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Gastric Neuroendocrine Tumors
Introduction
Gastric neuroendocrine tumors (GNETs) are neoplasms arising from enterochromaffin-like cells within the gastric mucosa. These tumors represent <1% of all gastric neoplasms but are increasingly diagnosed due to the widespread use of upper endoscopy. GNETs are classified into 3 main subtypes based on their pathophysiology, clinical behavior, and association with hypergastrinemia: type 1, type 2, and type 3. Type 1 GNETs, the most common subtype, occur in the setting of chronic atrophic gastritis and hypergastrinemia, leading to hyperplasia of enterochromaffin-like cells. These tumors are typically small, multifocal, and have a low risk of metastasis. Type 2 GNETs are associated with Zollinger-Ellison syndrome (ZES) and multiple endocrine neoplasia type 1 (MEN1), driven by excessive gastrin secretion from gastrinomas. They have a variable clinical course and a slightly higher metastatic potential than type 1. In contrast, type 3 GNETs are sporadic, gastrin-independent, and more aggressive, often presenting as solitary, large tumors with a significant risk of metastasis.[1][2][3]
GNETs are diagnosed using a combination of endoscopic evaluation, histopathology, and biochemical markers, including serum gastrin levels and chromogranin A. Endoscopic ultrasound (EUS) and cross-sectional imaging help assess tumor invasion and metastatic spread. Management strategies depend on tumor type, size, grade, and metastatic potential. Type 1 and select type 2 GNETs may be managed with surveillance or endoscopic resection, while type 3 GNETs often require aggressive surgical intervention and, in some cases, systemic therapy.[1][2][3] Given their heterogeneous nature, GNETs require an interprofessional approach to optimize diagnosis, treatment, and long-term surveillance. Understanding their classification, pathogenesis, and therapeutic options is crucial for improving patient outcomes and guiding evidence-based management strategies.
Etiology
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Etiology
The etiology of GNETs varies depending on their classification and underlying pathophysiological mechanisms. Type 1 GNETs, the most common subtype, arise in chronic atrophic gastritis, particularly autoimmune gastritis, which leads to achlorhydria and hypergastrinemia. Chronic gastrin stimulation promotes enterochromaffin-like (ECL) cell hyperplasia and, over time, neoplastic transformation. Long-term proton pump inhibitor (PPI) use has been implicated in the pathogenesis of type 1 GNETs due to its role in inducing hypergastrinemia. By inhibiting gastric acid secretion, PPIs lead to a compensatory increase in serum gastrin levels, which may contribute to ECL cell proliferation. Although the clinical significance of PPI-induced hypergastrinemia remains debated, prolonged PPI therapy in patients with underlying gastric atrophy may potentiate the risk of GNET development.[4]
Type 2 GNETs develop in association with ZES, often in the context of MEN1. In these cases, excessive gastrin production from gastrinoma results in ECL cell proliferation and tumor formation, although the presence of MEN1 mutations also contributes to their pathogenesis. While PPI use is standard in managing ZES to control acid hypersecretion, it does not directly contribute to tumorigenesis in these patients, as the underlying gastrinoma is the primary driver of hypergastrinemia.[1][2][3]
In contrast, type 3 GNETs are sporadic and independent of gastrin stimulation. They arise de novo from ECL cells and exhibit more aggressive biological behavior, frequently driven by genetic mutations affecting key oncogenic pathways, eg, TP53, RB1, and MEN1. Unlike type 1 and type 2 GNETs, type 3 tumors are not associated with chronic hypergastrinemia and often present with higher rates of metastasis at diagnosis. Given their gastrin-independent nature, PPI use does not affect their development or progression.[1][2][3]
Epidemiology
