Randomized trial of busulfan vs total body irradiation containing conditioning regimens for children with acute lymphoblastic leukemia: a Pediatric Blood and Marrow Transplant Consortium study

Late effects of total body irradiation and hematopoietic stem cell transplant in children under 3 years of age

BACKGROUND

Total body irradiation (TBI) is an important component of hematopoietic stem cell transplant (SCT) for pediatric malignancies. With increasing survival rates, late effects of SCT become more important. Younger children may be at particular risk of late effects of radiation and SCT.

METHODS

We retrospectively reviewed outcomes of children less than 3 years of age who received TBI as part of their preparative regimen for SCT at Children's Hospital Colorado. Clinical information including the date of last follow-up, most recent lab values, and physiologic tests were extracted from the medical record.

RESULTS

Of 81 patients who underwent SCT, 19 received TBI and of those, 15 were long-term survivors available for review. Late effects occurring in greater than 50% of the children included abnormalities involving endocrine, metabolic, renal, cataracts, and neurocognitive systems. Other organs involved less commonly included liver, skeletal, and cardiac abnormalities. Solid tumors were a rare finding with only one patient developing a benign osteochondroma and no identified secondary malignancies.

CONCLUSIONS

TBI has been shown to be an important part of the preparative regimen for patients undergoing SCT. Our results, similar to other studies, suggest TBI in patients less than 3 years of age will likely result in multi-organ dysfunction including endocrine, metabolic, renal, eye, and neurocognitive abnormalities. A longitudinal study with standardized testing of these systems would further clarify the late effects concerns in this patient population.

Final height and body mass index after fractionated total body irradiation and allogeneic stem cell transplantation in childhood leukemia

Impaired linear growth has been reported in patients treated during childhood with allogeneic stem cell transplantation and fractionated total body irradiation (fTBI). The objective of this study was to determine the final height and body mass index (BMI) achieved. Forty-nine patients with leukemia were included and surveyed for more than 5 years. Median age at follow-up was 24.3 years (range, 18.9-35.8) and median follow-up time from allograft was 14.4 years (range, 4.5-21.9). Mean height standard deviation score (s.d.s.) at final examination (-1.1 ± 1.3,) was significantly lower than at fTBI (0.3 ± 1.2; P = .001). Final height s.d.s. was significantly correlated with age at diagnosis, age at fTBI, and target height (P = .001; P < .001; P < .001, respectively). Final height was significantly lower in children transplanted before age 5 (P = .006). Growth hormone treatment (n = 6) had only a modest effect on growth velocity. Mean BMI at follow-up was normal at 19.6 kg/m(2) for boys and 21.2 for girls, but with a significant decrease since allograft only for boys (-1.2 ± 1.5 s.d.s.) (P = .003). In conclusion, final height is decreased; BMI is normal but decreased from fTBI in boys.

The outcome of allogeneic hematopoietic stem cell transplants without total body irradiation in pediatric patients with acute lymphoblastic leukemia: single centre experience

The most widely accepted conditioning regimen to allogeneic hematopoietic stem cell transplantation consists of total body irradiation, especially in patients affected by acute lymphoblastic leukemia (ALL). In this retrospective study, we report our experience on hematopoietic stem cell transplantation in 44 pediatric patients with acute lymphoblastic leukemia using a non-radiation-based conditioning regimen (busulfan/cyclophosphamide). Median age at transplantation was 12.5 years (range, 4 to 14 y). 39 out of 44 patients received transplants in complete remission. At a median follow-up of 390 days, the probabilities of 3-year disease-free survival and overall survival were 50% and 68%, respectively. Disease status of hematopoietic stem cell transplantation was the only significant variable affecting the overall survival. Acute and chronic graft-versus-host disease occurred in 23 (64%) and 12(18%) patients, respectively. Relapse was significantly higher among patients transplanted in advanced disease status. The results of the study indicate that non-radiation-based preparative regimens can be used in pediatric patients with ALL. However, well-designed comparative trials are needed to better clarify the difference between radiation and non-radiation-based conditioning regimens in pediatric ALL.

Feasibility of non-TBI conditioning with busulfan and fludarabine for allogeneic stem cell transplantation in lymphoid malignancy

BACKGROUND/AIMS

This retrospective study evaluated the transplantation outcomes of patients with adult lymphoid malignancies who received chemotherapy-based conditioning with busulfan and fludarabine (BuFlu) and busulfan and cyclophosphamide (BuCy2).

METHODS

Thirty-eight patients (34 with acute lymphoblastic leukemia and 4 with lymphoblastic lymphoma) were included in the current study. The conditioning regimen was BuCy2 for 14 patients and BuFlu for the remaining 24 patients. Eight and 13 patients were high risk disease in the BuCy2 and BuFlu groups, respectively.

