The impact of karyotype on remission rates in adult patients with de novo acute myeloid leukemia receiving high-dose cytarabine-based induction chemotherapy

Outcome of high-dose cytarabine-based induction therapy followed by hematopoietic stem cell transplantation in acute myeloid leukemia: influence of karyotype

One-hundred-twenty consecutive adult patients aged 15-69 years (median 40) with acute myeloid leukemia (AML) excluding t(15;17) received induction therapy comprising idarubicin, high-dose cytarabine and etoposide. Planned post-induction treatment included two courses of moderate-intensity consolidation therapy followed by stem cell transplantation. 11 patients (9%) died during induction therapy. The complete remission (CR) rate with a single cycle of induction therapy was 71%. The overall CR rate, after salvage chemotherapy but excluding allogeneic transplantation for primary refractory disease, was 82%. CR rates with one cycle of therapy for patients with good, intermediate and poor karyotype were 96, 72 and 41%, respectively (P<0.0001). The impact of karyotype on the overall CR rate was also significant (96 vs. 88 vs. 59%; P=0.001). Overall, 84 of 98 patients (86%) attaining CR underwent autologous (n=59), allogeneic (n=23) or syngeneic (n=2) hematopoietic stem cell transplantation in first CR. The 5-year overall survival (OS) of 43% (95% CI: 34-52%) was significantly influenced by the karyotype: good 73%, intermediate 41%, and poor 18% (P=0.0001). These data suggest that the sequence of therapy employed is active in AML, but additional steps are needed to improve the outcome of patients with intermediate- and high-risk cytogenetic abnormalities.

Use of physiological doses of human growth hormone in haematological patients receiving intensive chemotherapy promotes haematopoietic recovery: a double-blind randomized, placebo-controlled study

In vivo and in vitro studies suggest human growth hormone (hGH) receptors on bone marrow stem cells may be biologically active and could be exploited to promote haemopoetic recovery after intensive chemotherapy. Patients with haematological malignancies receiving intensive chemotherapy and requiring hospitalization were randomized in a double-blind, placebo-controlled single-centre trial. Patients were randomly assigned to receive either hGH 500 microg/day or placebo, for 6 weeks. There was no significant difference in patient characteristics at baseline between the placebo and treatment arms. Patients treated with hGH showed significantly faster recovery of platelets to 25 x 10(9)/l (median of 16 versus 19 days; P = 0.03) compared to the placebo-controlled arm (hazard ratio 1.47 favouring hGH, 95% confidence interval (CI), 1.03-2.08). Time to relapse did not differ significantly between arms. There was no change in the anthropometric parameters at the start and end of hGH/placebo therapy. The study drug was well tolerated. Treatment with hGH in physiological doses improves platelet recovery, but is not associated with a lower relapse rate or improved anthropometric parameters in patients receiving intensive chemotherapy.

Reassessing autotransplantation for acute myeloid leukaemia in first remission – a matched pair analysis of autologous marrow vs peripheral blood stem cells

The role of autologous stem cell transplantation in adult patients with acute myeloid leukaemia (AML) in first remission is unclear, yet it has become standard treatment for myeloma and this paper explores whether the source of transplanted stem cells may explain this paradox. In total, 57 patients from the Royal Marsden Hospital who received an unpurged bone marrow transplant (ABMT) were matched with 114 patients from the EBMT registry who had undergone peripheral blood stem cell transplantation (PBSCT). Patients were matched for karyotype, FAB type, remission-autograft interval and age. In the PBSCT group, haematopoietic recovery was significantly faster and nonrelapse mortality at 4 years was significantly lower (13 vs 1%, P=0.04). The relapse rate and overall survival at 4 years (20 vs 31% and 77 vs 63%) were also better with PBSCT, although the differences were not statistically significant. Autografting should be reassessed in a randomised trial for first remission AML patients using peripheral blood as a source of stem cells rather than bone marrow.

Impact of cytogenetics on the outcome of autotransplantation for acute myeloid leukemia in first remission: is the benefit of intensive pretransplant therapy limited to patients with good karyotypes?

A total of 81 adults with acute myeloid leukemia (AML) (47% favorable karyotypes) were autografted in first remission after melphalan-total body irradiation, having received 0 (n=7), 1 (n=19), 2 (n=51), or 3 (n=4) consolidation chemotherapy cycles before harvest. The cumulative 5-year incidences of relapse and transplant-related mortality were 37 and 17%, respectively. The actuarial 5-year probability of disease-free survival (DFS) was 46%. In Cox analysis, favorable karyotypes, increasing numbers of consolidation cycles (0 vs > or =1 or 1 vs >1), and higher nucleated cell doses were associated with lower relapse rates and higher DFS. Patients with favorable karyotypes benefited from every additional cycle of consolidation therapy (0 vs > or =1 as well as 1 vs >1). Among patients with other karyotypes, while the benefit of one cycle of consolidation was clear (0 vs > or =1), there was no obvious beneficial impact of further consolidation therapy (1 vs >1). Administration of consolidation chemotherapy prior to harvest is essential in AML. While it is possible to enhance the benefit of consolidation with favorable karyotypes by delivering two cycles, its usefulness is limited in others. In them, it may be worthwhile exploring alternatives not normally used in AML (eg high-dose cyclophosphamide) that could have antileukemic effects while permitting mobilization of stem cells.

