Assessment of Digital PCR as a Primary Reference Measurement Procedure to Support Advances in Precision Medicine

Genetic testing for point mutations guides patient management in many cancers when analysing the DNA from tumour and, increasingly, liquid biopsies. Such measurements are going to be increasingly important in supporting the implementation of precision medicine that many predict will revolutionise clinical care. However, there are currently no reference measurement procedures available to aid harmonisation of existing testing and support implementation of newer, often more complex, tests into routine use. This study assessed the accuracy of digital PCR for copy number quantification of point mutations by evaluating potential sources of uncertainty influencing measurements of a frequently occurring mutation in colorectal cancer (KRAS G12D). Concentration values for samples containing single or mixed KRAS G12D and WT plasmid templates varied by <1.2-fold and <1.3-fold when measured using five assays differing in chemistry or with five commercial dPCR platforms. Orthogonal comparison with a chemical method (ICP-MS) via P quantification also demonstrated 1.2-fold agreement between techniques. dPCR showed robust quantification for templates of differing fragment sizes (186 – 4343 bp) and high intra- and inter-laboratory precision (%CV: 2-8% and 5-10% respectively). This work supports dPCR being more widely accepted as a SI traceable reference measurement procedure for value assignment of DNA reference materials of varying sizes in an aqueous (calibration) solution for copy-number concentration and allelic frequency measurements. Such high accuracy measurements using dPCR will be able to support the implementation and harmonisation of the molecular diagnostic procedures such as those needed to support the predicted advances in precision and personalised medicine.

WHALE Alexandra S.;  JONES Gerwyn;  PAVŠIČ Jernej;  DREO Tanja;  REDSHAW Nicholas;  AKYÜREK Sema;  AKGOZ M;  DIVIETO Carla;  SASSI Maria Paola;  HE Hua-Jun;  COLE Kenneth;  BAE Y.Y.;  PARK Sang-Ryoul;  DEPREZ Liesbet;  CORBISIER Philippe;  GARRIGOU Sonia;  TALY Valérie;  LARIOS Raquel;  COWEN Simon;  O’SULLIVAN Denise;  BUSHELL C;  GOENAGA INFANTE Heidi;  FOY C.A.;  WOOLFORD Alison J.;  PARKES H.;  HUGGETT Jim;  DEVONSHIRE A.S.; 

2019-01-23

AMER ASSOC CLINICAL CHEMISTRY

JRC109099

0009-9147 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC109099,   

10.1373/clinchem.2017.285478 (online),