence-free survival (RFS) was 31 months (95% CI: 7.6-54.4). Among clinico-pathological and biochemical parameters investigated, endoscopic intervention compared with surgery (P-value = .009) and higher serum-gastrin levels (s-gastrin) at baseline and first-year follow-up were associated with recurrence (P-value = .022 and .003 respectively) and also shorter RFS (log-rank P = .009 for type of intervention and .014 for s-gastrin, respectively). Receiver Operator Curve analysis of s-gastrin levels at first-year follow-up for recurrence demonstrated an area under the curve of 0.702.

CONCLUSION

Despite the relatively high prevalence of G2 tumours, endoscopically and/or surgically treated GNEN1 remains an indolent disease with a low metastatic propensity and no disease-specific mortality reported in our series. Many patients though will experience local recurrence, warranting long-term endoscopic surveillance with s-gastrin biomarker being a complementary tool in recurrence prediction.

Clinical characteristics of early neuroendocrine carcinoma in stomach: A case report and review of literature

INTRODUCTION

Gastric neuroendocrine carcinoma (NEC) is rare. It is considered to be aggressive and has a poor prognosis since the diagnosis is usually made at its advanced stage. However, the survival rate is increased in some early gastric NECs. This study showed a case and reviewed the clinical characteristics of early NECs in stomach.

PATIENT CONCERNS

A 38-year-old man displayed no symptoms and underwent the gastric endoscopy test for his health examination, which showed a red slightly depressed lesion 1.0 cm in size on the lesser curvature of gastric cardia. Magnifying endoscopy with narrow-band imaging (NBI) revealed a clear demarcation and an irregular mesh in vessels within the depressed area. The background mucosa was negative for atrophic gastritis and Helicobacter Pylori infection. A contrast-enhanced computed tomography (CT) scan disclosed no obvious thickening of stomach and lymphadenopathy. Blood tests and physical examination were unremarkable. He had not received any surgical treatment and denied a family history of cancer and any genetic disorders. The pathologic result of biopsy from the lesion was suspicious of superficial carcinoma. Then endoscopic submucosal dissection (ESD) was performed.

DIAGNOSIS

Gastric NEC G3 in the early stage (T1aN0M0).

INTERVENTIONS

Concerning this patient's situation, we considered the ESD as a curable treatment. And no radical surgery or adjuvant chemotherapy was arranged.

OUTCOMES

The patient is doing well and displays no recurrence for 11 months, who is still in follow-up.

LESSONS SUBSECTIONS AS PER STYLE

The early diagnosis and effective treatment by endoscopy would contribute to improve the prognosis of gastric NECs.

Gastric carcinoids: Does type of surgery or tumor affect survival?

BACKGROUND

Gastric carcinoids are rare neuroendocrine tumors of the gastrointestinal tract. They are typically managed according to their etiology. However, there is little known about the impact of surgical strategy on the long-term outcomes of these patients.

METHODS

All patients who underwent resection of gastric carcinoids at 8 institutions from 2000 to 2016 were analyzed retrospectively. Tumors were stratified according to subtype (I, II, III, IV) and resection type (local resection, LR or formal gastrectomy, FG). Clinicopathological parameters, recurrence-free (RFS) and overall survival (OS) were compared between groups.

RESULTS

Of 79 patients identified with gastric carcinoids, 34 had type I lesions associated with atrophic gastritis, 4 had type II lesions associated with a gastrinoma, 37 had type III sporadic lesions, and 4 had type IV poorly-differentiated lesions. The mean age of presentation was 56 years in predominantly Caucasian (77%) and female (63%) patients. Mean tumor size was 2.4 cm and multifocal tumors were found in 24 (30%) of patients with the majority occurring in those with type I tumors. Lymph node positive tumors were seen in 15 (19%) patients and 7 (8%) had M1 disease; both most often in type IV followed by type III tumors. R0 resection was achieved in 56 (71%) patients while 15 (19%) had R1 resections and 6 (8%) R2 resections. Patients with type I and III tumors were equally likely to have a LR (50% and 43% respectively) compared to FG while those with type II and IV all had FG with one exception. Type IV tumors had the poorest RFS and OS while Type II tumors had the most favorable RFS and OS (p < 0.04 and p < 0.0004, respectively). While there was no difference in RFS in those patients undergoing FG versus LR, OS was worse in the FG group (p < 0.017). This trend persisted when type II and type IV groups were excluded (p < 0.045).

CONCLUSION

Gastric carcinoid treatment should be tailored to tumor type, as biologic behavior rather than resection technique is the more important factor contributing to long-term outcomes.

Should Ki67 immunohistochemistry be performed on all lesions in multifocal small intestinal neuroendocrine tumours?

AIMS

Well-differentiated small intestinal neuroendocrine tumours (SI-NETs) are often multifocal, and this has been suggested to impart worse disease-free survival. Practice guidelines have not been established for World Health Organisation (WHO) grading of multiple primary lesions.

