Gastric NET Archives

Tag: Gastric NET

NETs in the stomach are known as Gastric NETs.

Clinically, gastric NETs are categorized into types I, II, III and some texts list a type IV. Gastrin is produced by G cells in the stomach after ingestion of food. Gastrin binds to cholecystokinin-2 receptors on ECL cells, which subsequently release histamine to activate parietal cells to produce hydrochloric acid. Acid production is regulated by negative feedback so that D cells in the antrum produce somatostatin that inhibits G cell production of gastrin. Therefore, in states where acid production is lacking (achlorhydria), there is compensatory G cell hyperplasia and hypergastrinemia that leads to ECL cell hyperplasia in an effort to boost acid production. Hypersecretory states with unchecked gastrin production, such as Zollinger–Ellison syndrome (ZES), are also predisposed to ECL cell hyperplasia and NET growth. Type I and II gastric NETs develop due to hypergastrinemia and ECL cell hyperplasia, while type III gastric NETs arise sporadically.

Type I tumors are most common and represent 70–80% of all gastric NETs. They tend to be multiple, smaller than 1 cm in size, and are often discovered incidentally or during endoscopic evaluation for anemia. Their behaviour is typically indolent, and metastases are infrequent (occurring in <10% of patients for lesions <2 cm in size). Achlorhydric conditions associated with type I gastric NETs include chronic atrophic gastritis (e.g. from type A autoimmune gastritis or vagotomy). Although long-term use of proton pump inhibitor (PPI) leads to chronic hypergastrinemia, there have only been case reports of gastric NETs associated with PPI use.

Type II gastric NETs represent 5–10% of gastric NETs. Like type I disease, they are also typically multiple, small, asymptomatic, and well-differentiated tumors. The risk of metastasis is slightly higher in type II gastric NETs compared to type I lesions but is still low. Overall, tumor invasion beyond the submucosa into the muscularis propria or lymph node and liver involvement occurs in 5–12% of cases. Type II gastric NETs are also associated with hypergastrinemia, but the feature that distinguishes them from type I tumors is their association with ZES and multiple endocrine neoplasia type 1 (MEN1) syndrome, which are hypersecretory states. Up to 30–50% of patients with MEN1 syndrome will develop gastric NETs, especially if ZES is present. Type II gastric NETs unsurprisingly have a high rate of loss of heterogyzosity at the MEN1 gene locus of 75–100%. Interestingly, 17–73% of type I gastric NETs and 25–50% of type III gastric NETs carry the same mutation, suggesting that MEN1 mutations cannot be used to distinguish among the 3 types of gastric NETs. Type II gastric NETs are typically non-functioning tumors, and symptoms upon presentation are usually secondary to peptic ulcer disease and ZES. While other genetic syndromes such as type 1 neurofibromatosis, von Hippel–Landau disease, and tuberous sclerosis complex are associated with NETs, gastric involvement is rare.

Type III. Approximately 10–15% of gastric NETs are categorized as type III tumors. These lesions typically exist as solitary larger tumors, often >2 cm in size. Histopathologically, they vary from well- to poorly differentiated tumours (where they would be called NEC), and their overall prognosis is relatively poor. Upon initial presentation, the incidence of concurrent metastasis is >50%, typically with hepatic involvement. Unlike type I and II gastric NETs, type III lesions do not have any associated predisposing conditions. Fasting gastrin levels are normal without any G cell or ECL cell hyperplasia. While type I and II gastric NETs tend to be non-functional tumours, type III NETs with hepatic metastases may be associated with carcinoid syndrome, although this occurrence is rare.

Type IV. Tends to be used for the much less common scenario of a poorly differentiated Gastric Neuroendocrine Carcinoma (NEC)

Articles from RonnyAllan.NET will be listed below.