GNETs are rare but increasingly recognized neoplasms, with an estimated incidence of 0.2 to 2 per 100,000 people annually. Their prevalence has risen due to increased endoscopic surveillance and improved histopathologic detection. In the United States, GNETs account for approximately 7% of all neuroendocrine tumors and less than 1% of all gastric malignancies. Type 1 GNETs, the most common subtype, comprise 70% to 80% of cases, with a higher prevalence among middle-aged women (female-to-male ratio of approximately 2:1), largely due to their strong association with autoimmune atrophic gastritis, which disproportionately affects women. Type 2 GNETs, accounting for about 5% to 6% of cases, occur equally in both sexes and are associated with ZES, particularly in patients with MEN1. Type 3 GNETs, which represent 15% to 25% of cases, exhibit no apparent sex predilection and tend to occur later in life, typically in individuals aged 50 to 70 years.[5][6][7]
Globally, GNETs have shown a rising incidence, with reports suggesting an increase in the number of diagnosed cases in Europe and Asia, particularly in countries with widespread gastric cancer screening programs. In Europe, incidence rates are similar to those in the United States. At the same time, in Asian populations, where Helicobacter pylori infection and chronic gastritis are more prevalent, the incidence of type 1 GNETs may be higher. Despite this increase in detection, the overall mortality remains relatively low for type 1 and type 2 tumors due to their generally indolent nature. In contrast, type 3 tumors exhibit aggressive behavior with a poorer prognosis, often presenting with distant metastases at diagnosis.[5]
Pathophysiology
GNETs arise from ECL cells within the gastric mucosa, and their pathophysiology is dictated mainly by the underlying mechanism driving tumorigenesis. Gastrin-mediated ECL cell hyperplasia, genetic mutations, and aberrant cellular signaling pathways primarily influence the development of GNETs.
Type 1 Gastric Neuroendocrine Tumors
Type 1 GNETs develop in the setting of chronic atrophic gastritis, particularly autoimmune gastritis, which leads to achlorhydria and subsequent hypergastrinemia due to loss of negative feedback inhibition on gastrin-secreting G cells. Prolonged hypergastrinemia induces progressive ECL cell hyperplasia, leading to the formation of multiple small, well-differentiated neuroendocrine tumors. These tumors are typically slow-growing with low malignant potential, though long-standing hypergastrinemia can contribute to dysplastic changes over time.[1][2][3]
Type 2 Gastric Neuroendocrine Tumors
Type 2 GNETs are associated with ZES and MEN1. In these cases, gastrinomas—most commonly found in the pancreas or duodenum—cause excessive gastrin secretion, leading to chronic ECL cell stimulation and hyperplasia, similar to type 1 tumors. However, due to the genetic predisposition associated with MEN1 mutations, type 2 GNETs may demonstrate a higher proliferative capacity and an increased risk of progression to invasive malignancy.[1][2][3]
Type 3 Gastric Neuroendocrine Tumors
Type 3 GNETs are sporadic, gastrin-independent tumors that arise de novo from ECL cells without prior hyperplasia. These tumors exhibit more aggressive behavior, characterized by rapid proliferation, local invasion, and a high propensity for metastasis. Genetic alterations in key oncogenic pathways, eg, TP53, RB1, and MEN1 mutations, contribute to their malignant potential. Unlike type 1 and type 2 GNETs, type 3 tumors are not driven by hypergastrinemia and typically present as solitary, poorly differentiated lesions with a high Ki-67 index, reflecting their aggressive nature.[1][2][3]
Histopathology
The histopathology of GNETs is characterized by uniform, round-to-oval neoplastic cells with eosinophilic or amphophilic cytoplasm arranged in nests, trabeculae or solid sheets within the gastric mucosa and submucosa. These tumors express neuroendocrine markers, including chromogranin A, synaptophysin, and CD56, which help confirm their neuroendocrine differentiation. GNETs are further graded based on the Ki-67 proliferation index and mitotic count, following the World Health Organization (WHO) classification (see Table. World Health Organization 2022 Classification of Neuroendocrine Tumors).
