The role of hematopoietic stem cell transplantation with relapsed or primary refractory childhood B-cell non-Hodgkin lymphoma and mature B-cell leukemia: a retrospective analysis of enrolled cases in Japan

Prognostic Factors and Treatment Outcome of Relapsing and Refractory Pediatric Mature B-cell Non-Hodgkin Lymphoma, Children's Cancer Hospital Egypt Experience

BACKGROUND

Relapsed non-Hodgkin lymphoma treated by chemotherapy and hematopoietic stem cell transplantation (HSCT) has a dismal prognosis.

PATIENTS

It is a retrospective study, including pediatric patients diagnosed as mature B-cell non-Hodgkin lymphoma who were primarily refractory or relapsed over 8 years at CCHE. The aim of the study was to analyze the prognostic factors and outcomes of this group of patients. Our result is, 53 of 750 (7%) patients were included. Thirty-four (64.2%) patients had Burkitt lymphoma. Forty-eight (90.6%) patients received LMB 96 protocol initially. The median delay of duration between chemotherapy cycles in first-line treatment was 37 days. Thirty-five (66%) patients relapsed, 23 (65.7%) of them relapsed early, whereas 18 (34%) had tumor progression. Thirty-one (58.5%) patients presented with stage IV at the time of relapse. rituximab, ifosfamide, carboplatin, etoposide was the second line of treatment in 42 (79.24%) patients, and complete second remission was achieved only in 13 (24.3%) patients. Allogeneic HSCT was done for 4 (7.5%) patients, and auto HSCT was done for 3 (5.7%) patients. Three years of overall survival for relapsed and progressed patients were 35.3% and 11.1%, respectively, with a P-value of 0.009. Three years overall survival for patients who underwent HSCT was 85.7% compared with 18.1% for no HSCT with a P-value of 0.007.

CONCLUSIONS

The relapse rate is higher than literatures because of the delay of duration between chemotherapy cycles in first-line treatment and more advanced stage at time of relapse. Progression of the disease had a worse outcome than relapse. HSCT in patients with the second remission markedly improved the outcome.

Burkitt lymphoma

Burkitt lymphoma (BL) is an aggressive form of B cell lymphoma that can affect children and adults. The study of BL led to the identification of the first recurrent chromosomal aberration in lymphoma, t(8;14)(q24;q32), and subsequent discovery of the central role of MYC and Epstein-Barr virus (EBV) in tumorigenesis. Most patients with BL are cured with chemotherapy but those with relapsed or refractory disease usually die of lymphoma. Historically, endemic BL, non-endemic sporadic BL and the immunodeficiency-associated BL have been recognized, but differentiation of these epidemiological variants is confounded by the frequency of EBV positivity. Subtyping into EBV⁺ and EBV^- BL might better describe the biological heterogeneity of the disease. Phenotypically resembling germinal centre B cells, all types of BL are characterized by dysregulation of MYC due to enhancer activation via juxtaposition with one of the three immunoglobulin loci. Additional molecular changes commonly affect B cell receptor and sphingosine-1-phosphate signalling, proliferation, survival and SWI-SNF chromatin remodelling. BL is diagnosed on the basis of morphology and high expression of MYC. BL can be effectively treated in children and adolescents with short durations of high dose-intensity multiagent chemotherapy regimens. Adults are more susceptible to toxic effects but are effectively treated with chemotherapy, including modified versions of paediatric regimens. The outcomes in patients with BL are good in high-income countries with low mortality and few late effects, but in low-income and middle-income countries, BL is diagnosed late and is usually treated with less-effective regimens affecting the overall good outcomes in patients with this lymphoma.

Sequential different B cell antigen-targeted CAR T-cell therapy for pediatric refractory/relapsed Burkitt Lymphoma

Sequential CAR T-cell therapy may result in a durable response and is safe in pediatric patients with R/R Burkitt lymphoma.