METHODS AND RESULTS

We identified 68 patients with ileal/jejunal SI-NET for a combined total of 207 primary lesions. Each case was evaluated for patient age and sex; size of all tumours; presence of lymph node metastases, mesenteric tumour deposits or distant metastases; and disease-specific outcome. Ki67 staining was performed on all 207 primary lesions. The relationship between multifocality and clinicopathological factors was compared using Fisher's exact test. Outcome was tested using Cox proportional hazard regression. Forty-two patients had unifocal disease, and 26 had multifocal disease (median five lesions, range = 2-32). Most tumours were WHO grade 1 (201 of 207, 97%). Of the five patients with grades 2/3 tumours, three patients had unifocal disease, one patient had two subcentimetre grade 2 lesions (including the largest) and eight subcentimetre grade 1 lesions, and one patient had one 1.6-cm grade 3 lesion and one subcentimetre grade 1 lesion. There was a positive correlation between tumour size and Ki67 index (coefficient 0.28; 95% confidence interval 0.05-0.52, P = 0.017). There was no significant association between multifocality and nodal metastases, mesenteric tumour deposits, distant metastases or disease-specific survival.

CONCLUSIONS

In patients with multifocal SI-NET, unless a particular lesion has a high mitotic rate, only staining the largest lesion for Ki67 should serve to grade almost all cases accurately. Multifocality does not appear to significantly impact patient survival.

Clinicopathological features and prognosis of patients with gastric neuroendocrine tumors: A population-based study

Background

Despite its rarity, studies have shown the incidence of gastric neuroendocrine tumors (G‐NETs) is increasing. This study investigated the risk factors affecting the survival of G‐NETs patients and their prognosis over time.

Method

A retrospective analysis of 506 G‐NETs patients who underwent surgery for nonmetastatic disease from the Surveillance, Epidemiology and End Result database from 1988 to 2011 was conducted. Multivariate Cox regression analyses identified the prognostic factors affecting overall survival (OS) and disease‐specific survival (DSS). Three‐year conditional survival (COS3 and CDS3) estimates at “x” year after treatment were calculated as follows: COS3 = OS(x + 3)/OS(x) and CDS3 = DSS(x + 3)/DSS(x).

Results

The 1‐, 3‐, and 5‐year OS rates of all patients after surgery were 90.2%, 77.3%, and 68.8%, respectively. The 1‐, 3‐, and 5‐year DSS rates after surgery were 93.9%, 84.5%, and 80.9%, respectively. In the multivariate analysis, age, tumor grade, and T stage were independent prognostic factors of OS and DSS (all P < 0.05). With 1‐, 3‐, and 5‐year survivorship, the COS3 improved by +5.2 (82.2%), +7.2 (84.4%), and +8.5 (85.5%), respectively, and the CDS3 improved by +4.4 (89.4%), +9.1 (94.1%), and +12.5 (97.5%), respectively. Notably, the CDS3 improved dramatically among patients with advanced stage disease (eg, N0 stage: 93.0%‐98.9%, Δ5.9% vs N1 stage: 52.0%‐95.7%, Δ43.7%).

Conclusion

For G‐NETs patients, age, tumor grade, T stage, and N stage were the clinicopathological factors significantly associated with prognosis. There were excellent outcomes for most G‐NETs patients, with a CDS3 of greater than 90% across all independent prognostic factors after 5 years of survival.

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.

Clinical features and outcomes of gastric neuroendocrine tumors after endoscopic diagnosis and treatment: A Digestive Endoscopy Society of Tawian (DEST)

Gastric neuroendocrine tumors (GNETs) are a heterogeneous group of neoplasm with varying biological characteristics. This study aimed to investigate the clinical features and outcomes of GNET patients after endoscopic diagnosis and treatment in a multicenter registry. Patients with GNETs confirmed histologically were recruited from 17 hospitals between January 2010 and April 2016 in Taiwan. Clinical, laboratory, radiological, endoscopic, pathological data, treatment strategies, follow-up periods, and survivals were collected retrospectively. Totally 187 (107 female, 80 male) patients were recruited. Mean ( ± standard deviation [SD]) age and size of tumors were 63.2-year-old ( ± 14.6) and 2.3-cm ( ± 3.0). World Health Organization (WHO) grading were 93 (49.7%) G1, 26 (13.9%) G2, 40 (21.4%) G3, and 28 (15.0%) unknown. G3 patients were older (mean ± SD, 71.6 ± 12.4 vs. 60.9 ± 14.3/56.7 ± 15.4 years), larger (6.1 ± 4.0 vs.1.2 ± 1.3/2.4 ± 2.5 cm), more distally located (35.0% vs. 7.6%/15.4%), lower proportion of superficial lesions (17.5% vs. 61.9%/53.8%) and higher rates of lymphovascular invasion (32.5% vs. 3.2%/7.7%) than G1/G2. There was no nodal or distant organ metastases despite different grading of lesions≦10 mm and those <20 mm limited to mucosa and submucosa layers. GNETs larger than 20 mm with G1, G2, and G3 had lymph node (LN) metastatic rates of 21.4%, 30.0%, and 59.3%, respectively. Survivals were different between grading for those >20 mm (log-rank test P = .02). Male gender (P = .01), deeper invasion (P = .0001), nodal (P < .0001), and distant organ metastases (P = .0001) were associated with worse outcome. In conclusion, treatment strategies for GNET should be decided by grading, size, invasiveness, and LN metastasis risk. Curative endoscopic resection is feasible for G1/2 lesions less than 20 mm and limited to mucosa/submucosa layers without lymphovascular invasion.