Type 1 and 2 GNETs are typically well-differentiated, low-grade tumors with minimal cytologic atypia. In contrast, type 3 GNETs often display high-grade features, including marked nuclear pleomorphism, high mitotic activity, necrosis, and invasive growth patterns. Type 3 tumors may also exhibit poorly differentiated neuroendocrine carcinoma (NEC) morphology, resembling small-cell or large-cell neuroendocrine carcinoma. Immunohistochemical staining for gastrin receptors is often positive in type 1 and type 2 GNETs, reflecting their gastrin-dependent pathogenesis, whereas type 3 GNETs are gastrin-independent. The 2022 WHO classification of neuroendocrine tumors based on tumor mitoses, Ki67 percent, and morphology is the most widely used.[8]
Table. World Health Organization 2022 Classification of Neuroendocrine Tumors
| Neuroendocrine Neoplasm | Classification | Diagnostic Criteria |
| Well-differentiated neuroendocrine tumor (NET) | NET, grade 1 | <2 mitoses/2 mm2or Ki67 <3% |
| NET, grade 2 | 2 to 20 mitoses/2 mm2 or Ki67 3% to 20% | |
| NET, grade 3 | >20 mitoses/2 mm2 or Ki67 >20% | |
| Poorly differentiated neuroendocrine carcinoma (NEC) | Small cell NEC | >20 mitoses/2 mm2or Ki67 >20% (often >70%), and small cell cytomorphology |
| Large cell NEC | >20 mitoses/2 mm2 or Ki67 >20% (often >70%), and large cell cytomorphology |
History and Physical
Clinical History
Many GNETs, particularly type 1 and type 2, are asymptomatic and discovered incidentally during upper endoscopy performed for unrelated reasons. When symptoms are present, they are often vague and nonspecific, including dyspepsia, epigastric discomfort, early satiety, or mild nausea. In some cases, patients may report symptoms of anemia, eg, fatigue, pallor, and dyspnea on exertion due to chronic occult gastrointestinal bleeding.
The type of GNET influences symptom presentation. Type 1 GNETs are strongly associated with chronic atrophic gastritis and pernicious anemia, conditions that lead to hypergastrinemia and subsequent ECL cell hyperplasia. A history of long-standing anemia or autoimmune gastritis should raise suspicion. Type 2 GNETs occur in the context of ZES as part of MEN1. These patients may report severe, refractory gastroesophageal reflux disease, peptic ulcer disease, and diarrhea due to excess gastric acid production. Type 3 GNETs, which are sporadic and more aggressive, may present with symptoms related to mass effects, eg, abdominal pain, weight loss, or gastrointestinal bleeding. Rarely, metastatic GNETs may be functional and secrete bioactive hormones, leading to carcinoid syndrome, characterized by flushing, diarrhea, wheezing, and right-sided valvular heart disease.[1][2][3]
A detailed medication history is also important, as long-term PPI use can induce hypergastrinemia, mimicking the biochemical environment seen in type 1 and 2 GNETs. Additionally, a family history of neuroendocrine tumors, hyperparathyroidism, or pituitary adenomas may suggest MEN1, necessitating further endocrine evaluation.
Physical Examination
The physical examination of a patient with suspected GNETs is often unremarkable, particularly in early or asymptomatic cases. However, findings may vary depending on tumor burden and associated syndromes. In patients with type 1 GNETs, signs of chronic atrophic gastritis or pernicious anemia may be evident, including glossitis, cheilitis, and pale conjunctivae due to vitamin B12 deficiency. Neurological manifestations, eg, paresthesia, ataxia, and cognitive changes, may also be present in cases of severe B12 deficiency.
For type 2 GNETs, clinical features of ZES and MEN1 should be assessed. Patients may have epigastric tenderness related to peptic ulcers. Signs of MEN1, including hyperparathyroidism (eg, nephrolithiasis, bone pain, or hypertension), pituitary tumors (eg, visual field defects, acromegaly, or Cushing’s syndrome), or cutaneous manifestations (eg, angiofibromas, collagenomas, or lipomas), should prompt further endocrine workup.