Sequential CAR T-cell therapy may benefit pediatric patients with R/R Burkitt lymphoma with CNS involvement.

Single antigen–targeted chimeric antigen receptor (CAR) T-cell therapy may be insufficient to induce a durable response in pediatric aggressive B-cell lymphomas. This clinical trial examined the feasibility of sequential different B-cell antigen–targeted CAR T-cell therapy for pediatric relapsed/refractory (R/R) Burkitt lymphoma. Twenty-three patients received the first CD19 CAR T-cell infusion. The patients who did not achieve an ongoing complete response (CR) underwent 1 or more sequential infusions of CAR T-cell therapy that targeted CD22 followed by CD20 according to their disease status and CAR T-cell persistence after each infusion. The median time from the last infusion to the cutoff date was 17 months (range, 15-23 months). The estimated 18-month CR rate was 78% (95% confidence interval [CI], 54%-91%). The estimated 18-month progression-free survival rate was 78% (95% CI, 55%-90%), with 78% (95% CI, 37%-94%) in patients with bulky disease and 60% (95% CI, 25%-83%) in patients with central nervous system (CNS) involvement. During the first CD19 CAR T-cell infusion, grade ≥3 cytokine release syndrome (CRS) occurred in 34.8% and neurotoxicity occurred in 21.7% of all patients. During subsequent infusions, there were only a few incidences of grade >2 CRS and neurotoxicity. All adverse events were reversible. The severity of neurotoxicity was not significantly different between patients with CNS involvement and those who did not have CNS involvement. Sequential CAR T-cell therapy may result in a durable response and is safe in pediatric R/R Burkitt lymphoma. Patients with CNS involvement may benefit from sequential CAR T-cell therapy. This trial was registered at www.chictr.org.cn/index.aspx as #ChiCTR1800014457.

Value of baseline and end of chemotherapy 18F-FDG PET/CT in pediatric patients with Burkitt lymphoma

The aim of this study was to analyze whether the baseline metabolic parameters of ¹⁸F-FDG PET/CT in pediatric patients with Burkitt lymphoma (BL) can predict treatment response and prognosis. We retrospectively analyzed 68 pediatric patients with BL who underwent PET/CT before treatment. PET images were analyzed semi-quantitatively by measuring the maximum standardized uptake (SUVmax), total metabolic tumor volume (tMTV), and total lesion glycolysis (TLG). Survival curves were plotted according to the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression models were used to assess the relation between potential variables and outcomes. tMTV and TLG were significantly lower in patients with complete response compared with those with partial response at the end of treatment. PET metabolic parameters (tMTV and TLG) were the independent prognostic values for outcome. TMTV and TLG were significantly connected with treatment response and prognosis in pediatric with BL.

Pediatric Aggressive Mature B-Cell Lymphomas, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Pediatric aggressive mature B-cell lymphomas are the most common types of non-Hodgkin lymphoma in children, and they include Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). These diseases are highly aggressive but curable, the treatment is complex, and patients may have many complicated supportive care issues. The NCCN Guidelines for Pediatric Aggressive Mature B-Cell Lymphomas provide guidance regarding pathology and diagnosis, staging, initial treatment, disease reassessment, surveillance, therapy for relapsed/refractory disease, and supportive care for clinicians who treat sporadic pediatric BL and DLBCL.

Nationwide study of pediatric B-cell precursor acute lymphoblastic leukemia with chromosome 8q24/MYC rearrangement in Japan

BACKGROUND

Rearrangements of chromosome 8q24/MYC (8q24/MYC-r), resulting from t(8;14)(q24;q32), t(2;8)(p11;q24), or t(8;22)(q24;q11), are mainly associated with Burkitt lymphoma/leukemia (BL) and rarely observed in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The characteristics of BCP-ALL with 8q24/MYC-r are poorly understood.

PROCEDURE

A retrospective nationwide study of data from patients with pediatric BCP-ALL with 8q24/MYC-r in Japan was conducted to clarify the clinical and biological characteristics associated with 8q24/MYC-r BCP-ALL.

