Ipsogen, a molecular diagnostic company specialising in diagnostic assays for breast cancer and leukaemia, has announced the European launch of the Mapquant Dx HR test.
Running on an Affymetrix micro-array diagnostic platform, this genomic test is intended to improve the identification of endocrine-responsive tumours by measuring the expression of genes related to oestrogen and progesterone biology in breast cancer.
According to the company, determining the endocrine responsiveness of breast cancer is essential, as it guides the use of hormonotherapy, based primarily on tamoxifen and aromatase inhibitors such as letrozole and anastrozole.
Currently, endocrine responsiveness is routinely assessed by immunohistochemistry (IHC): a semi-quantitative method measuring the expression of hormone receptors (HR) for oestrogen (ER) and progesterone (PR) on tissue sections.
However, despite constant efforts towards technical standardisation, IHC reproducibility and accuracy is not satisfactory, with as much as 15 per cent of cases reported as equivocal, according to the company.
This may lead to inappropriate treatment decisions.
Beyond the technical and standardisation issues, two biological problems are unsolved.
First, do ER-/PR+ tumours exist or should they be considered as technical artefacts? Second, how can the threshold for receptor positivity be defined and which is different in US and European Union (EU) pathology practices? The genomic HR test measures the hormone receptor status of invasive breast tumours.
It has been developed on a training set of 137 tumours with unequivocal receptor expression by IHC.
It was validated in seven independent datasets, totalling 691 tumours.
By micro-array technology, it measures the expression profile of genes selected to best discriminate tumours expressing ER and/or PR proteins.
The company claims that these genes, selected on a statistical rationale, are known to be related to the ER and PR biology, adding a strong pathological rationale to the selection process.
Through this micro-array technique, an objective and biologically relevant cut-off for receptor positivity could be identified.
The company claims that more than 97 per cent of tumours could be given an unequivocal result.
Additionally, no tumour expressing PR or ER could be identified, supporting the current hypothesis that such PR+/ER- tumours could be artefacts of the IHC technique.
Together with the genomic grade test and the genomic HER2 test, the genomic HR test provides a complete genomic testing panel for breast cancer that will help pathologists to better determine tumour grade and HR and HER2 status and, ultimately, allow a more individualised treatment decision in breast-cancer patients.
The Genomic HR test is made available for diagnostic use in Europe through an ISO-17025/CLIA laboratory service performed by DNAVision SA, based Gosselies, Belgium.
It can also be performed directly by cancer-care centres equipped with the CE-marked, FDA-cleared Affymetrix Genechip 3000Dx2 (GCS3000Dx2) system.
The Mapquant Dx testing solution for routine micro-array profiling of breast tumours also includes: a CE-marked path kit facilitating sampling, RNA preservation and sample shipping at ambient temperature; and CE-compliant software, ensuring reliable quality controls, data processing and genomic test computation.
Mapquant Dx is developed under the Innovation Support Programme of the French Health Products Safety Agency (Afssaps).
