Impact of minimal residual disease on outcomes after umbilical cord blood transplantation for adults with Philadelphia-positive acute lymphoblastic leukaemia: an analysis on behalf of Eurocord, Cord Blood Committee and the Acute Leukaemia working party of the European group for Blood and Marrow Transplantation.

The status of umbilical cord blood transplantation (UCBT) in adults with Philadelphia-positive acute lymphoblastic leukaemia (Ph+ALL) and the impact of minimal residual disease (MRD) before transplant are not well established. We analysed 98 patients receiving UCBT for Ph+ALL in first (CR1) or second (CR2) complete remission (CR1, n = 79; CR2, n = 19) with MRD available before UCBT (92% analysed by reverse transcription polymerase chain reaction). Median age was 38 years and median follow-up was 36 months; 63% of patients received myeloablative conditioning and 42% received double-unit UCBT. Eighty-three patients were treated with at least one tyrosine kinase inhibitor before UCBT. MRD was negative (-) in 39 and positive (+) in 59 patients. Three-year cumulative incidence of relapse was 34%; 45% in MRD+ and 16% in MRD- patients (P =0·013). Three-year cumulative incidence of non-relapse mortality was 31%; it was increased in patients older than 35 years (P = 0·02). Leukaemia-free survival (LFS) at 3 years was 36%; 27% in MRD+ and 49% in MRD- patients (P = 0·05), and 41% for CR1 and 14% for CR2 (P = 0·008). Multivariate analysis identified only CR1 as being associated with improved LFS. In conclusion, MRD+ before UCBT is associated with increased relapse. Strategies to decrease relapse in UCBT recipients with Ph+ALL and MRD+ are needed.

Comparison of intensive chemotherapy, allogeneic, or autologous stem-cell transplantation as postremission treatment for children with very high risk acute lymphoblastic leukemia: PETHEMA ALL-93 Trial.

PURPOSE: The optimal postremission therapy for children with very high-risk (VHR) acute lymphoblastic leukemia (ALL) is not well established. This randomized trial compared three options of postremission therapy: chemotherapy and allogeneic or autologous stem-cell transplantation (SCT). PATIENTS AND METHODS: All 106 VHR-ALL patients received induction with five drugs followed by intensification with three cycles of chemotherapy. Patients in complete remission (CR) with an HLA-identical family donor were assigned to allogeneic SCT (n = 24) and the remaining were randomly assigned to autologous SCT (n = 38) or to delayed intensification followed by maintenance chemotherapy up to 2 years in CR (n = 38). RESULTS: Overall, 100 patients achieved CR (94%). With a median follow-up of 6.5 years, 5-year disease-free survival (DFS) and overall survival (OS) probabilities were 45% (95% CI, 37% to 54%) and 48% (95% CI, 40% to 57%), respectively. The three groups were comparable in the main pretreatment ALL characteristics. Intention-to-treat analysis showed no differences for donor versus no donor in DFS (45%; 95% CI, 27% to 65% v 45%; 95% CI, 37% to 55%) and OS (48%; 95% CI, 30% to 67% v 51%; 95% CI, 43% to 61%), as well as for autologous SCT versus chemotherapy comparisons (DFS: 44%; 95% CI, 29% to 60% v 46%; 95% CI, 32% to 62%; OS: 45%; 95% CI, 31% to 62% v 57%; 95% CI, 43% to 73%). No differences were found within the different subgroups of ALL and neither were differences observed when the analysis was made by treatment actually performed. CONCLUSION: This study failed to prove that, when a family donor is available, allogeneic SCT produces a better outcome than autologous SCT or chemotherapy in children with VHR-ALL.

Prognostic value of karyotypic analysis in children and adults with high-risk acute lymphoblastic leukemia included in the PETHEMA ALL-93 trial.

BACKGROUND AND OBJECTIVES: Cytogenetic analysis is one of the most reliable prognostic factors in acute lymphoblastic leukemia. The objective of this study was to analyze the prognostic value of cytogenetic analysis in children and adults with high-risk acute lymphoblastic leukemia (HR-ALL) included in a prospective multicenter trial. DESIGN AND METHODS: One hundred and thirty patients (44 children and 86 adults) with HR-ALL included in the PETHEMA ALL-93 trial had an adequate cytogenetic study after review. Cytogenetic subgroups were established according to the cancer and acute leukemia group B criteria (unfavorable: 11q23, t(9;22), -7 and +8; normal; miscellaneous: the remaining chromosome abnormalities) and their main clinicobiological features were compared. Univariable and multivariable analyses for complete remission (CR) attainment, event-free survival (EFS) and overall survival (OS) were performed. RESULTS: The mean SD age was 26 14 years. Two were infants (<1 year), 42 were children and 86 adults (19-50 years). The cytogenetic study was normal in 44 (34%) cases. The most frequent chromosomal rearrangement was t(9;22)(q34;q11) (34 cases, 26%, 30 adults), followed by 11q23 (12 cases, 9% -8 children-, including t(4;11)(q21;q23) in 8, 7 children). Patients with t(9;22) were older than the remaining cases, whereas those with 11q23 rearrangements were younger and had higher WBC counts. Multivariable analyses showed two associated factors in adults with a lower frequency of CR and a shorter EFS and OS: t(9;22) and slow response to therapy (assessed by a percentage of blast cells higher than 10% in bone marrow study on day 14). For children with very high-risk ALL, only slow response to therapy (assessed by the presence of blast cells in peripheral blood on day 8) was associated with a negative impact on CR, EFS and OS. INTERPRETATION AND CONCLUSIONS: In adult patients with high-risk acute lymphoblastic leukemia included in the PETHEMA ALL-93 protocol, cytogenetic analysis at diagnosis is a useful independent prognostic marker. The poorest prognosis for patients with t(9;22) justifies the development of specific treatments for these patients. In this small subgroup of children with very high-risk ALL no cytogenetic characteristics was found to influence the results of therapy, slow response to therapy being the only prognostic factor.