Incidence and prevalence of neuroendocrine tumors of the lung: analysis of a US commercial insurance claims database

BACKGROUND

As reported in Surveillance, Epidemiology, and End Results (SEER) data, US incidence and prevalence of neuroendocrine tumors (NET) has increased over recent years. The study objective was to update incidence and prevalence information for lung NET using administrative claims.

METHODS

This descriptive epidemiological study used 2009-2014 data from 2 US claims databases: MarketScan and PharMetrics. Patients (18-64 years old) had ≥1 inpatient or ≥ 2 outpatient claims with NET of bronchus or lung, identified by International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes. Prevalence was number of lung NET patients divided by number of enrollees/year. Incidence was number of patients with a first observed NET diagnosis who were disease-free for 2 years prior, divided by number of enrollees. Age and gender adjustments performed.

RESULTS

The annual number of patients with lung NET identified from 2009 to 2014 ranged from 435 to 796 (MarketScan) and 419-648 (PharMetrics). In MarketScan, there was a 7.4% (95%CI 2.1-13.0; p = 0.027) annual percent change (APC) in the age-adjusted incidence for males and 6.8% (- 0.2-14.3; 0.052) for females. In PharMetrics, APC was - 2.9% (- 13.8-9.4; 0.395) for males; 14.7% (- 12.9-51.2; 0.165) for females. In MarketScan, APC in age-adjusted prevalence for males was 9.9% (4.7-15.3; 0.006); 16.2% (11.4-21.1; <.001) for females. For PharMetrics, APCs were 9.5% (2.3-17.2; 0.021) for males; 16.3% (9.6-23.5; 0.002) for females.

CONCLUSIONS

From 2009 to 2014 there was a statistically significant increase in age-adjusted lung NET incidence for males in MarketScan, and a statistically significant increase in age-adjusted prevalence for both genders in PharMetrics. Incidence and prevalence changes, to the extent they exist, may be due to better diagnostic methods, increased awareness of NET among clinicians and pathologists, and/or an actual increase in US disease occurrence. Differences in rates across databases are difficult to explain. These results suggest the need for awareness of the clinically effective and safe treatment options available for lung NET patients among healthcare providers.

Clinicopathological features and outcome of type 3 gastric neuroendocrine tumours

BACKGROUND

With the widespread use of endoscopy, small and low-grade type 3 gastric neuroendocrine tumours (NETs) are increasingly being detected. The clinicopathological features, biological behaviour and appropriate treatment strategy for these NETs remain unclear.

METHODS

Patients with biopsy-proven gastric NET and a normal fasting serum gastrin level were identified from a prospectively maintained database. Clinicopathological features and long-term outcome of local resection for type 3 NETs were reviewed retrospectively and compared according to tumour grade.

RESULTS

Some 32 patients with type 3 gastric NETs were included (25 patients with NET grade G1, 5 with G2 and 2 with G3). Pathological tumour size was 2·0 cm or less in 30 patients. All tumours were well differentiated, even G3 lesions, and all tumours but one were confined to the submucosal layer. G1 NETs were significantly smaller and had a significantly lower lymphovascular invasion rate than G2 and G3 NETs. Twenty-two patients with a G1 NET without lymphovascular invasion were treated with wedge or endoscopic resection. After a median follow-up of 59 (range 6-102) months, no patient with a G1 NET of 1·5 cm or smaller developed recurrence and one patient with a G1 NET larger than 1·5 cm had recurrence in a perigastric lymph node. Among seven patients with a G2 or G3 NET, two had lymph node metastasis and one had liver metastases.

CONCLUSION

Low-grade type 3 gastric NET has non-aggressive features and a favourable prognosis. Wedge or endoscopic resection may be a valid option for patients with type 3 gastric G1 NET no larger than 1·5 cm without lymphovascular invasion.

The effect of hypergastrinemia following sleeve gastrectomy and pantoprazole on type 2 diabetes mellitus and beta-cell mass in Goto-Kakizaki rats

PURPOSE

Metabolic surgery alters the secretion of gastrointestinal hormones that influence glycemic control. Elevated gastrin has been suggested to benefit patients with type 2 diabetes and has been reported following sleeve gastrectomy in rats. The present study compares the effect of hypergastrinemia following sleeve gastrectomy with proton-pump inhibitor therapy on glycemic control and beta-cell mass in lean, diabetic animals.

METHODS

Thirty-three diabetic Goto-Kakizaki rats were randomized into pantoprazole + sham operation (GK-PPI), sleeve gastrectomy (GK-SG) and vehicle + sham operation (GK-V). Body weight, glucose parameters, HbA1c, glucagon-like peptide 1, gastrin, insulin and lipids were evaluated for eighteen postoperative weeks. Total beta-cell mass was quantified by optical projection tomography.

