Tests after a diagnosis of NETs

The tests you have help to ensure that your team has all the information they need recommend the best treatment for you. Some tests may also be used to see how well you are responding to treatment.

Tests can show:

• How big is the tumour?
• Where exactly is the cancer?
• Has the cancer spread to any other parts of your body?

This is called staging. Read more about staging NETs

Blood tests

CgA test

This measures the level of a protein called chromogranin A (CgA) in the blood. It can be used to help diagnose NETs, as people with a NET may have a raised level of CgA. It can also be used to monitor how you are responding to treatment. This test needs to be put on ice when taken by the phlebotomist.

PRoBNP test

A test used for people with carcinoid syndrome. It measures a peptide in your blood which gives your team information about your heart function.

Blood tests can also measure:

• Kidney function (urea and electrolytes)
• Liver function
• Thyroid function
• Pituitary hormones (e.g. adrenocorticotrophic hormone (ACTH), prolactin, growth hormones and cortisol)
• Serum calcium, parathyroid hormone levels (as a simple screening test for MEN-1 syndrome)
• Levels of other hormones
• Levels of vitamins and minerals

5HIAA urine test

This test measures a substance called 5HIAA, which is found in the urine (pee) if your tumour is producing high levels of serotonin. this test can show the amount of serotonin in the body to confirm a diagnosis of carcinoid syndrome. It is also used to monitor patients with carcinoid syndrome.

For 24 hours, every time you pee you will collect it in a container and then you will return the urine to the hospital. 

The hospital will advise you on how to collect and store the urine. They will also advise you on foods and medicines to avoid before the test, as some can affect the results.

Scans

CT scan

This is a type of X-ray that gives a detailed 3D picture of the tissues inside your body. It can show the position and size of tumours. You may have regular scans to find out more about the rate of tumour growth and how the tumour is responding to treatment.

PET scan

A PET scan can show if the cancer has spread to other tissues and organs. 

Gallium-68 (Ga68) PET scan

This a special type of PET scan that is more sensitive. This test can help reveal the size and position of NET tumours in the body. It can also show if your NET might respond to targeted treatments, such as PRRT or targeted drug treatments.

You may have to travel to a specialist centre to have a PET scan or a Gallium 68 scan, as not every hospital has these scanners. You will be slightly radioactive after the PET scan. You should avoid close contact with pregnant women, babies or young children for a few hours after the scan.
Drink plenty of fluids and empty your bladder regularly after the scan; this can help flush the radiotracer from your body.

MRI scan

This is a scan that uses magnetic energy and radio waves to create a picture of the tissues inside your body. An MRI scan can be used to see where a tumour is. Further tests may be needed to confirm the type of tumour.

Scoping tests

Scoping tests use a tube with a camera and a light attached which is passed into your body. Your doctor or nurse can see inside your body and check for any abnormal areas. Samples of tissue (biopsies) can also be taken during a scoping test.

Endoscopy (gastroscopy)

Endoscopy is a scoping test that looks inside your body. It often refers to a test that examines your upper digestive system (oesophagus, stomach, start of the small intestine). This can also be called a gastroscopy. The tube with the camera is inserted down the back of your throat. 

Sometimes an ultrasound probe is attached to the tube inserted. This is called an EUS – endoscopic ultrasound. It can give a clearer view of the tumour and surrounding areas.

Colonoscopy

A colonoscopy looks at your large intestine (colon) and rectum. The tube with the camera is inserted into your back passage. 
 

Biopsy

Taking a sample of the tumour using a fine needle. This may be done during a scoping test, where a tube is passed into your body. Sometimes this may be guided using ultrasound or another method to help ensure the targeted tumour is biopsied.

The sample is examined in a laboratory by a specialist called a histopathologist to give information about what type of NET cancer it is, and how it is growing.

Echocardiogram

This is a type of ultrasound scan, which uses sound waves to build up a picture of your heart.

A gel will be spread over the area the doctors are checking. A small device like a microphone is moved back and forth over your skin to take the scan. This can be used to check for heart issues which may occur due to carcinoid syndrome.

Waiting for results

It can take a number of weeks for all the test results to come back. Usually your consultant or specialist nurse will discuss your test results with you at your next hospital visit.