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A guide to cancer tests

The tests and scans you have to diagnose your breast cancer will likely be repeated by your oncologist throughout your treatment at regular check-ups

These tests help determine if your treatment is effective and the tumour has shrunk (remission) or stopped growing (stable disease), or if treatment has to be changed because the tumour is growing again (progression).



These are blood tests. They may be done at your doctor’s surgery or at a blood testing centre. If you have had breast cancer before, you were likely to be getting your white blood cell or T-cell count checked regularly.

High or low levels of certain substances in your body can be signs of breast cancer.
So, lab tests of the blood, urine, or other bodily fluids that measure these substances can help doctors make a diagnosis. However, abnormal lab results are not a sure sign of cancer.


CT or CAT Scan

A CAT scan uses an x-ray machine linked to a computer to take a series of detailed pictures of your organs. You may receive an injection of a dye or other contrast material to highlight areas inside the body.

This helps to make the pictures easier to read.
This is usually a visit lasting a few hours and takes place at an imaging centre or at a hospital.


Nuclear or radionuclide scan

For this scan, you receive an injection of a small amount of radioactive material, which can be called a tracer. It flows through your bloodstream and collects in certain bones or organs.

A machine called a scanner detects and measures the radioactivity.
The scanner creates pictures of bones or organs on a computer screen or on film. Your body gets rid of the radioactive substance quickly. This type of scan may also be called a radionuclide scan.

This procedure must be done at a nuclear medicine facility or radiation centre, or at your hospital.



An ultrasound device sends out sound waves that people cannot hear. The waves bounce off tissues inside your body. This picture is called a sonogram.

This is the same test given to pregnant women to check on the growth of a baby. It may be done in your doctor’s surgery.



An MRI uses a strong magnet linked to a computer to take detailed pictures of areas inside your body.

Your doctor can view these pictures on a monitor and print them on film. This appointment can take a few hours and is usually done at an imaging centre or at a hospital.



For this scan, you receive an injection of a tracer.
Then, a machine creates 3-D pictures that show where the tracer collects in the body. These scans show how organs and tissues are working.
This appointment can take a few hours and is usually done at an imaging centre or at a hospital.



X-rays use low doses of radiation to create images of the inside of your body. This test may be done at your doctor’s surgery.
A mammogram uses x-rays.



In most cases, doctors need to do a biopsy to make a diagnosis of cancer, even if you have already had a biopsy.
A biopsy is a procedure in which the doctor removes a sample of tissue.
A pathologist looks at the tissue under a microscope to see if it is cancerous. The sample may be removed in several ways:

With a needle: The doctor uses a needle to withdraw tissue or fluid.

With an endoscope: The doctor looks at areas inside the body using a thin, lighted tube called an endoscope. The scope is inserted through a natural opening, such as the mouth. Then, the doctor uses a special tool to remove tissue or cells through the tube.
This is known as an endoscopy.

With surgery: Breast cancer surgery may be excisional or incisional.

In an excisional biopsy, also known as a lumpectomy, the surgeon removes the entire tumour. Often some of the normal tissue around the tumour also is removed.
In an incisional biopsy, the surgeon removes just part of the tumour.