RESULTS

After surgery, body weight development was equal among groups (P _g = 0.75). Fasting and stimulated gastrin increased for GK-PPI and GK-SG vs. GK-V (p < 0.05 for all). Fasting blood glucose was decreased for GK-PPI and GK-SG vs. GK-V (p < 0.05 and p = 0.052). HbA1c was lower for GK-SG vs. GK-V at 6 weeks and for GK-PPI vs. GK-V at twelve- and eighteen weeks postoperative (p < 0.05 for all); a borderline difference was observed for GK-SG vs. GK-V at 18 weeks (p = 0.054). Total- and LDL cholesterol was elevated for GK-PPI compared to the other two groups (p < 0.05 for all). Beta-cell mass did not differ among groups (p = 0.35).

CONCLUSIONS

Hypergastrinemia following sleeve gastrectomy and pantoprazole has a similar, modest effect on glycemic control in Goto-Kakizaki rats but does not enhance beta-cell mass after 18 weeks. Hypergastrinemia in the setting of T2DM might be of clinical relevance.

How should incidental NEN of the pancreas and gastrointestinal tract be followed?

Neuroendocrine gastro-entero-pancreatic neoplasms (GEP-NENs) constitute a heterogeneous group of tumors, whose incidence has increased over the years. The most frequent site for primary disease is the stomach followed by small and large intestine, and pancreas. In the last decade, a dramatic growing in the incidence of small, incidental GEP-NENs has been recorded. In parallel, an increasing attitude toward more conservative approaches instead of surgical management has being widely spreading. This is particularly true for small, asymptomatic, pancreatic NEN as for these tumor forms an active surveillance has proven to be safe and feasible. Primary site and biological features of the neoplasms lead to different strategies and indications for surveillance and follow-up. This review focuses on the current evidence on modality and timing of surveillance and conservative treatment of incidentally discovered lesions.

Pitfalls in the Diagnosis of Neuroendocrine Tumors: Atypical Clinical and Radiological Findings as Cause of Medical Mistakes

Aims and background

Carcinoids are infrequent neoplasms arising from neuroendocrine cells. Due to blurred symptoms and the presence of equivocal diagnostic findings, these tumors are sometimes misdiagnosed. Therefore, increased rates of false neuroendocrine tumors represent an emerging problem in clinical practice. Our aim is to alert clinicians on this matter by supplying them with useful warnings.

Methods

In the specialized neuroendocrine tumor study Center Centro di Riferimento per lo Studio e la Cura dei Carcinoidi e dei Tumori Neuroendocrini (Ce.Ri.Ca), some patients highly suspected to have a neuroendocrine tumor have been recognized as having false neuroendocrine tumors. The related clinical and instrumental findings leading to a previous wrong neuroendocrine tumor diagnosis are reported.

Results

From July 2006 to December 2008, 88 consecutive cases of neuroendocrine tumors (Nets) were referred at Ce.Ri.Ca. In the former group, 8 cases of false Nets were discovered while in the remaining 80 cases a correct Net diagnosis was carried out. Watchful differential diagnoses and skill appraisal of laboratory investigations resulted in: chronic atrophic gastritis with enterochromaffin-like cell hyperplasia (4 cases), estrogen-deprivation syndrome (1), hypochondriac disorder (1), metabolic syndrome (1), and sarcoidosis (1).

Conclusions

Neuroendocrine tumors are still relatively known clinical entities. To discriminate false neuroendocrine tumors from neuroendocrine tumors requires a good expertise and a large daily practice with the disease. Good knowledge and skillfulness in identifying biochemical alterations and false radiological positive results could avoid both patient inconvenience and very expensive workup. The importance of a multidisciplinary approach in specialized centers is emphasized.

Diagnosis and Management of Upper Gastrointestinal Neuroendocrine Tumors

Upper gastrointestinal neuroendocrine tumors (NETs) are rare tumors which are increasingly recognised by practising endoscopists. After confirmation by endoscopic biopsies of these focal lesions, many questions may arise. As NETs are less frequently encountered compared to other malignancies or gastrointestinal pathology, many endoscopists may not fully understand the natural history, diagnosis and management of these tumors. In this review, we aim to update the practising endoscopist on the key clinical features and management of patients with upper gastrointestinal NET.

Early Gastroenteropancreatic Neuroendocrine Tumors: Endoscopic Therapy and Surveillance

Neuroendocrine neoplasias (NEN) of the stomach, duodenum, pancreas, appendix, or rectum that are ≤1 cm in size as well as well-differentiated with World Health Organization grade 1 (G1) can be considered 'early' neuroendocrine tumors; they have a very good prognosis. Regarding prognosis, neuroendocrine tumors (NET) G1 must be distinguished from well-differentiated NET G2 and poorly differentiated neuroendocrine carcinomas (NEC) G3. NET are increasing, with a rise in the age-adjusted incidence in the USA by about 700% in the last 40 years. Earlier diagnosis of NET is one of the main epidemiological changes of clinically detected NEN. The general availability of high-resolution endoscopy and advanced radiological imaging techniques has contributed to a shift in the discovery to smaller-sized (≤10 mm) gastrointestinal and pancreatic NET and earlier tumor stages at diagnosis. Thus, screening colonoscopy is effective in the early diagnosis not only of colorectal adenomas and adenocarcinomas but also of rectal NET. Endoscopic resection is the treatment of choice in NET G1 of the stomach, duodenum (despite gastrinoma), and rectum that are ≤10 mm in size, do not infiltrate the muscularis propria (T1), and do not show angioinvasion (V0, L0). Similarly, histologically proven, early pancreatic NET G1 (≤10 mm) may be managed conservatively by regular surveillance. In contrast, small (≤1 cm) NET G1 of the jejunum or ileum are not 'early' tumors and have to be resected surgically with lymph node dissection.