For diagnosis and management, this succinct diagram from UKINETs is very good. Always check with your NET specialist as this may differ between countries and between healthcare systems.

https://www.ukinets.org/wp-content/uploads/UKINETS-bitesize-guidance-Management-of-GNENs-1.pdf

27 Feb 2026

By Ronny Allan

0 Comments

Neuroendocrine Tumours (NET) – Vitamin B12 (Cobalamin)

Diet and Nutrition, Patient AdvocacyAtrophic gastritis, Autoimmune gastritis, B12 Cobalamin, Bile acid diarrhea, Diarrhea, Gastric NET, Lung NETs, Midgut, Pancreatic NET (PanNET), Pernicious anaemia, Right hemicolectomy, Small intestine bacterial overgrowth (SIBO), Small intestine NET (SI NET), Somatostatin analogues, Vitamin B12, Whipple procedure

Before you read thisThis information is designed to help you understand how vitamins work in the body and how certain NET-related factors might affect them. It is not a substitute for personalised medical advice. Every NET patient is different — tumour type, treatments, surgery, symptoms, and nutritional needs can vary widely.If you have concerns about vitamin levels, supplements, or symptoms, please speak with your NET clinical team. They can assess your individual situation and guide you safely. Vitamin B12 is a water-soluble vitamin. Unlike fat-soluble vitamins, they are not stored in your body long term. They enter your bloodstream,…

01 Dec 2024

By Ronny Allan

23 Comments

Neuroendocrine Cancer – tumour markers and hormone levels

A Spotlight on NENs - Testing Series, Patient Advocacy131I-Metaiodobenzylguanidine (mIBG), 5-HIAA, 5-HT, 5-HTP, 5-Hydrotryptophan (5-HTP), 5-Hydroxyindoleacetic Acid (5-HIAA), 5-Hydroxytryptamine (5-HT), Adrenocorticotropic Hormone (ACTH), Biopsy, C-peptide, Calcitonin, Carcinoid crisis, Carcinoid heart disease, Carcinoid syndrome, Catecholamines, Chromaffin cells, Chromogranin, Chromogranin A (CgA), Chromogranin B (CgB), Chromogranin C (CgC), Cortisol, Electrolytes, Endocrine, Fasting Gut Endocrine Profile, Flushing, Gastric NET, Gastrin, Gastrin pH, Gastrinoma, Gastroesophageal reflux disease (GERD), Genetic testing, Glucagon, Glucagonoma, Hedinger syndrome, Histamine, Hormones, Hypertension, Insulin, Insulinoma, MEN1 syndrome, Metanephrines, Molecular markers, NETest, Neuroendocrine, Neuroendocrine cancer, Neuroendocrine carcinoma (NEC), Neuroendocrine tumour (NET), Neurokinin A (NKA), NKA, NT-proBNP, Pancreastatin, Pancreatic cancer, Pancreatic NET (PanNET), Pancreatic polypeptide (PP), Pheochromocytoma, Plasma 5HIAA, PPoma, Proinsulin, Proton pump inhibitors (PPI), Red blood count (RBC), Renal insufficiency, Serotonin, Serum serotonin, Somatostatin, Somatostatinoma, Substance K, Substance P, Tachycardia, Tachykinin, VIPoma, Wheezing, Zollinger-Ellison Syndrome

Originally published 2016, updated October 2025 Background Some people hear the terms "tumour markers" and "hormone levels" when they are diagnosed with Neuroendocrine Neoplasms (NENs). That might be confusing or even alarming at the time. Most people diagnosed with cancer will have had a form of medical testing at some point in their life, i.e. the sampling and testing of blood, urine, saliva, stool or body tissue. With NENs, the medical staff are just measuring the content of a 'substance' and then taking a view whether this is normal or not based on pre-determined ranges. These tests are normally done…