RESULTS

Ten patients with BCP-ALL with 8q24/MYC-r, including three with double-hit leukemia (DHL) (two with t(8;14)(q24;q32) and t(14;18)(q32;q21) and one with t(8;14) and t(3;22)(q27;q11)), were identified. Patients with BCP-ALL with 8q24/MYC-r had higher median age and uric acid and lactate dehydrogenase levels, than those without 8q24/MYC-r. All patients were initially treated with ALL-type chemotherapy; however, four, including one with DHL, were switched to BL-type chemotherapy, based on cytogenetic findings. One patient relapsed after standard-risk ALL-type chemotherapy, and two patients with DHL did not attain complete remission with chemotherapy; all three died within 11 months. The other seven patients treated with BL-type or high-risk ALL-type chemotherapy are alive without disease.

CONCLUSIONS

The clinical and laboratory features of BL with IG-MYC rearrangement, displaying a BCP immunophenotype (Wagener et al. and Herbrueggen et al. termed it as pre-BLL), are similar to those of BCP-ALL with 8q24/MYC-r. Low-risk ALL-type chemotherapy may not be appropriate for them, and further studies are required to establish an adequate therapeutic strategy. Further studies of DHL to identify new treatment strategies are also needed.

Treatment of relapsed/refractory paediatric aggressive B-cell non-Hodgkin lymphoma

Aggressive B-cell non-Hodgkin lymphoma (B-NHL) accounts for ≈60% of NHL in children/adolescents. In newly diagnosed Burkitt lymphoma and diffuse large B-cell lymphoma, short intensive multiagent chemotherapy is associated with a five-year event-free survival of around 90%. Very few children/adolescents with aggressive B-NHL show a relapsed/refractory (r/r) disease. The outcome is poor, with cure rates <30%, and there is no standard of care. Rituximab-containing salvage regimens may provide a complete/partial response in 60-70% of cases. However, long-term survival is <10% for non-transplanted patients. Autologous or allogeneic haematopoietic stem cell transplant is, nowadays, the best option for responding patients, with survival rates around 50%. The benefit of autologous versus allogeneic HSCT is not clear. Numerous novel therapies for r/r B-NHL are currently being tested in adults, including next-generation monoclonal antibodies, novel cellular therapy strategies and therapies directed against new targets. Some are under investigation also in children/adolescents, with promising preliminary results.

Outcome of relapse in children and adolescents with B-cell non-Hodgkin lymphoma and mature acute leukemia: A report from the French LMB study

INTRODUCTION

In order to describe relapsed B-cell non-Hodgkin lymphoma and mature acute leukemia in children/adolescents treated with the Lymphomes Malins B (LMB) regimen and their outcome in the rituximab era, relapses in the French LMB2001 study were reviewed.

METHODS

Between February 2001 and December 2011, 33 patients out of 773 (4.3%) relapsed; 27 had Burkitt lymphoma and six large B-cell histology. Median age at diagnosis was 10.1 years. One patient was initially treated in risk group A, 21 in group B, and 11 in group C.

RESULTS

Median time to relapse after diagnosis was 4.5 months (range 2.4-13.6). Thirty-two patients received salvage therapy. Twenty-seven received rituximab mainly in addition to high-dose cytarabine and etoposide (n = 18) and/or ifosfamide, carboplatin, and etoposide (n = 7). First-line salvage chemotherapy response rate was 66% with 47% being complete remission (CR). Twenty-one patients received high-dose chemotherapy (HDC) followed by autologous (n = 13) or allogeneic (n = 8) transplant. With a median follow-up of 6.8 years, the 5-year survival rate after relapse was 36.4% (95% confidence interval [CI] 22-53%). Twelve patients were still alive; all but one (group A) received consolidation treatment. Achieving CR before consolidation was significantly associated with better survival, with a 5-year survival rate of 75% (95% CI 46.8-91.1%) for patients in CR before HDC, 33% (95% CI 9.7-70%) for patients in partial remission, and 0% for nonresponders (P = .033).