Medical Therapy of Gastrointestinal Neuroendocrine Tumors

Intestinal neuroendocrine tumors (NETs) constitute a heterogeneous group with duodenal, small intestinal, colonic and rectal NETs. They constitute more than half of all NETs, with the highest frequencies in the rectum, small intestine, and colon. The tumor biology varies with the location of the primary tumor as well as with the grade and staging of the tumor. Small intestinal NETs usually present low proliferation and are treated in the first line with somatostatin analogs according to current guidelines. If progression occurs, one can add interferon alpha or change the treatment to everolimus. Peptide receptor radionuclide therapy (PRRT) with Lutetium¹⁷⁷-DOTATATE can be an option in the future after registration of the compound. Rectal tumors are usually small when they metastasize; they can be treated with somatostatin analogs but more so with PRRT, while another option is of course everolimus. Colonic NETs are more aggressive than the rest of intestinal NETs and will be treated with everolimus, sometimes in combination with somatostatin analogs based on positive scintigraphy. Another option is a cytotoxic agent such as streptozotocin plus 5-fluorouracil (5-FU) or temozolomide plus capecitabine. The most aggressive tumors, i.e. neuroendocrine carcinoma G3, are treated with a platin-based therapy plus etoposide; if they present with a lower proliferation, i.e. <50%, temozolomide plus capecitabine plus bevacizumab can also be attempted. Duodenal NETs are mostly treated similar to pancreatic NETs, either with cytotoxic agents, streptozotocin plus 5-FU, or temozolomide plus capecitabine, or with targeted agents such as everolimus.

Management of gastric neuro-endocrine tumours in a large French national cohort (GTE)

INTRODUCTION

Gastric neuro-endocrine tumours are rare. European guidelines for the management of neuro-endocrine tumours have been published in 2012. The aim of our survey was to study the management of gastric neuro-endocrine tumours registered in the national cohort. A prospective national cohort registers the Neuro-endocrine tumours in France since January 2003 (GTE network). We reviewed all the individual medical reports of gastric neuro-endocrine tumours in order to collect data on treatment.

RESULTS

One hundred and ninety seven gastric neuro-endocrine tumours diagnosed between 1964 and 2013 in 20 centres were registered. For 181 cases data were considered complete for our survey. Eighty four tumours were type 1 (46.4%); five types 2 (2.8%); 52 types 3 (28.7%) and 40 types 4 (22.1%). Types 1 and 2 were first endoscopically managed in 93 and 60% of cases, respectively, whereas surgery was first done in 45 and 42%, respectively, of types 3 and 4. Systemic treatment, chemotherapy and/or somatostatin analogue, was first administered exclusively for types 3 and 4. Near 3% of types 1 and 40% of types 2 received at a time somatostatin analogue treatment. Five-year survival rates were 98.3, 100, 63.2 and 31.8% for types 1, 2, 3 and 4, respectively.

CONCLUSION

The great majority of gastric neuro-endocrine tumours registered in this national cohort are treated in accordance with the current guidelines. The survival rates we reported must be interpreted with caution, because this cohort registered preferentially selected patients eligible for treatment. The registration of all the gastric neuro-endocrine tumours, in particular type 1 considered as benign and type 4 not eligible for specific anti-cancer treatment must be encouraged.

Evaluation and management of gastric epithelial polyps

Gastric polyps include a wide spectrum of lesions with different histology and neoplastic potential. They are found in up to 6% of upper gastrointestinal endoscopy and are usually asymptomatic and incidentally diagnosed, being in the vast majority epithelial gastric polyps. Hyperplastic, fundic gland and adenomas are the most common types of gastric polyps and, although each type may have typical endoscopic appearances, they all must be sampled at the initial endoscopy for histological assessment. Also, the normal appearing gastric mucosa should be sampled to stage atrophic changes, rule out endoscopically non-visible dysplasia and to diagnose Helicobacter pylori. Polyposis syndromes that affect the stomach are rare but should be taken into account. Hamartomatous polyps can be found in Juvenile polyposis, Cowden syndrome and Peutz-Jeghers syndrome. On the other hand, multiple fundic gland polyps are present in the majority of patients with familial adenomatous polyposis. In this study we provide a comprehensive review on the evaluation and management of gastric epithelial polyps, in this way helping physicians to properly handle this type of lesions.

Comparison of relapse-free survival in gastric neuroendocrine carcinoma (WHO grade 3) and gastric carcinoma

BACKGROUND

We compared relapse-free survival (RFS) in gastric neuroendocrine carcinoma (WHO grade 3) and gastric carcinoma (GC). This is one of very few studies that compare the prognosis of poorly differentiated neuroendocrine carcinoma (WHO grade 3, G3 NEC) with that of GC.

