Treatment of childhood acute lymphoblastic leukemia in second remission with allogeneic bone marrow transplantation and chemotherapy: 10-year GITMO/AIEOP experience

To compare the results of allogeneic bone marrow transplantation (AlloBMT) with those obtained with chemotherapy (CHEMO) in children with acute lymphoblastic leukemia (ALL) in second complete remission (CR) after a marrow relapse. The experience of the Italian Bone Marrow Transplantation Group and the Italian Pediatric Hematology Oncology Association is summarized. All children who had a relapse in the period 1980 to 1989 in 27 centers in Italy were eligible for the study. Of 287 eligible patients, 230 were treated with CHEMO, most of them (93%) according to a standard multiple-drug relapse protocol. The remaining 57 children underwent AlloBMT. Preparative regimens included total-body irradiation and chemotherapy (n = 51) or chemotherapy alone (n = 6). Statistical analysis was performed with a Cox regression model adjusting for waiting time to transplant and prognostic factors. In the whole series, minimum and median follow-up after second CR were 3 and 6.2 years, respectively; at 8 years from second CR, disease-free survival (DFS) was 20.0% (SE 2.5) and survival was 26.4% (SE 2.9). In the group of patients with an early first relapse, DFS was significantly longer after AlloBMT than after CHEMO (relative risk [RR] = 0.45, P = .002). No significant advantage of AlloBMT over CHEMO was found for patients with a late relapse (> 30 months since diagnosis). Duration of first CR significantly influenced prognosis in the CHEMO group (RR = 0.32, P = .0001 for patients with late first relapse versus patients with early first relapse). Results suggest an advantage in DFS of AlloBMT over CHEMO in ALL patients who experienced an early first medullary relapse. Prospective trials are needed to address efficacy of AlloBMT versus CHEMO in patients with late bone marrow relapse.