Chemotherapy tests

You have tests before and during your chemotherapy course. These help your doctor decide whether you are well enough for treatment. They can also compare the results with future tests to see how your treatment is working. 

Some of the tests might depend on the chemotherapy drugs you are having and the side effects they can cause.

Tests may include:

  • blood tests

  • your height and weight

  • physical examination

  • x-rays

  • scans

Blood tests

Chemotherapy drugs can stop your bone marrow producing enough of these blood cells:  

  • red blood cells (RBC) Open a glossary item
  • white blood cells (WBC) Open a glossary item 
  • platelets Open a glossary item 

So before treatment starts you need to have a blood test to check your levels of these. 

If your RBC is too low, you may need a blood transfusion. If your WBC or your platelet count is too low, having more treatment could push them down to a level that isn’t safe.

You have blood tests to check your kidneys and liver. Your liver breaks down the chemotherapy drugs, and the kidneys get rid of them from your body. Some chemotherapy drugs can affect how well your liver and kidneys work. You might also have a test using a collection of your urine to see how well the kidneys are working.

You may have other blood tests, depending on your type of cancer.

Waiting for results

After your blood test, you’ll have to wait for the results to come back. If they are OK, you can go ahead with your treatment.

All chemotherapy drugs are specially prepared for each patient. This means 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 can often have the blood tests a day or two before treatment. This could either be at the hospital or at your GP's surgery. Ask your chemotherapy nurse about this, if you think it would make things easier for you. 

Your blood results

If your blood counts are abnormal, then 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.

Physical examination

Your nurse checks your height and weight as the dose of chemotherapy is based on your size (body mass index). They might also check your blood pressure, pulse and oxygen levels.

During treatment your healthcare team will ask you about any side effects you have had.

Tests to check your lungs

Some chemotherapy drugs can affect the way your lungs work.

Your doctor will arrange for you to 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, and during treatment. 

You might 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 scan to check the force that your heart is pumping with. This is either an echocardiogram (ECHO) or a multigated acquisition (MUGA) scan.

Tests to check for viruses

Before treatment you might have blood tests to check for viruses such as hepatitis B, hepatitis C and HIV. Chemotherapy could weaken your immune system Open a glossary item so infections like this could worsen or become active again if you've had them in the past. You may have medicines to prevent or treat infection. 

Treatments for these viruses can interact with chemotherapy. Your healthcare team discuss this with you.

Tests to check how well chemotherapy is working

Some cancers produce chemicals (biomarkers) that can be found in the blood. Your doctor might take some blood to test for these markers. They can use this to see how well your treatment is working.

Your doctor might want to measure the cancer during treatment to see if the chemotherapy is working. This could be by:

  • x-rays
  • scans
  • measuring the lump if you can feel or see it from the outside of your body

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

Sperm and egg collection and storage

Some chemotherapy drugs are more likely than others to cause infertility Open a glossary item. You might be able to bank sperm, or freeze eggs or embryos before your treatment begins.

Whether your infertility is temporary or permanent depends partly on your drugs and doses. You can ask your doctors if the drugs you’re having are likely to make you infertile.

Dental checks

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 chemotherapy can be more complicated. This is because there could be more risk of you getting an infection.

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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact with details of the particular issue you are interested in.

Last reviewed: 
21 May 2024
Next review due: 
21 May 2027

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