Outcome of and prognostic factors for relapse in children and adolescents with mature B-cell lymphoma and leukemia treated in three consecutive prospective "Lymphomes Malins B" protocols. A Société Française des Cancers de l'Enfant study.

To describe relapsed B-cell lymphoma or leukemia in children/adolescents treated with a "Lymphomes Malins B" regimen and their outcome and to identify prognostic factors for survival, we studied relapses in the LMB89, 96 and 2001 studies of the Société Française d'Oncologie Pédiatrique (Société Française des Cancers de l'Enfant). Therapeutic guidelines at relapse were to obtain a second complete remission and to consolidate the remission with high-dose chemotherapy followed by autologous stem-cell transplantation. Between July 1989 and March 2007, 67 patients of 1322 (5%) relapsed: 57 had Burkitt lymphoma and 10 had large-cell histology. Three patients were initially treated in risk group A, 41 in group B and 23 in group C. Thirty-three patients had a relapse in one site (15 in the central nervous system) and 34 at multiple sites. Sixty-five patients received salvage chemotherapy and 33 achieved complete remission. Forty-one patients also received high-dose chemotherapy followed by autologous (n=33) or allogeneic (n=8) transplantation. With a median follow-up of 6.4 years, the 5-year survival rate was 29.9%. Nineteen patients were still alive, all but one (group A) received consolidation treatment. Multivariate analysis showed the following factors to be significantly associated with better survival: relapse at one site (P=0.0006), large-cell histology (P=0.012), initial prognostic group A or B with lactate dehydrogenase level below twice the normal value (P=0.005), and time to relapse more than 6 months (P=0.04).