RESULTS

The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 56.5% and 55.2% and that of extensive chronic GVHD 17.0% and 55.6% (p = 0.018) for the BuFlu and BuCy2 groups, respectively. The 3-year relapse rate was 27.8% and 31.4% and 3-year overall survival 34.3% and 46.8% for the BuFlu and BuCy2 groups, respectively. Treatment-related mortality (TRM) was significantly lower in the BuFlu group (16.9%) than in the BuCy2 group (57.1%, p = 0.010). In multivariate analyses, the BuFlu regimen was identified as an independent favorable risk factor for TRM (hazard ratio [HR], 0.036; p = 0.017) and extensive chronic GVHD (HR, 0.168; p = 0.034).

CONCLUSIONS

Our BuFlu regimen would appear to be an acceptable conditioning option for lymphoid malignancies, including high-risk diseases. It was safely administered with a lower TRM rate than BuCy2 conditioning.

Busulphan-cyclophosphamide cause endothelial injury, remodeling of resistance arteries and enhanced expression of endothelial nitric oxide synthase

Stem cell transplantation (SCT) is a curative treatment for malignant and non malignant diseases. However, transplantation-related complications including cardiovascular disease deteriorate the clinical outcome and quality of life. We have investigated the acute effects of conditioning regimen on the pharmacology, physiology and structure of large elastic arteries and small resistance-sized arteries in a SCT mouse model. Mesenteric resistance arteries and aorta were dissected from Balb/c mice conditioned with busulphan (Bu) and cyclophosphamide (Cy). In vitro isometric force development and pharmacology, in combination with RT-PCR, Western blotting and electron microscopy were used to study vascular properties. Compared with controls, mesenteric resistance arteries from the Bu-Cy group had larger internal circumference, showed enhanced endothelium mediated relaxation and increased expression of endothelial nitric oxide synthase (eNOS). Bu-Cy treated animals had lower mean blood pressure and signs of endothelial injury. Aortas of treated animals had a higher reactivity to noradrenaline. We conclude that short-term consequences of Bu-Cy treatment divergently affect large and small arteries of the cardiovascular system. The increased noradrenaline reactivity of large elastic arteries was not associated with increased blood pressure at rest. Instead, Bu-Cy treatment lowered blood pressure via augmented microvascular endothelial dependent relaxation, increased expression of vascular eNOS and remodeling toward a larger lumen. The changes in the properties of resistance arteries can be associated with direct effects of the compounds on vascular wall or possibly indirectly induced via altered translational activity associated with the reduced hematocrit and shear stress. This study contributes to understanding the mechanisms that underlie the early effects of conditioning regimen on resistance arteries and may help in designing further investigations to understand the late effects on vascular system.

Role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of pediatric acute lymphoblastic leukemia: update of the 2005 evidence-based review

Clinical research published since the first evidence-based review on the role of hematopoietic stem cell transplantation (SCT) in the treatment of pediatric acute lymphoblastic leukemia (ALL) is presented and critically evaluated in this update. Treatment recommendations are provided by an expert panel. Allogeneic SCT is recommended for children who: are in second complete remission (CR2) after experiencing an early marrow relapse for precursor-B ALL; experienced primary induction failure, but subsequently achieved a CR1; have T-lineage ALL in CR2; or have ALL in third or greater remission. Although the 2005 pediatric ALL evidence-based review (EBR) recommended allogeneic SCT for children with Philadelphia chromosome positive (Ph+) ALL in CR1, preliminary tyrosine kinase inhibitor (TKI) data demonstrate that early outcomes are comparable for allogeneic SCT and chemotherapy + imatinib. Based on the evidence, autologous SCT is not recommended for ALL in CR1. Allogeneic SCT is not recommended for: T-lineage ALL in CR1; mixed-lineage leukemia (MLL)+ ALL when it is the sole adverse risk factor; isolated central nervous system (CNS) relapse in precursor-B ALL. Based on expert opinion, allogeneic SCT may be considered for hypodiploid ALL and persistent minimal residual disease [corrected] (MRD) positivity in ALL in CR1 or greater, although these are areas that need further study. Treatment recommendations pertaining to various transplantation techniques are also provided, as are areas of needed future research.

