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Getting diagnosed

Tests to diagnose neuroendocrine cancer

You usually have tests to diagnose cancer. If you have neuroendocrine cancer the test results help the doctors find out the cancer type and how far it has grown. And they help doctors plan treatment.

Tests your GP might do

Most people with symptoms start by seeing their GP. Your GP might do some tests to help them decide if you need to see a specialist. These tests include:

  • blood tests

  • a physical examination

Your GP may also arrange for you to have other tests. For example, an x-ray or . You usually have these tests at your local hospital. 

Blood tests

There isn't a blood test that will show whether or not you have cancer. But blood tests can check your general health. They can also sometimes pick up problems caused by neuroendocrine cancer. Blood tests can check:

  • how well your liver and kidneys are working

  • the number of blood cells in your blood such as ​​ and ​​  

  • if there is a higher than normal level of ​​ in your blood

Physical examination

Your doctor usually asks you to lie or sit down. They look at and feel your skin and check for any abnormalities or areas that are swollen. Things they look for include signs of bleeding, bruising and infection.

They may also listen to your chest and tummy (abdomen) to find out if they sound normal.

You can ask for someone else to be in the room with you if you want, to act as a chaperone. A chaperone is a trained healthcare professional such as a nurse. A friend or relative can also stay with you for support. They can be with you during the examination.

Tests your specialist might do

Depending on your symptoms and the results of your blood tests, your GP might arrange for you to go to the hospital. 

The specialist you see at the hospital depends on your symptoms. For example you might see:

  • a ​​ or gastric surgeon

  • an endocrinologist who specialises in conditions that affect your hormone system

  • a lung specialist

If they suspect neuroendocrine cancer, they refer you to a neuroendocrine ​​ . 

Your specialist usually repeats the blood tests done by your GP. You also have more tests. These might include:

  • further blood tests 

  • scans such as ​, ​, ​​ and ​

  • tests to look inside your body - such as endoscopy, bronchoscopy or colonoscopy

  • an ​​ scan to look inside your abdomen 

You can read more about these tests further down this page.

Further blood tests

Your specialist might request further blood tests if you haven't had these done:

Blood tests to check hormone levels

The tests you have depend on where the cancer is and your symptoms. 

If your doctor suspects a neuroendocrine cancer they might look at the levels of a specific hormone. These include:

  • gastrin

  • glucagon

  • insulin

  • serotonin

  • vasoactive intestinal peptide

You mustn't eat before some hormone tests. 

For example, if your doctor suspects you have an ​​, you have a long fasting test. This is to check if your blood sugar levels go down if you don’t eat. 

Your nurse takes regular blood samples to check your blood sugar. You can drink water but not eat or drink anything else for up to 72 hours. You stay in hospital for this test. 

Chromogranin (CgA test)

The chromogranin A (CgA) test measures the amount of CgA in the blood. CgA is a protein that many neuroendocrine cells produce. But CgA can also be raised for other reasons that are not related to cancer. So, the test is not used on its own to diagnose neuroendocrine cancer.

You might have a blood test to check for the level of the protein chromogranin B (CgB) in the blood. This is less common than having a CgA test.

N-terminal pro-brain natriuretic peptide (NT-proBNP) blood test

You might have this blood test, especially if you have carcinoid syndrome. This is one of the tests to check for a complication called carcinoid heart disease.

Read more about carcinoid syndrome

Checking for multiple endocrine neoplasia 1 (MEN 1)

Specialist doctors (​​ doctors) might request an extra blood test, This is to check for a rare inherited condition called​. Research shows that people with MEN1 have a higher risk of developing pancreatic NETs.

Urine tests

Neuroendocrine tumours sometimes release high amounts of ​​. This breaks down into a substance called 5-HIAA. Your doctor can test for this in your wee (urine).

A raised amount of 5-HIAA in your urine can be a sign of a neuroendocrine tumour. But it can also be caused by other medical conditions. 

You might collect all your urine over 24 hours to measure the amount of 5-HIAA. Or you might be able to give one urine sample. Your nurse or doctor will give you a container to collect your urine in.

Some medicines can also affect the level of 5-HIAA in your urine. You might need to stop taking them for a few days before your test. Let your doctor or nurse know about any medicines or herbal remedies you are taking.

Tests to look inside your body

The test you have depends on where the suspected neuroendocrine cancer is. 

You might have a gastroscopy. This is also called an endoscopy or oesophago gastric duodenoscopy. This is when the doctor passes a thin tube (endoscope) through your mouth. They can look at your stomach and take ​​ of any abnormal looking tissue.