Type 3 GNETs, being more aggressive, may present with findings suggestive of advanced disease, including palpable abdominal masses, hepatomegaly due to metastatic spread to the liver, or signs of gastrointestinal bleeding such as melena or hematemesis. If carcinoid syndrome is present, characteristic flushing, wheezing, and telangiectasias may be observed, particularly in cases with liver metastases, where vasoactive substances bypass hepatic metabolism.[1][2][3]
Evaluation
Evaluating GNETs involves a combination of biochemical, endoscopic, histopathologic, and imaging studies. Proper classification and staging are essential to guide management, as GNETs have distinct biological behaviors depending on their type.[1][2][3]
Laboratory and Biochemical Testing
Serum gastrin levels should be measured in all patients suspected of having a GNET, as hypergastrinemia is a key feature of type 1 and type 2 GNETs. If hypergastrinemia is detected, gastric pH should be assessed via endoscopic aspiration to differentiate between achlorhydria (seen in type 1 GNETs due to chronic atrophic gastritis) and acid hypersecretion seen in type 2 GNETs associated with ZES. Type 3 GNETs, in contrast, typically occur with normal gastrin levels.[1][2][3]
Chromogranin A is a widely used neuroendocrine tumor marker. However, this tumor marker is nonspecific and can be elevated in conditions, eg, chronic atrophic gastritis, PPI use, and renal or hepatic dysfunction. Additional markers may be evaluated in select cases, including neuron-specific enolase (NSE) and pancreatic polypeptide. If carcinoid syndrome is suspected, serum serotonin and urinary 5-hydroxyindoleacetic acid levels should be obtained. In patients with type 2 GNETs, screening for MEN1 should be considered, including measurements of parathyroid hormone, calcium, and prolactin levels.[9][10][11]
Endoscopic Evaluation and Biopsy
Upper gastrointestinal endoscopy is the cornerstone of GNET diagnosis. Type 1 GNETs typically appear as multiple small (≤1 cm), polypoid, or sessile lesions in the gastric fundus and body. Type 2 GNETs are similar in appearance but may be associated with thickened gastric folds due to hypertrophic gastritis caused by hypergastrinemia. Type 3 GNETs are usually solitary, larger (>2 cm), and ulcerated or infiltrative, often resembling gastric adenocarcinoma.
Endoscopic biopsy with histopathologic examination is essential for confirmation. The biopsy should assess tumor morphology, degree of differentiation, and Ki-67 proliferation index. Immunohistochemical staining for neuroendocrine markers, including synaptophysin and chromogranin A, confirms the neuroendocrine origin. The Ki-67 index and mitotic count classify tumors into well-differentiated neuroendocrine tumors (NET grade 1, NET grade 2) or poorly differentiated neuroendocrine carcinomas (NEC grade 3). Additionally, adjacent gastric mucosa should be biopsied to evaluate for chronic atrophic gastritis, ECL cell hyperplasia, and Helicobacter pylori infection.[12][13][14]
Imaging Studies
For localized disease, EUS is valuable in assessing tumor invasion depth and lymph node involvement. Type 1 and type 2 GNETs are often confined to the mucosa and submucosa, whereas type 3 GNETs may show deeper infiltration. For systemic staging, contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the abdomen and pelvis is recommended, particularly for type 3 GNETs or those with high-risk features (size >2 cm, Ki-67 >2%, or invasion beyond the submucosa). Functional imaging with somatostatin receptor-based modalities, such as 68Ga-dotatate positron emission tomography/computed tomography (PET/CT) or octreotide scintigraphy (Octreoscan), helps detect metastases and assess somatostatin receptor expression, which has therapeutic implications for peptide receptor radionuclide therapy (PRRT). In poorly differentiated neuroendocrine carcinomas, 18F-fluorodeoxyglucose (FDG) PET/CT may be more helpful, as these tumors often have high metabolic activity.[1][2][3]
Treatment / Management
Type 1 Gastric Neuroendocrine Tumors
Type 1 GNETs are usually indolent and rarely metastasize, making conservative management appropriate for most patients.[1][2][3][15] Small tumors (<1 cm) confined to the mucosa or superficial submucosa are best managed with periodic endoscopic surveillance. Lesions between 1 to 2 cm can often be removed via endoscopic mucosal resection or endoscopic submucosal dissection, particularly if they show concerning features such as increased size, ulceration, or Ki-67 >2%. More invasive surgical therapy is rarely required but may be considered in cases of large, recurrent, or multifocal tumors refractory to endoscopic management. Total gastrectomy is seldom needed.(A1)
Medical therapies, including PPIs and somatostatin analogs, may also be utilized as indicated. While long-term PPI use can contribute to hypergastrinemia, it may be beneficial in preventing reflux-related complications in patients with atrophic gastritis. Octreotide or lanreotide may reduce serum gastrin levels and suppress ECL cell proliferation in select cases with multiple or recurrent tumors.
