ISOLATED EXTRAMEDULLARY RELAPSE IN CHILDREN WITH ACUTE LYMPHOBLASTIC-LEUKEMIA - A COMPARISON BETWEEN TREATMENT RESULTS OF CHEMOTHERAPY AND BONE-MARROW TRANSPLANTATION

The purpose of this study was to determine the therapeutic efficacy of different treatment strategies, namely chemotherapy, allogeneic and a utologous bone marrow transplantation (BMT), for extramedullary relaps e of acute lymphoblastic leukemia (ALL) in children in second or subse quent remission. Between 1983 and 1993, 165 patients up to 19 years of age with extramedullary relapse of ALL were registered in the multice nter ALL-REZ BFM trials. One hundred and thirty four children received chemotherapy only; 17 children were grafted from HLA-identical siblin g donors 152 days (46-392 days) after diagnosis of relapse, and 14 chi ldren underwent autologous BMT after a median time of 137 (range 23-30 0) days. Event-free survival (EFS) at 5 years was 0.47 +/- 0.05 for pa tients receiving chemotherapy: 0.76 +/- 0.07 for late, 0.33 +/- 0.08 f or early and 0.33 +/- 0.07 for very early relapsed patients. Sixty fiv e patients are in complete remission (CR), 61 patients relapsed, 5 die d from therapy related complications, 2 patients in CR were lost to fo llow-up and one patient developed a second malignancy. For patients wh o had undergone BMT, EFS at 5 years was 0.36 +/- 0.10 without signific ant difference between autologous BMT (8 of 14 in CR, 6 relapsed) and allogeneic BMT (6 of 17 in CR, 4 died of acute toxicity, and 7 relapse d). After statistical adjustment for the time to BMT, there is a signi ficant difference (P < 0.05) between the results of chemotherapy and B MT (S-year EFS 0.50 +/- 0.05 and 0.36 +/- 0.10, respectively). The sit e of relapse in childhood ALL has to be considered in the treatment de cision. In general BMT is felt to be the treatment of choice in case o f systemic relapse. Our data suggest that BMT with its well-known ther apy-related toxicity and late effects seems not to be necessary for ex tramedullary relapse because the chances of cure are not superior to t hose with salvage chemotherapy.