XI. How to treat children and adolescents with relapsed non-Hodgkin lymphoma?

Treatment for childhood and adolescent non-Hodgkin lymphoma (NHL) has been optimised within the major biological subgroups for the last 30 years. Event-free survival rates reach almost 90% for mature B-cell NHL (B-NHL), 80% for lymphoblastic lymphomas (LBL) and 70% for anaplastic large cell lymphomas (ALCL). The efficacy of the front-line treatment leaves highly refractory relapsed disease, and few patients are available to study reinduction and consolidation approaches. With the exception of few phase II studies and one ongoing prospective trial, therefore, data on children with relapsed NHL are limited to retrospective analyses. Most of these analyses include low patient numbers and summarise patients over more than 10 years during which time first line therapies often changed. The influence of front-line therapy efficacy on outcome in relapse can be highlighted by two examples: The Japanese group reported survival of 43% of 48 LBLrelapse patients, altogether 89% of 260 LBL patients survived [1]. Only 14% of 34 LBL relapse patients survived in a Berlin-Frankfurt-Muenster (BFM) series, leading to a comparable survival of 91% of all 324 LBL patients [2]. A second example with potential future implications for paediatric relapsed mature B-NHL is the dismal outcome of adult diffuse large B-cell lymphoma (DLBCL) relapse patients who received rituximab in first-line therapy compared to those who did not get rituximab first-line [3]. Outcome in relapse further differs according to the NHL subtype. Both retrospective data and an unpublished NHLBFM analysis suggest that patients with relapsed ALCL or DLBCL have a fair chance to survive (40–60%), whereas survival of patients with relapsed Burkitt lymphoma (BL) and LBL stays less than 30%. Based on these observations, the questions which re-induction therapy andwhat kind of consolidation therapy to chose—autologous, allogeneic blood stem cell transplantation (SCT) or maintenance chemotherapy—