Type 2 Gastric Neuroendocrine Tumors
Type 2 GNETs have a higher malignant potential than type 1 but still exhibit a relatively indolent course in most cases.[1][2][3][15] Management of ZES includes:(A1)
- PPIs (high-dose therapy): Control of acid hypersecretion is essential to prevent complications (eg, peptic ulcer disease).
- Somatostatin analogs: May be used to control hormone secretion and tumor growth in patients with somatostatin receptor-positive disease.
Small, localized tumors (<2 cm) can often be managed endoscopically. Larger or infiltrative lesions require surgical resection, particularly in the presence of nodal involvement or distant metastases. A factor that should be considered in the treatment of MEN1 is that given the risk of multifocal disease and associated endocrine tumors (eg, parathyroid and pituitary adenomas), treatment should be individualized and managed in an interprofessional setting.
Type 1 Gastric Neuroendocrine Tumors
Type 3 GNETs behave more aggressively, with a higher risk of deep invasion, nodal involvement, and distant metastases.[1][2][3][15] The following management approaches are recommended based on the extent of disease:(A1)
- Surgical resection: Gastrectomy with lymphadenectomy is the preferred treatment for resectable tumors. The extent of resection depends on tumor size, invasion depth, and lymph node status.
- Systemic therapy for unresectable or metastatic disease
- Somatostatin analogs: First-line therapy for somatostatin receptor-positive tumors to control symptoms and slow disease progression.
- PRRT: 68Ga-dotatate PET-positive tumors may be treated with Lutetium-177 (177Lu)-dotatate therapy.
- Chemotherapy: Poorly differentiated NEC often requires platinum-based chemotherapy (eg, cisplatin or carboplatin with etoposide).
- Targeted therapy: Everolimus (an mTOR inhibitor) and sunitinib (a tyrosine kinase inhibitor) may be considered for progressive, unresectable disease.
Management of Neuroendocrine Carcinomas
NECs (poorly differentiated, high-grade) are treated aggressively due to their rapid progression and poor prognosis.[1][2][3][15] The following management approaches are recommended based on the extent of disease:(A1)
- Systemic chemotherapy: Platinum-based regimens (cisplatin/carboplatin + etoposide) are standard first-line treatments.
- Surgical resection: Considered in highly selected cases with limited disease.
- Radiation therapy: May be used in cases of unresectable or metastatic disease with symptomatic local involvement.
