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Pictogramme horloge May 2016

“Classic” prognostic and predictive factors for breast cancer: reminders

These include clinical, histological and hormonal factors.

The main validated prognostic factors are as follows: patient age, tumour size, HER2 status and nodal status.

Oestrogen and progesterone hormone receptor status and HER2 status are used as factors to predict therapeutic response. The treatment used will depend on the status of these 3 receptors, (hormone therapy or anti-HER2).

Molecular factors: a new and personalised approach

The use of molecular biology tests offers a complementary approach by providing a more detailed classification of the tumour and an assessment of the risk of recurrence. These tests are known as gene expression or gene signature assays, and they examine the different genes implicated in tumour proliferation.  The gene expression profiles reveal 4 subtypes of breast cancer: luminal A, luminal B, HER2-positive and basal-like.

Each profile and each molecular subtype has a different prognosis and different risk of recurrence, and therefore requires specific treatment personalised to suite each patient. This is an example of what is known as “personalised medicine”: treatments are no longer based on general principles and factors, instead they vary according to the specific characteristics of each patient.

The Prosigna® NanoString assay

There are several breast cancer gene signature tests on the market.

The Prosigna test uses RNA isolated and extracted from tumour tissue: the nCounter automated system, which is marketed by NanoString, simultaneously measures the expression of 50 genes.

An algorithm is applied to the results of this analysis of 50 genes, combined with tumour size and number of nodes, to produce 4 test results:

  • the molecular type of tumour
  • the individual probability of recurrence at 10 years
  • a risk score for recurrence on a scale of 0 to 100
  • a rating for risk of recurrence at 10 years: low, medium or high

The 4 results viewed together allow the doctor to tailor treatment and to decide whether or not to use chemotherapy. There is also a psychological factor. Even if the calculated risk is only a probability, it is important for the patient that they better know and understand the future risk.

This test has been available since February 2016 from Biomnis’ Department of Molecular Genetics, working in partnership with the Department of Anatomical Pathology.

In particular, Biomnis performs the Prosigna® prognostic breast cancer gene signature assay for the specialist anti-cancer centres that make up the Unicancer Group.

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