Fludarabine and pharmacokinetic-targeted busulfan before allografting for adults with acute lymphoid leukemia

We aimed to evaluate the safety and efficacy of fludarabine (FLU) and pharmacokinetic-targeted busulfan (BU) as conditioning regimen for hematopoietic cell transplantation (HCT) in adult patients with acute lymphoid leukemia (ALL). Forty-four patients with ALL (27 in first complete remission [CR1] and 17 in more advanced disease stage: 4 with primary induction failure [PIF], 12 in CR2, and 1 in CR3) received FLU and pharmacokinetic-targeted BU as preparative therapy for HCT. Grafts were T-replete, filgrastim-mobilized peripheral blood stem cells (PBSC). Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus (TAC) and short-course methotrexate in 36 patients, TAC and sirolimus in 3, and TAC and mycophenolate mofetil in 5. Primary engraftment was achieved in all 44 patients. The cumulative incidence of transplant-related mortality (TRM) was 2% (95% confidence interval [CI] 0%-16%) at 100 days and 18% (95% CI 10%-34%) at 2 years. The 2-year cumulative incidence of relapse was 19% (95% CI 8%-41%) for those transplanted in CR1, and 48% (29%-80%) for those with more advanced disease. After a median follow-up of 32 months (range: 15-69 months), the 2-year overall survival (OS) was 54% (95% CI 39%-69%). Relapse-free survival (RFS) at 2 years was 63% (95% CI 45%-81%) for patients transplanted in CR1 and 34% (95% CI 11%-57%) for patients transplanted in more advanced disease. When compared to irradiation-containing regimens, FLU and PK-targeted BU appear safer and similarly effective in controlling ALL, providing a treatment option for adult patients with ALL.

BU- vs TBI-based conditioning for adult patients with ALL

Evidence suggests an advantage for TBI over BU as a component of conditioning regimens for allogeneic hematopoietic cell transplant in patients with ALL. We have employed both TBI and BU for conditioning in ALL and reviewed our experience to compare outcomes. From July 1989 to June 2008, we identified 86-adult ALL patients treated with either a TBI- or BU-based regimen and transplanted with either a well-matched sibling or unrelated donor. Data including demographics, immunophenotype, disease status and cytogenetic risk were examined by Cox proportional hazards analysis. Patients treated with TBI were older (median age 40 vs 33 years; P=0.018), had a higher-risk cytogenetic profile (P=0.010), were more often transplanted using an unrelated donor (P=0.038) and were treated more recently (P<0.001). There was a significant improvement in EFS (P=0.046), and a trend to improved OS (P=0.08) in patients treated with TBI compared with those treated with BU. However, the advantage for TBI could not be confirmed by multivariable analysis where only disease status retained statistical significance.

Pediatric Acute Lymphoblastic Leukemia: Is There Still a Role for Transplant?

Constant questioning of the applicability of transplant for any diagnosis is appropriate. This is particularly necessary in fields such as pediatric leukemia, in which significant progress in therapy and risk classification is being made. Outcomes with chemotherapy are constantly improving, and donor availability and transplant outcomes are also better. It is important to be aware of likely outcomes when counseling families and recommending therapy, and to consider issues of likely late side effects. Biological studies that predict prognosis, for example, array-based studies, hold hope of identifying the children destined to relapse at the outset of disease. However, a rigorous approach must be taken in determining whether transplant does improve outcome whenever this strategy is applied.

Phase 1/2 trial of total marrow and lymph node irradiation to augment reduced-intensity transplantation for advanced hematologic malignancies

This phase 1/2 study assessed the augmentation of reduced-intensity conditioning (RIC) with total marrow and lymph node irradiation (TMLI), for peripheral blood stem cell transplantation, in patients with advanced hematologic disease. The regimen consisted of fludarabine 25 mg/m(2) per day for 5 days, melphalan 140 mg/m(2) for one day, and TMLI radiation at 150 cGy/fraction in 8 fractions over 4 days. Eligible patients were over 50 years old and/or had compromised organ function. Median age of the 33 evaluable patients was 55.2 years. Eighteen events of nonhematologic grade III or higher toxicities occurred in 9 patients. Day 30 and day 100 mortalities were 3% and 15%, respectively. Patients achieved myeloid and platelet engraftment at a median of 14 days after transplantation. Long-term toxicities occurred in 2 patients: hypokalemia and tremor, both grade III, on days 370 and 361 after transplantation. Fourteen patients died, 7 of relapse-related causes and 7 of non-relapse-related causes. With a median follow-up for living patients of 14.7 months, 1-year overall survival, event-free survival, and non-relapse-related mortality were 75%, 65%, and 19%, respectively. Addition of TMLI to RIC is feasible and safe and could be offered to patients with advanced hematologic malignancies who might not otherwise be candidates for RIC.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

Hematopoietic stem cell transplantation for leukemia

Leukemia represents the most common pediatric malignancy, accounting for approximately 30% of all cancers in children less than 20 years of age. Most children diagnosed with leukemia are cured without hematopoietic stem cell transplantation (HSCT), but for some high-risk subgroups, allogeneic HSCT plays an important role in their therapeutic approach. The characteristics of these high-risk subgroups and the role of HSCT in childhood leukemias are discussed.

