Standardisation of molecular monitoring for chronic myeloid leukaemia

Molecular monitoring of chronic myeloid leukaemia (CML) patients by real time quantitative reverse transcriptase PCR (RQ-PCR) is of clinical value, but the use of diverse laboratory protocols and units of measurement make it difficult to compare results between and sometimes within centres. This review explores the intrinsic difficulties in standardising the RQ-PCR analysis, summarises the progress that has been made following the proposal for a new International Scale for BCR-ABL measurement and discusses how further improvements are likely to be made.