01 Aug 2024

By Ronny Allan

2 Comments

Neuroendocrine Cancer: Glossary of Terms

Awareness, Clinical Trials and Research, Diet and Nutrition, Living with Neuroendocrine Cancer, Patient Advocacy, Survivorship, TreatmentAdvanced neuroendocrine cancer, Afinitor, Appendiceal NET, Carcinoid syndrome, Chemotherapy, Clinical trial, COVID-19, Diagnosis, Diarrhea, Diet, Everolimus, Flushing, Ga68 PET/CT, Gastric NET, Gastro-entero-pancreatic neuroendocrine tumour (GEP-NET), Hormones, Immunotherapy, Incurable cancer, Lanreotide, Lung NETs, Lutathera, Malabsorption, Metastatic Neuroendocrine Cancer, Multiple Endocrine Neoplasia (MEN), Neuroendocrine, Neuroendocrine carcinoma (NEC), Neuroendocrine neoplasm (NEN), Neuroendocrine tumour (NET), Nutrition, Octreotide, Octreotide scan, Pancreatic cancer, Pancreatic NET (PanNET), Paraganglioma, Peptide receptor radionuclide therapy (PRRT), Pheochromocytoma, Quality of LIfe (QoL), Serotonin, Small intestine NET (SI NET), Somatostatin analogues, Somatostatin receptors (SSTR), Surgery

Welcome to my Neuroendocrine Cancer terms and definitions list providing a source of meanings for acronyms and medical terms, all sourced from top Neuroendocrine Cancer sites. How to use this list: 1. If your term begins with an A, see the list of As etc. Ditto for B to Z. Select your term from the list, the definition will show along with any of my blogs where that term is mentioned – this adds context. . 2. Numerical terms are also listed. Please note I’m constantly working on the repository to clean up all definitions, adding and removing links where necessary, and…

20 Apr 2024

By Ronny Allan

41 Comments

Carcinoid vs Neuroendocrine

Awareness, Patient AdvocacyAppendiceal NET, Benign tumour, Carcinoid, Carcinoid crisis, Carcinoid heart disease, Carcinoid syndrome, ENETS, Gastric NET, Gastro-entero-pancreatic neuroendocrine tumour (GEP-NET), Gastrointestinal NET (GI-NET), Hedinger syndrome, Karzinoide, Lung NETs, NET syndromes, Neuroendocrine cancer, Neuroendocrine carcinoma (NEC), Pathology, Pheochromocytoma, Rectal NET, Serotonin, Siegfried Oberndorfer, Small intestine NET (SI NET), World Health Organisation (WHO)

There's a constant debate regarding the validity of the term 'Carcinoid'. I've posted about this a few times and as far as I know, the debate has been raging for some years. This post was originally generated in April 2015 (and hasn't changed that much!). EDIT MARCH 2024. There is now a consolidated Endocrine/Neuroendocrine Tumour classification system (Blue Book). Still in print but you can see a summary of changes by clicking here. This change should provide some leverage to Neuroendocrine committees particularly about what things should be called. EDIT MARCH 2022. The latest classification system for Lung Neuroendocrine Neoplasms…

22 Mar 2024

By Ronny Allan

15 Comments

Neuroendocrine Cancer – Horrible Hormones

Patient Advocacy24-hour urinary catacholamines and metanephrines, 5-HIAA, 5-Hydrotryptophan (5-HTP), Addison's disease, Adrenal insufficiency, Adrenaline, Adrenocorticotropic Hormone (ACTH), Aldosterone, Anaphylactic shock, Androgrens, Antihistamines, Appendiceal NET, Bradykinin, Calcitonin, Calcitonin gene-related peptide (CGRP), Carcinoid crisis, Carcinoid heart disease, Carcinoid syndrome, Catecholamines, Chromogranin A (CgA), Corticotrophin releasing hormone (CRH), Cushing's disease, Cushing's syndrome, Diarrhea, Endocrine, Enterochromaffin cells, Epinephrine, Estrogen, Fight or flight, Flushing, Ga68 PET/CT, Gastric NET, Gastrin, Glucagon, Histamine, Hormones, HPA axis, Hyperparathyroidism, Hypocortisolism, Hypotension, Hypothalamus, Insulin, Intraoperative hypertensive crisis, Islet cell, Islet of Langerhams, Kallikrein, Lanreotide, Lung NETs, Malabsorption, Mast cell, Medullary thyroid cancer (MTC), Metanephrines, Multiple Endocrine Neoplasia (MEN), NET syndromes, Neuroendocrine, Neuroendocrine neoplasm (NEN), Neurokinin A (NKA), Neuropeptide K, Neurotensin, Neurotransmitter, Norepinephrine, Nutrition, Octreotide, Octreotide scan, Ovarian NEN, Pancreastatin, Pancreatic NET (PanNET), Pancreatic polypeptide (PP), Paraganglioma, Pellagra, Peptide, Pheochromocytoma, PPoma, Prostaglandin, Pruritus, Serotonin, Somatostatin, Somatostatinoma, Substance P, Tachycardia, Tachykinin, Telotristat ethyl (Xermelo), Testosterone, The 5 E's, Tryptophan, Vasoactive intestinal peptide (VIP), Vasodilation, VIPoma, Xermelo (Telotristat ethyl)