Impact of conditioning regimen in allogeneic hematopoetic stem cell transplantation for children with acute myelogenous leukemia beyond first complete remission: a pediatric blood and marrow transplant consortium (PBMTC) study

Total body irradiation (TBI)-based conditioning regimens for pediatric patients with acute myelogenous leukemia (AML) beyond first complete remission (CR1) are controversial. Because the long-term morbidity of busulfan (Bu)-based regimens appears to be lower, determining efficacy is critical. We retrospectively evaluated 151 pediatric patients with AML beyond CR1, comparing outcomes in 90 patients who received a TBI-based conditioning regimen and 61 patients who received a Bu-based conditioning regimen. There were no differences between the 2 groups with respect to age, sex, duration of CR1, time from most recent remission to transplantation, or donor source. The probability of relapse at 2 years also did not differ between the 2 groups (26% and 27%, respectively; P=.93). No significant difference in event-free survival (EFS) (P=.29) or overall survival (OS) (P=.11) was noted between the 2 groups. These findings were supported by a multivariate analysis in which TBI was not associated with improved EFS (hazard ratio [HR]=1.17; 95% confidence interval [CI]=0.66-2.10; P=.58) or OS (HR=1.42; 95% CI=0.76-2.64; P=.27). Shorter CR1 and receiving an HLA-mismatched transplant adversely affected EFS and OS in this cohort. Our study provides no evidence of an advantage to using TBI in children with AML beyond CR1. A prospective, randomized study is needed to confirm these results.

[Total body irradiation: present and future]

Total body irradiation (TBI) has an established role as preparative regimen for bone-marrow transplantation in the treatment of hematological malignancies. Many randomized trials demonstrated that the clinical outcomes obtained from the association of TBI and cyclophosphamide are equivalent, or, sometimes, better than those based on chemotherapeutic agents. Despite the therapeutic progress of the last years, and the consequent improvement in the overall survival, this preparative regimen remains always associated with a relatively high rate of acute and late toxicity. In this article, we review the actual indications of TBI in clinical practice, and analyze the technological progress in this domain. We focus on the hypothesis that a selective irradiation of the hematopoietic or lymphoid organs is actually possible with intensity-modulated radiotherapy. Technical limits and preliminary results in terms of acute and late toxicities of intensity-modulated TBI are analyzed. With these new technologies, treatment-related toxicity is not anymore a major limiting factor in the preparative regimens for bone-marrow transplantation, allowing for a larger spectrum of TBI indications, a possible extension to patients older than 50 years, or a dose escalation. Preliminary results warrant, however, further evaluation in clinical trials to better assess the impact of this new approach on disease control and the long-term toxicity.

Safety of hematopoietic stem cell transplantation in children less than three years of age

Allogeneic hematopoietic stem cell transplantation (HSCT) is a standard treatment for a variety of hematologic conditions. However, very young children may experience different complications of HSCT compared to older patients. The authors retrospectively analyzed the results of 51 transplants performed on children less than 3 years of age between June 1987 and October 2005. Donors were matched-related (n = 21), partially mismatched related (n = 3), and unrelated (n = 27). The majority of patients had one or more grade III organ toxicities, but all nonrelapse deaths were attributable to infection. Perineal dermatitis was found in a large number (73%) of recipients of cyclophosphamide-based conditioning regimens. The 1-year transplant-related mortality (TRM) was 14%, but significantly declined in the more modern period. Grades II-IV acute graft-versus-host-disease (GvHD) was seen in 22% of patients, while chronic extensive GvHD developed in only 7% of patients. Relapse was seen in 40% of transplants performed for a malignant condition, most commonly in those patients not in remission at time of HSCT. The 5-year event-free survival (EFS) and overall survival (OS) were 53 and 64%, respectively. Recipients of fractionated total body irradiation (fTBI) were more likely to have at least one long-term sequelae than patients who received chemotherapy-based regimens (p = .014). These data demonstrate that HSCT can be performed safely in very young children, especially as supportive-care techniques improve. Cyclophosphamide-related perineal dermatitis is a unique complication in very young children. Finally, the incidence of acute and chronic GvHD in this population is low.

Early outcomes after allogeneic hematopoietic SCT in pediatric patients with hematologic malignancies following single fraction TBI

Fractionated TBI (FTBI) followed by allogeneic hematopoietic SCT results in donor engraftment and improves survival in children with high-risk hematologic malignancies. However, acute toxicities (skin, lung and mucosa) are common after FTBI. Late complications include cataracts, endocrine dysfunction, sterility and impaired neurodevelopment. Instead of FTBI, we used low-dose single fraction TBI (550 cGy) with CY as transplant conditioning for pediatric hematologic malignancies. GVHD prophylaxis included CYA and short-course MTX; methylprednisolone was added for unrelated donor transplants. A total of 55 children in first (40%) or second remission and beyond (60%) underwent transplantation from BM (65%) or peripheral blood; 62% from unrelated donors; 22% were mismatched. Median follow-up was 18.5 months (1-68). Overall survival and disease-free survival at 1 year were 60 and 47%, respectively. Acute toxicities included grade 3-4 mucositis (18%), invasive infections (11%), multiorgan failure/shock (11%), hemolytic anemia (7%), veno-occlusive disease (4%) and renal failure (4%). TRM was 11% at 100 days. Non-relapse mortality was 6% thereafter. Graft rejection occurred in 2%. Three patients (5%) died of GVHD. The regimen was well tolerated even in heavily pretreated children and supported donor cell engraftment; long-term follow up is in progress.

