Autologous Hematopoietic Stem-Cell Transplantation for Children With Acute Myeloid Leukemia in First or Second Complete Remission: A Prognostic Factor Analysis

Consequent and intensified relapse therapy improved survival in pediatric AML: results of relapse treatment in 379 patients of three consecutive AML-BFM trials

Relapse remains the major cause of treatment failure in pediatric acute myeloid leukemia (AML). We analyzed the clinical characteristics, treatment response to relapse treatment and overall survival (OS) of 379 children with AML relapse treated according to three consecutive frontline protocols of the AML-Berlin/Frankfurt/Muenster study group (AML-BFM-87/-93/-98). Of 313 treated patients with data on remission status, 198 children (63%) achieved a second complete remission (CR2). There were no significant differences in remission rates and OS for the intensive reinduction treatment schedules used. The 5-year OS rate was 23% for the total group and 29% for patients treated with curative intent. OS rates increased with study periods from 18 to 34% (P(log rank)=0.012), whereas the proportion of patients receiving only palliative treatment decreased from 23 to 11% (P(CMH)=0.005). Late relapse, no allogeneic stem cell transplantation (SCT) in CR1, age <10 years and favorable cytogenetics were independent favorable prognostic factors for survival. Achievement of CR2 was the most important prognostic factor (OS 44 vs 3%; P(log rank)<0.0001). Overall, one-third of children with relapsed AML can be cured today. SCT in CR2 is recommended for most patients, although its impact on CR2 is discussed.

Allogeneic stem cell transplantation for children with acute myeloid leukemia in second complete remission

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapy for patients with relapsed acute myeloid leukemia. In this retrospective, multicenter study, we analyzed the outcome of 63 children (median age, 7 y; range, 0.2 to 17) who received unmanipulated allo-HSCT in second complete remission. Either a matched family donor or an unrelated donor was used in 29 (46%) and 34 (54%) patients, respectively. The stem cell source was bone marrow in 53 children (84%), peripheral blood in 7 (11%), and cord blood in 3 patients (5%). Preparative regimen included total body irradiation in 25 patients (40%). The 5-year estimates of overall survival and leukemia-free survival were 53% [95% confidence interval (CI) 39-66] and 49% (95% CI 35-63), respectively, whereas the cumulative incidence of relapse and transplant-related mortality (TRM) were 26% (95% CI 16-41) and 25% (95% CI 15-40), respectively. In multivariate analysis, the use of a matched family donor predicted a better probability of LFS [relative risk (RR) 2.29, P=0.05]. Both chronic graft-versus-host disease occurrence and age at diagnosis greater than 11 years were associated with an increased TRM (RR 8.08, P=0.04 and RR 4.38, P=0.05, respectively). These results indicate that allo-HSCT is a procedure able to rescue a significant proportion of children with acute myeloid leukemia in second complete remission, especially if an human leukocyte antigen-compatible relative is employed as donor. Both leukemia recurrence and TRM contributed to treatment failure. Optimization of donor selection and of strategies for both prophylaxis and treatment of graft-versus-host disease may improve the results of unrelated donor allo-HSCT.

Autologous hematopoietic stem cell transplantation for adults with acute myeloid leukemia in complete remission: the Edouard Herriot Hospital experience

We retrospectively assess the long-term outcome and determined prognostic factors correlated with outcomes in adults with acute myeloid leukemia (AML) undergoing autologous hematopoietic stem cell transplantation (HSCT) in our institution over a 19-year period. A total of 78 adults who received autologous HSCT for AML in first complete remission (CR) and of 21 adults in further CR were included in the study. Bone marrow (n = 14) or peripheral blood stem cells (PBSC) (n = 85) transplantation was performed at a median of 2.9 months from CR. Hematologic recovery was significantly reduced in the PBSC group. Five-year cumulative incidences of relapse were 56 and 49%, respectively. Corresponding 5-year probabilities of event-free survival (EFS) were 33 and 35%, while those of overall survival (OS) were 38 and 49%, respectively. In multivariate analyses, cytogenetics was the main prognostic factor for outcome. Treatment-related mortality (TRM) was of 15% at 5 years, but higher in females as compared to males (p = 0.04). We confirmed that long-term EFS can be achieved after autologous HSCT in adult patients with AML. Results in adults who experience a relapse after conventional chemotherapy support the use of autologous HSCT as salvage therapy if such patients achieve a subsequent CR.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myeloid leukemia in children: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute myeloid leukemia (AML) in children is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in the table entitled "Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Myeloid Leukemia" and were reached unanimously by a panel of experts in AML. The identified priority areas of needed future research in pediatric AML include: What is the role of risk group stratification, including the role of cytogenetics, in selection of patients for allogeneic SCT, especially those in first CR? What is the appropriate timing and use of alternative donor SCT, given that matched unrelated donor SCT appears to yield outcomes equivalent to matched related donor SCT? What is the role of reduced intensity SCT (including the use of fludarabine-based preparative regimens) and/or other immunomodulatory approaches to maximize the graft-versus-leukemic effect? and What is the role of biologically targeted agents (ie, tyrosine kinase inhibitors, farnesyl transferase inhibitors, Flt-3 inhibitors, etc) in the treatment of AML, including induction, consolidation, conditioning regimens, and after SCT?