CONCLUSION

Survival of children/adolescents with mature B-cell lymphoma/leukemia remains poor after relapse with no apparent improvement with rituximab. Response rates to salvage chemo-immunotherapies are insufficient and new drugs are urgently needed to improve disease control.

Hematopoietic stem cell transplantation in children and adolescents with relapsed or refractory B-cell non-Hodgkin lymphoma

We undertook a retrospective study using the national registry data of hematopoietic stem cell transplantation (HSCT) in Japan to investigate the effect of graft source, particularly autologous or allogeneic tissue, on the treatment outcome in patients aged less than 18 years with relapsed or refractory B-cell non-Hodgkin lymphoma (B-NHL). Survival analysis was conducted on 31 autologous HSCT (auto-HSCT) and 48 allogeneic HSCT (allo-HSCT) recipients between 1990 and 2013. The 5-year survival rates were significantly lower for allo-HSCT compared to auto-HSCT recipients (32% vs. 55%; P = 0.036). Multivariate analysis of survival rates identified allogeneic graft, Burkitt histology, and lack of response to chemotherapy as poor prognostic factors for survival. The cumulative incidence of treatment-related mortality (TRM) was significantly higher in allo-HSCT compared to auto-HSCT recipients (P = 0.017), explaining the difference in survival rates. In patients with Burkitt lymphoma (BL), overall survival was significantly inferior in the group of patients undergoing HSCT within 12 months from the initial diagnosis (P = 0.039). These data indicate that treatment outcomes for HSCT in children and adolescents with B-NHL were better in autograft recipients, suggesting that greater attention should be paid to the risk of TRM, especially after allografts, for patients with BL.

Overall survival of children and adolescents with mature B cell non-Hodgkin lymphoma who had refractory or relapsed disease during or after treatment with FAB/LMB 96: A report from the FAB/LMB 96 study group

We determined the risk factors associated with poor survival in children and adolescents with de novo mature B cell non-Hodgkin lymphoma (B-NHL) who had refractory or relapsed disease during or after the French-American-British mature lymphoma B (FAB/LMB) 96 multi-agent chemotherapy. Among the 1 111 registered on study, 104 patients (9·4%) had refractory disease or disease relapse after first complete remission. Among these 104 patients, 28 (27%) patients had refractory disease and 76 (73%) had relapsed disease. The estimated 1- and 2-year overall survival (OS) (95% confidence interval) was 31·5% (23·3-41·0%) and 22·3% (15·3-31·4%), respectively. Prognostic analysis of OS using a Cox multivariate model showed that factors independently associated with OS included lactate dehydrogenase ≥2 upper normal limit [hazard ratio (HR) = 2·86 (1·57-5·2), P = 0·0006]; time to failure (>6 months) [HR = 0·59 (0·36-0·97), P = 0·038]; and failure in bone marrow [HR = 2·78 (1·65-4·68), P = 0·0001]. New therapeutic strategies are required to significantly reduce refractory disease and disease relapse in patients with newly diagnosed mature B-NHL and, more importantly, there is a critical need to develop novel retrieval approaches in patients with chemotherapy-resistant disease.

Relapsed/refractory pediatric B-cell non-Hodgkin lymphoma treated with rituximab combination therapy: A report from the Japanese Pediatric Leukemia/Lymphoma Study Group

BACKGROUND

Pediatric relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) has been reported to be extremely difficult to cure, but rituximab is expected to be effective in improving the prognosis of pediatric R/R B-NHL patients. Here, we assessed the treatment and prognosis of pediatric R/R B-NHL in the rituximab era in Japan.

METHODS

We collected information on patients with R/R B-NHL who were registered with the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) B-NHL03 protocol, a nationwide multicenter trial for newly diagnosed patients. We assessed the treatment and outcome of 33 pediatric R/R B-NHL cases.

