Pancreatic neuroendocrine cancers (PancNETs)

Neuroendocrine cancers develop in neuroendocrine cells, which are found in different organs or parts of the body. Neuroendocrine cells make hormones that help to control how our bodies work.

Pancreatic neuroendocrine cancers start in cells in the pancreas called Islet of Langerhans cells (see diagram). These cells make hormones, including insulin and glucagon, which control the sugar levels in the blood. There are two main types of pancreatic neuroendocrine cancer:

• neuroendocrine tumours (NETs), which tend to grow slowly
• neuroendocrine carcinomas (NECs), which grow faster and cause symptoms similar to PDAC.

We use the term pancreatic neuroendocrine cancer for both. But remember that they behave differently, so speak to your doctor about whether your cancer is a NET or NEC.

We don’t know why most neuroendocrine cancers happen. But a very small number of rare inherited genetic conditions are linked to pancreatic neuroendocrine cancer.

Neuroendocrine Cancer UK have more detailed information about the different neuroendocrine cancers, including pancreatic neuroendocrine cancer.

Pancreatic neuroendocrine cancers may be called functioning or non-functioning. This depends on whether they produce higher levels of hormones, which cause symptoms. Most are non-functioning. This means that they don’t produce more hormones than normal.

Non-functioning pancreatic neuroendocrine cancers

Most pancreatic neuroendocrine cancers (60-90%) are called non-functioning pancreatic neuroendocrine cancers. They don’t make higher levels of hormones. Rarely, they can cause symptoms that are similar to the symptoms of pancreatic ductal adenocarcinoma. These include pain, weight loss, jaundice and diarrhoea.

Non-functioning neuroendocrine cancers may be harder to detect and diagnose than functioning neuroendocrine cancers. This is because they don’t cause specific symptoms. They are often diagnosed during tests for another problem.

Functioning pancreatic neuroendocrine cancers

Some pancreatic neuroendocrine cancers produce higher levels of certain hormones, which can cause specific symptoms. These are called functioning neuroendocrine cancers. Up to 30 in 100 (30%) of pancreatic neuroendocrine cancers are functioning.

Insulinomas

Insulinomas can occur anywhere in the pancreas. They make too much of the hormone insulin, causing low blood sugar levels. Low blood sugar levels can cause symptoms like dizziness, light headedness, sweating, hunger, confusion and irritability.

Gastrinomas

Gastrinomas are found in the pancreas and the duodenum (first part of the small intestine). They produce too much of a gut hormone called gastrin. High levels of gastrin means that too much stomach acid is made.

Symptoms may include chest and/or tummy pain, acid reflux, heartburn, diarrhoea and tiredness. These combined symptoms are called Zollinger-Ellison syndrome. Excess gastrin may also cause irritation of the stomach or duodenum, leading to ulcers and bleeding.

Up to 30 in 100 gastrinomas (30%) are linked to a family cancer syndrome called multiple endocrine neoplasia type 1 (MEN1).

Glucagonomas

Glucagonomas are mostly found in the body and tail of the pancreas. They make too much of the gut hormone glucagon, which helps to control blood sugar levels.

Symptoms include a distinct type of skin rash (redness and blisters), particularly on the face, tummy, bottom and feet. Glucagonomas can also cause diabetes (high blood sugar levels), diarrhoea (runny poo), weight loss, changes in mood, anaemia (low levels of red blood cells), blood clots, and sore mouth and tongue.

VIPomas

VIPomas are more common in the tail of the pancreas. They make too much of a hormone called vasoactive intestinal peptide (VIP). VIP normally helps to neutralise stomach acid and control how quickly food passes through the bowel.

Symptoms include lots of watery diarrhoea, dehydration, low levels of potassium in the blood (hypokalaemia), tummy pain, bloating, and a flushed face.

Other functioning pancreatic neuroendocrine cancers include:

• Somatostatinomas which produce too much somatostatin. This can lead to symptoms including gallstones, steatorrhoea (pale, oily, poo), anaemia, tummy pain, high blood sugar levels and jaundice.
• ACTHomas which produce too much ACTH (adrenocorticotropic hormone). This can cause symptoms of Cushings disease, including weight gain, easy bruising, anaemia, depression, increased risk of infection and darkened skin.
• PTHrPomas which produce too much PTHrP (Parathyroid hormone-related protein). This can cause symptoms including high calcium levels, tummy pain, feeling and being sick, constipation, bone pain, osteoporosis, fatigue, and confusion.
• Ppomas which produce too much pancreatic polypeptide. This can cause symptoms including diarrhoea, abdominal pain and weight loss.

Finding out more

Speak to your medical team with any questions about pancreatic neuroendocrine cancers and how they are treated.

Neuroendocrine Cancer UK have more detailed information and support around diagnosing, treating, managing and living with pancreatic neuroendocrine cancer. They have a helpline with a specialist nurse, online and local support groups, an online community and a dedicated neuroendocrine cancer counselling team.

Published July 2022

To be reviewed July 2025