Minimal Residual Disease in Paediatric ALL: Significance and Methodological Approaches

Minimal residual disease has played a key role in the treatment of childhood acute lymphoblastic leukaemia for more than two decades. It has been applied in all stages of treatment, including modern immunotherapies. Classical methods for detection and quantification of minimal residual disease have undergone a challenging process of standardization, allowing for risk stratification and prognostication in large international treatment trials. At the same time, new technological approaches are emerging that promise higher specificity and potentially higher sensitivity of detection. The use of new approaches to monitor minimal residual disease also provides new insights into the biology of some subtypes of childhood acute lymphoblastic leukaemias.