Bone-marrow relapse in paediatric acute lymphoblastic leukaemia

Marrow relapse is the major obstacle to cure for 10-15% of young patients with acute lymphoblastic leukaemia (ALL). Recent investigations into the biology of minimal residual disease indicate that many early relapses derive from residual cells present at first diagnosis, but some late relapses might represent new mutations in leukaemic cells not eliminated by conventional therapy. Treatment of marrow relapse involves higher doses and more intensive schedules of the drugs used for initial therapy with or without haemopoietic stem cell transplantation. In most reports, transplantation is better than continuation chemotherapy in early marrow relapse, but its role in later relapse is less clear. Current therapy cures 10% of patients with early marrow relapses and 50% of those with late relapses, but outcomes have changed little in the past two decades. Understanding the molecular biology of ALL underlies development of improved risk stratification and new therapies. Although better drugs are needed, introduction of new agents into clinical trials in paediatric disease has been difficult. Innovative trial designs and use of valid surrogate endpoints may expedite this process.

Image-guided total-marrow irradiation using helical tomotherapy in patients with multiple myeloma and acute leukemia undergoing hematopoietic cell transplantation

PURPOSE

Total-body irradiation (TBI) has an important role in patients undergoing hematopoietic cell transplantation (HCT), but is associated with significant toxicities. Targeted TBI using helical tomotherapy results in reduced doses to normal organs, which predicts for reduced toxicities compared with standard TBI.

METHODS AND MATERIALS

Thirteen patients with multiple myeloma were treated in an autologous tandem transplantation Phase I trial with high-dose melphalan, followed 6 weeks later by total-marrow irradiation (TMI) to skeletal bone. Dose levels were 10, 12, 14, and 16 Gy at 2 Gy daily/twice daily. In a separate allogeneic HCT trial, 8 patients (5 with acute myelogenous leukemia, 1 with acute lymphoblastic leukemia, 1 with non-Hodgkin's lymphoma, and 1 with multiple myeloma) were treated with TMI plus total lymphoid irradiation plus splenic radiotherapy to 12 Gy (1.5 Gy twice daily) combined with fludarabine/melphalan.

RESULTS

For the 13 patients in the tandem autologous HCT trial, median age was 54 years (range, 42-66 years). Median organ doses were 15-65% that of the gross target volume dose. Primarily Grades 1-2 acute toxicities were observed. Six patients reported no vomiting; 9 patients, no mucositis; 6 patients, no fatigue; and 8 patients, no diarrhea. For the 8 patients in the allogeneic HCT trial, median age was 52 years (range, 24-61 years). Grades 2-3 nausea, vomiting, mucositis, and diarrhea were observed. In both trials, no Grade 4 nonhematologic toxicity was observed, and all patients underwent successful engraftment.

CONCLUSIONS

This study shows that TMI using helical tomotherapy is clinically feasible. The reduced acute toxicities observed compare favorably with those seen with standard TBI. Initial results are encouraging and warrant further evaluation as a method to dose escalate with acceptable toxicity or to offer TBI-containing regimens to patients unable to tolerate standard approaches.

Indications and donor selections for allogeneic stem cell transplantation in children with hematologic malignancies

Allogeneic stem cell transplantation (SCT) is the only curative approach for many patients with advanced or high-risk leukemia. Advances in supportive care and management of graft-versus-host disease have resulted in improvements in outcomes of related and unrelated donor SCT, creating controversies as to which strategy might be the optimal therapy for individual patients. This article discusses the indications and donor selection strategies for SCT in patients with malignant hematologic disease.

Outcome After Relapse Among Children With Standard-Risk Acute Lymphoblastic Leukemia: Children's Oncology Group Study CCG-1952

Purpose

The event-free survival (EFS) of children with standard-risk acute lymphoblastic leukemia (SR-ALL) is now more than 80%. However, prognosis after relapse continues to be poor. We examined postrelapse outcomes of children initially treated on the Children's Cancer Group CCG-1952 study.

