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 |
10-20% |
Triple negative - Human epidermal growth factor receptor negative and do not exhibit oestrogen or progesterone receptors |
15-20% |
Luminal type A: ER+ and/or PR+, HER2-, low Ki67 |
40% |
Luminal type B: ER+ and/or PR+, HER2+ (or HER2- with high Ki67) |