RESULTS

Twenty-eight patients received rituximab combination therapy as salvage treatment. R-ICE (rituximab, ifosfamide, carboplatin, and etoposide), the most common regimen, was used in 22 patients as first-line salvage therapy. Twenty-three patients received hematopoietic stem cell transplantation (HSCT). Among all 33 patients, 23 (70.0%) achieved partial remission or complete remission. Their 5-year overall survival rate was 48.5%, which was far superior to that in both our previous study and in another study on pediatric R/R B-NHL. Four toxic deaths associated with viral infection occurred after allogeneic HSCT following on rituximab combined salvage therapy. Risk factor multivariate analysis for survival in patients receiving rituximab combination therapy showed central nervous system combined relapse had inferior outcome.

CONCLUSIONS

The prognosis of pediatric R/R B-NHL in a Japanese cohort remained poor but is showing improvement in the rituximab era. Rituximab combination therapy is effective for R/R B-NHL patients who did not receive rituximab as primary treatment. We need to consider possible viral infections in allogeneic HSCT after rituximab treatment.

Autologous peripheral blood stem cell transplantation in children and adolescents with non-Hodgkin lymphoma

The aim of this study was to evaluate the effect and safety of autologous peripheral blood stem cell transplantation (APBSCT) in children and adolescents with non-Hodgkin lymphoma (NHL). Ten patients with NHL were analyzed retrospectively. In all the patients, lymph node enlargement was most frequently detected. Patients with a mediastinal mass presented with a cough, palpitation and shortness of breath. Extranodal patients presented with abdominal pain, inability to walk and vaginal bleeding. All patients underwent APBSCT with conditioning regimens BEAM or BuCy. Among them, four patients with B-cell NHL received rituximab in addition to the conditioning regimen. Hematopoietic reconstitution was observed in all patients. Severe toxicity and transplant-related mortality were not observed. Prior to APBSCT, nine patients with a status of complete response (CR) and CR unconfirmed achieved continuing complete remission. Only one patient with partial response succumbed to progressive disease. APBSCT in children and adolescents with NHL is a safe, convenient and efficient treatment. The BEAM conditioning regimen was shown to be effective and tolerable for children and adolescents with NHL. Rituximab is a safe agent in the transplantation. The CR status at the time of transplantation demonstrated a higher survival rate.

Non-Hodgkin Lymphoma in Children and Adolescents: Progress Through Effective Collaboration, Current Knowledge, and Challenges Ahead

Non-Hodgkin lymphoma is the fourth most common malignancy in children, has an even higher incidence in adolescents, and is primarily represented by only a few histologic subtypes. Dramatic progress has been achieved, with survival rates exceeding 80%, in large part because of a better understanding of the biology of the different subtypes and national and international collaborations. Most patients with Burkitt lymphoma and diffuse large B-cell lymphoma are cured with short intensive pulse chemotherapy containing cyclophosphamide, cytarabine, and high-dose methotrexate. The benefit of the addition of rituximab has not been established except in the case of primary mediastinal B-cell lymphoma. Lymphoblastic lymphoma is treated with intensive, semi-continuous, longer leukemia-derived protocols. Relapses in B-cell and lymphoblastic lymphomas are rare and infrequently curable, even with intensive approaches. Event-free survival rates of approximately 75% have been achieved in anaplastic large-cell lymphomas with various regimens that generally include a short intensive B-like regimen. Immunity seems to play an important role in prognosis and needs further exploration to determine its therapeutic application. ALK inhibitor therapeutic approaches are currently under investigation. For all pediatric lymphomas, the intensity of induction/consolidation therapy correlates with acute toxicities, but because of low cumulative doses of anthracyclines and alkylating agents, minimal or no long-term toxicity is expected. Challenges that remain include defining the value of prognostic factors, such as early response on positron emission tomography/computed tomography and minimal disseminated and residual disease, using new biologic technologies to improve risk stratification, and developing innovative therapies, both in the first-line setting and for relapse.

