Outcome After First Relapse in Children With Acute Lymphoblastic Leukemia:A Report Based on the Dutch Childhood Oncology Group (DCOG) Relapse ALL 98 Protocol

Background. We report on the treatment of children and adolescents with acute lymphoblastic leukemia (ALL) in first relapse. The protocol focused on: (1) Intensive chemotherapy preceding allogeneic stem cell transplantation (SCT) in early bone marrow relapse; (2) Rotational chemotherapy in late relapse, without donor; (3) Postponement of cerebro-spinal irradiation in late isolated CNS relapse; and (4) Treatment in very late bone marrow relapse with chemotherapy only. Methods. From January 1999 until July 2006 all 158 Dutch pediatric patients with ALL in first relapse were recorded. Ninety-nine patients were eligible; 54 patients with early and 45 with late relapse. Eighteen patients had an isolated extramedullary relapse; 69 patients had bone marrow involvement only. Results. Five-years EFS rates for early and late relapses were 12% and 35%, respectively. For early relapses 5 years EFSs were 25% for patients transplanted; 0% for non-transplanted patients. For late relapses 5 years EFS was 64% for patients treated with chemotherapy only, and 16% for transplanted patients. For very late relapses EFS was 58%. Conclusions. Our data suggest the superiority of SCT for early relapse patients. For late relapses a better outcome is achieved with chemotherapy only using the rotational chemotherapy scheme. The most important factor for survival was interval between first CR and occurrence of the first relapse. Pediatr Blood Cancer. 2011; 57: 210-216. (C) 2011 Wiley-Liss, Inc.