Gastrinoma is a rare type of neuroendocrine tumour that primarily affects the pancreas and the upper small intestine. Known for producing excessive amounts of the hormone gastrin, gastrinomas are challenging to diagnose and manage due to their varied presentation and the severe gastrointestinal symptoms they can cause.
This article explores the nature of gastrinoma, its causes, its effects on the body, and the comprehensive approach required for its diagnosis and management.
At Neuroendocrine Cancer Australia, our mission is to support patients affected by neuroendocrine tumours (NETs), including those diagnosed with gastrinoma, and their families. We offer a wealth of resources, educational materials, and advocacy to deepen understanding of NETs, enhance the quality of care, and foster research in the field. For individuals confronting a gastrinoma diagnosis, engage with our comprehensive support and information by calling our NET nurse line.
Gastrinomas are part of a group of tumours known as pancreatic neuroendocrine tumours (pNETs). These tumours produce high levels of gastrin, a hormone that stimulates the stomach to secrete acid.
Like other pNETs, gastrinoma has a higher incidence in males and is generally diagnosed in people over 55. People of any age and sex can develop this disease.
Most gastrinomas are malignant and can spread to other parts of the body. They are sometimes diagnosed in the context of Zollinger-Ellison Syndrome (ZES), a condition characterised by excessive gastric acid production leading to severe peptic ulcers.
Like many other neuroendocrine tumours, the exact causes of gastrinoma are not fully understood, However, they can occur sporadically or be associated with genetic syndromes, particularly Multiple Endocrine Neoplasia type 1 (MEN1). Genetic mutations in genes responsible for cell growth and hormone regulation are thought to play a role in the development of these tumours. Genetic Counselling may be required for some people diagnosed with a gastrinoma.
Gastrinomas significantly impact the gastrointestinal system due to the overproduction of gastrin, which leads to excessive gastric acid secretion. This acid can damage the lining of the stomach and duodenum, leading to ulcers and, in severe cases, to complications such as bleeding or perforation of the stomach or intestinal walls.
The symptoms of gastrinoma are often persistent and resistant to standard ulcer treatments, which can be a clue to the presence of the disease.
The primary symptoms of gastrinoma include:
Diagnosing gastrinoma presents significant challenges, primarily due to its often subtle and non-specific symptoms that closely mimic those of more common gastrointestinal disorders. This similarity can lead to misdiagnosis or significant delays in identifying the correct condition.
Gastrinomas are also rare, which means that many healthcare providers may encounter them infrequently, adding another layer of complexity to achieving an early and accurate diagnosis. Early detection is crucial, as it significantly improves the potential for successful treatment outcomes.
There are three main avenues for successfully diagnosing gastrinoma:
The diagnostic process begins with a thorough medical history and physical examination. Physicians will look for symptoms suggestive of Zollinger-Ellison Syndrome and note any history of peptic ulcer disease, especially if it is resistant to conventional treatments. A physical examination may reveal signs of weight loss, abdominal tenderness, or other gastrointestinal disturbances.
Initial blood tests to diagnose gastrinoma include fasting serum gastrin levels, which are typically elevated in affected individuals. Additional tests might assess stomach pH levels to confirm excessive acid production. Imaging studies such as endoscopic ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI) are crucial for locating the tumour and determining the extent of the disease.
Confirmatory testing involves a secretin stimulation test, which measures the increase in gastrin levels in response to an injection of the hormone secretin. An abnormal increase in gastrin levels following secretin administration strongly suggests gastrinoma. This test is particularly effective because gastrinomas typically have an exaggerated response to secretin compared to normal cells.
Treating gastrinoma effectively requires a multifaceted approach due to the complex nature of this kind of neuroendocrine tumour. The primary treatment options typically include surgical removal of the tumour when feasible, which can potentially offer a cure.
For non-resectable tumours or those that have metastasised, a combination of drug therapies such as proton pump inhibitors to manage excessive gastric acid production and somatostatin analogues to inhibit hormone secretion is used.
Each patient’s treatment plan must be customised based on the tumour’s characteristics and the individual’s overall health, making the management of gastrinoma particularly challenging. As always, consultation with medical teams is the best way to seek the most effective course of treatment.
Surgical intervention is the cornerstone of treatment for gastrinoma when the tumour is localised and accessible. The primary goal of surgery is the complete removal of the tumour, which can offer a cure. In cases where the tumour has spread, or if complete removal is not possible, debulking surgery may be performed to reduce the size of the tumour and alleviate symptoms.