METHODS

Between 1996 and 2014, 63 patients were diagnosed with G3 NEC of the stomach and 56 with gastric neuroendocrine tumors (NETs) with GC at Asan Medical Center in Seoul, Korea. We also randomly selected 762 patients diagnosed with GC between 1999 and 2008.

RESULTS

Patients with G3 NEC tumors that invaded the muscularis propria or shallower had poorer RFS than those with GC of the same type, while G3 NEC that invaded the subserosa or deeper had similar RFS to GC of that type. Patients diagnosed with G3 NEC with N0 or N2 had poorer RFS than the corresponding patients with GC, while those who had G3 NEC with N1 or N3 had similar RFS to the corresponding patients with GC. G3 NEC patients had poorer RFS than well-differentiated, moderately differentiated and poorly differentiated GC patients, while G3 NEC patients had similar RFS to that of those with signet ring cell carcinoma (SRC). In addition, patients with G3 NEC of stages I or IIa had poorer RFS than those with corresponding GC, while G3 NEC stage IIb or greater had similar RFS to the corresponding GC.

CONCLUSIONS

Non-advanced G3 NEC showed poorer RFS than GC excluding SRC, while advanced G3 NEC has a similar RFS to that of GC without SRC. Therefore, we recommend that patients with non-advanced G3 NEC of the stomach be given a more aggressive treatment and surveillance than those with non-advanced GC excluding SRC.

Type 1 Gastric Carcinoid in the Indian Population and Its Association with Multifocal Gastric Atrophy

Aim

Recent studies have shown an increase in the incidence of gastric neuroendocrine tumors (NETs) (carcinoids). This may be attributable to the frequent employment of endoscopy in clinical practice and the increasing use of proton pump inhibitors. From the literature that is available, it is interesting to note that the profile of patients with gastric carcinoids is different in the Asian population when compared to the western societies. As limited data is available from India, we evaluated retrospectively the clinical profile and pathology of gastric carcinoids presenting to our hospital.

Materials and methods

A total of 31 patients with gastric carcinoids who presented to our institution from 2006 till 2013 were included in this study. The clinical data were obtained from the case files and the histopathology slides were reviewed.

Results

Gastric carcinoids constituted about 32% of all gastrointestinal (GI) NETs and were second only to duodenal carcinoids in frequency. Men were more commonly affected (74%) and the majority were of type 1 (90%). Multifocal gastric atrophy with intestinal metaplasia was additional features seen in the majority of cases with type 1 carcinoids.

Conclusion

This study, one of the largest series reported from India, shows that the frequency and profile of gastric carcinoids is different in this population when compared to the west. It also raises the possibility that Helicobacter pylori induced multifocal gastric atrophy might be a triggering factor for the most common type 1 gastric carcinoid rather than autoimmune gastritis.

Clinical significance

Eradication of H.pylori may be a potential preventive strategy for the occurrence of gastric carcinoids.

How to cite this article

Ananthamurthy A, Correa M, Patil M. Type 1 Gastric Carcinoid in the Indian Population and Its Association with Multifocal Gastric Atrophy. Euroasian J Hepato-Gastroenterol 2016;6(2):106-110.

Netazepide, a gastrin/cholecystokinin-2 receptor antagonist, can eradicate gastric neuroendocrine tumours in patients with autoimmune chronic atrophic gastritis

AIMS

Netazepide, a gastrin/cholecystokinin 2 receptor antagonist, once daily for 12 weeks reduced the number of tumours and size of the largest one in 16 patients with autoimmune chronic atrophic gastritis (CAG), achlorhydria, hypergastrinaemia and multiple gastric neuroendocrine tumours (type 1 gastric NETs), and normalized circulating chromogranin A (CgA) produced by enterochromaffin-like cells, the source of the tumours. The aim was to assess whether longer-term netazepide treatment can eradicate type 1 gastric NETs.

METHODS

After a mean 14 months off netazepide, 13 of the 16 patients took it for another 52 weeks. Assessments were: gastroscopy; gene-transcript expression in corpus biopsies using quantitative polymerase chain reaction; blood CgA and gastrin concentrations; and safety assessments.

RESULTS

While off-treatment, the number of tumours, the size of the largest one, and CgA all increased again. Netazepide for 52 weeks: cleared all tumours in 5 patients; cleared all but one tumour in one patient; reduced the number of tumours and size of the largest one in the other patients; normalized CgA in all patients; and reduced mRNA abundances of CgA and histidine decarboxylase in biopsies. Gastrin did not increase further, confirming that the patients had achlorhydria. Netazepide was safe and well tolerated.

CONCLUSIONS

A gastrin/cholecystokinin 2 receptor antagonist is a potential medical and targeted treatment for type 1 gastric NETs, and an alternative to regular gastroscopy or surgery. Treatment should be continuous because the tumours will regrow if it is stopped. Progress can be monitored by CgA in blood or biomarkers in mucosal biopsies.

