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Fairley JA, Cheetham MH, Patton SJ, Rouleau E, Denis M, Dequeker EMC, Schuuring E, van Casteren K, Fenizia F, Normanno N, Deans ZC. Results of a worldwide external quality assessment of cfDNA testing in lung Cancer. BMC Cancer 2022; 22:759. [PMID: 35820813 PMCID: PMC9275131 DOI: 10.1186/s12885-022-09849-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 07/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Circulating cell free DNA (cfDNA) testing of plasma for EGFR somatic variants in lung cancer patients is being widely implemented and with any new service, external quality assessment (EQA) is required to ensure patient safety. An international consortium, International Quality Network for Pathology (IQNPath), has delivered a second round of assessment to measure the accuracy of cfDNA testing for lung cancer and the interpretation of the results. METHODS A collaboration of five EQA provider organisations, all members of IQNPath, have delivered the assessment during 2018-19 to a total of 264 laboratories from 45 countries. Bespoke plasma reference material containing a range of EGFR mutations at varying allelic frequencies were supplied to laboratories for testing and reporting according to routine procedures. The genotyping accuracy and clinical reporting was reviewed against standardised criteria and feedback was provided to participants. RESULTS The overall genotyping error rate in the EQA was found to be 11.1%. Low allelic frequency samples were the most challenging and were not detected by some testing methods, resulting in critical genotyping errors. This was reflected in higher false negative rates for samples with variant allele frequencies (VAF) rates less than 1.5% compared to higher frequencies. A sample with two different EGFR mutations gave inconsistent detection of both mutations. However, for one sample, where two variants were present at a VAF of less than 1% then both mutations were correctly detected in 145/263 laboratories. Reports often did not address the risk that tumour DNA may have not been tested and limitations of the methodologies provided by participants were insufficient. This was reflected in the average interpretation score for the EQA being 1.49 out of a maximum of 2. CONCLUSIONS The variability in the standard of genotyping and reporting highlighted the need for EQA and educational guidance in this field to ensure the delivery of high-quality clinical services where testing of cfDNA is the only option for clinical management.
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Affiliation(s)
- Jennifer A Fairley
- GenQA, Nine, Edinburgh Bioquarter, 9 Little France Road, Edinburgh, EH16 4SA, UK.
| | - Melanie H Cheetham
- EMQN CIC, Unit 4, Enterprise House, Pencroft Way, Manchester Science Park, Manchester, M15 6SE, UK
| | - Simon J Patton
- EMQN CIC, Unit 4, Enterprise House, Pencroft Way, Manchester Science Park, Manchester, M15 6SE, UK
| | - Etienne Rouleau
- Medical Biology and Pathology Department, Gustave Roussy, Villejuif, France
| | - Marc Denis
- Department of Biochemistry and INSERM U1232, Centre Hospitalier Universitaire de Nantes, 9 quai Moncousu, F-44093, Nantes Cedex, France
| | - Elisabeth M C Dequeker
- Department of Public Health and Primary Care, Biomedical Quality Assurance Research Unit, KU Leuven, Kapucijnenvoer 35d, 3000, Leuven, Belgium
| | - Ed Schuuring
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Kaat van Casteren
- Department of Public Health and Primary Care, Biomedical Quality Assurance Research Unit, KU Leuven, Kapucijnenvoer 35d, 3000, Leuven, Belgium
| | | | - Nicola Normanno
- Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, 80131, Napoli, Italy
| | - Zandra C Deans
- GenQA, Nine, Edinburgh Bioquarter, 9 Little France Road, Edinburgh, EH16 4SA, UK
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