AUTOLOGOUS BONE-MARROW TRANSPLANTATION IN HEMATOLOGICAL MALIGNANCIES

Autologous bone marrow transplantation (ABMT) has developed considerably in the past 15 years and is now a routine procedure for the consolidation of acute leukemias, non-Hodgkin's lymphomas and Hodgkin's disease. In addition, ABMT has been tested in multiple myeloma (MM) and even considered in highly selected cases of chronic myelocytic leukemia (CML). Interest has resulted from the discovery of new purging procedures such as long-term cultures with or without serum-free media containing various lymphokines, the evaluation of cryoinjury on malignant cells, the increased detection of minimal residual disease using PCR, and the acceleration of hemopoietic recovery post-ABMT through the use of peripheral blood stem cells and/or lymphokines. Results presented include data from the international (ABMTR) and European (EBMT) registries, and our own unit in Paris. With respect to acute leukemias, (a) the EBMT listed 1,688 patients. The overall results were as follows: for patients autografted in complete remission (CR) 1, the leukemia-free survival and relapse rate at 7 years were 48 +/- 2% and 41 +/- 3% for AML and 44 +/- 5% and 45 +/- 5% in acute lymphoblastic leukemia (ALL), respectively. In CR2, the figures were 34 +/- 4% and 54 +/- 5% for AML and 32 +/- 3% and 62 +/- 4% for ALL, respectively. Patients not relapsing at 1 year post-ABMT had a probability of being cured at 7 years of 86 and 71% if autografted in CR1 and CR2 for AML and 81 and 59% for ALL, respectively. Mutivariate analysis of relapse rates in several subpopulations confirmed the efficacy of marrow purging in AML CR1: in patients transplanted prior to January 1988 (minimum follow-up of 2 years), the relapse rate with purged marrow was 35 +/- 5% vs. 47 +/- 3% (p < 0.005). (b) In Paris, St-Antoine, using TBI and marrow purged with mafosfamide at levels individually adjusted (Blood 1986;67:1367), the probability of remission and DFS were 84 and 62% in AML CR1 63 and 59% in ALL CR1, respectively. There was a statistically significant relationship between the relapse rate and the residual amount of CFUGM progenitors in the marrow after purging. The cutoff point was 0.3%, with a relapse rate of 54% in those receiving marrow containing the higher residual CFUGM fractions and only 29% in those receiving less. With respect to non-Hodgkin's lymphomas, the EBMT listed 698 patients. In intermediate or high grade lymphomas, the DFS at 6 years was 30% and 18% in sensitive and resistant relapses, respectively. For CR2, the DFS was 48%. The question of autograft in CR1 (DFS of 70% at 9 years) is still debatable. With respect to Hodgkin's disease. ABMT should be performed as soon as possible in the absence of CR following four courses of a standard MOPP/ABVD regimen.