Surveillance and Follow-Up
Patients with type 1 and type 2 GNETs require periodic endoscopic surveillance to monitor for recurrence or progression. Surveillance intervals vary based on tumor size and histopathologic features but typically range from 1 to 3 years.[1][2][3][15] Patients with type 3 GNETs and NEC aggressive tumors need closer follow-up with serial imaging (CT/MRI) and biomarker assessments (chromogranin A, NSE) every 3 to 6 months, depending on disease burden and response to treatment.[1][2][3][15](A1)
Differential Diagnosis
The differential diagnosis of GNETs includes a variety of gastric lesions and systemic conditions that can present with similar clinical, endoscopic, or histopathologic features. Gastric adenocarcinoma is a key consideration, especially for type 3 GNETs, which may appear as solitary, ulcerated, or infiltrative lesions resembling poorly differentiated gastric malignancies. Gastrointestinal stromal tumors (GISTs) should also be considered, particularly when evaluating subepithelial gastric masses; these tumors can be distinguished by immunohistochemical staining for KIT (CD117) and DOG1. Lymphomas of the stomach, including mucosa-associated lymphoid tissue (MALT) lymphoma, may present as gastric nodularity, thickened mucosal folds, or mass-like lesions and require histopathologic confirmation with lymphoid markers such as CD20 or CD3. Peptic ulcer disease and ZES should be considered, especially in patients with hypergastrinemia. However, ZES-associated lesions are typically multiple and occur in the duodenum rather than the stomach.[1][2][3][15]
Autoimmune gastritis with ECL cell hyperplasia can mimic type 1 GNETs but lacks the clonal proliferation characteristic of actual neuroendocrine tumors. Additionally, metastatic neuroendocrine tumors from the pancreas or small intestine should be ruled out in cases of multiple gastric lesions or liver metastases, as they may mimic primary GNETs. Distinguishing GNETs from these entities requires endoscopic assessment, histopathology with immunohistochemical markers (eg, chromogranin A, synaptophysin, and Ki-67 index), and biochemical evaluation for hypergastrinemia and hormone secretion.[1][2][3][15]
Prognosis
The prognosis of GNETs varies significantly depending on the tumor type, grade, and stage at diagnosis. Type 1 GNETs have an excellent prognosis, with a low risk of metastasis (<5%) and indolent behavior. Most patients with type 1 tumors experience long-term survival with endoscopic management and periodic surveillance. Type 2 GNETs have a slightly higher malignant potential than type 1 tumors, with an estimated metastasis rate of 10% to 30%. Still, the prognosis remains favorable when the underlying ZES and MEN1 are managed appropriately. However, mortality in type 2 GNETs is often associated with MEN1-related complications rather than the tumor itself.
In contrast, type 3 GNETs are aggressive, with a high risk of deep invasion, nodal involvement, and distant metastases. The prognosis is significantly worse than type 1 and 2, with 5-year survival rates ranging from 30% to 50%, depending on tumor size, Ki-67 index, and lymph node involvement. Poorly differentiated NECs have the worst prognosis, as they behave more like conventional gastric adenocarcinomas. These tumors have rapid progression, a high metastatic potential at diagnosis, and an overall 5-year survival rate below 20%, even with aggressive treatment. The presence of distant metastases, high Ki-67 proliferation index (>20%), and high mitotic rates correlate with worse survival across all GNET subtypes.[1][2][3][15]
Complications
GNET complications depend on tumor type, size, and metastatic spread. Local complications include gastrointestinal bleeding due to ulceration, particularly in larger or infiltrative tumors. Obstruction may occur with more advanced type 3 GNETs or NECs invading the gastric wall or adjacent structures. Anemia is a frequent complication in type 1 and 2 GNETs due to chronic atrophic gastritis and vitamin B12 deficiency, leading to pernicious anemia and associated neurological symptoms. Functional complications arise in type 2 GNETs when excessive gastrin production leads to ZES, resulting in severe gastroesophageal reflux disease, multiple peptic ulcers, and diarrhea. Rarely, functional GNETs may secrete serotonin or other bioactive amines, causing carcinoid syndrome with flushing, diarrhea, wheezing, and right-sided heart valve fibrosis in cases of liver metastases.
