Which Genetic Tests for Breast Cancer?

The type of breast cancer a patient has determines the way in which the cancer is likely to behave or might metastasise to other parts of the body. The types of breast cancer are largely now defined according to their histology and size as well as now to the presence or absence of gene mutations (see chart below). The form of treatment that a patient receives therefore needs to be tailored to their individual gene mix.

If the patient gene mix is not assessed prior to deciding the best course there is a risk that the cancer may be under- or over-treated. For example, many patients would not benefit from chemotherapy and these patients need to be identified using the latest routine lab genetic profiling systems.

Testing Breast Genes

In this way, the latest genetic tests are both diagnostic (defining the type of breast cancer), as well as prognostic (definining the likelyhood of reoccurence, and therefore recommended treatment regimen).

In his patient facing article, "Why do Patients with Breast Cancer need Gene Testing", breast cancer expert, Mr Simon Marsh explains how, "Recent studies have shown that the detailed analysis of the growth behaviour of a tumour at the genetic level is an accurate marker of the subsequent actual behaviour of the cancer, as well as what form of treatment the tumour will respond to. These test results now form the basis for the latest recognised medical guidelines."

Mr Marsh goes on to describe the latest diagnostic and prognostic methods now available to breast clinicians and their patients. He says, "The EndoPredict test combines genetic markers with other more traditional histology pathology test indicators such as tumour nodal status and tumour size, and provides a major step forward in helping breast cancer specialists to avoid the over and under treatment of breast cancer with chemotherapy. Following sampling, test results are normally available for clinical assessment within a few days".

Classifying Types of Breast Cancer

Type of Breast Tumour

Approximate proportion of all primary breast tumours found

Her2+ - Human epidermal growth

factor receptor positive


Triple negative - Human epidermal growth

factor receptor negative and do not exhibit oestrogen or progesterone receptors


Luminal type A: ER+ and/or PR+, HER2-, low Ki67


Luminal type B: ER+ and/or PR+, HER2+ (or HER2- with high Ki67)

Abnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. Full medical glossary
The basic unit of all living organisms. Full medical glossary
The use of chemical substances to treat disease, particularly cancer. Full medical glossary
The basic unit of genetic material carried on chromosomes. Full medical glossary
Relating to the genes, the basic units of genetic material. Full medical glossary
The spread of a malignant tumour to other parts of the body. Full medical glossary
A change in the genetic material (DNA) of a cell, or the change this this causes in a characteristic of the individual, which is not caused by normal genetic processes. Full medical glossary
A hormone involved in female sexual development, produced by the ovaries. Full medical glossary
An abnormal swelling. Full medical glossary