Treatment of pediatric lymphoma in Japan: Current status and plans for the future

Results of pediatric lymphoma treatment have improved markedly over the past 30 years. In Hodgkin's lymphoma, the 5 year event-free survival (EFS) was 81.5% in a retrospective study. In the ALB-NHL03 study, the 5 year EFS according to clinical stage in patients with lymphoblastic T-cell lymphoma (T-LBL) was 70.6% for stage III and 88.9% for stage IV. In mature B-cell lymphoma, the B-NHL03 study indicated that the 4 year EFS according to treatment group was 94% for group 1, 98% for group 2, 84% for group 3, and 78% for group 4. Moreover, the 2 year EFS rate was 81% in Japanese advanced stage patients based on the international ALCL99 study. Thus, EFS >80% was achieved in any subtype of pediatric lymphoma. With regard to refractory or recurrent lymphoma, however, treatment methods for improvement of the survival rate in these patients still need to be developed. Also the difference between child, and adolescent and young adult patients still needs to be clarified, and treatment protocols developed. Although lymphoma treatment does not greatly change according to country, it does differ between other countries and Japan for some subtypes of lymphoma. In particular, the results of treatment of stage III T-LBL in Japan are worse than those in the USA and Europe. The priority in future studies will be to collect data on these differences, and the reasons for these differences.

Outcome of and prognostic factors for relapse in children and adolescents with mature B-cell lymphoma and leukemia treated in three consecutive prospective "Lymphomes Malins B" protocols. A Société Française des Cancers de l'Enfant study

To describe relapsed B-cell lymphoma or leukemia in children/adolescents treated with a "Lymphomes Malins B" regimen and their outcome and to identify prognostic factors for survival, we studied relapses in the LMB89, 96 and 2001 studies of the Société Française d'Oncologie Pédiatrique (Société Française des Cancers de l'Enfant). Therapeutic guidelines at relapse were to obtain a second complete remission and to consolidate the remission with high-dose chemotherapy followed by autologous stem-cell transplantation. Between July 1989 and March 2007, 67 patients of 1322 (5%) relapsed: 57 had Burkitt lymphoma and 10 had large-cell histology. Three patients were initially treated in risk group A, 41 in group B and 23 in group C. Thirty-three patients had a relapse in one site (15 in the central nervous system) and 34 at multiple sites. Sixty-five patients received salvage chemotherapy and 33 achieved complete remission. Forty-one patients also received high-dose chemotherapy followed by autologous (n=33) or allogeneic (n=8) transplantation. With a median follow-up of 6.4 years, the 5-year survival rate was 29.9%. Nineteen patients were still alive, all but one (group A) received consolidation treatment. Multivariate analysis showed the following factors to be significantly associated with better survival: relapse at one site (P=0.0006), large-cell histology (P=0.012), initial prognostic group A or B with lactate dehydrogenase level below twice the normal value (P=0.005), and time to relapse more than 6 months (P=0.04).

Outcome of pediatric patients with lymphoma following stem cell transplant: a single institution report

Hematopoietic stem cell transplant (HSCT) is recommended for pediatric patients with relapsed/refractory lymphoma even though the evidence for this is limited. We retrospectively reviewed records of 57 patients (29 Hodgkin lymphoma [HL], 28 non-Hodgkin lymphoma [NHL]) who underwent HSCT between 1995 and 2012. All demonstrated chemoresponsiveness prior to HSCT and 44 patients had a complete response. All underwent myeloablative conditioning, 38 chemotherapy-based and 19 total body irradiation-based. Forty-one patients received autologous and 16 allogeneic HSCT. Twelve (21%) died within 100 days post-HSCT, and 25 patients relapsed at a median of 1.6 months post-HSCT. Three patients developed second malignant neoplasms. Five-year overall survival (OS) was 50.5% and event-free survival (EFS) was 43.4%. Outcomes for HL were significantly better than those for NHL (OS 61.9% vs. 38.7% [p = 0.005] and EFS 60.4% vs. 26% [p = 0.008]). In summary, approximately half of all pediatric patients with lymphoma who failed first-line therapy and demonstrated chemosensitivity to second-line therapy can be salvaged with HSCT.