High-dose cytarabine as consolidation treatment for patients with acute myeloid leukemia with t(8;21)

Seventeen patients affected by acute myeloid leukemia (AML) with t(8;21) were prospectively programmed to receive three courses of high-dose cytarabine (HDARA-C) as post-remission therapy. The median age was 39 years and in all cases t(8;21) was the only karyotypic abnormality. Complete remission (CR) was achieved in 14 out of 17 cases (82%) and, after first consolidation with NOVIA regimen (intermediate dose ARA-C plus mitoxantrone), all patients received the three planned courses of HDARA-C (3g/m(2) q12h on days 1, 3, 5). There were two documented infections, while all patients experienced fever of unknown origin (FUO). Nonhematological toxicity was mild. Thirteen out of 14 patients are in continuous CR after a median follow-up of 44 months. One patient relapsed at 16 months and, following CR2 achievement, underwent allogeneic transplantation; he died 3 months later while in CR from acute graft versus host disease (GVHD). Survival at 5 years is projected at 79%. Our data confirm the efficacy of repeated courses of HDARAC for patients with t(8;21) AML.

Allogeneic transplantation from HLA-matched sibling or partially HLA-mismatched related donors for primary refractory acute leukemia

Allogeneic transplantation is successful in a minority of patients with primary refractory acute leukemia (PRAL). An HLA-matched sibling donor (MSD) is available only in 30-40% of the patients, whereas a partially mismatched related donor (PMRD) is available for most. We compared the outcome of 24 MSD (median age 24 years) and 19 PMRD (median age 34 years; P = 0.04) allograft recipients with PRAL. All MSD patients received non-T cell-depleted marrow whereas all PMRD patients received partially T cell-depleted marrow. All evaluable PMRD patients and 90% of the evaluable MSD patients attained CR. Six patients in each group with recurrent/persistent disease died. Ten PMRD (3-year probability 70%) and 14 MSD (3-year probability 63%) patients died of treatment-related causes. At the last follow-up, three PMRD (18-50 months; 3-year probability 14%) and four MSD (20-166 months; 3-year probability 20%) patients were alive and well. We conclude that allogeneic transplantation is a viable therapeutic option for PRAL. PMRD transplantation is a reasonable alternative in patients with no MSD, and results in similar outcome. In terms of identifying a donor and harvesting cells, a PMRD transplant is significantly quicker than an unrelated donor transplant - a point of great practical importance in the setting of failed induction chemotherapy where time is of the essence.

Current status and perspectives of therapy for acute myeloid leukemia

Intensification of induction and postremission chemotherapies has resulted in a steady improvement in outcomes for adults with acute myeloid leukemia (AML) over the past two decades. The global response to initial therapy is now in the range of 60% to 80%, with 20% to 30% of patients experiencing long-term disease-free survival. Modern methodologies have revealed that cytogenetic aberrations are closely related to treatment outcome and have allowed subgroups of patients to be identified who have AML with a good, intermediate, or poor prognosis. The actions and interactions of cytogenetics and therapy in determining treatment outcome have been investigated in a series of clinical trials conducted by the German AML Cooperative Group. Evidence is presented that therapy and cytogenetics can independently influence outcome. It is hoped that our increasing understanding of the biological mechanisms that dictate disease characteristics will lead to improved outcomes for patients with AML.

Clinical importance of cytogenetics in acute myeloid leukaemia

Acquired chromosome aberrations are present in the marrow of most patients with acute myeloid leukaemia (AML) at diagnosis. Cytogenetically, AML is a very heterogeneous disease with over 160 structural chromosome abnormalities observed recurrently to date. Molecular dissection of many reciprocal translocations and inversions has resulted in cloning of the genes involved in leukaemogenesis. Some recurrent aberrations and the resulting gene rearrangements, namely inv(16)/t(16;16) and CBFbeta- MYH11, t(8;21) and CBFA2-CBFA2T1, t(15;17) and PML-RARalpha, and rearrangements of band 11q23 and the MLL gene, are now used to help define distinct disease entities within AML in the new World Health Organization classification of haematological malignancies. Moreover, cytogenetic abnormalities, whether molecularly characterized or not, are among the most important, independent prognostic factors in AML, and are being used in the management of AML patients. This review presents current information on chromosome abnormalities in AML, and on associations between karyotype and clinical characteristics and outcome of AML patients.