For other parts of your body you might have:

  • a bronchoscopy - to look inside your lung

  • a colonoscopy - to look inside your bowel

Select your type of test in our cancer tests section

Ultrasound scan and endoscopic ultrasound

An ultrasound scan uses high frequency sound waves to create a picture of a part of the inside of your body.

The ultrasound scanner has a probe that gives off sound waves. The probe looks a bit like a microphone. The sonographer presses the probe against your skin. They move it around the area they are scanning.

The sound waves bounce off the organs inside your body, and the probe picks them up. The probe links to a computer that turns the sound waves into a picture on the screen.

Read about ultrasound scans

You can also have an ultrasound inside your body. You have this during an endoscopy and it is called an ​​ .

Read about endoscopic ultrasound scans

Taking a sample (biopsy) of the cancer

A biopsy means removing a piece of tissue so that a ​​ can look at it under a microscope. This is the only way to be certain if an abnormal area is cancer and what type it is.

You might have a biopsy at the same time as other tests for neuroendocrine cancer. For example, during an endoscopy or ultrasound scan.

How you have a biopsy depends on where your doctor is taking the sample from. Doctors can use scans such as ultrasound or CT scans to help guide many types of biopsies.

Read more about having a biopsy

CT scan

A CT scan uses x-rays and a computer to create detailed pictures of the inside of your body.

You might have a CT scan of your chest, tummy (abdomen) or pelvis. 

Read about CT scans

MRI scan

MRI stands for magnetic resonance imaging. It uses magnetism and radio waves to create pictures of the inside of body. 

MRI scans can sometimes show up soft tissue more clearly than CT scans. 

Read more about having an MRI scan

PET-CT scan

A PET-CT scan combines a CT scan and a PET scan. PET stands for positron emission tomography. The PET scan uses a mildly radioactive drug to show up areas of your body where cells are more active than normal.

The CT scan takes a series of x-rays from all around your body. The computer puts them together to create a 3 dimensional (3D) picture.

PET-CT scans can be useful for some types of neuroendocrine cancer. Your doctor will tell you if you need this type of scan.  

There are 2 types of PET scans for neuroendocrine cancer:

  • FDG PET CT scans assess faster growing neuroendocrine cancers. 

  • Gallium dotatate PET CT scans are specialised scans. They are only available in a few hospitals. They are to assess neuroendocrine tumours (NETs).

Read about having a PET-CT scan

Radioactive scans

Radioactive scans can help your doctors diagnose some types of neuroendocrine cancer. You have an injection of a low dose radioactive substance. This can show up on a scan.

Radioactive scans include:

  • octreotide scans (or Octreoscans) – these are also called somatostatin receptor scintigraphy scans

  • tektroyd scans

  • gallium dotatate PET scans

You might also have an mIBG scan, but this is less common now. mIBG stands for metaiodobenzylguanidine.

Read more about radioactive scans for neuroendocrine cancer

Treatment for neuroendocrine cancer

The tests you have help your doctor find out if you have neuroendocrine cancer. And it tells them what type it is, and where it is in your body.

This is important because doctors use this information to recommend the best treatment for you.

Read more about treatment for neuroendocrine cancer

Coping with neuroendocrine cancer

Coping with a diagnosis of neuroendocrine cancer can be difficult. There is help and support available for you and your family.

Read more about coping with neuroendocrine cancer

Last reviewed: 28 Feb 2025

Next review due: 28 Feb 2028

Referral to a specialist for neuroendocrine cancer

Your GP will refer you to see a specialist doctor if you have symptoms that could be due to cancer.

What is neuroendocrine cancer?

Neuroendocrine cancers are also called neuroendocrine neoplasms (NENs). There are 2 key groups - neuroendocrine tumours (NETs) and neuroendocrine carcinomas (NECs).

Types of neuroendocrine cancer

There are many different types of neuroendocrine cancer. They are usually named after the part of the body where they develop.

Grades and stages of neuroendocrine cancer

A  pathologist  reports how abnormal the cancer cells look (differentiation) and how quickly they are growing (grading). Your stage is the size of the cancer and whether it has spread.

Treatment for neuroendocrine cancer

Treatment depends on the type of neuroendocrine cancer you have, where it is, its size and whether it has spread (the stage).

Neuroendocrine cancer main page

Neuroendocrine cancers develop in cells of the neuroendocrine system. They can develop in different parts of the body including the lungs, stomach, pancreas and bowel.

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