Clinical outcome of relapsed or refractory burkitt lymphoma and mature B-cell lymphoblastic leukemia in children and adolescents

Purpose

Despite the rapid improvement in survival rate from Burkitt lymphoma and mature B-cell lymphoblastic leukemia (B-ALL) in children, a small subset of patients do not respond to first-line chemotherapy or experience relapse (RL). Herein, we report the clinical characteristics and outcomes of these patients.

Materials and Methods

RL or refractory Burkitt lymphoma and mature B-ALL in 125 patients diagnosed from 1990 to 2009 were retrospectively analyzed.

Results

Nineteen patients experienced RL or progressive disease (PD). Among them, 12 patients had PD or RL less than six months after initial treatment and seven had late RL. Seven patients achieved complete response (CR), 11 had PD, and one had no more therapy. Six patients who achieved CR survived without evidence of disease and four of them underwent high-dose chemotherapy (HDC) followed by stem cell transplantation (SCT). However, 11 patients who failed to obtain CR eventually died of their disease. Five-year overall survival (OS) was 31.6±10.7%. OS of patients with late RL was superior to that of patients with early RL (57.1±18.7%, vs. 16.7±10.8%, p=0.014). Achievement of CR after reinduction had significant OS (p < 0.001). OS for patients who were transplanted was superior (p < 0.01). In multivariate analysis, achievement of CR after reinduction chemotherapy showed an association with improved OS (p=0.05).

Conclusion

Late RL and chemotherapy-sensitive patients have the chance to achieve continuous CR using HDC/SCT, whereas patients who are refractory to retrieval therapy have poor prognosis. Therefore, novel salvage strategy is required for improvement of survival for this small set of patients.

Mature B-cell lymphoma and leukemia in children and adolescents-review of standard chemotherapy regimen and perspectives

Mature B-cell non-Hodgkin lymphoma (B-NHL) comprises more than 50% of all non-Hodgkin lymphoma (NHL) in children and adolescents. Many B-NHL subtypes frequently observed in adults are rarely diagnosed in children and adolescents. In this age group, Burkitt lymphoma (BL), Burkitt leukemia or FAB L3 leukemia (B-AL), diffuse large B-cell lymphoma (DLBCL), primary mediastinal large B-cell lymphoma (PMLBL), follicular lymphoma (FL), and aggressive mature B-NHL not further classifiable (B-NHL nfc) are the most common subtypes. Diverse clinical trials demonstrated similar results of current combination chemotherapy regimens succeeding in overall survival rates of more than 80%. However, treatment-related toxicity and the poor prognosis of relapse are serious concerns. Furthermore, specific histological B-NHL subtypes are rare in children and optimal treatment is not established. New treatment modalities are urgently needed for these patient groups. Rituximab, a monoclonal antibody that is already established in the treatment of adults with mature B-NHL, demonstrated promising results in pediatric patients. The definitive role of rituximab in the treatment of children and adolescents with B-NHL needs to be evaluated in prospective controlled clinical trials. This review provides a comprehensive overview of chemotherapy regimens and the perspectives for children and adolescents with mature B-cell lymphoma and leukemia.

