Gastrinoma
Gastrinomas are rare neuroendocrine tumours (NETs). They start in the 
making cells of the pancreas and small bowel ().
Neuroendocrine tumours (NETs) are a group of neuroendocrine cancers. Doctors also use the term neuroendocrine neoplasm (NEN) for neuroendocrine cancer.
NETs start in and can develop in different parts of the body.
NETs can be slow or fast growing. The cancer cells look abnormal. But they still have some similarities to normal neuroendocrine cells.
Gastrin is a which controls the amount of acid in your stomach. It helps to digest food. Gastrinomas make large amounts of gastrin which causes high levels of stomach acid. Too much acid can cause ulcers in the stomach and the small bowel.
Zollinger - Ellison Syndrome (ZES) is the name for the collection of symptoms you have with a gastrinoma. ZES refers to the combination of:
- high levels of gastrin
- too much acid
- stomach or small bowel ulcers
Doctors sometimes group NETs depending on whether they make abnormal levels of hormone:
- Non-functioning NETs make and release normal levels of hormone.
- Functioning NETs make and release abnormal levels of hormone.
Gastrinomas are a type of functioning NET. They are also called gastro entero pancreatic neuroendocrine tumours (GEP NETs) or pancreatic neuroendocrine tumours (pNETs).
The pancreas and duodenum
The pancreas and duodenum are part of our .
The pancreas is a large gland that makes digestive juices and hormones. The juices flow down a tube (duct) into the duodenum. The duodenum is the first part of the small bowel.
Another duct called the bile duct joins the duodenum to the liver and the pancreas. The bile duct comes down from the and liver and joins the duodenum right next to the pancreatic duct.
Where does gastrinoma start?
Around 70 out of every 100 gastrinomas (around 70%) start in the duodenum. Tumours that start in the duodenum are usually small. They are often less than 1 cm across. They are called duodenal gastrinomas.
About 25 out of every 100 gastrinomas (about 25%) start in the pancreas. Pancreatic gastrinomas usually start in the widest part of the pancreas. This is called the head of the pancreas. It is the part closest to the duodenum. Pancreatic gastrinomas are often bigger than duodenal gastrinomas.
More rarely gastrinomas can start in the:
- stomach
- liver
- bile duct
- ovary
- heart
- lungs
All gastrinomas are cancers. Some gastrinomas grow slowly and don't spread to other parts of the body. But some can spread (metastasise) to other parts of the body.
Gastrinomas that start in the pancreas are more likely to spread to other parts of the body, than gastrinomas that start in the duodenum:
- up to 35 out of every 100 pancreatic gastrinomas (up to 35%) spread to the liver
- up to 10 out of every 100 duodenal gastrinomas (up to 10%) spread to the liver
Gastrinomas can also spread to the nearby .
How common is a gastrinoma?
Gastrinomas are very rare. Fewer than 2 people in every million develop a gastrinoma every year.
Symptoms of gastrinoma
You usually have symptoms caused by the increase in the amount of stomach acid. Gastrinomas make large amounts of the hormone gastrin. Gastrin controls the amount of acid in your stomach, which helps to digest food.
The symptoms can be vague and might include:
- tummy pain, usually caused by a stomach or duodenal ulcer
- diarrhoea
- indigestion (heart burn)
- bleeding in your poo or vomit
- feeling or being sick
- unexplained weight loss
Symptoms of gastrinomas are often also caused by other medical conditions. Your symptoms are unlikely to be cancer, but it is important to get them checked by a doctor.
Zollinger-Ellison Syndrome (ZES)
Zollinger-Ellison Syndrome (ZES) is the name doctors use for the collection of symptoms caused by high levels of the hormone gastrin. ZES often causes:
- stomach or small bowel ulcers (peptic ulcer disease)
- acid reflux (gastro oesophageal reflux or GOR for short)
Seeing your GP and referral to a specialist
If you have symptoms, you usually see your GP first. They might organise some tests. Your GP will decide if you need to see a specialist. They might refer you to a gastroenterology specialist. These doctors specialise in problems affecting the digestive system.
Gastrinomas are rare tumours. So your doctor might ask you to have tests that check for other conditions first.
If your specialist suspects cancer, you have tests to check the type of cancer you have. If tests show that you have a gastrinoma, they will refer you to a team of doctors and specialist nurses who have expertise in treating NETs.
Tests to diagnose gastrinoma
Your GP and specialist arrange tests. Tests also show the size of the cancer and whether it has spread. Some of the tests help your doctor plan your treatment.
Tests you might have include:
- a blood test to check the amount of gastrin
- other blood tests to check your general health and check levels of other substances raised by neuroendocrine cancer
- a blood test to check for a rare inherited condition called
multiple endocrine neoplasia 1 (MEN1) endoscopy to look inside your food pipe, stomach and small intestine and take abiopsy endoscopic ultrasound CT scan MRI scan - radioactive scans – these are
octreoscans and gallium PET scans - gastric PH test to measure how much acid is in your stomach
- selective angiography with secretin stimulation
Selective angiography with secretin stimulation
This test combines an x-ray of your blood vessels (angiography) and a test which makes gastrinomas produce gastrin.
Your doctor gives an injection of calcium into each one of the main blood vessels (arteries) in the gut. This makes gastrinomas produce gastrin and release it into the bloodstream. After 30 seconds, your doctor takes blood samples from each artery to measure the amount of gastrin.
This test can show the position of the gastrinoma based on which blood vessel it is close to.
You may have other tests, depending on your symptoms. Your doctor can tell you which tests you need.
Grades and stages of gastrinoma
Grade
The looks at a sample of gastrinoma cells under a microscope. They look at:
- how abnormal the cancer cells look – doctors call this differentiation
- how quickly or slowly they are dividing and growing – this is grading
Gastrinomas are well differentiated cancers. This means the NET cells look abnormal. But they still have some similarities to normal neuroendocrine cells.
