Diagnosis of neuroendocrine cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing cancer often means first ruling out other health conditions that share similar symptoms with cancer. It can be a very worrying time for you and your loved ones. Sometimes this process is quick. Sometimes it can feel long and frustrating. But it’s important for doctors to get all the information they need before making a diagnosis of cancer.

Diagnosing neuroendocrine cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and may do a physical exam. Based on this information, your doctor may refer you to a specialist or order tests to check for neuroendocrine cancer or other health problems.

The following tests are usually used to rule out or diagnose neuroendocrine cancer. Many of the tests that are used to diagnose cancer are also used to find out the stage (how far the cancer has spread). Your doctor may also order other tests to check your general health and to help plan your treatment.

Your health history is a record of your symptoms and risks and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest neuroendocrine cancer
• multiple endocrine neoplasia (MEN)
• smoking

Your doctor may also ask about a family history of:

• neuroendocrine cancer
• risks for neuroendocrine cancer
• other cancers

A physical exam allows your doctor to look for any signs of neuroendocrine cancer. During a physical exam, your doctor may:

• measure your temperature and blood pressure
• feel and press on parts of your body, such as the abdomen, to check if the organs are of normal size and if you feel pain when they are pressed
• check for enlarged lymph nodes in your underarm and neck
• examine the lungs

Find out more about a physical exam.

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check your general health. It is also done to check for anemia from long-term (chronic) bleeding.

Find out more about a complete blood count (CBC).

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working and can help find problems. Blood chemistry tests used to diagnose neuroendocrine cancer include the following.

Electrolyte panel measures the level of water in the body, muscle function and other body functions. High or low levels of electrolytes may mean there are problems with certain organs.

Blood sugar (glucose) test measures how well your body uses energy from foods. Abnormal blood glucose levels many mean you have diabetes, problems with the pancreas or a syndrome such as Cushing syndrome.

Depending on the symptoms you have, you may have tests for certain chemicals such as:

• calcitonin
• cortisol
• adrenocorticotropic hormone (ACTH)
• gastrin
• glucagon
• insulin
• somatostatin
• vasoactive intestinal polypeptide (VIP)
• pancreatic polypeptide (PP)
• metanephrines

Find out more about blood chemistry tests.

Tumour markers are substances found in the blood, tissues or fluids removed from the body. An abnormal amount of a tumour marker may mean that a person has neuroendocrine cancer. It can also mean that a person who has neuroendocrine cancer also has a hormonal syndrome such as carcinoid syndrome, which is caused by some types of neuroendocrine tumours (NETs) that release many types of substances including serotonin.

Tumour marker tests can be used to help diagnose neuroendocrine cancer, but they are generally used to check how treatment is working, or your response to cancer treatment.

The following tumour markers may be measured for neuroendocrine cancer.

Chromogranin A (CgA) is a protein found throughout neuroendocrine tissues. It also circulates in the blood. Because most neuroendocrine cancers cause increased CgA levels, CgA is often the first marker used to check for neuroendocrine cancers. You may have a false-positive result to this test if you’re taking proton pump inhibitors (PPIs), a type of medicine that reduces how much acid your stomach makes. Some non-cancerous conditions including liver or kidney dysfunction, or an autoimmune disease such as atrophic gastritis, can also cause increased CgA levels.

5-HIAA (5-hydroxyindoleacetic acid) is a substance made from serotonin and measured in the urine (pee). High levels may mean a person has serotonin-producing neuroendocrine cancer cells. 5-HIAA is usually the first biochemical marker checked when a person has symptoms of carcinoid syndrome. But many foods and medicines affect the levels of 5-HIAA, and some neuroendocrine cancers do not make 5-HIAA. So having a high level of 5-HIAA does not always mean a person has neuroendocrine cancer.

Find out more about tumour marker tests.

An ultrasound uses high-frequency sound waves to make images of parts of the body. It is used to check the abdomen for tumours or other abnormalities. It may also be used during an endoscopy or to guide a biopsy needle to a tumour.

An echocardiogram is an ultrasound of the heart. It may be used to check the health of the heart and if any heart damage is developing because of carcinoid syndrome.

