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Performances of the Idylla GeneFusion Assay: contribution to a rapid diagnosis of targetable gene fusions in tumour samples
  1. Matthieu Guillard1,
  2. Charline Caumont2,3,
  3. Pascale Marcorelles1,4,
  4. Jean-Philippe Merlio2,3,
  5. David Cappellen2,3,
  6. Arnaud Uguen1,4
  1. 1Service d'Anatomie et Cytologie Pathologiques, CHRU Brest, Brest, France
  2. 2Service de Biologie des Tumeurs, CHU Bordeaux, Pessac, France
  3. 3BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, Université de Bordeaux, Pessac, France
  4. 4LBAI, UMR1227 INSERM, Université de Bretagne Occidentale, Brest, France
  1. Correspondence to Pr Arnaud Uguen, UMR1227, Brest 29609, France; arnaud.uguen{at}


Aims We aimed to evaluate the performances of the Idylla GeneFusion Assay (IGFA) designed to detect, in a single, rapid and fully automated assay, ALK, ROS1, RET, NTRK1, NTRK2 and NTRK3 gene fusions and MET exon 14 skipping in cancer samples.

Methods Based on a set of tumours enriched in cases with gene fusions, we applied the IGFA to tumour areas of various sizes and tumour cell contents. IGFA results were compared with those obtained with other methods (immunohistochemistry, fluorescent in situ hybridisation, DNA and RNA next-generation sequencing).

Results We selected 68 tumours: 49 cases with known gene fusions (8 ALK, 8 ROS1, 5 RET, 7 NTRK1, 3 NTRK2 and 6 NTRK3 ones) or MET exon 14 skipping mutations (12 cases) and 19 cases with no fusion and no MET mutation. We performed 128 IGFA tests on distinct tissue areas. The global sensitivity and specificity of the IGFA were, respectively, 62.82% and 99.2% with variations between molecular targets and tissue areas. Of note, 72.5% sensitivity and 98.79% specificity were obtained in 37 tissue areas fulfilling the manufacturer’s recommendations (ie, at least 10% of tumour cells in at least 20 mm² of tissue area). The rate of non-conclusive results was higher in small samples with low percentages of tumour cells.

Conclusions The IGFA could contribute to the rapid detection of targetable gene fusions and mutations, especially in context of rapidly growing cancers requiring urgent therapeutic choices.

  • colorectal neoplasms
  • lung neoplasms
  • cytogenetics
  • polymerase chain reaction
  • central nervous system

Data availability statement

All data relevant to the study are included in the article or uploaded as online supplemental information.

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Data availability statement

All data relevant to the study are included in the article or uploaded as online supplemental information.

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  • Handling editor Runjan Chetty.

  • Contributors Design of the study: AU, MG and PM; Idylla analyses: MG; FISH and IHC analyses: AU; RNAseq analyses: CC, DC and J-PM. Analysis of data, writing, editing and approving the final manuscript: MG, CC, PM, J-PM, DC and AU. Guarantor: AU.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests Biocartis company has provided Idylla dedicated cartridges for this study but has not taken part in data interpretation or manuscript writing in this work. The authors declare no financial or non-financial competing interests in this work.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.