Patients and Methods

We evaluated outcomes after bone marrow (BM) relapse and isolated extramedullary (EM) relapse for 347 patients with SR-ALL (WBC < 50,000/μL; age, 1 to 9 years). The prognostic significance of several factors for EFS after relapse (EFS2) was assessed by Cox regression analysis. Stem-cell transplant (SCT) was compared with chemotherapy as salvage treatment.

Results

The mean ± SE times to isolated central nervous system relapse, BM relapse, and isolated testicular relapse were 23 ± 1 months (range, 1 to 88 months), 36 ± 1 months (range, 2 to 79 months), and 40 ± 2 months (range, 16 to 64 months), respectively. The estimated percent ± SE 3-year EFS2 and overall survival rates after BM relapse were 37% ± 4% and 46% ± 4%, respectively, and rates after isolated EM relapse were 57% ± 5% and 71% ± 5%, respectively. By multivariate analysis, we found the duration of first remission to be the most significant predictor of EFS2 for either BM relapse or isolated EM relapse. Outcome was equivalent with SCT or chemotherapy after early or late relapse of SR-ALL at any site.

Conclusion

Duration of first remission remains the most significant predictor of outcome after either BM or isolated EM relapse of SR-ALL. Prognosis after early BM relapse remains poor and is not improved with SCT in this cohort.

Allogeneic transplantation for childhood ALL

More than 80% of children with ALL are now cured with chemotherapy without need for transplantation. This remarkable progress is the result of serial large-scale randomized clinical trials incorporating improvements in risk group assignment, administration of risk-adjusted therapy and intensified therapy for children with high-risk disease. Despite these advances, significant numbers of children still die of relapsed or refractory ALL, as ALL is the most frequent malignancy of childhood. This review focuses on the appropriate use of transplantation for children with ALL and optimization of transplant procedures to improve survival and reduce late consequences of therapy.

Long-term follow-up of busulfan, etoposide, and nimustine hydrochloride (ACNU) or melphalan as conditioning regimens for childhood acute leukemia and lymphoma

We retrospectively evaluated early and long-term complications of an intensified conditioning regimen consisting of busulfan and etoposide in combination with either nimustine hydrochloride (ACNU) (BVA regimen, n = 18) or melphalan (BVL regimen, n = 34) in 52 children with acute leukemia or non-Hodgkin's lymphoma. With a median follow-up of 13.2 years after the BVA regimen and 8.1 years after the BVL regimen, 61% and 76% of patients, respectively, are in continuous complete remission. Transplantation-related mortality was 17% and 6% after the BVA and BVL regimens, respectively, and the corresponding relapse rates were 17% and 15%. The most common and severe toxicity was pulmonary complication in the BVA regimen, which was seen in 67% of patients and was life-threatening in 20%. Thirty-three percent of patients after the BVA regimen and 24% after BVL died of relapse or disease progression (n = 9), interstitial pneumonia (n = 2), fungal pneumonia (n = 1), or chronic graft-versus-host disease (n = 2). One of the long-term survivors developed secondary leukemia. A significant decrease in the height standard deviation score of more than 2 SD from diagnosis to the last follow-up was seen in 17% of the patients, with hypothyroidism in 15%, and alopecia in 42%. Because our experience is limited to a small heterogeneous population of patients who mainly underwent transplantation in the first remission, we cannot draw conclusions on the treatment's effectiveness. The BVL regimen is tolerable, however, because no regimen-related death was observed, whereas the BVA regimen is not recommended because of the high incidence of pulmonary complications. The effectiveness of the BVL regimen requires further study.

Risk assessment in haematopoietic stem cell transplantation: conditioning

After the introduction of cyclophosphamide and total body irradiation in the 1970s, a variety of conditioning regimens has been developed. However, none has proven to be superior. Fractionation of the irradiation results in less toxic side-effects, but the total dose has to be increased to obtain similar immunosuppressive effects. Data from randomized trials indicate that among patients with myeloid leukaemia, busulfan in combination with cyclophosphamide results in similar outcome, while a regimen containing total body irradiation is probably still the best for patients with acute lymphoblastic leukaemia. Busulfan treatment can be optimized by targeted steady-state concentration or with the use of intravenous preparations. Intensified regimens decrease the relapse incidence, but because of a higher mortality from transplant-related causes survival is unchanged. Reduced-intensity conditioning can reduce transplant-related mortality and offer otherwise ineligible patients a potentially curative treatment. Long-term results are unknown.

