TEST:

MammaTyper® Kit

MTClin may predict pCR and recurrence in HER2-positive BC, supporting tailored escalation or de-escalation treatment.

MammaTyper demonstrated high concordance and reliability on cytological and biopsy samples, supporting its use in minimally invasive diagnostics. Despite the discrepancies in some markers, cytology offers a cost-effective, less invasive alternative to biopsies for molecular subtyping, aligning with precision medicine goals.

Although HER2 ISH has long been considered as the gold standard to establish the HER2 status in BC, the equivocal "gray zone" between amplified and nonamplified BCs is prone to interobserver variability. Potential solutions could comprise the involvement of at least 3 different observers for assessment of equivocal ISH cases, and/or evaluation of HER2 mRNA as a more objective alternative method.

P=N/A, N=234, Recruiting, IRCCS Azienda Ospedaliero-Universitaria di Bologna

The cohort was divided into 2 groups: a trastuzumab-treated group (n=159) and a chemotherapy-only treated group (n=128)...Validation analysis revealed that 11/36 ERBB2-negative cases were IHC 2+/ISH positive with very low level of gene amplification and 25 cases were false classified as HER2 positive using current protocols. Combining MammaTyper® assay with IHC to assess HER2 status improves the identification of HER2-positive BC patients who would benefit from anti-HER2 therapy.

MammaTyper®reclassifies cases considered HER2 +2 by IHC and positive by FISH, identifying 36% (7 out of 19) as HER2 positive and 42% (8 out of 19) as HER2 low. Given the critical role of accurately quantifying HER2 expression for selecting appropriate anti-HER2 treatments, this technique should be considered.

Our findings indicate a strong agreement between mRNA expression quantified by RT-qPCR and HER2 IHC scores, although there was a substantial proportion of discordant HER2 results between both methods owing to overestimation of HER2 expression by MammaTyper compared to IHC. Future large-scale trials should determine which technique is best associated with clinical outcome.

Although p53abn ECs are clinically aggressive, these tumours may present different molecular features as HER2 overexpression/amplification. Anti-HER2 target therapy represents a new therapeutic option. HER2-positive carcinomas represent a subgroup of tumours characterized by distinct histological features, although without significant prognostic impact.

Overall, MammaTyper® pCR score may serve as a standardized tool for predicting NACT response in HR+/HER2-negative BC, potentially guiding treatment strategies. Additionally, it could provide a more standardized and reproducible assessment of ER, PR, HER2, and Ki67 status.

RT-qPCR-based assessment of the mRNA expression of ESR1, PGR, ERBB2, and MKI67 showed high concordance with IHC, suggesting that the MammaTyper test on core needle biopsies represents a reliable, efficient, and reproducible alternative for breast cancer classification and refining HER2 low categorisation.

"Cerca Biotech GmbH announces that in the 14th European Breast Cancer Conference (EBCC-14) in Milan, Italy from March 20 to 22, results from five different studies on MammaTyper® were presented by leading experts and researchers."

In bifocal BC, intertumoral heterogeneity on the morphological, immunohistochemical and molecular level is common, with discordant intrinsic subtype in up to 25% between individual foci, with about 8% clinically relevant discordances.