Gastrinoma

Order fasting serum gastrin with assessment of gastric acidity in patients with recurrent or refractory peptic ulceration, severe gastroesophageal reflux, chronic diarrhea, or complications such as upper gastrointestinal bleeding, perforation, or stricturing disease. These are the actionable manifestations of gastrinoma-associated Zollinger-Ellison syndrome (ZES). BMJ+1BMJBritish Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancerPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

Interpret gastrin only in physiologic context. Hypergastrinemia is the biochemical hallmark of ZES but has multiple causes; a high gastrin concentration alone does not establish gastrinoma. The diagnostic question is whether gastrin is elevated despite an acidic stomach, indicating inappropriate gastrin secretion and acid hypersecretion. PubMedPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

Actively consider multiple endocrine neoplasia type 1 (MEN1) when gastrinoma is suspected, because gastrinomas may be sporadic or MEN1-associated and MEN1 changes tumor multiplicity, localization strategy, and operative decision-making. Wiley+2WileyAll you need to know about gastrinoma today | Gastrinoma and Zollinger‐Ellison syndrome: A thorough update - Chatzipanagiotou - 2023 - Journal of Neuroendocrinology - Wiley Online LibraryPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedAll you need to know about gastrinoma today | Gastrinoma and Zollinger-Ellison syndrome: A thorough update - PubMed

Measure fasting serum gastrin and gastric pH. A fasting gastrin concentration >1000 pg/mL with gastric pH <2 is considered diagnostic for gastrinoma. This combination establishes marked hypergastrinemia in the setting of persistent acid secretion, rather than hypergastrinemia secondary to hypochlorhydria or pharmacologic acid suppression. PubMed+1PubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

For patients receiving antisecretory drugs, planned medication interruption requires risk assessment and close supervision. One review describes withholding PPIs for at least 1 week and H2-receptor antagonists for 48 hours before laboratory diagnosis; however, interruption of antisecretory treatment can be hazardous in ZES, and PPI exposure can produce false-positive secretin tests. Do not use an unsupervised drug holiday solely to obtain a gastrin value in a patient with severe acid-related disease. ScienceDirect+1ScienceDirectFalse-Positive Secretin Stimulation Test for Gastrinoma Associated With the Use of Proton Pump Inhibitor Therapy - ScienceDirectPubMedAll you need to know about gastrinoma today | Gastrinoma and Zollinger-Ellison syndrome: A thorough update - PubMed

Use a secretin stimulation test selectively when biochemical diagnosis remains uncertain after fasting gastrin and gastric acidity assessment. Secretin testing is not widely available, and false-positive results have been reported during PPI therapy; therefore, interpret the result with medication exposure and gastric pH rather than as a stand-alone diagnostic test. ScienceDirect+2ScienceDirectFalse-Positive Secretin Stimulation Test for Gastrinoma Associated With the Use of Proton Pump Inhibitor Therapy - ScienceDirectPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

Do not pursue localization as a substitute for biochemical confirmation when the diagnosis remains equivocal. Imaging identifies tumor distribution and resectability but does not resolve the central distinction between gastrinoma and other causes of hypergastrinemia. PubMed+1PubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

Start or intensify a proton pump inhibitor promptly in confirmed or strongly suspected ZES with ulcer disease, reflux, or diarrhea. High-dose PPI therapy, for example omeprazole 60-120 mg or an equivalent regimen, is cited for gastrinoma-associated acid hypersecretion; individual dose requirements vary, and some patients require more frequent dosing to maintain adequate acid suppression. BMJ+1BMJBritish Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancerPubMedZollinger-Ellison Syndrome: Classical Considerations and Current Controversies - PMC

Use symptom response as a clinical measure but do not equate symptom relief with mucosal healing. Regular endoscopic surveillance has been recommended because mucosal healing does not correlate reliably with symptom improvement. PubMedPubMedZollinger-Ellison Syndrome: Classical Considerations and Current Controversies - PMC