Find out more about an ultrasound and an echocardiogram.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.

A CT scan is used to:

• check for tumours in the abdomen, pelvis and chest
• find out where the tumours are in those areas
• find out if neuroendocrine cancer has spread to the liver or lung
• determine when a surgery can be done

Doctors can also use a CT scan to guide a biopsy needle to a specific area in the body. This is called a CT-guided biopsy.

Find out more about CT scans.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

An MRI is used to check for tumours and find out where they are in the body. It may be used instead of a CT scan.

Find out more about MRIs.

A positron emission tomography (PET) scan uses radioactive materials called radiopharmaceuticals to look for changes in the metabolic activity of body tissues. A computer analyzes the radioactive patterns and makes 3D colour images of the area being scanned.

A PET scan is used to spot tumours and find out if the cancer has spread to other organs. It may be used in some cases when other imaging tests are not clear.

Find out more about a PET scan.

A gallium-68 DOTATATE PET scan uses a radiopharmaceutical called gallium-68. It acts as a tracer and binds to somatostatin receptors on tumours to make them more visible during PET scans.

A gallium-68 DOTATATE PET scan has higher sensitivity than a traditional PET scan. It provides clearer images that help detect slow-growing NETs.

An MIBG scan is a nuclear medicine imaging test that combines a radioactive material with a substance called metaiodobenzylguanidine (MIBG) to find certain types of tumours in the body. After the radioactive MIBG is injected into the body, the body is scanned and a computer makes images to show where the MIBG has collected. An MIBG scan is also called an MIBG scintigraphy or MIBG scintiscan.

An MIBG scan is used to find certain tumours, such as pheochromocytomas (a type of neuroendocrine cancer that starts in the adrenal glands), and where they are in the body.

MIBG scans may not be widely available in all provinces or covered by all provincial and territorial health plans.

Find out more about an MIBG scan.

Barium tests use a contrast medium called barium sulphate and x-rays to make pictures of the upper or lower part of the gastrointestinal (GI) tract. They are used to check for tumours and find the cause of GI symptoms. Barium tests used to help diagnose neuroendocrine cancer include:

• an upper GI series to examine the upper GI tract including the esophagus, stomach and small intestine
• a barium enema to examine the lower GI tract including the whole large intestine

Find out more about an upper gastrointestinal (GI) series and a barium enema.

An endoscopy is done to check if a tumour is causing symptoms. It allows a doctor to look inside the body using a flexible tube with a light and lens on the end. This tool is called an endoscope.

The type of endoscopy done depends on which part of the body needs to be examined and may include:

• upper GI endoscopy to check the esophagus, stomach and first part of the small intestine (called the duodenum)
• colonoscopy to check the large intestine
• bronchoscopy to check the airways of the lungs

In an endoscopic ultrasound, an ultrasound probe is attached to the end of the endoscope to produce ultrasound images during the endoscopy.

Find out more about an endoscopy, a colonoscopy and a bronchoscopy.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from the pathologist will show whether or not cancer cells are found in the sample. The pathologist will also examine the tissue or cells to determine the features of the tumour, such as the type of hormone released by the tumour and how quickly the cells are dividing and growing.

The type of biopsy done depends on where the tumour is located. Biopsies used to diagnose neuroendocrine cancer include the following.

A fine needle aspiration (FNA) uses a very thin needle and syringe to collect a sample of cells, tissue or fluid from an abnormal area or lump. It can be used to take a sample from a lump that may be neuroendocrine cancer.

A core biopsy uses a hollow needle to remove tissue. It’s a larger biopsy than an FNA so it’s often used when more tests need to be done on the tumour.

An endoscopic biopsy removes small amounts of tissue or a growth during an endoscopy. It’s most often used for tumours in the GI tract or lungs.

Find out more about a biopsy, a fine needle aspiration (FNA) and a core biopsy.

A bone scan uses bone-seeking radiopharmaceuticals and a computer to create a picture of the bones. It’s used to find out if neuroendocrine cancer has spread to the bones.

Find out more about a bone scan.

Find out more about a diagnosis. To make the decisions that are right for you, ask your healthcare team questions about diagnosis.