Tests used to diagnose Cancer
Medical tests to find out what is wrong with someone are often referred to as ‘investigations’. This term is used to describe any test at all from a blood test to a Computerised Tomography (CT) scan to endoscopy. Any test that examines the structure of the body or organs is also called ‘imaging’ or ‘imaging investigation’.
The most appropriate individual tests or investigations are determined by the type of symptoms a person has and what the problem is thought to be. In addition to discovering the cause of a symptom, specific investigations may be carried out to exclude cancer as a cause as well – sometimes cancers are picked up this way.
What is the purpose of investigations?
Investigations are used together to locate cancers, measure their size and see if they have spread to adjacent organs. This information is used to see if they are removable and curable. The investigations are also used to measure response to treatments like chemotherapy and radiotherapy that can shrink tumours. A typical example of the use of imaging would be:
Mammogram: an x-ray of the breast tissue picks up a small lump in one breast. An ultrasound scan is used to locate the lump so that an accurate biopsy of the tumour tissue can be taken.
The biopsy specimen is looked at under the microscope to check what kind of cancer is present. Further tests are done including an ultrasound of the liver to check for ‘secondaries’ and a bone scan to check for bone ‘secondaries’. The results are clear and the tumour has not spread so a mastectomy (removal of the whole breast and lymph nodes from the armpit) is planned.