Updated and reviewed 20th March 2024 Hormonal imbalances are quite common in many conditions including day to day stuff. With Neuroendocrine Cancer, it can be a real challenge both at diagnostic and maintenance phases. In addition to the cancer angle, there's some strange stuff going on, inexplicable, frightening for the patient, an unwanted ingredient causing chaos! Until I was diagnosed with metastatic Neuroendocrine Cancer, I didn't have a clue about hormones - it's one of those things you just take for granted. However, hormones are vital to human health (male and female) and it's only when things go wrong you…

06 Feb 2024

By Ronny Allan

0 Comments

Histamine – NET or NOT?

Patient Advocacy, The NET Effect Series5-HT, Carcinoid syndrome, Duodenal NET (dNET), Gastric NET, Gastrin, Gastrinoma, Histamine, Hypergastrinemia, Lung NETs, Pancreatic NET (PanNET)

Histamine is mentioned a lot in both patient groups and in literature as somehow connected with NETs, particularly with so called carcinoid syndrome (CS). In fact, various putative mediators, including serotonin, catecholamines, brady- and tachykinins, kallikrein, histamine, motilin, and prostaglandins, have been suggested as potential causative factors for the symptoms and complications associated with CS. It is generally believed that most of these tumour-derived secretory products are inactivated by hepatocytes and, therefore, only cause symptoms when they either bypass or are secreted outside of the portal vein drainage system. I wanted to focus on Histamine in this article. But what is the…

13 Nov 2023

By Ronny Allan

1 Comment

European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for Duodenal neuroendocrine tumours (NETs) G1–G3

Latest ENETS GuidelinesDuodenal NET (dNET), Gastric NET, Gastrinoma

The ENETS 2023 guideline for dNETs are combined with the guidelines for Gastric NET (gNET) due to their close relationship in anatomical terms. But there are functional linkages to the pancreas, therefore also links to that as above. The duodenum is technically part of the small intestine, and you can find that in most anatomy-based descriptions. One of the research references I used was titled “Somewhere between the pancreas and the small intestine” and in the case of Duodenal NENs (dNENs), I can understand why they adopted that unconventional anatomy description. I suspect they contextually meant that they are not…

16 Mar 2023

By Ronny Allan

0 Comments

Experimental drug for Gastric NET – Netazepide

Clinical Trials and Research, TreatmentAtrophic gastritis, Clinical trial, Gastric NET, Gastrin, Netazepide, Neuroendocrine tumour (NET)

Update Apr 2026. Nothing has been published about this trial for some years. I spoke to a leading UK Gastroenterologist who thinks it has been quietly dropped. I will keep this blog open for a year or more just in case anything crops up. Gastric NETs When I wrote my post entitled "Spotlight on Gastric Neuroendocrine Neoplasms", I explained what these were with some emphasis on the association with hypergastrinemia (elevated fasting serum gastrin levels) with Type 1 and 2 gNETs being differentiated by the settings in which this occurs. This oversecretion is not the same as so called carcinoid…

