Tests to diagnose metastases

Breast cancer can spread to parts of your body such as your lungs, liver, bones or brain.

It's a good idea to see a doctor if:

• you develop new symptoms, such as pain or shortness of breath
• existing signs or symptoms don't go away or become worse.

Your doctor may arrange scans and tests called ‘staging’ tests. They provide a clearer picture of what is happening, so your doctors know the best steps to take. The type of tests will depend on:

• your symptoms
• the results of a clinical examination
• your general health and wellbeing.

We explain what the tests are and what to expect.

Physical examination

Physical examinations will depend on your individual situation. For example, your doctor may:

• assess your pain and check any areas where you have pain or tenderness
• listen to your chest
• check for enlarged lymph nodes
• test your vision, balance and strength.

After the physical examination, your doctor may order further scans or tests to confirm the diagnosis.

Blood tests

Blood tests can be used for a range of reasons. You may have regular blood tests to check:

• how the metastases are affecting your organ function
• the impact treatment is having on your body.

Chest X-ray

Your GP or specialist may order an X-ray. An X-ray is a scan that uses high-energy radiation (low-dose) to take pictures of bones. X-rays are painless and take only a few minutes.

They are useful to:

• detect fractures, which may be a symptom of bone metastases
• show defects or abnormalities in the bone
• show if there is a build-up of fluid around your lungs ('pleural effusion').

CT/CAT scan

Computerised tomography (CT) provides an image or images of the area being studied. A CT is a combination of X-rays and high-tech computer imagery.

Before the scan

Sometimes a liquid called ‘contrast’ is injected into a vein, usually in the arm. This helps show any cancer deposits more clearly. Your oncologist may arrange a blood test to check your kidney function before deciding if you can have the contrast.

Tell your doctor if you’re allergic to iodine or seafood.

During the scan

You will need to lie without moving for about 30 minutes.

The scan does not cause any pain.
The contrast material may cause you to feel hot or flushed but it is important you do not move during the scan.

PET scan

Positron emission tomography (PET) uses radioactive gamma rays to create a 3D picture of your body.

PET scans are useful to:

• show if abnormalities seen on a CT scan might be cancer
• monitor how your cancer is responding to treatment.

Before the scan

A small amount of radioactive material (‘tracer’) is injected 90 minutes before the scan.

You can ask for a mild sedative if you feel anxious.

During the scan

The scan takes about 30 minutes. It does not cause any pain. As you move through the scanner, it detects radiation from the tracer. This creates images.

Important: not everything that lights up in the PET scan is definitely cancer. Sometimes scans show signs of tracer in organs such as thyroid or bowel. These may be benign.

Bone scan

A bone scan is more sensitive than an X-ray and can find smaller areas of metastases. It scans all your bones to see:

• which ones may contain cancer
• how much damage the cancer has done.

Before the scan

You will have a small amount of radioactive material injected into a vein, usually in your arm.

Two to 3 hours later, when this material has travelled through your body, the scan is taken.

The bone cells ('osteoblasts') absorb the radioactive material. When the cells are damaged, they are more active. They show up as ‘hot spots’ on the scan.

Hot spots can be caused by:

• damage to the bone, such as from cancer
• old or new fractures
• arthritis.

The pattern of hot spots can give the specialist a good idea of the cause. You may need other tests to be sure.

Follow-up bone scans

After you begin treatment, bone scans can look worse (‘flare’) before they look better. This is because the osteoblasts are more active as they heal.

If you have other signs that your treatment is working, such as less pain and better tumour markers, your doctor might suggest they delay the first follow-up bone scan for 6 months or so.

Biopsy

A biopsy is a procedure to take a small sample of tissue so it can be looked at under a microscope.

You may need a biopsy to confirm the diagnosis after an MRI or CT scan.

A biopsy is useful:

• to show whether the abnormality is due to a metastasis from breast cancer or another cause
• for your doctor to re-check the tumour receptors (ER, PR and HER2). Sometimes these can be different from your primary breast cancer. This information is important to help your team decide the best treatment for you.

The type of biopsy depends on where the metastases are.

Bronchoscopy: this is done under local anaesthetic if the abnormality is central in the chest and close to the main bronchi. Usually, you are also sedated (like during a colonoscopy or endoscopy). A small tube with a light at the end (‘bronchoscope’) is passed through the mouth into a bronchus to take a small piece of tissue.

CT guided biopsy: this is done under local anaesthetic. If the abnormality is near the surface, for example some parts of the liver, lung or lymph nodes, a small needle can be passed through the skin into the lung under the guidance of a CT scan.

Mediastinoscopy: if the abnormality is in the space between the lungs and behind the breast bone (the ‘mediastinum’), you may need keyhole surgery (‘Mediastinoscopy‘) to take a biopsy. This needs a general anaesthetic and a short hospital stay.

Tumour markers

Tumour markers are substances – usually proteins such as CA15-3 and CEA – that:

• the body can produce in response to cancer
• the cancer tissue itself can produce.

If the tumour marker levels are higher than normal, this can mean metastases are present.

Usually, doctors use tumour markers to see if the cancer is responding to treatment.

It’s important to remember that tumour markers are not always a reliable way to measure the cancer and its activity. For example, your levels may go up even though other evidence shows that the cancer is responding to treatment.

Some breast cancers do not produce tumour markers at all. For this reason, some medical oncologists don’t check tumour markers.

Other medical oncologists use them with other tests, such as scans and blood tests, to understand if the cancer is responding to treatment.

MRI scan

Magnetic resonance imaging (MRI) uses magnetic waves to scan areas of your body. An MRI is not painful. It provides very detailed views of the tissue it is scanning.

An MRI can be used to scan different parts of the body, most commonly the brain, liver and bones.

If you have bone metastases in your back or spine, doctors may suggest an MRI if they're worried the cancer could be pressing on a nerve or the spinal cord. This is called a 'spinal cord compression' and is serious. You may need urgent treatment.

An MRI can also show very tiny cancer spots in:

• the brain and the lining of the brain (the 'meninges')
• in the fluid that surrounds your brain and spine ('cerebrospinal fluid/CSF').

You cannot have an MRI if you have any metal in your body such as:

• some cardiac pacemakers
• a breast tissue expander with a magnetic port.

Before the scan

You might have an injection of ‘contrast’ before the scan. This shows any cancer deposits more clearly. Your oncologist may arrange a blood test to check your kidney function before deciding if you can have the contrast.

Tell your doctor if you are claustrophobic. They may offer some sedation to help you relax.

During the scan

You need to lie still in a cylinder for 30 to 45 minutes. 
MRI machines are very noisy. The technician will probably give you ear plugs and headphones to wear during the scan. Ask if you can take your own music or podcasts if you prefer.

Lumbar puncture

In a lumbar puncture, doctors remove a small amount of fluid (‘cerebrospinal fluid’) around the spinal cord. They send the fluid to pathology to check for the presence of cancer cells.

Your doctor may arrange a lumbar puncture if they suspect you have meningeal carcinomatosis. Meningeal (or leptomeningeal) carcinomatosis is when cancer deposits are found in:

• the thin layers of tissue (‘meninges’) that cover and protect the brain and spinal cord
• the cerebrospinal fluid surrounding the brain and spinal cord.

During the procedure

You have a local anaesthetic to numb the area in your lower back. The doctor passes a needle through the gap between 2 vertebrae into the space that surrounds the spinal cord. This is called the sub-arachnoid space and it is filled with fluid.

After the procedure

You need to lie flat after the lumbar puncture, usually for at least an hour, to avoid developing a headache.