This page tells you about glucagonoma. This is a very rare type of tumour which develops in the pancreas. There is information about
Glucagonomas are tumours that develop in the pancreas. They develop in cells that make hormones. These cells are called islet cells.
There are different types of islet cells, each producing different hormones. Glucagonomas develop in the alpha-2 islet cells. They produce too much of a hormone called glucagon. This hormone helps to raise blood sugar levels in the body. When blood sugar falls, the pancreas produces glucagon which makes the liver change stored glycogen into glucose. The liver releases the glucose into the bloodstream, which raises the blood sugar level again.
Glucagonomas are extremely rare. In the UK they are diagnosed in less than 1 in a million people each year.
Between 5 and 8 out of every 10 glucagonomas (50 to 80%) are cancerous (malignant). The rest are benign tumours. It may not always be possible to tell if you have a benign or a malignant tumour. The tests you have, such as an MRI scan or CT scan, may show if the tumour has spread to the nearby lymph nodes or elsewhere. But it may not be until you have surgery that you know for certain if the tumour is benign or malignant.
Glucagonomas are slow growing, with slowly developing symptoms. But some people have cancer that has already spread at diagnosis.
Glucagonomas are a type of neuroendocrine tumour. Neuro means nerve and endocrine means hormone producing. Neuroendocrine tumours (NETs) are tumours that develop in cells that are triggered by nerve cells to produce hormones.
Glucagonomas are a particular type of gastroenteropancreatic neuroendocrine tumour (GEP NET). They are also called pancreatic neuroendocrine tumours (pNETs or PETs).
There is a separate page about neuroendocrine tumours.
Most symptoms are caused by the increase in the amount of the hormone glucagon. The symptoms may start slowly and become worse. They include
- A rash – this starts with small circles of redness which develop into itchy, painful blisters
- Weight loss
- Diabetes mellitus
- A sore mouth
- Blood clots (deep vein thrombosis)
The rash is called necrolytic migratory erythema (pronounced neck-row-lit-ik my-grate-or-ree air-ith-em-a). It can affect any part of the body but most commonly affects the buttocks, groin, genital and anal area, and lower legs. This develops because the increase in glucagon reduces the amount of zinc and amino acids in the body.
Symptoms of diabetes mellitus include feeling thirsty, a dry mouth, passing urine frequently, weight loss, tiredness, and blurred vision.
The first tests you have are blood tests. These check your general health and the amount of glucagon in your blood. You will also have a fasting blood sugar test. With this test you don’t eat anything for eight hours and then you have a blood test to measure the amount of sugar in your blood. You may also have a test to measure the level of glucagon in your blood.
Other tests you may have include
An octreoscan is also sometimes called somatostatin receptor scintigraphy (SSRS). You have an injection of a substance called octreotide and then have a scan using a special type of scanner. Octreotide is taken up by some neuroendocrine tumour cells. Doctors can attach a radioactive substance to the octreotide that shows up on the scan.
You may also have tests to check for MEN-1. This includes blood tests to check your levels of parathyroid hormone, calcium, and the hormone prolactin.
The first treatment you have is to control your symptoms. This includes correcting your blood sugar level. You may have tablets or insulin injections. If you have a rash you may also take zinc tablets and amino acids, which can reduce it.
Drugs called somatostatin analogues, such as octreotide and lanreotide, can also help to control symptoms such as diarrhoea. There is information about somatostatin analogues in the carcinoid section.
Once your symptoms are under control the main treatment is surgery. But surgery is not always possible. Some glucagonomas have already spread when they are diagnosed. If you can’t have surgery you will have treatment to control your symptoms.
Some surgery aims to cure the glucagonoma whether it is a benign or a cancerous tumour. The type of surgery you have depends on
- Whether you have one or more tumours
- Where the tumour is
- The size of the tumour
You may have surgery to remove
- Just the tumour
- The tail of your pancreas (a distal pancreatectomy)
- The nearby lymph nodes
Whichever type of surgery you have, if your tumour is cancerous your surgeon will also remove nearby lymph nodes.
If you have a cancer and it has spread to your liver, your surgeon may be able to remove the liver tumour at the same time. This may be just the tumour or may include some of the surrounding liver tissue.
These are major operations and there are risks with having this type of surgery. But the aim is to try to get rid of your glucagonoma so you may feel it is worth some risks.
It may not be possible to get rid of the glucagonoma completely. But your doctor may still recommend surgery to control symptoms. Your doctor will only suggest this if is possible to remove at least 9 tenths (90%) of the tumour.
You can read more about the surgery for tumours in the pancreas, and possible side effects, on the page about surgery to try to cure pancreatic cancer.