Metastatic complications are most commonly seen in type 3 GNETs and NECs, and they frequently spread to the liver, lymph nodes, peritoneum, and bones. Liver metastases can cause hepatomegaly, liver dysfunction, and, in cases of extensive tumor burden, carcinoid syndrome. Bone metastases may result in skeletal pain and pathologic fractures. Poorly differentiated NECs often exhibit rapid dissemination and may involve atypical metastatic sites such as the lungs or brain.
Finally, treatment-related complications include postendoscopic bleeding or perforation after endoscopic resection, particularly for larger lesions. Surgical complications include anastomotic leakage, delayed gastric emptying, and postoperative infections. Patients receiving systemic therapies, such as somatostatin analogs, PRRT, or chemotherapy, may experience nausea, diarrhea, cytopenias, or nephrotoxicity, necessitating careful monitoring.
Deterrence and Patient Education
Preventing GNETs focuses on managing underlying risk factors and ensuring early detection. For type 1 GNETs, controlling chronic atrophic gastritis through Helicobacter pylori eradication and monitoring for pernicious anemia can help reduce ECL cell hyperplasia and tumor formation. In type 2 GNETs, optimizing the management of ZES with PPIs and somatostatin analogs can suppress gastrin-driven tumor growth. In contrast, patients with MEN1 should undergo regular endocrine surveillance. Type 3 GNETs and NECs arise sporadically, making prevention challenging, but routine endoscopic monitoring in high-risk individuals may allow for early detection. Patients should also be cautioned against the unnecessary long-term use of PPIs, which may contribute to hypergastrinemia and ECL cell proliferation.
Patient education is essential to ensure adherence to surveillance protocols and optimize long-term outcomes. Patients with type 1 and GNETs should be counseled on the typically indolent nature of their disease and the necessity of regular endoscopic monitoring to detect changes in tumor characteristics. Those with MEN1 should be informed about its genetic implications and consider genetic counseling. In contrast, Type 3 GNETs and NECs require a more aggressive approach, with education focused on treatment options, potential complications, and the importance of promptly reporting symptoms like unexplained weight loss, abdominal pain, or gastrointestinal bleeding. Encouraging a healthy lifestyle, smoking cessation, and interprofessional care involving gastroenterologists, oncologists, and endocrinologists further supports comprehensive patient management.
Enhancing Healthcare Team Outcomes
Managing GNETs requires a collaborative, interprofessional approach involving gastroenterologists, oncologists, endocrinologists, surgeons, radiologists, nurses, and pharmacists to ensure optimal patient-centered care. Physicians and advanced practitioners must be able to diagnose and classify GNETs accurately, interpret endoscopic and imaging findings, and determine the most appropriate treatment strategies based on tumor type, grade, and stage. This involves managing hypergastrinemia in Type 1 and Type 2 GNETs, recognizing when endoscopic resection is sufficient versus when surgical intervention is necessary, and initiating systemic therapies for advanced or metastatic disease.
Surgical specialists play a crucial role in cases of large or invasive tumors, while oncologists and nuclear medicine specialists contribute to the management of metastatic or high-grade neuroendocrine carcinomas through targeted therapies and PRRT. Pharmacists ensure the safe and effective use of medications such as proton pump inhibitors, somatostatin analogs, and chemotherapy agents, helping to mitigate adverse effects and optimize treatment outcomes. Nurses serve as vital care coordinators, providing education, symptom management, and emotional support to patients throughout their treatment journey. Their role in facilitating communication between patients and clinicians enhances adherence to treatment plans and ensures that patient concerns are promptly addressed.
Effective interprofessional communication fosters a collaborative environment where all team members contribute their expertise, reducing delays and improving care efficiency. Ethical considerations, including shared decision-making and respecting patient autonomy, are central to treatment planning, particularly when weighing the risks and benefits of surveillance versus intervention. Clear role delineation and structured care coordination streamline the diagnostic and therapeutic processes, minimizing fragmentation in care. By integrating expertise across disciplines, the healthcare team enhances patient safety, optimizes clinical outcomes, and ensures comprehensive, compassionate care tailored to the unique needs of individuals with GNETs.
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