Autologous bone marrow transplantation in children with acute myeloblastic leukemia: report from the Italian National Pediatric Registry (AIEOP-BMT)

: This report summarizes indications and results of autologous bone marrow transplantation (ABMT) performed in childhood acute myeloid leukemia (AML) in Italy since 1984. A total of 158 patients have been reported from 12 teams to the AIEOP-BMT Registry: 110 have been autografted in first complete remission (CR) and 48 in second remission. Several conditioning regimens have been utilized, mainly consisting of BAVC (an original polichemotherapy schedule, BCNU, mAMSA, VP-16 and Ara-C) (63 cases) and of total body irradiation (TBI) plus Melphalan (33 cases): other 28 patients received different TBI-including regimens, and 34 received various chemotherapy regimens (Busulfan plus cyclophosphamide +/- VP-16, Busulfan plus Melphalan, Melphalan alone). Projected event-free survival (EFS) for patients autografted in first CR is 41.4% (S.E. 5.5%) at 7 years, with a total of 53 patients in continuous CR. EFS is better in patients receiving a TBI-including regimen: 78.8% versus 27.2% (p = 0.0001). In particular, results obtained in a subgroup of 21 cases receiving TBI + melphalan and purged marrow are particularly encouraging, with a EFS > 85% projected a 7 years. The overall EFS in second CR is 41.5% at 7 years, and no difference have been observed after a TBI-including regimen or after a chemotherapy regimen, being EFS 43.1% and 39.3% for these 2 groups respectively. A total of 11 transplant-related deaths occurred, with 5 patients (4.5%) dead in first CR and 6 (12%) dead in second CR within 100 days from transplant. From these data, ABMT is confirmed to represent an effective treatment for AML after first relapse, while the encouraging results obtained in first CR with TBI-including regimens should be confirmed with a longer follow up and a larger number of patients.