Medical Research Council and Leukaemia and Lymphoma Research.

No abstract

Assessment of minimal residual disease (MRD) has acquired a prominent position in European treatment protocols for patients with acute lymphoblastic leukemia (ALL), on the basis of its high prognostic value for predicting outcome and the possibilities for implementation of MRD diagnostics in treatment stratification. Therefore, there is an increasing need for standardization of methodologies and harmonization of terminology. For this purpose, a panel of representatives of all major European study groups on childhood and adult ALL and of international experts on PCR-and flow cytometry-based MRD assessment was built in the context of the Second International Symposium on MRD assessment in Kiel, Germany, 18-20 September 2008. The panel summarized the current state of MRD diagnostics in ALL and developed recommendations on the minimal technical requirements that should be fulfilled before implementation of MRD diagnostics into clinical trials. Finally, a common terminology for a standard description of MRD response and monitoring was established defining the terms 'complete MRD response', 'MRD persistence' and 'MRD reappearance'. The proposed MRD terminology may allow a refined and standardized assessment of response to treatment in adult and childhood ALL, and provides a sound basis for the comparison of MRD results between different treatment protocols.

Key Points• Infection is the major cause of treatment-related mortality in pediatric acute lymphoblastic leukemia and is greatest during the induction phase.• Children with Down syndrome are at high risk for infectionrelated mortality throughout all treatment phases, including the low-intensity maintenance phase.

SummaryWe investigated the outcome for children and young people with Early T-precursor acute lymphoblastic leukaemia (ETP-ALL), a recently described poor prognosis subgroup of T-ALL, treated on a contemporary protocol, UKALL 2003. After a median follow-up of 4 years and 10 months, the ETP sub-group, representing 16% of T-ALL patients, had non-significantly inferior 5-year event-free survival (76Á7% vs. 84Á6%, P = 0Á2) and overall survival (82Á4% vs. 90Á9%, P = 0Á1), and a higher relapse rate (18Á6% vs. 9Á6%, P = 0Á1) compared to typical T-ALL. ETP-ALL has an intermediate risk outcome, which does not warrant experimental treatment or first remission allogeneic transplant for the group universally.