Somatostatinoma
Somatostatinomas are a type of neuroendocrine tumour (NET). They start in neuroendocrine cells that make the hormone 
. Somatostatinomas usually develop in the and small bowel (duodenum).
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.
Most somatostatinomas make large amounts of the hormone somatostatin. This hormone controls the production of other hormones by the pancreas. It also controls how the gut works.
Doctors sometimes group NETs depending on whether they make and release abnormal levels of hormones:
- Non-functioning NETs make and release normal levels of hormones.
- Functioning NETs make and release abnormal levels of hormones.
Somatostatinomas are a type of functioning NET.
They are also called gastro entero pancreatic neuroendocrine tumours (GEP NETs). Or if they develop in the pancreas, 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 somatostatinoma start?
More than 50 out of every 100 somatostatinomas (more than 50%) start in the pancreas. Pancreatic tumours usually start in the widest part of the pancreas. This is called the head of the pancreas.
The remaining somatostatinomas usually start in the duodenum.
More rarely somatostatinomas can start in:
- the middle part of the small bowel (jejunum)
- a tube called the cystic duct that connects the gallbladder to the common bile duct
- the ampulla of vater – this is where the bile duct and pancreatic duct join and meet the duodenum
All somatostatinomas are cancers. Some grow slowly and don't spread to other parts of the body. Others can spread (metastasise) to different parts of the body. The most common place to spread to is the liver and .
How common is somatostatinoma?
Somatostatinoma is very rare. Only around 1 person in every 40 million people develop a somatostatinoma every year.
Symptoms of somatostatinoma
Some people don’t have any symptoms. Or the symptoms can be vague.
You may have symptoms caused by the tumour itself. These can include:
- tummy pain
- unexplained weight loss
- yellowing of the skin and whites of your eyes (
jaundice ) - a bowel blockage (
obstruction ) - bleeding in the bowel or stomach – you may see blood in your vomit or poo
Somatostatinomas make large amounts of the hormone somatostatin. Less often, people have symptoms caused by the increase in the amount of somatostatin in your body. Doctors call this somatostatinoma syndrome. This is more common in pancreatic somatostatinomas than duodenal somatostatinomas.
The symptoms of somatostatinoma syndrome include:
- high blood sugars (diabetes)
- diarrhoea
- gallstones
- fatty poo – your poo might be pale and float, and be difficult to flush away
These symptoms could be due to somatostatinomas. But they can also be caused by other more common medical conditions. It’s important to get them checked by a doctor.
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.
Somatostatinomas are rare tumours. So your doctor might ask you to have tests that check for other conditions first.
If your doctor suspects cancer, you have tests to check the type of cancer you have. If tests show that you have a gastrinoma, your specialist will refer you to a team of doctors and specialist nurses who have expertise in treating NETs.
Tests for somatostatinoma
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 have might include:
- a blood test to check the amount of somatostatin
- 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 – this is to look inside your food pipe, stomach and small intestine and take a biopsy endoscopic ultrasound - this combines an ultrasound and endoscopy to look at the inside of your food pipe, stomach, pancreas and bile ductsendoscopic retrograde cholangio pancreatography (ERCP) to look at abnormal areas in your liver, bile duct, pancreas or gallbladderCT scan MRI scan - radioactive scans – these include octreotide scans (or
octreoscans ) and gallium PET scans
Grades and stages of somatostatinoma
Grades
The looks at a sample of somatoatatinoma 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
Somatostatinomas 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 somatostatinoma – grade 1, 2 and 3. Grade 1 grow slowly, and grade 3 grow quickly. Grade 2 grow at a moderate speed.
Stages
You have tests to find out the size of the somatostatinoma and whether it has spread. This is your stage. Doctors use your stage to plan your treatment.
There are different ways to stage somatostatinomas. Doctors usually use the TNM system or number stages. There are 4 main stages of NETs - stage 1 to stage 4.
The staging also depends on whether the somatostatinoma develops in your pancreas or duodenum.
We have separate information about staging neuroendocrine cancers that start in the duodenum.
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 Somatostatinoma
Surgery is the main treatment for somatostatinomas. But surgery is not always possible. Some somatostatinomas 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 which 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 somatostatinoma
Surgery is the main treatment for somatostatinoma.
Some of these are major operations and there are risks. But if the aim is to try to cure your somatostatinoma, 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. Your surgeon makes a large cut (incision) in your tummy (abdomen) to remove the tumour. You also have an ultrasound scan during your operation to check for other tumours. Your surgeon might also remove the nearby .
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.
You have treatment to control the blood sugar levels if they become too high. This is usually tablets, but you may also have insulin injections.
You might see a if you have lost a lot of weight. They will give you advice about what you are eating and drinking. You might need to have:
- vitamin or mineral supplements
- drip or tube feeding if you have lost a lot of weight
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 somatostatinoma
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.