For patients where surgery is not feasible or for those dealing with metastatic disease, medications play a crucial role. Proton pump inhibitors (PPIs) are commonly used to manage the excessive gastric acid production caused by high levels of gastrin.
PPIs effectively reduce stomach acidity, alleviating ulcer symptoms and preventing complications like bleeding. In addition to PPIs, somatostatin analogues such as octreotide or lanreotide are used to suppress gastrin secretion and slow the growth of gastrin-producing tumours.
Advanced treatments such as peptide receptor radionuclide therapy (PRRT) are available for patients with inoperable or metastatic gastrinoma. PRRT involves using a radioactive substance coupled with a somatostatin analogue to target and destroy tumour cells selectively. This treatment can be particularly effective in controlling tumour growth and alleviating symptoms.
Chemotherapy and other targeted medications such as sunitinib and everolimus may also be considered in treatment of advanced gastrinomas.
Living with gastrinoma requires careful management to improve and maintain quality of life, given the impact of the tumour’s symptoms on daily activities. Patients must adapt to a lifestyle that includes regular medical monitoring and adjustments in treatment to manage symptoms effectively.
Dietary changes are often necessary to mitigate the effects of excessive gastric acid production, involving a diet low in acidic and spicy foods and structured around smaller, more frequent meals to ease digestive processes.
Additionally, supportive care, including psychological counselling and patient support groups, plays a crucial role in helping individuals cope with the emotional and physical burdens of the disease. By focusing on these aspects, patients with gastrinoma can achieve a better quality of life despite the challenges posed by their condition.
Dietary management is crucial for patients with gastrinoma to mitigate symptoms and manage the effects of excessive gastric acid. A diet low in acidic foods and beverages, such as citrus fruits, spicy foods, and caffeinated drinks, is recommended to reduce gastric irritation. Patients may also benefit from small, frequent meals to avoid large amounts of gastric acid release at once.
Regular monitoring of symptoms is essential for effectively managing gastrinoma. Patients should keep track of their abdominal pain, heartburn, nausea, and any signs of gastrointestinal bleeding. Regular follow-ups with a gastroenterologist are necessary to adjust treatment plans based on symptom progression or regression.
Living with gastrinoma can be challenging, not only physically but also emotionally. Patients benefit from a robust support system, including access to counselling services, support groups, and patient education programs. Neuroendocrine Cancer Australia is dedicated to neuroendocrine tumour advocacy and provides valuable patient support resources for patients and their families.
Research and future directions in the treatment of gastrinoma offer significant hope to patients, as ongoing studies and clinical trials continually push the boundaries of medical science to improve outcomes.
Innovations in targeted therapies and advancements in genetic profiling are particularly promising, aiming to tailor treatments more precisely to individual tumour characteristics.
Additionally, developments in minimally invasive surgical techniques and novel drug therapies are expected to enhance the effectiveness of treatments while minimising side effects.
The landscape of research not only promises to extend survival rates but also aims to significantly improve the quality of life for those living with gastrinoma, fostering optimism among patients and their families about the future of their care.
Research into gastrinoma receives more investment every year, with numerous ongoing studies and clinical trials aimed at discovering more effective treatments and diagnostic tools. These studies focus on everything from new drug therapies and novel surgical techniques to improvements in diagnostic imaging and biomarker discovery.
The future of gastrinoma treatment holds promise with several potential breakthroughs on the horizon. Innovations in molecular genetics may lead to treatments that are specifically tailored to the genetic profile of an individual’s tumour, enhancing treatment efficacy and minimising side effects. Additionally, advancements in immunotherapy hold the potential to harness the patient’s immune system to fight the tumour more effectively.
Gastrinoma is a rare and complex condition that requires a nuanced approach to diagnosis and management. Due to its potential severity and the risk of misdiagnosis, understanding the underlying causes, effects, and symptoms is crucial for effective treatment.
The ongoing advancements in medical research provide hope for more effective treatments in the future, delivering better outcomes for patients with this challenging condition. Engaging with healthcare providers, staying informed about new research, and accessing supportive resources are essential for patients to manage their health and improve their quality of life.
For patients diagnosed with gastrinoma, engage with our comprehensive support and information by calling our NET nurse line.
