Neuroendocrine cells are cells which show some of the features of nerve tissue and some of the features of glandular tissue. Neuroendocrine tumours can occur in various parts of the body and a number of different tumours of neuroendocrine cells may develop in the pancreas. These include insulinomas, gastrinomas, VIPomas and non-functioning neuroendocrine tumours. All these tumours are very rare - for example, insulinomas are the commonest but only one person in every million will develop an insulinoma in any one year. The average age of onset for these tumours is between 50-60.
The different types of neuroendocrine tumour produce different sets of symptoms.
Insulinomas produce an excess of insulin which causes the blood sugar level to fall (hypoglycamia). When this happens it leads to headache, sweating, palpitations weakness and even loss of consciousness. These episodes most commonly occur first thing in the morning, on exercise or after missing a meal. They are relieved by eating food or drinking sugary drinks.
Gastrinomas produce an excess of the hormone gastrin which leads to ulcers in the stomach and small intestine. These are often multiple and do not respond well to normal ulcer medicines.
VIPomas (vasoactive intestinal polypeptide tumour) produce a substance called vasoactive intestinal peptide. This causes excessive watery diarrhoea, which can result in dehydration, weight loss and cramping pain.
The non-functioning neuroendocrine tumours are so-called because they do not produce any hormones or peptides. They usually cause symptoms as a result of their size, leading to abdominal pain, backache, sickness or jaundice (yellowing of the skin and the whites of the eyes).
These tumours vary in their behaviour. The majority of insulinomas (90%) are benign (non-cancerous) whereas the majority of gastrinomas (60%), VIPomas (80%) and non-functioning tumours are cancers.
These tumours are often quite difficult to diagnose and a number of blood tests, x-rays and specials scans may be needed. The diagnosis may be made by a small piece of tissue removed from the tumour using a needle. The doctor guides the needle to the right area by carrying out a scan such as an ultrasound scan or a CT scan at the same time. Sometimes the diagnosis is only made by having an exploratory operation.
Quite often these neuroendocrine tumours grow slowly over several years.
The cornerstone of treatment for these tumours is surgery. Very often insulinomas and gastrinomas can be completely removed, although this is less often the case for VIPomas and non-functioning tumours, where partial removal is more likely. When the tumours are benign and are completely removed the cure rates are excellent. Those that are malignant (cancerous) may still do well. Those that are slow growing may benefit from a partial removal of the tumour which may help to prolong life and it is not uncommon for people to live for several years despite having cancer remaining after surgery.
If an operation to remove all the cancer is not possible, there are several other possible treatments for these cancers. The symptoms caused by the chemicals they may produce can often be controlled by injections of a substance called octreotide. In the past this drug had to be given by injection several times per day but there are now long acting forms which can be given once or twice a month.
Some of these tumours may take up large amounts of particular chemicals such as MIBG or octreotide. If this is the case then it may be possible to give the chemical together with radioactivity attached. Because the cancer takes the chemical into itself in relatively large quantities it also takes in the radioactivity and therefore receives much larger doses of radioactivity than the normal tissues and the treatment causes few side effects. This treatment is only possible if the cancer takes up large quantities of these chemicals so the doctor will first do a scan using a tiny amount of radioactivity and will only give the full treatment if the scan shows that there is good uptake.
Sometimes the growth of the cancers can be slowed by blocking the blood supply to the tumours. This is called embolisation and is done by putting a tube into the artery that provides the blood supply to the tumour and injecting a substance that blocks the artery.
Various types of drug treatment may also be given when the tumour has not been completely removed. Interferon is a natural part of the body's defences against infections and cancers and can now be produced in large amounts, which can be helpful in controlling these cancers. Chemotherapy may also help to control some neuroendocrine cancers. The type of chemotherapy used may be influenced by what the cancer cells looks like under the microscope with different chemotherapy drugs being given depending on whether they appear to be slow or fast growing.
Clearly for your husband the important thing is to discuss the situation further with his doctors to get more information about the type of neuroendocrine tumour they think he has. This should give you a better idea of the likely treatment and long-term outcome.