22 Feb 2023

By Ronny Allan

2 Comments

A spotlight on Gastric Neuroendocrine Neoplasms (based on 2026 WHO Classification)

A spotlight on NENs - Types, Awareness, Patient Advocacy, Spotlight on NENs - Types Series, TreatmentAtrophic gastritis, Gastric NET, Gastrin, Gastrin pH, Gastrinoma, Hypergastrinemia, Neuroendocrine carcinoma (NEC), Neuroendocrine neoplasm (NEN), Neuroendocrine tumour (NET), Pernicious anaemia, Proton pump inhibitors (PPI)

What are Gastric NENs Unlike other anatomical types, the word Gastric is used to indicate a tumour (NET) or carcinoma (NEC) in the stomach. The stomach lies at the bottom of your oesophagus and connects to the first part of the small intestine (the duodenum). Clearly a key part of the gastrointestinal system, it processes food on its journey downwards. The stomach produces strong acid. This kills many microorganisms that might have been swallowed along with the food. It also contains special chemicals called enzymes. These are important for breaking down the food so it can be absorbed by the…

05 Feb 2019

By Ronny Allan

1 Comment

Proton Pump Inhibitors (…..and H2 Blockers) the NET Effect

The NET Effect Series, TreatmentAcid reflux, Antiacids, Axid (Nizatidine), Barrett's Esophagus, Carcinoid tumour, Chromogranin A (CgA), Cimetidine, Dexilent, Dexlansoprazole, ENETS, Esomeprazole magnesium, Famotidine, Gastric NET, Gastrin, Gastrinoma, Gastroesophageal reflux disease (GERD), H2 blockers, H2 receptor antagonist (H2RA), Hormones, Hypergastrinemia, Lansoprazole, Neuroendocrine, Neuroendocrine cancer, Neuroendocrine tumour (NET), Nexium, Nizatidine, Nutrition, Omeprazole, Omeprazole and sodium bicarbonate, Pancreastatin, Pantoloc control, Pantoprazole, Pepcid (Famotidine), Prevacid (Lansoprazole), Prilosec (Omeprazole), Proton pump inhibitors (PPI), Protonix (Pantoprazole), Quality of LIfe (QoL), Rabeprazole (Aciphex), Ranitidine (Zantac), Stomach ulcer, Tagamet, Vimovo, Zantac, Zollinger-Ellison Syndrome

What are Proton pump inhibitors (PPIs)? Proton pump inhibitors (PPIs) are among the most commonly used medications in the world. They reduce the production of acid by blocking the enzyme in the wall of the stomach that produces acid. Acid is necessary for the formation of most ulcers in the oesophagus, stomach, and duodenum, and the reduction of acid with PPIs prevents ulcers and allows any ulcers that exist in the oesophagus, stomach, and duodenum to heal. PPIs are prescribed to treat acid-related conditions such as: Esophageal, duodenal and stomach ulcers NSAID-associated ulcer Ulcers Gastroesophageal reflux disease (GERD) Zollinger-Ellison Syndrome…

28 Sep 2017

By Ronny Allan

19 Comments

Ever wonder what caused your Neuroendocrine Cancer?

Patient AdvocacyAtrophic gastritis, Carcinoid tumour, DNA, Gastric NET, Hereditary cancer syndrome, Incurable cancer, Neuroendocrine cancer, Neuroendocrine tumour (NET), Neurofibromatosis type 1 (NF1), Pernicious anaemia, Pheochromocytoma, Small cell lung cancer (SCLC), Small intestine NET (SI NET), Zollinger-Ellison Syndrome

OPINION. When you're diagnosed, you go through a whole host of emotions. It's not just the initial shock, the disbelief, the anxiety and morbid worry produced by the words "you have cancer", it's other stuff such as anger and denial. With the latter, the denial normally wears off as you finally accept the predicament.In hindsight, the anger is interesting because there can be a mixture of thoughts including "why me", "what could I have done to head this off"; and would you believe I was even angry that my diagnosis was going to affect my performance at work and even…