A case of mixed adenoneuroendocrine carcinoma of the stomach with focal intestinal metaplasia and hypergastrinemia

Among neuroendocrine neoplasms, mixed exocrine and endocrine characteristics with at least 30% of each component are classified into mixed adenoneuroendocrine carcinoma (MANEC), according to the 2010 World Health Organization classification. We experienced a rare case of MANEC of the stomach with focal intestinal metaplasia and hypergastrinemia. A 76-year-old Japanese male was diagnosed as having gastric adenocarcinoma and underwent total gastrectomy. The pathologic diagnosis was MANEC of the stomach accompanied by unusual mucosal atrophy without Helicobacter pylori infection, the characteristics of which were different from both type A and type B atrophic gastritis. The patient has a history of long-term use of a proton pump inhibitor. Additional serum chemistry examination using preoperatively obtained plasma from the patient revealed hypergastrinemia. The mechanism of gastric MANEC carcinogenesis is still unclear, but that might be correlated with unusual intestinal metaplasia and hypergastrinemia in this case.

Management of gastric and duodenal neuroendocrine tumors

Gastrointestinal neuroendocrine tumors (GI-NETs) are rare neoplasms, like all NETs. However, the incidence of GI-NETS has been increasing in recent years. Gastric NETs (G-NETs) and duodenal NETs (D-NETs) are the common types of upper GI-NETs based on tumor location. G-NETs are classified into three distinct subgroups: type I, II, and III. Type I G-NETs, which are the most common subtype (70%-80% of all G-NETs), are associated with chronic atrophic gastritis, including autoimmune gastritis and Helicobacter pylori associated atrophic gastritis. Type II G-NETs (5%-6%) are associated with multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome (MEN1-ZES). Both type I and II G-NETs are related to hypergastrinemia, are small in size, occur in multiple numbers, and are generally benign. In contrast, type III G-NETs (10%-15%) are not associated with hypergastrinemia, are large-sized single tumors, and are usually malignant. Therefore, surgical resection and chemotherapy are generally necessary for type III G-NETs, while endoscopic resection and follow-up, which are acceptable for the treatment of most type I and II G-NETs, are only acceptable for small and well differentiated type III G-NETs. D-NETs include gastrinomas (50%-60%), somatostatin-producing tumors (15%), nonfunctional serotonin-containing tumors (20%), poorly differentiated neuroendocrine carcinomas (< 3%), and gangliocytic paragangliomas (< 2%). Most D-NETs are located in the first or second part of the duodenum, with 20% occurring in the periampullary region. Therapy for D-NETs is based on tumor size, location, histological grade, stage, and tumor type. While endoscopic resection may be considered for small nonfunctional D-NETs (G1) located in the higher papilla region, surgical resection is necessary for most other D-NETs. However, there is no consensus regarding the ideal treatment of D-NETs.

A 15-year experience with gastric neuroendocrine tumors: Does type make a difference?

BACKGROUND

Gastric neuroendocrine tumors (GNETs) are rare and classified into three types by disease etiology and typical behavior.

METHODS

The aim was to describe outcomes after GNET resection at a single institution from 2000 to 2014, stratified by tumor type. Given the small patient number, P-values were not assigned.

RESULTS

Of 22 patients, 12 patients (55%) had Type 1, none (0%) had Type 2, and 10 (45%) had Type 3 tumors. Compared to Type 3, Type 1 patients were younger (mean age: 52 vs. 59 years) with similar rates of endoscopic resection (25% vs. 20%). Type 1 GNETs often had multiple tumors (60% vs. 10%) and were not poorly differentiated (0% vs. 11%). Only 33% of Type 1 had nodal metastases compared to 71% of Type 3. Type 1 GNETs presented with metastatic disease less often (17% vs. 40%). Three year recurrence-free survival was 33% for Type 1 compared to 86% for Type 3. Disease-specific survival at 3-years was 100% and 75% for Types 1 and 3, respectively.

CONCLUSION

Type 1 GNETs are often indolent and multifocal without nodal involvement, but have high recurrence risk. Type 3 is more aggressive with increased nodal involvement; nodal evaluation should be routinely performed. Determination of GNET type is paramount to treating patients with this rare disease. J. Surg. Oncol. 2016;114:576-580. © 2016 Wiley Periodicals, Inc.

Does long-term profound inhibition of gastric acid secretion increase the risk of ECL cell-derived tumors in man?

OBJECTIVE

Since the description of ECL cell-derived tumors in rodents after long-term profound acid inhibition inducing hypergastrinemia, there has been concern that proton pump inhibitors (PPIs) could also do that in man. The recent description of a Spanish family with gastric ECL cell tumors at the age of about 30 years secondary to a defect in the proton pump due to mutation in the ATP4A gene clearly shows that hypergastrinemia alone also is sufficient to induce ECL cell neoplasia in man. The present review aims to evaluate the risk of gastric neoplasia secondary to gastric acid inhibition.

METHODS

Literature (MEDLINE) was searched for the role of the ECL cell in gastric carcinogenesis in animals and man in general and particularly secondary to long-term inhibition of acid secretion.

RESULTS

An important proportion of patients treated with PPI develops hypergastrinemia causing ECL cell hyperplasia and the first descriptions of ECL cell carcinoids secondary to PPI have been reported. The role of the ECL cell has hitherto been under estimated in gastric carcinogenesis in man where for instance the signet ring cell type of gastric carcinoma seems to originate from the ECL cell.

