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…