Hematopoietic stem cell transplantation in adult acute lymphoblastic leukemia : a single-centre analysis

The role of autologous or allogeneic hematopoietic stem cell transplantation (HSCT) in ALL is controversial because of its adverse risk/benefit ratio, and the main policy is to reserve it for high-risk patients. In our Institution, between 1984 and 2002, 40 patients received an allogeneic HSCT and 39 underwent autografting. The conditioning regimen included HD-Ara-C, HD-CTX and 10 Gy fractionated TBI. After allogeneic SCT in first CR, four patients relapsed, leading to a 10-year EFS chance of 78.3%; of the other patients, 5 are still in CR. After autografting in first CR, there was an early death, one secondary AML, one death in CR and six relapses, leading to a 10-year EFS chance of 44.4%; of the other patients, 6 are still in CR. Even considering the limited number of patients and the slow accrual rate, selection bias cannot be considered a sufficient explanation for the favorable outcome of allografting in first CR as the majority of the patients had adverse prognostic factors. It cannot be claimed that allogeneic SCT was performed in patients already cured, as the autografted patients had a notably worse outcome, and a 10-year EFS chance of about 80% is an uncommon finding even in standardrisk ALL patients. It might be inferred that the timing of SCT as late intensification, in addition to a rather aggressive conditioning regimen, helped to minimize the leukemic burden, thus favoring the expression of a GVL effect. Conversely, the results in more advanced disease phases are discouraging, due to poor quality CRs and inefficacy of GVL in managing large residual disease.