CONCLUSIONS

The first two of three steps in rodent ECL cell carcinogenesis (hyperplasia, carcinoid, and carcinoma) secondary to PPI dosing, have been described for man. It is every reason to believe that the final step, gastric carcinoma, will develop also in man. Clinical decisions should be based not only on so-called evidence based medicine, but also on physiological knowledge and animal studies.

Recurrent gastric neuroendocrine tumors treated with total gastrectomy

Gastric neuroendocrine tumors are rare; however, the incidence has recently increased due to the increasing use of upper endoscopy. Neuroendocrine tumors arise from the excess proliferation of enterochromaffin-like (ECL) cells. The proliferative changes of enterochromaffin cells evolve through a hyperplasia-dysplasia-neoplasia sequence that is believed to underlie the pathogenesis of gastric neuroendocrine tumors. Endoscopic resection is recommended as the initial treatment if the tumor is not in an advanced stage. However, there is no definite guideline for the treatment of recurrent gastric neuroendocrine tumors following endoscopic resection. Here, we report a rare case of gastric neuroendocrine tumors in a 56-year-old male who experienced two recurrences within 11 years after endoscopic resection. The patient finally underwent a total gastrectomy. The pathological features of the resected stomach exhibited the full hyperplasia-dysplasia-neoplasia sequence of the ECL cells in a single specimen.

Intermittent treatment of recurrent type-1 gastric carcinoids with somatostatin analogues in patients with chronic autoimmune atrophic gastritis

BACKGROUND

Optimal management and treatment of type-1 gastric carcinoids is under debate.

AIMS

This prospective study evaluates the outcome of patients with recurrent type-1 gastric carcinoids treated with somatostatin analogues.

METHODS

From 2000 to 2013, among a population of 107 chronic atrophic gastritis patients, 25 (20% males, median age 62 years) developed type-1 gastric carcinoids and underwent regular clinical and endoscopic follow-up (median 77 months, range 6-165) after the initial treatment. Those patients showing recurrent disease were treated with somatostatin analogues until carcinoid disappearance.

RESULTS

12/25 patients (33% males, median age 65 years) showed recurrent gastric carcinoids and were treated with somatostatin analogues for a median duration of 12 months. Median gastrin and chromogranin A levels, which were 802 pg/mL and 33 U/L, respectively, decreased to 299 pg/mL (p=0.002) and 15.6 U/L (p=0.001) at the end of the treatment. Gastric carcinoids disappeared after a median length of treatment of 12 months. After a median time of 19.5 months from somatostatin analogues discontinuation, 4/12 patients (25% males, median age 56 years) showed a further recurrence. A new cycle of treatment was performed successfully.

CONCLUSIONS

This study confirms that type-1 gastric carcinoids are a recurring disease and somatostatin analogues, administered on 12-month cycles, represent an effective treatment.

Differing Clinical Courses and Prognoses in Patients With Gastric Neuroendocrine Tumors Based on the 2010-WHO Classification Scheme

The aim of this study is to test the prognostic accuracy of the 2010-WHO classification for postsurgery survival in nonmetastatic gastric neuroendocrine tumor (NET) cases. Whether the 2010-WHO classification of NETs can predict relapse after surgical resection has not yet been established.We selected 175 nonmetastatic gastric NET patients at Asan Medical Center, Seoul, Korea between 1996 and 2013. All tumors were classified using the WHO-2010 scheme.Among 175 patients with gastric NETs, we diagnosed 39 cases as WHO grade 1, 13 cases as grade 2, 66 cases as grade 3 (neuroendocrine carcinomas; NECs), and 57 cases as mixed with adenocarcinoma. Patients with grade 3 had a lower relapse-free survival (RFS) and overall survival (OS) than those with WHO grade 1/2 and had a lower OS than patients with mixed type tumors. Patients with grade 1/2 had a better OS than patients with mixed type. There was no significant difference in RFS and OS between small and large cell type lesions. Among WHO grade 1/2 patients with ≤1 cm sized lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion, and we detected no lymph node metastases or recurrences.Our findings strongly suggest that WHO grade 3 behaves more aggressively than adenocarcinoma. Additionally, the survival of cases with large and small cell NEC was similar. Among WHO grade 1/2 patients who had ≤1 cm lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion and all could be treated by endoscopic resection or minimally invasive surgery without node dissection.

Multicentric Type 3 Gastric Neuroendocrine Tumors

A 50-year-old woman with incidentally detected multiple gastric polyps and biopsy-proven neuroendocrine tumor (NET) was referred to our hospital. More than 10 polypoid lesions (less than 15 mm) with normal gastric mucosa were detected from the gastric body to the fundus. The serum level of gastrin was within the normal limits. There was no evidence of atrophic changes on endoscopy and serologic marker as pepsinogen I/II ratio. Computed tomography of the abdomen and pelvis revealed no evidence of metastatic lesions. She refused surgery, and we performed endoscopic polypectomy for almost all the gastric polyps that were greater than 5 mm. Although the histological examination revealed that all the removed polys were diagnosed as NET G1, three of them extended to the lateral or vertical resection margins, while two exhibited lymphovascular invasion. A follow-up upper endoscopy that was performed 6 months after the diagnosis showed multiple remnant gastric polyps that were suggestive of remnant gastric NET.