Reserve somatostatin analog therapy for selected patients whose hypersecretion or diarrhea remains inadequately controlled with PPI or H2-receptor blockade, or as part of management for advanced somatostatin receptor-expressing disease. Octreotide long-acting release can further reduce acid hypersecretion and improve diarrhea in some gastrinoma patients. PubMed+1PubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCema europa eu[PDF] sandostatin-lar-article-30-referral-annex-iii_en.pdf

Avoid acid-reducing surgery as routine management of hypersecretion; effective PPI therapy has virtually eliminated the need for acid-reducing surgical procedures. Surgical planning should focus on tumor resection, not gastrectomy for acid control, except in exceptional individualized circumstances. PubMedPubMedZollinger-Ellison Syndrome: Classical Considerations and Current Controversies - PMC

Obtain imaging to localize the primary tumor and assess metastases once gastrinoma-associated ZES is biochemically established or strongly supported. Gastrinomas arise most often in the duodenum or pancreas, and the localization strategy must account for small duodenal primaries as well as pancreatic neuroendocrine tumors. BMJ+2BMJBritish Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancerWileyAll you need to know about gastrinoma today | Gastrinoma and Zollinger‐Ellison syndrome: A thorough update - Chatzipanagiotou - 2023 - Journal of Neuroendocrinology - Wiley Online LibraryPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMC

Use endoscopic ultrasound (EUS) for primary localization and local staging, particularly when a pancreatic lesion or MEN1-associated disease is suspected. EUS has reported sensitivity as high as 83% for pancreatic gastrinomas but substantially lower detection rates for duodenal lesions; a negative EUS therefore does not exclude a duodenal primary. PubMed+1PubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedAll you need to know about gastrinoma today | Gastrinoma and Zollinger-Ellison syndrome: A thorough update - PubMed

Add cross-sectional CT or MRI for anatomic staging and metastatic assessment. Somatostatin receptor imaging is useful for detecting primary and metastatic gastrinomas; older somatostatin receptor scintigraphy data report detection of more than 90% of patients with metastatic liver disease, although this modality should be interpreted in the context of contemporary local imaging availability and multidisciplinary planning. ScienceDirect+1ScienceDirectZollinger Ellison Syndrome - an overview | ScienceDirect TopicsPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMC

Refer patients with suspected localized, multifocal, or metastatic disease to a multidisciplinary neuroendocrine tumor team that includes gastroenterology, surgical oncology, medical oncology, radiology, nuclear medicine, and pathology. Management decisions depend on disease distribution, comorbidity, performance status, and the feasibility of complete resection. BMJ+1BMJBritish Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancerPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMC

For localized gastrinoma, maintain PPI therapy and pursue surgical evaluation for curative-intent resection whenever feasible. This combined approach is described as the hallmark of localized gastrinoma treatment; surgery is directed at tumor removal after control of acid-related complications. PubMed+1PubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMCPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PubMed

The operative approach differs between sporadic and MEN1-associated ZES because MEN1 may involve multiple lesions and has a lower probability of straightforward cure. Surgical decisions should therefore integrate tumor localization, extent of disease, MEN1 status, and the ability to achieve negative microscopic margins. ScienceDirect+1ScienceDirectZollinger Ellison Syndrome - an overview | ScienceDirect TopicsPubMedZollinger-Ellison Syndrome: Classical Considerations and Current Controversies - PMC

After resection, follow serum gastrin; an elevated postoperative gastrin should trigger imaging for recurrent or persistent disease. Management of recurrent or metastatic disease remains individualized, but aggressive resection or cytoreduction is favored in the cited surgical review. PubMedPubMedZollinger-Ellison Syndrome: Classical Considerations and Current Controversies - PMC

For unresectable or metastatic disease, continue acid suppression and consider somatostatin analogs, peptide receptor radionuclide therapy (PRRT), liver-directed embolization approaches, systemic chemotherapy, or tyrosine kinase inhibitors according to disease burden, receptor expression, symptoms, and multidisciplinary review. These options are listed for advanced gastrinoma management, not as interchangeable first-line therapies. BMJ+1BMJBritish Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancerPubMedGastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies - PMC