Understanding your investigation
Gene expression profiling (GEP) is a method of looking at cancer cells and analysing the activity of certain genes.
This can help predict the behaviour of the cancer, including the likelihood that it will grow rapidly and spread to other parts of the body.
The tests can be done on core biopsies, which are performed under local anaesthetic in the clinic. However, they are often carried out on sections from the tumour, after it has been removed.
This allows your consultant to plan whether any further treatment after surgery would be valuable.
It is important to understand that gene expression profiling (GEP) is not the same as genetic testing.
Genetic testing focuses on conditions that run in some families. For breast cancer, this involves looking for the faulty genes BRCA1 and BRCA2, which may be linked to cancer in around 1 in 20 women.