There are 3 grades of gastrinomas – grade 1, 2 and 3. Grade 1 grow slowly, and grade 3 grow quickly. Grade 2 grow at a moderate speed.
Most gastrinomas are grade 1 or 2.
Stage
You have tests to find out the size of the gastrinoma and whether it has spread. This is your stage. Doctors use your stage to plan your treatment.
There are different ways to stage gastrinomas. Doctors usually use the TNM system or number stages. There are 4 main stages of NETs - stage 1 to stage 4.
The staging system doctors use also depends on whether the gastrinoma develops in your pancreas or duodenum.
We have separate information about staging neuroendocrine cancers.
Risks and causes
A risk factor is anything that increases your risk of getting a disease.
We don’t know what causes most neuroendocrine cancers. But there are some risks factors that can increase your risk of developing it. Having one of these risk factors doesn’t mean that you will definitely develop a cancer.
The risk factors for pancreatic NETs include:
- an inherited condition called multiple endocrine neoplasia 1 (MEN1)
- having a family history of cancer
Treatment for gastrinoma
Surgery is the main treatment for gastrinomas. But surgery is not always possible. Some gastrinomas might have already started to spread. Or you may not be well enough to have an operation.
You might have other treatments if surgery isn’t an option.
Deciding what treatment you need
A team of doctors and other professionals discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).
The treatment you have depends on:
- where the NET is and its size
- how many tumours you have
- whether it has spread to other parts of the body
- your general health and fitness
- the symptoms you have
Your doctor will discuss your treatment. And tell you about its benefits and the possible side effects.
You are likely to have a clinical nurse specialist (CNS). They go to the MDT meetings. They can help answer your questions and support you. They are often your main point of contact throughout your treatment.
Types of treatment for gastrinoma
Surgery to remove the gastrinoma is usually the main treatment. The type of surgery you have depends on whether the gastrinoma started in your duodenum or the pancreas.
Some of these are major operations and there are risks. But if the aim is to try to cure the NET, you might feel it is worth some risks. Talk to your doctor about the risks and benefits of your surgery.
You usually have open surgery. This means having a large cut (incision) in your tummy (abdomen). You also have an during your operation to check for other tumours. Your surgeon might also remove the nearby .
You might have an operation called a duodenectomy. Your surgeon makes an incision in your abdomen to open the duodenum and remove the tumour.
Types of surgery to remove cancer from the pancreas
There are different operations:
Enucleation means the surgeon removes just the tumour. They leave the healthy pancreatic tissue behind.
A distal pancreatectomy means the surgeon removes:
- the narrowest part of the pancreas
- the body of the pancreas
A pylorus preserving pancreaticoduodenectomy (PPPD) means the surgeon removes:
- the widest part of the pancreas
- the duodenum
- the gallbladder
- part of the bile duct
A Whipple’s operation means the surgeon removes:
- the widest part of the pancreas
- duodenum
- gallbladder
- part of the bile duct
- part of the stomach
If the cancer has spread to the liver, your surgeon might remove the liver tumours at the same time as the main surgery. Your surgeon may remove just the tumour or part of the liver.
Gastrinomas make large amounts of the hormone gastrin. This increases the amount of acid in your stomach. So you usually have treatment to stop your stomach from making too much acid.
The main treatment to stop you from making too much acid are drugs called proton pump inhibitors (PPIs). You usually have 1 of the following drugs:
- omeprazole
- lansoprazole
- pantoprazole
- esomeprazole
You might have other treatments if:
- you can’t have surgery to remove the NET
- the NET has spread to another part of the body
- the NET came back after the initial treatment
These treatments can control your symptoms and help you feel better but won’t get rid of the NET. There are a number of different treatment options:
somatostatin analogues - drugs include octreotide and lanreotide- peptide receptor radionuclide therapy (PRRT) - this uses a radioactive medicine to treat the NET
chemotherapy – drugs include temozolomide, fluorouracil, capecitabine, streptozotocintargeted cancer drugs – drugs include everolimus and sunitinib
For cancer that has spread to your liver you might have:
- trans arterial embolisation (TAE) to cancer in your liver
radiofrequency ablation - surgery to remove cancer from your liver
- a liver transplant – this is a rare treatment for NETs
Doctors are always trying to improve treatments and reduce the side effects. As part of your treatment, your doctor might ask you to take part in a clinical trial. This might be to test a new treatment or to look at different combinations of existing treatments.
Follow up
You usually have follow up appointments after treatment. This is to check how you are and see whether you have any problems or worries.
You might also have tests on some visits. The tests might include:
- blood tests
- an MRI or CT scan
How often you see your doctor depends on:
- the grade of your NET
- whether it has spread to other parts of the body
- what treatment you have had
- any side effects you might have
It is important you contact your doctors if you have any worrying symptoms between appointments.
Survival (prognosis) for gastrinoma
The best person to talk to you about your outlook () is your doctor. Not everyone wants to know. People cope differently with cancer and want different information.
Survival depends on many factors. So no one can tell you exactly how long you will live. Your doctor might be able to give you some guide, based on their knowledge and experience.
Your prognosis will depend on the type of NET you have and what it is.
Coping with neuroendocrine cancer
You might have physical changes to your body because of your cancer or the treatment. These changes can be hard to cope with and can affect the way you feel about yourself. It can help to talk to friends and family. Or join a support group to meet people in a similar situation.
We have a discussion forum called Cancer Chat. It is a place for anyone affected by cancer. You can share experiences, stories and information with other people with cancer.
You might need practical advice about benefits or financial help. There is help and support available. There are also organisations to support and provide information to people affected by neuroendocrine cancer.