Treating symptoms of glucagonoma
If surgery cannot remove a glucagonoma, or if it comes back after surgery, you may have treatment to control the amount of glucagon the tumour is producing. The aim of this treatment is to control any symptoms you have rather than cure the glucagonoma. You may also have these treatments if surgery is not possible due to other medical conditions.
Treatments may include
- Surgery to remove some of the tumour
- Drugs to reduce the amount of glucagon you produce
Your specialist may suggest you have surgery even if your glucagonoma can’t be completely removed. Taking away as much of the tumour as possible can help to reduce symptoms.
If a malignant glucagonoma spreads to another part of the body, one of the most common areas for it to go to is the liver. Your surgeon may offer surgery to remove tumours in your liver. As this is a major operation and there are risks, you need to think carefully about the benefits. Will it improve your quality of life enough to make it worth having such a big operation? Your surgeon will talk to you about the risks and benefits and answer any questions you have.
Instead of having major open surgery for glucagonomas that have spread to your liver, you may be able to have radiofrequency ablation, cryotherapy, or transarterial chemoembolisation (TACE) to reduce your symptoms. Or you may have selective internal radiotherapy (SIRT).
Radiofrequency ablation uses heat made by radio waves to kill cancer cells.
Cryotherapy uses a cold probe to destroy cells and tissue by freezing.
Both radiofrequency ablation and cryotherapy treatment can be done using a laparoscopy or using a CT scan.
A laparoscopy is a small operation. Your doctor makes small cuts (incisions) in your tummy (abdomen) and gently pushes a laparoscope inside. A laparoscope is a tube with a camera and a light that helps the doctor to see the tumour. The doctor puts the radiofrequency ablation probe or cryoprobe through the skin and onto the tumour.
If you are having treatment using a CT scan, you either have a general anaesthetic or a local anaesthetic. The doctor makes a small cut in the skin of your tummy (abdomen) and then uses the CT scan to position the radiofrequency ablation probe or cryoprobe onto the tumour to treat it.
TACE is when you have chemotherapy injected directly into the area of the tumour in the liver. You also have an injection of another substance which blocks the blood supply to the tumour. This substance may be a gel or tiny plastic beads and helps to keep the chemotherapy around the tumour.
SIRT is when tiny beads that are coated with a radioactive substance called Yttrium-90 are injected into the blood supply to the liver. This is one type of targeted radiotherapy.
You may also have somatostatin analogues as explained above. There is some evidence to suggest that somatostatin analogues may also help to control the growth of the cancer. If the somatostatin analogues aren’t controlling your symptoms, or have stopped working, then you may have interferon. Interferon can help to control symptoms in some people.
Research is always more difficult with rare conditions. There are fewer people available to take part in trials, so it takes longer to recruit enough people.
There is research looking into diagnosing and monitoring these tumours. There is also research into different types of chemotherapy and biological therapies.
A recent phase 3 trial found that people having everolimus for advanced neuroendocrine tumours (NETs) had a longer time before their cancer started growing again compared to people having a dummy drug (placebo). The average time before the tumour started growing again was 11 months compared to 4.6 months in people having the placebo.
Another phase 3 trial comparing sunitinib with a placebo for advanced NET found that the average time before the cancer started growing again was 11.4 months compared to 5.5 months in people having the placebo.
The All Wales Medicines Strategy Group (AWMSG) and the Scottish Medicines Consortium say that sunitinib and everolimus should be available on the NHS. You should be able to have sunitinib or everolimus if other treatments are not working and you have pancreatic neuroendocrine tumours that cannot be removed with surgery, or have spread to other parts of the body. In England NICE have not looked at these drugs for NET. They may be available through individual funding through your PCT or through the cancer drugs fund if your doctor thinks they may be helpful.
Researchers are also looking into targeted radiotherapy or radio labelled treatment. You may hear this called peptide receptor radioligand therapy (PRRT). This is a way of getting radiotherapy directly to the individual tumour cells.
Cells have receptors that cause changes within the cell when they are triggered. PRRT works in a similar way to an octreoscan. By attaching radiotherapy to a substance that attaches to the receptors, you can deliver radiotherapy directly to them. It is too early in the research to know how well this treatment will work for glucagonomas.
We need more research to find out which of these new treatments work best and when to use them.
To find out more about neuroendocrine tumour trials go to our clinical trials database.
Coping with a rare condition can be difficult both practically and emotionally. Being well informed about your condition and possible treatments can make it easier to make decisions and cope with what happens.
It can also help to talk to people with the same condition. But it can be hard to find someone with a rare tumour. Check out Cancer Chat – Cancer Research UK’s discussion forum. It is a place to share experiences, stories, and information with other people who know what you are going through.
You might also find our general coping with cancer section helpful.
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