Multicenter Evaluation of the Idylla NRAS-BRAF Mutation Test in Metastatic Colorectal Cancer

J Mol Diagn. 2018 Sep;20(5):664-676. doi: 10.1016/j.jmoldx.2018.05.008. Epub 2018 Jun 26.


Treatment of colorectal cancer (CRC) with monoclonal antibodies against epidermal growth factor receptor requires the assessment of the mutational status of exons 2, 3, and 4 of the NRAS and KRAS oncogenes. Moreover, the mutational status of exon 15 of the BRAF oncogene is a marker of poor prognosis in CRC. The Idylla NRAS-BRAF Mutation Test is a reliable, simple (<2 minutes hands-on time), and quick (<2 hours turnaround time) sample-to-result solution, enabling the detection of clinically relevant mutations in NRAS (18 mutations) and BRAF (5 mutations). A multicenter study was conducted in 14 centers using the Idylla NRAS-BRAF Mutation Test to assess the NRAS and BRAF mutational status of 418 formalin-fixed, paraffin-embedded tissue samples from CRC patients. Results were compared with those obtained earlier by routine reference methods, including next-generation sequencing, pyrosequencing, mass spectrometry-based assays, PCR-based assays, and Sanger sequencing. In case of discordance, additional tests were performed by digital droplet PCR. Overall, after testing confirmation and excluding invalids/errors by design, concordances between the Idylla NRAS-BRAF Mutation Test and the reference test results were found in almost perfect agreement. In conclusion, the Idylla NRAS-BRAF Mutation Test enables the routine detection of all NRAS and BRAF mutations deemed clinically relevant according to the latest clinical guidelines, without necessitating molecular expertise or infrastructure.

Publication types

  • Evaluation Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / secondary*
  • DNA Mutational Analysis
  • GTP Phosphohydrolases / genetics*
  • Humans
  • Membrane Proteins / genetics*
  • Mutation / genetics*
  • Proto-Oncogene Proteins B-raf / genetics*
  • Reference Standards
  • Reproducibility of Results


  • Membrane Proteins
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • GTP Phosphohydrolases
  • NRAS protein, human