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Chemotherapy tests

Before and during your chemotherapy course, you need some tests. These help your doctor decide whether you are fit enough for treatment, and how well treatment is working.

Tests before treatment starts

Before your first treatment you’ll have tests to help your doctor decide what treatment you need. They can also compare the results with future tests to see how your treatment is working. 

Tests may include: 

  • blood tests
  • x-rays
  • scans
  • your height and weight
  • physical examination

Your doctor checks your height and weight as the dose of chemotherapy is based on your size (body mass index). 

Chemotherapy drugs can stop your bone marrow producing enough red blood cells, white blood cells and platelets. So before your treatment starts you need to have a blood test to check your levels of these. You may also have other blood tests, depending on your type of cancer.

You might also have some of the following tests, depending on your treatment:

Tests to check your lungs

Some chemotherapy drugs can affect the way your lungs work.

Your doctor will suggest you have a lung function test before you start taking any of these drugs. This measures how much air your lungs can hold and how well you're taking in oxygen.

Tests to check your heart

Some chemotherapy drugs can affect the muscles of the heart. This could change the rhythm of your heartbeat. In most people, this will go back to normal after you finish the chemotherapy.

If you’re going to have one of these drugs, you need to have your heart checked before you start treatment. 

You might also have a recording of the electrical activity of your heart. This test is called an electrocardiogram (ECG). An ECG tells your doctor how well your heart is working.

You might also have a heart ultrasound. This test is called an echocardiogram (or an ECHO). An ECHO checks the force that your heart is pumping with.

Both of these tests are painless.

Tests to check your liver

Some chemotherapy drugs can damage the liver, so you might have blood tests to check how well your liver is working.

The liver breaks down many drugs. So it needs to be working well to get rid of the chemo.

Tests to check your kidneys

Some chemotherapy drugs can affect your kidneys. So you might have blood tests or need to collect your urine for testing.

The kidneys also get rid of the chemo drugs when they've been broken down in the body, so they need to be working well.

HIV and hepatitis tests

Your blood might be tested for HIV and hepatitis. Your doctors will explain this to you and you’ll need to sign a consent form to say that you agree to your blood being tested.

Other tests

You could need other tests, depending on the type of chemotherapy you have and the side effects it may cause.

These may include:

  • a hearing test (audiogram), if the chemotherapy can affect hearing
  • more regular blood tests to check your clotting, if you're taking warfarin
  • more regular blood sugar tests, if you have diabetes and are taking steroids

Your doctor might also suggest you see your dentist, if there's time before you start treatment. Having any dental treatment while you’re having chemo can be more complicated. This is because there could be more risk of you getting an infection.

Sperm collection and storage

If you’re a man and the chemotherapy is likely to make you infertile, you might be able to bank sperm before your treatment begins.

Tests when you go for your treatment

Blood tests

When you go to the hospital or clinic, the first thing you have each time is a blood test. In some centres you have this a day or two before your treatment.

It’s important that your chemotherapy nurse checks your red blood cell (RBC), white blood cell (WBC) and platelet count before you have your next treatment. If your RBC is too low, you may need a blood transfusion. If either your WBC or your platelet count is too low, having more treatment could push them down to a level that isn’t safe.  

You’ll also have blood tests to check how well your kidneys and liver are working. If they aren't working as well as they should, the chemo may give you more side effects.

Waiting for results

After your blood has been taken, you’ll have to wait for the results to come back. If everything’s OK, you can go ahead with your treatment.

All chemotherapy drugs are prepared specially for each patient, so you may have to wait while the hospital pharmacy prepares your drugs. This can take a while, so you might want to take something with you to pass the time.

To reduce the amount of time you have to wait, you might be able to have the blood tests the day before you’re due to have treatment. This could either be at the hospital or at your GP's surgery. Ask your chemo nurse about this, if you think it would make things easier for you. 

Your blood results

If your blood counts are too low, then unfortunately your treatment will have to be delayed. You’ll get another appointment to come back and have another blood test. This is usually about a week later. 

If the tests to check your liver and kidneys show that there have been changes in how well they’re working, you may need the dose of your treatment changed. Sometimes people may need a different treatment, but this is rare.

Last reviewed: 
06 Jan 2016
  • Handbook of Cancer Chemotherapy (8th edition)
    Skeel, R.T. and Khleif, S.N.
    Lippincott, Williams and Wilkins, 2011

  • The Chemotherapy Source Book (4th edition)
    Michael C Perry
    Lippincott, Williams and Wilkins, 2008

  • The Royal Marsden Hospital Manual of Clinical Nursing Procedures (8th edition)
    Dougherty, L. and Lister, S. 
    Wiley-Black, 2011

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