Analytical validation of OncoMasTR, a multigene test for predicting risk of distant recurrence in hormone receptor-positive early stage breast cancer

Research output: Contribution to journalArticle

Abstract

Background: OncoMasTR is a new multigene prognostic test that was discovered via a novel transcriptional network analysis method that identified upstream Master Transcription Regulators (MTRs), which regulate previously identified prognostic biomarkers. The optimised OncoMasTR signature incorporating clinicopathological information has been shown to be significantly prognostic for predicting distant recurrence in two independent cohorts (TransATAC & a subset of TAILORx from participating Irish centres). The analytical performance characteristics of the OncoMasTR test, comprising solely three prognostic MTRs, were determined. Methods: Relative gene expression levels were measured by RT-qPCR. Assay precision and input ranges were determined using a panel of samples representative of low and high recurrence risk tested across a number of runs incorporating different sources of variation. Serial dilutions of a pooled patient RNA sample was used to establish the linear range and efficiency of the individual gene assays. Results: The overall standard deviation of the OncoMasTR risk score was 0.15, which represents less than 2% of the 10-unit risk score range. The majority of the variability in OncoMasTR results was related to within-run variation (78.2%) with other between-run variation sources contributing relatively little (PCR instrument (0.6%), assay operator (5.2%), reagent lots (7.3%) or loading position (8.7%)). Consistent risk scores were measured for individual samples from 40ng down to < 1ng RNA per PCR reaction. Individual gene assays were linear over >500-fold RNA input range corresponding to CT values of 23 – 36, demonstrating the ability of the test to reliably detect low level expression of the OncoMasTR panel. Importantly, PCR efficiencies were similar for the individual MTR and reference gene assays which ranged from 79 – 95%. Conclusions: The OncoMasTR prognostic test displays robust analytical and clinical performance and is being launched as a CE-marked test. The concise nature of the three gene signature and a simplified workflow that can be readily adopted using standard laboratory equipment will enable convenient qualification by local laboratories for decentralised use.

Details

Authors
  • T. Loughman
  • A. Chan-Ju Wang
  • P. Dynoodt
  • B. Fender
  • C. Lopez Ruiz
  • S. Barron
  • S. Stapleton
  • D. O'Leary
  • A. Fabre
  • C. Quinn
  • B. Nodin
  • K. Jirstrom
  • A. Bracken
  • W. M. Gallagher
Organisations
External organisations
  • St Vincent's University Hospital
  • Trinity College Dublin
  • University College Dublin
  • OncoMark Ltd
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology
Original languageEnglish
Pages (from-to)viii65
JournalAnnals of oncology : official journal of the European Society for Medical Oncology
Volume29
Issue numberSuppl. 8
Publication statusPublished - 2018
Publication categoryResearch
Peer-reviewedYes