Cancer screening tests

Blood Tests

Your GP or specialist may organise various blood tests to screen for cancer.
Tests that may be included include:

Full Blood Count (FBC)

The FBC includes measurement of :
  • Haemoglobin: to check for anaemia.
  • White blood cells: to assess if your body is trying to mount an immune response, for example, if you have an infection.
  • Platelets: these cells help in preventing bruising and bleeding.

Tumour markers

  • Tumour markers are proteins produced by cancers and can be detected in the blood.
  • They are useful screening tools used by both GPs and specialists. They can also be used to assess how effective your cancer treatment is.

Other blood tests

  • You may have a variety of other blood tests depending on your exact symptoms and the type of cancer for which you are being screened.
  • For example, urea and electrolyte levels are check to assess kidney function.

Cervical smear

  • A smear test aims to collect cells from your cervix to detect any abnormalities before cancer even starts to develop.
  • This is done at regular intervals as part of the UK national screening programme.


  • Endoscopy is a term used to describe looking inside your body via a tube with a camera attached. This allows direct visualisation of your body and enables biopsies to be taken.
  • Examples include:
    • Bronchoscopy explores the bronchi, which are the main airways in your lungs.
    • Gastroscopy looks at your upper gastrointestinal tract (your oesophagus and stomach).
    • Colonoscopy detects bowel anomalies, by inserting the endoscope into your intestines via the anus.


X-rays are fundamental in screening for cancers, most commonly lung or bone cancers.


  • Ultrasound scans show a shadow image of your internal organs on a monitor, which is interpreted by a radiologist.
  • Gel is applied to your skin and the doctor will place a probe on this area.
  • It is quick, painless and gives immediate results.


Mammography is an X-ray of your breasts and is used in the UK national breast cancer screening programme.


  • A biopsy consists oftaking a sample of tissue from the organ suspected to be cancerous.
  • This sample is then examined under a microscope to check whether any cancer cells are present.
  • The biopsy is usually done under local anaesthesia, or during other tests such as a colonoscopy.
  • In some circumstances, a small needle is used to obtain the tissue sample - this is called a fine-needle aspiration biopsy and is often used for breast or thyroid biopsies.

Computerised Tomography (CT Scan) and Magnetic Resonance Imaging (MRI scan)

  • CT scans are valuable as they take consecutive x-rays which are then re-assembled by the computer to produce thorough scan images used in screening, diagnosis and monitoring of treatment.
  • MRI scans give very detailed images of your internal organs used a magnetic field.
  • You have to lie down and remain still on a flat table and a donut-type scanner surrounds you and examines the area needing to be screened.
  • The scans both involve lots of X-rays which are analysed by a computer and reported by a radiologist.
  • They take approximately 30 minutes and are painless.
  • If you are claustrophobic, please mention this to your doctor as there are open scanners available.
  • Three dimensional scans are now also available.
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