Allogeneic transplantation for adult acute leukemia in first and second remission with a novel regimen incorporating daily intravenous busulfan, fludarabine, 400 CGY total-body irradiation, and thymoglobulin

A myeloablative conditioning regimen incorporating daily intravenous busulfan, fludarabine, and 400 cGy total-body irradiation was given before allogeneic stem cell transplantation (SCT) to 64 adults with acute leukemia in first and second remission. Graft-versus-host disease (GVHD) prophylaxis included methotrexate, cyclosporine A, and rabbit antithymocyte globulin (Thymoglobulin). For 31 matched related (MRD) and 33 alternate donor (AD) SCT the incidence of acute GVHD grade II-IV was 11% +/- 6% versus 35% +/- 9% (P = .047), acute GVHD grade III-IV was 0% versus 10% +/- 6% (P = .09), and chronic GVHD was 40% +/- 9% versus 66% +/- 9% (P = NS), respectively. Overall transplant-related mortality (TRM) was 3% +/- 2%. Projected disease-free (DFS) and overall survival (OS) at 3 years for acute myelogenous leukemia (AML) (n = 36) are the same at 83% +/- 6%, and for acute lymphoblastic leukemia (ALL) (n = 28) are 65% +/- 10% and 78% +/- 8%, respectively. For MRD SCT DFS is 77% +/- 9%, OS 87% +/- 6%, for AD SCT the respective figures are 71% +/- 8% and 74% +/- 8%. OS and DFS in patients without and with high-risk features are 100% versus 71% +/- 7% (P = .007) and 88% +/- 8% versus 68% +/- 7% (P = .04), respectively. This combination appears relatively well tolerated, gives equivalent final outcomes from MRD and AD, and may be a reasonable alternative to conventional myeloablative regimens.

A Meta-Analysis of Unrelated Donor Umbilical Cord Blood Transplantation versus Unrelated Donor Bone Marrow Transplantation in Adult and Pediatric Patients

Several studies have compared the results of unrelated donor bone marrow transplantation (UBMT) and unrelated donor cord blood transplantation (UCBT). To objectively analyze these data, we performed a systematic review and meta-analysis of pooled data on comparative studies of UCBT and UBMT in patients requiring hematopoietic stem cell transplantation. Combining the studies, 161 children and 316 adults undergoing UCBT (mostly 1 or 2 antigen-mismatched), along with 316 children and 996 adults undergoing UBMT (almost entirely fully matched with the recipient), were analyzed. T-cell-depleted UBMT was excluded; where data were available, only fully matched UBMT was used in the analysis. Pooled comparisons of studies of UCBT and UBMT in children found that the incidence of chronic graft-versus-host disease (GVHD) was lower with UCBT (relative risk [RR] = 0.26; 95% confidence interval [CI] = 0.12-0.57; P = .16), but the incidence of grade III-IV acute GVHD did not differ (RR = 1.46; 95% CI = 0.42-5.03; P = .55). There was no difference in 2-year OS in children when studies were pooled (RR = 0.76; 95% CI = 0.31-1.87; P = .55). For adults, transplantation-related mortality (pooled estimate, 1.04; 95% CI = 0.52-2.08; P = .91) and disease-free survival (DFS) (pooled estimate, 0.59; 95% CI = 0.18-1.96; P = .39) were not statistically different. Because of the unavailability of randomized controlled trials, pooled analysis of nonrandomized comparative studies was performed. Thus, our meta-analysis confirmed that UCBT in children and adults had consistently equivalent survival outcomes compared with UBMT despite greater donor-recipient HLA disparity with UCBT.

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.

[Twenty years of treating childhood acute lymphoblastic leukemia]

BACKGROUND

Conventional prognostic factors for relapse in patients with acute lymphoblastic leukemia (ALL) are the main basis of risk-stratified treatments.

OBJECTIVES

To analyze conventional risk factors for relapse and design a predictive model for relapse in our series, after 20 years of experience in treating ALL.

PATIENTS AND METHOD

We performed a multivariate analysis of conventional prognostic factors in the treatment of ALL in our unit and compared them with the risk groups in the Berlin-Frankfurt-Münster (BFM-ALL) treatment protocols.

RESULTS

Between 1984 and 2004, 232 children were diagnosed with ALL and treated according to the different versions of the BFM protocols (BFM83, BFM86, BFM90 and BFM95) at the Hospital Niño Jesús, Madrid, Spain. The event-free survival for all patients was 79.4 % (95 % CI: 72.7-85.4). Overall survival among patients who relapsed was 10.72 % (95 % CI: 6-27.3). The only significant prognostic factor for relapse identified by multivariate analysis was leukocyte [white blood cell (WBC)] count higher than 80,000/ml at diagnosis (hazard ratio [HR]: 4.63; 95 % CI: 1.61-13.3; p 5 0,004). The sensitivity and specificity of WBC in predicting relapses were 31.4 % and 87.5 %, respectively. The sensitivity and specificity of BFM risk group stratification in predicting relapses were 25 and 85.9 respectively.

CONCLUSIONS

A leukocyte count at diagnosis higher than 80,000/ml and BFM risk-stratified treatment have insufficient sensitivity and specificity to identify relapses.

