Precision Oncology Clinical Diagnostic Study In Primary and Metastatic Breast Cancer (PRISM)

This is a pragmatic single-arm diagnostic interventional study. The study will use the Illumine TruSight Oncology 500 assay for research use only under Article 5(5) in-house exemption of the EU IVDR (EU 2017/746). Testing will be performed on paraffin embedded tumour tissue. This assay will target 523 genes to assess all somatic DNA variants as well as microsatellite instability (MSI), tumour mutational burden (TMB), and homologous recombination deficiency (HRD). Testing will be performed centrally in the molecular diagnostics laboratory (ISO 15189 accredited) at Beaumont hospital on the Next Seq 550Dx. This lab currently uses this platform for diagnostic comprehensive genomic profiling. Bioinformatic analysis will be undertaken to identify clinically actionable mutations. Results will be discussed at the multi-disciplinary Molecular Tumour Board, Beaumont RCSI Cancer Centre and full data along with treatment recommendation will be provided to the treating oncology team.