Posted on Nov 15, 2022
November is a busy month for the team at Cerca Biotech: we are presenting in Barcelona, Spain for the European Breast Cancer Conference (EBCC) between 16-18 November.
At EBCC we’re presenting exciting new research, as part of the ‘optimal diagnosis’ sessions. The data compares MammaTyper® to traditional immunohistochemistry (IHC) from three different reference centre cohorts in needle core biopsies of breast cancer.
Why does this research matter?
Breast cancer biomarkers help clinicians determine a patient’s breast cancer sub-type. This plays a vital role in tailoring treatment effectively.
Currently breast cancer sub-types are distinguished using immunohistochemistry (IHC). A staining process that enables pathologists to visualize proteins within cells that are important in the biologic pathways of breast cancer. This can help clinicians work out how aggressive a tumour is, as well as how it will grow. Newer multigene tests such as MammaTyper® go further in assessing intrinsic properties of breast cancer tumours that impact on tumour behaviour.
MammaTyper® RT-qPCR is a multigene test that works through an easily replicated, standardised and quantitative measurement of marker gene expression. It assesses four biomarkers that enable classifying breast cancer into five subtypes. Offering a more accurate, faster and local laboratory result.
The biomarkers are:
- HER2 or ERBB2 (human epidermal growth factor receptor 2)
- ER or ESR1 (estrogen receptor 1)
- PR or PGR (progesterone receptor)
- MKI67 (marker of proliferation Ki-67, a marker expressed in proliferating cells)
These markers are used to identify 5 distinct breast cancer subtypes:
- Luminal A-like
- Luminal B-like (HER2 negative)
- Luminal B-like (HER2 positive)
- HER2 positive (non-luminal)
- Triple negative (ductal)
Each of these subtypes is associated with a clear therapy recommendation and distinct characteristics for patient prognosis.
Traditional immunohistochemistry (IHC) staining methods may not offer precise differentiation between sub-types.
For example, between HER2-negative and HER2 low tumours, as well as Luminal B-like and less aggressive Luminal A-like cancer, which has remained challenging, IHC is only semi-quantitative, and its accuracy can be influenced by human differences in interpretation. For HER2, ER, and PR, several studies have reported divergences of up to 20%. IHC is also poorly robust for Ki-67 protein levels which are an important maker to distinguish between Luminal B and Luminal A cancer.
The ability to precisely define which breast cancer sub-types will improve personalization of treatment, and open access to new therapies such as trastuzumab deruxtecan. A targeted therapy produces statistically significant and clinically meaningful progression-free survival and overall survival for patients with HER2-low metastatic breast cancer. However, issues with IHC mean that some patients who may benefit from new life-extending cancer treatments may not be picked up and therefore will not have access to these therapies.
New research presented at the European Breast Cancer Conference (EBCC)
At EBCC we’re presenting data involving research centres across three countries: United Kingdom, Portugal and China.
In the UK, researchers led by Dr Abeer Shabaan, a specialist breast pathologist at Queen Elizabeth Hospital, compared breast cancer biopsy analysis. The researchers concluded that MammaTyper® has a high concordance with IHC. MammaTyper® assessment of Ki67 was also well matched with digital image analysis of samples. Using MammaTyper® to assess breast cancer biopsy samples appears to be reliable, efficient and reproducible alternative for molecular subtyping.
In China , scientists compared results using ICH and FISH (fluorescence in situ hybridization) with MammaTyper analysis. FISH is a laboratory technique used to detect and locate a specific DNA sequence on a chromosome. The authors concluded that compared with IHC/FISH, MammaTyper® qRT-PCR assay may be a promising alternative for actual detection of ERBB2 expression. This will assist with better definition of HER2-low breast cancer.
In Portugal, Regina Pinto and her team took breast cancer samples where analysis was inconclusive for Ki-67 using traditional IHC methods. They compared these results with the subtype assessed by MammaTyper®. Results indicate potential superiority of MammaTyper® in being able to distinguish between the molecular subtypes Luminal A-like from Luminal B-like (HER2-negative) cancers.
Where next for MammaTyper®?
This growing body of evidence supports MammaTyper® as not only a safe, but in many ways superior, alternative to IHC. At Cerca Biotech we are continuing to forge new relationships with key centres and partners across Europe and beyond.
If you’re interested in being part of this movement for change, get in touch or come and visit us at EBCC.