Outcome of childhood relapsed or refractory mature B-cell non-Hodgkin lymphoma and acute lymphoblastic leukemia

Patients with childhood relapsed and refractory mature B-cell non-Hodgkin lymphoma (B-NHL) and acute lymphoblastic leukemia (B-ALL) are rare and have a dismal prognosis. The previous UK national analysis of 26 children over a 7-year period prior to 1996 had highlighted the poor outcome, with only three survivors. This 10-year multicenter study evaluated recent data, since 2000. Of 33 children, nine survived (27.3%), with a median follow-up of 4.3 years. On exclusion of six children treated with palliative intent, the survival was one-third (nine of 27; 33.3%). All patients with primary refractory disease (n = 7) and all except one with early relapse (n = 11) died. Administration of four doses of 375 mg/m(2) of rituximab was associated with a longer survival (p = 0.006). Response to reinduction (p < 0.001) and autologous hematopoietic stem cell transplant (auto-HSCT) (p = 0.003) were significant on multivariate analysis. Patients with a time to relapse of at least 6 months are potentially curable and must be offered intensive treatment with salvage chemotherapy, rituximab and auto-HSCT.

Treatment outcomes in children with Burkitt lymphoma and L3 acute lymphoblastic leukemia treated using the lymphoma malignancy B protocol at a single institution

Background

We compared the outcomes of patients with Burkitt lymphoma and French-American-British (FAB) L3 acute lymphoblastic leukemia treated using Lymphoma Malignancy B (LMB) or other treatment protocols.

Methods

Thirty-eight patients diagnosed between July 1996 and December 2007 were treated using LMB 96, and 22 patients diagnosed between January 1991 and May 1998 (defined as the early period) were treated using the D-COMP or CCG-106B protocols. We retrospectively reviewed their medical records and analyzed cumulative survival according to the treatment period by using Kaplan-Meier analysis.

Results

There were no intergroup differences in the distribution of age, disease stage, or risk group. The median follow-up period of the 33 live patients in the LMB group was 72 months (range, 36-170 months). Overall survival (OS) and event-free survival (EFS) of patients treated using LMB 96 were 86.8%±5.5% and 81.6%±6.3%, respectively, whereas OS and EFS of patients treated in the early period were 72.7%±9.6% and 68.2%±9.9%, respectively. In the LMB 96 group, OS of cases showing non-complete response (N=8) was 62.5%±17.1%, and OS of relapsed or primary refractory cases (N=6) was 33.3%±19.3%. Central nervous system (CNS) disease, high lactate dehydrogenase levels at diagnosis, and treatment response were significant prognostic factors.

Conclusion

Survival outcome has drastically improved over the last 2 decades with short-term, dose-intensive chemotherapy. However, CNS involvement or poor response to chemotherapy was worse prognostic factors; therefore, future studies addressing this therapeutic challenge are warranted.

Hematopoietic stem cell transplantation for refractory or recurrent non-Hodgkin lymphoma in children and adolescents

We examined the role of hematopoietic stem cell transplantation (HSCT) for patients aged< or =18 years with refractory or recurrent Burkitt (n=41), lymphoblastic (n=53), diffuse large B cell (DLBCL; n=52), and anaplastic large cell lymphoma (n=36), receiving autologous (n=90) or allogeneic (n=92; 43 matched sibling and 49 unrelated donor) HSCT in 1990-2005. Risk factors affecting event-free survival (EFS) were evaluated using stratified Cox regression. Characteristics of allogeneic and autologous HSCT recipients were similar. Allogeneic donor HSCT was more likely to use irradiation-containing conditioning regimens, bone marrow (BM) stem cells, be performed in more recent years, and for lymphoblastic lymphoma. EFS rates were lower for patients not in complete remission at HSCT, regardless of donor type. After adjusting for disease status, 5-year EFS were similar after allogeneic and autologous HSCT for DLBCL (50% vs 52%), Burkitt (31% vs 27%), and anaplastic large cell lymphoma (46% vs 35%). However, EFS was higher for lymphoblastic lymphoma, after allogeneic HSCT (40% vs 4%; P < .01). Predictors of EFS for progressive or recurrent disease after HSCT included disease status at HSCT and use of allogeneic donor for lymphoblastic lymphoma. These data were unable to demonstrate a difference in outcome by donor type for the other histological subtypes.