Summary:Over a 9-year period 37 consecutive adults with primary refractory (n = 13) or first relapse of ALL (n = 24) received an intensive salvage chemotherapy regimen with the final intention of undergoing stem cell transplantation (SCT). Twenty-nine patients who achieved complete remission (CR) were assigned to receive autologous SCT (autoSCT) or allogeneic SCT (alloSCT) based on age and availability of a histocompatible sibling. Of the 19 patients assigned to autoSCT, 10 did not reach the transplant due to early relapse (n = 9) or fungal infection (n = 1), and nine were transplanted a median of 2.5 months (1-8) from CR, eight with an immunologically purged graft. One patient died early from ARDS and eight relapsed 2-30 months post-SCT. Three of the 10 patients assigned to alloSCT relapsed early, but all 10 received the assigned transplant a median of 2.5 months (1-7) from CR. Four died from transplant-related complications 0.7-12 months post-SCT, and six are alive and disease-free 9.7-92.6 months after the procedure. In an intention-to-treat analysis, the mean overall survival from CR for those assigned to autoSCT and alloSCT are 11.3 months (0.5-34.3) and 60.1 (2.3-98.3), respectively (log-rank, P Ͻ 0.01). Only 65% of patients who reached CR and 51% of the initial 37 cases underwent the intended SCT. We conclude that few adults with refractory or relapsed ALL actually reach SCT in CR even when the protocol used is designed for this purpose. AutoSCT appears to offer little benefit in this setting, and an alloSCT from a related or unrelated donor should be rapidly pursued after achieving CR. Keywords: adult; acute lymphoblastic leukemia; stem cell transplantation Adult patients with ALL refractory to primary induction chemotherapy (CT) or who relapse following a first remission have a very poor short-term prognosis.1 Although remissions can be obtained in 40-70% of cases with salvage CT, these usually last less than 5 months, regardless of the post-remission therapy used, and with CT alone less than 5% are alive 2 years from the start of salvage CT.
1,2Both autologous and allogeneic stem cell transplantation (SCT, either bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT)) have been used in such patients as post-remission therapy in an effort to improve the disease-free survival.3-6 However, reports from transplant centers or registries usually include heterogeneous patients highly selected either by the transplant center(s), referral for BMT of only 'good-risk' responding cases or exclusion of those cases debilitated by the salvage CT. It is thus difficult to establish the actual role played by SCT in the overall therapeutic strategy of adults with primary resistant or relapsed ALL from most reports. In this report, we describe the results of 37 consecutive adult patients treated with uniform salvage induction consolidation CT, who were then to receive an autologous or allogeneic SCT within 3 months following CR, according to age and the availability of an HLA-compatible si...