Impact of age on outcome of pediatric acute myeloid leukemia: a report from 2 institutions

BACKGROUND

The prognostic significance of age among pediatric patients with acute myeloid leukemia (AML) was investigated.

METHODS

The authors reviewed the outcome of 424 patients who were <or=21 years of age at the time of diagnosis of AML (excluding acute promyelocytic leukemia) between 1983 and 2002 at St. Jude Children's Research Hospital (n=288) or the M. D. Anderson Cancer Center (n=136). Two treatment eras (1983-1989 and 1990-2002) were examined because of the greater intensity of treatment during the recent era.

RESULTS

After controlling for the effects of cytogenetics, white blood cell (WBC) count, French-American-British (FAB) subtype, and treatment era, they observed that age and treatment era interacted significantly in relation to event-free survival (EFS) (P=.033). Patients 10 years of age or older were at greater risk of an adverse event than younger patients in the recent era (hazard ratio=1.8; 95% confidence interval [CI]: 1.3-2.6; P=.005) but not in the early era. The rate of adverse events (death or recurrence) increased significantly with each year of age in the recent era (4.3%/year; 95% CI: 1.9-6.8%; P=.001) but not in the early era. The rate of death increased significantly with each year of age in both eras (4.4%/year; 95% CI: 2.3-6.5%; P<.001). EFS and survival showed no association with study site, and the effects of age were similar at the 2 sites.

CONCLUSIONS

These results suggest that age is an independent prognostic factor in childhood AML and that children younger than 10 years benefit more than older children from newer intensive therapies.

A phase II study of cloretazine (VNP40101M), a novel sulfonylhydrazine alkylating agent, in patients with very high risk relapsed acute myeloid leukemia

Cloretazine (VNP40101M) is a sulfonylhydrazine alkylating agent with significant anti-leukemia activity. A multicenter phase II study of cloretazine was conducted in patients with first relapse of acute myeloid leukemia (AML) following an initial complete remission (CR) of less than 12 months. Cloretazine was given as a single intravenous infusion at a dose of 600 mg/m(2). Fifty-three patients (median age 62 years (18-84), 41 of 44 (93%) evaluable with intermediate or high risk cytogenetics, 32 (60%) with initial CR durations < or =6 months) were treated on study. Two patients (4%) achieved a second CR. Five (9%) patients died within 30 days of receiving cloretazine therapy. Median overall survival (2.3 months) in the study cohort was directly comparable to that of 233 matched patients treated with other single agents. The study cloretazine regimen had minimal activity in a very high risk subset of patients with relapsed AML.

Treatment of childhood acute myeloid leukemia

Childhood acute myeloid leukemia is rare, but accounts for a significant number of malignancy-related deaths in this age group. However, the prognosis has improved over past decades, and survival rates of 60% and above have been reported. Still, this implies that more than a third of children and adolescents die from this disease. Moreover, treatment is intensive, and quality of life and late effects are worrying issues. Therefore, there is a need for further improved treatment of pediatric acute myeloid leukemia. This review describes several important developments in this respect, such as improved diagnostics, prognostic factors, subgroup-directed and tailored treatment, and targeted therapy. In addition, background information is provided and current treatment strategies are described, as well as the late effects of treatment. Most groups now have risk-group adapted protocols, with allogeneic stem cell transplantation often being reserved for the higher risk group. Even in these cases, the benefit of stem cell transplantation has not been demonstrated beyond reasonable doubt with current high-intensive chemotherapy. Similarly, the use of cranial irradiation for CNS prophylaxis and maintenance treatment does not seem to be indicated in general. Subgroup-directed treatment has become a reality for acute myeloid leukemia in young children with Down's syndrome and in acute promyelocytic leukemia. In addition to tailoring therapy according to biologic features and especially monitoring treatment by measurements of minimal residual disease, targeted therapy for subgroups with activating mutations in receptor tyrosine kinases will further optimize the treatment of pediatric acute myeloid leukemia. Together with the development of many novel agents that have different mechanisms of action than the currently available anticancer agents, and improved supportive care, it is realistic that the prognosis of acute myeloid leukemia in children and adolescents will improve further in the next 5-10 years.

Modelling intervention effects after cancer relapses

This article addresses the problem of incorporating information regarding the effects of treatments or interventions into models for repeated cancer relapses. In contrast to many existing models, our approach permits the impact of interventions to differ after each relapse. We adopt the general model for recurrent events proposed by Peña and Hollander, in which the effect of interventions is represented by an effective age process acting on the baseline hazard rate function. To accommodate the situation of cancer relapse, we propose an effective age function that encodes three possible therapeutic responses: complete remission, partial remission, and null response. The proposed model also incorporates the effect of covariates, the impact of previous relapses, and heterogeneity among individuals. We use our model to analyse the times to relapse for 63 patients with a particular subtype of indolent lymphoma and compare the results to those obtained using existing methods.