TEST:

APIS Breast Cancer Subtyping Kit

The APIS kit accurately measures HER2/ERBB2 expression. The findings indicate that relying solely on IHC stratification may not be sufficient to predict responses to novel anti-HER2 treatments, like T-Dxd. By leveraging the dynamic range of RNA expression, a ΔCt semi-quantitative scale using additional cut-offs has been developed to enhance the stratification of ERBB2 mRNA expression.

A high level of agreement between IHC/ISH and mRNA expression determined by the APIS kit was observed for all markers. Subtype call agreement improved when Ki67 status was excluded, likely due to the challenges in distinguishing high and low Ki67 expression with IHC, leading to ambiguity in differentiating luminal B HER2- from luminal A tumours. Molecular subtyping offers additional insights for guiding breast cancer management decisions.

By leveraging the dynamic range of RNA expression, this study established a ΔCt semi-quantitative scale for evaluating targets with the APIS Breast Cancer Subtyping Kit. This is particularly significant for the classification of HER-low, which has emerged to be critical in identifying patients who may benefit from novel anti-HER2 therapies.

Sufficient RNA yield and high agreement confirmed that RNA derived using all described methods is of sufficient quality to accurately detect biomarker expression via the APIS kit. Promega and BioEcho kits demonstrated high target call concordance, making them viable alternatives to QIAGEN's kit. Lower concordance seen with Thermofisher kit is most likely a result of tumour heterogeneity.

This study established a ΔCt semi-quantitative scale for evaluating targets with the APIS Breast Cancer Subtyping Kit, by leveraging the dynamic range of RNA expression. This is particularly significant for classifying HER-low, which has emerged as crucial for identifying patients who may benefit from novel anti-HER2 therapies.

The APIS Breast Cancer Subtyping Kit shows improved subtype call agreement with PAM50 in patients ≥65, indicating that molecular testing may be a more suitable method for determining proliferation and distinguishing between luminal A and B subtypes. Significant correlation between the APIS kit's PS, PAM50 and ODx indicates that APIS kit has the potential to accurately identify patients at risk of recurrence, although additional studies are needed to validate these results.

Conclusions This study demonstrates that PGR expression, as assessed by APIS Breast Cancer Subtyping Kit, could potentially predict low-risk tumours identified by Oncotype Dx reliably, offering a cost-effective pre-screening tool. Additional validation is necessary to affirm its diagnostic accuracy.

Since the ground truth is finally unknown there will also be further studies to investigate the functional and clinical relevance of these respective approaches using endpoints like outcome and chemo-endocrine responsiveness. In conclusion this approach is suitable to determine ER, PR, Her2 and Ki67 in cases where 1) IHC is not available, 2) where IHC should be benchmarked as a quality control measure and 3) in critical cases where IHC-results are inconclusive.

"PT Global Bioray Teknologi and APIS Assay Technologies Sign Collaboration to Commercialise the ESR1 Mutations Kit & the Breast Cancer Subtyping Kit..."

The APIS Breast Cancer Subtyping Kit accurately detects HER2/ERBB2 expression. The findings suggest that relying solely on IHC categorisation may not suffice for predicting response to novel anti-HER2 treatments. Utilising additional cut-offs could enhance the stratification of ERBB2 mRNA expression, distinguishing a ‘HER2- low’ group.

We have utilised the dynamic range of RNA expression to provide a ΔCt semi-quantitative scale for assessing targets with the APIS Breast Cancer Subtyping Kit in comparison to IHC % staining and immunoreactivity. This being particularly significant for HER2 low classification, emerging as a crucial marker to identify patients who could benefit from novel anti-HER2 therapies. Similarly, ER-low tumours are now being explored as a clinically and biologically unique subgroup.

All kits yielded suitable RNA for APIS Breast Cancer Subtyping Kit. High target agreement was observed in specimens extracted using Promega and BioEcho kits, making them viable alternatives to QIAGEN. Thermo Fisher’s kit could also be considered for use, accounting for possible tumour heterogeneity.