A Comparison of Cyclophosphamide and Total Body Irradiation with Etoposide and Total Body Irradiation as Conditioning Regimens for Patients Undergoing Sibling Allografting for Acute Lymphoblastic Leukemia in First or Second Complete Remission

We compared the outcomes of 298 patients with acute lymphoblastic leukemia in first or second complete remission (CR1 or CR2) receiving HLA-matched sibling allografts after cyclophosphamide and total body irradiation (Cy-TBI) conditioning with 204 patients receiving etoposide and TBI. Consequently, 4 groups were compared: Cy-TBI <13 Gy (n = 217), Cy-TBI > or =13 Gy (n = 81), etoposide-TBI <13 Gy (n = 53), and etoposide-TBI > or =13 Gy (n = 151). Analyses of relapse, leukemia-free survival (LFS), and survival were performed separately for CR1 and CR2 transplantations. Transplant-related mortality did not differ by conditioning regimen. In CR1, there were also no significant differences in relapse, LFS, or survival by conditioning regimen. In CR2, these outcomes differed among conditioning groups. In comparison with Cy-TBI <13 Gy, the risks of relapse, treatment failure (inverse of LFS), and mortality tended to be lower with etoposide (regardless of TBI dose) or with TBI doses > or =13 Gy. For both CR1 and CR2 transplantations, causes of death were similar among the groups; disease recurrence accounted for 47% of deaths. We conclude that for HLA-identical sibling allografts for acute lymphoblastic leukemia in CR2, there is an advantage in substituting etoposide for Cy or, when Cy is used, in increasing the TBI dose to > or =13 Gy.

The Role of Cytotoxic Therapy with Hematopoietic Stem Cell Transplantation in the Therapy of Acute Lymphoblastic Leukemia in Children: An Evidence-Based Review

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute lymphoblastic leukemia (ALL) 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 a table in this review (Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Lymphoblastic Leukemia) and were reached unanimously by a panel of ALL experts. The priority areas of needed future research in pediatric ALL are unrelated marrow or blood donor versus unrelated cord blood donor allogeneic SCT; alternative, nonfamily allogeneic donor versus autologous SCT; better methods for identifying high-relapse-risk patients; assessments of the effect of current chemotherapy regimens on early relapse; and use of pre-SCT detection of minimal residual disease to predict post-SCT outcomes.

Busulfan/melphalan/antithymocyte globulin followed by unrelated donor cord blood transplantation for treatment of infant leukemia and leukemia in young children: the Cord Blood Transplantation study (COBLT) experience

A non-total body irradiation-containing preparative regimen was studied in young children (<4 years old) undergoing unrelated donor cord blood transplantation as part of the Cord Blood Transplantation trial for the treatment of acute lymphoblastic leukemia (n = 14), acute myeloid leukemia (n = 13), undifferentiated leukemia (n = 1), juvenile myelomonocytic leukemia (n = 2), and myelodysplastic syndromes (n = 2). Donor/recipient HLA matching based on low-/intermediate-resolution molecular typing for HLA-A and -B and high-resolution HLA-DRB1 typing was 5/6 or 6/6 (n = 21) or 4/6 (n = 11). The preparative therapy consisted of busulfan, melphalan, and antithymocyte globulin, with cyclosporine and corticosteroids for graft-versus-host disease (GVHD) prophylaxis. The median age was 1.6 years (range, 0.5-3.9 years), and the median weight was 10.5 kg (range, 5.8-19.5 kg). Cord blood grafts contained a median of 10.7 x 10 7 nucleated cells per kilogram (range, 4.6-29.2) and 2.6 x 10(5) CD34+ cells per kilogram (range, 0.7-8.3). The cumulative incidence (CINC) of neutrophil recovery (absolute neutrophil count >500/microL) at day 42 was 0.59 (95% confidence interval [CI], 0.44-0.78) at a median of 31 days (range, 23-55 days). The CINC and Kaplan-Meier estimates of platelet engraftment at day 180 were 0.53 (95% CI, 0.34-0.69) and 0.82 (95% CI, 0.61-1.00), respectively. CINC estimates of grade III/IV acute GVHD at day 100 and chronic GVHD at 1 year were 0.25 (95% CI, 0.09-0.41) and 0.26 (95% CI, 0.09-0.44), respectively. The CINC estimate of relapse was 0.31 (95% CI, 0.16-0.47) at 2 years. With a median follow-up of 27.8 months (range, 23.4-46.7 months), the probability of survival at 1 year was 0.47 (95% CI, 0.30-0.64). A preparative regimen containing a busulfan/melphalan/antithymocyte globulin preparative regimen is well tolerated in the setting of unrelated donor cord blood transplantation for childhood leukemia and can serve as a platform preparative regimen for intensifying host immunosuppression and antileukemic therapy to allow for improved engraftment and improved relapse-free survival.