Linda C. Stork

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 Childrens 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/microL; 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.

Escalating intravenous methotrexate improves event-free survival in children with standard-risk acute lymphoblastic leukemia: a report from the Children's Oncology Group

Childrens Cancer Group-1991 selected 2 components from the Childrens Cancer Group studies shown to be effective in high-risk acute lymphoblastic leukemia and examined them in children with National Cancer Institute standard-risk acute B-precursor lymphoblastic leukemia. These were (1) vincristine and escalating IV methotrexate (MTX) without leucovorin rescue during the interim maintenance (IM) phases and (2) addition of a second delayed intensification (DI) phase. Eligible patients (n = 2078) were randomly assigned to regimens containing either oral (PO) MTX, PO mercaptopurine, dexamethasone, and vincristine or IV MTX during IM phases, and regimens with either single DI or double DI. Five-year event-free survival (EFS) and overall survival for patients on the PO MTX arms were 88.7% ± 1.4% and 96% ± 0.9% versus 92.6% ± 1.2% and 96.5% ± 0.8% for those on the IV MTX arms (P = .009, P = .66). Five-year EFS and overall survival for patients who received single DI were 90.9% ± 1.3% and 97.1% ± 0.8% versus 90.5% ± 1.3% and 95.4% ± 3.8% for those who received double DI (P = .71, P = .12). No advantage was found for a second DI; however, replacement of PO MTX, PO mercaptopurine, vincristine, and dexamethasone during IM with vincristine and escalating IV MTX improved EFS.

Lymphoblast biology and outcome among children with Down syndrome and ALL treated on CCG-1952.

Patients with Down syndrome (DS) and standard risk (SR) acute lymphoblastic leukemia (ALL‐DS) are reported to have inferior event free (EFS) and overall survival (OS) compared to patients without DS (ALL‐NDS).

Oral 6-mercaptopurine versus oral 6-thioguanine and veno-occlusive disease in children with standard-risk acute lymphoblastic leukemia: report of the Children's Oncology Group CCG-1952 clinical trial

The Childrens Cancer Group 1952 (CCG-1952) clinical trial studied the substitution of oral 6-thioguanine (TG) for 6-mercaptopurine (MP) and triple intrathecal therapy (ITT) for intrathecal methotrexate (IT-MTX) in the treatment of standard-risk acute lymphoblastic leukemia. After remission induction, 2027 patients were randomized to receive MP (n = 1010) or TG (n = 1017) and IT-MTX (n = 1018) or ITT (n = 1009). The results of the thiopurine comparison are as follows. The estimated 7-year event-free survival (EFS) for subjects randomized to TG was 84.1% (+/- 1.8%) and to MP was 79.0% (+/- 2.1%; P = .004 log rank), although overall survival was 91.9% (+/- 1.4%) and 91.2% (+/- 1.5%), respectively (P = .6 log rank). The TG starting dose was reduced from 60 to 50 mg/m(2) per day after recognition of hepatic veno-occlusive disease (VOD). A total of 257 patients on TG (25%) developed VOD or disproportionate thrombocytopenia and switched to MP. Once portal hypertension occurred, all subjects on TG were changed to MP. The benefit of randomization to TG over MP, as measured by EFS, was evident primarily in boys who began TG at 60 mg/m(2) (relative hazard rate [RHR] 0.65, P = .002). The toxicities of TG preclude its protracted use as given in this study. This study is registered at http://clinicaltrials.gov as NCT00002744.

Use of rituximab for refractory cytopenias associated with autoimmune lymphoproliferative syndrome (ALPS).

ALPS is a disorder of apoptosis resulting in accumulation of autoreactive lymphocytes, leading to marked lymphadenopathy, hepatosplenomegaly, and multilineage cytopenias due to splenic sequestration and/or autoimmune destruction often presenting in childhood. We summarize our experience of rituximab use during the last 8 years in 12 patients, 9 children, and 3 adults, out of 259 individuals with ALPS, belonging to 166 families currently enrolled in studies at the National Institutes of Health.

Clofarabine salvage therapy in refractory multifocal histiocytic disorders, including Langerhans cell histiocytosis, juvenile xanthogranuloma and Rosai-Dorfman disease

Existing therapies for recurrent or refractory histiocytoses, including Langerhans cell histiocytosis (LCH), juvenile xanthogranuloma (JXG), and Rosai–Dorfman disease (RDD), have limited effectiveness. We report our experience with using clofarabine as therapy in children with recurrent or refractory histiocytic disorders, including LCH (11 patients), systemic JXG (4 patients), and RDD (3 patients).

Comparison of Neurocognitive Functioning in Children Previously Randomly Assigned to Intrathecal Methotrexate Compared With Triple Intrathecal Therapy for the Treatment of Childhood Acute Lymphoblastic Leukemia

PURPOSE For the majority of children with acute lymphoblastic leukemia (ALL), CNS prophylaxis consists of either intrathecal (IT) methotrexate or triple IT therapy (ie, methotrexate with both cytarabine and hydrocortisone). The long-term neurotoxicities of these two IT strategies have not yet been directly compared. PATIENTS AND METHODS In this multisite study, 171 children with standard-risk ALL, age 1 to 9.99 years at diagnosis, previously randomly assigned to IT methotrexate (n = 82) or to triple IT therapy (n = 89) on CCG 1952, underwent neurocognitive evaluation by a licensed psychologist at a mean of 5.9 years after random assignment. RESULTS Patients who received IT methotrexate had a mean Processing Speed Index that was 3.6 points lower, about one fourth of a standard deviation, than those who received triple IT therapy (P = .04) after analysis was adjusted for age, sex, and time since diagnosis. Likewise, 19.5% of children in the IT methotrexate group had a Processing Speed Index score in the below-average range compared with 6.9% in the triple IT therapy group (P = .02). Otherwise, the groups performed similarly on tests of full-scale intelligence quotient, academic achievement, attention/concentration, memory, and visual motor integration. The association of treatment with measures of cognitive functioning was not modified by sex or age at diagnosis. In the post-therapy period, there were no group differences in special education services, neurologic events, or use of psychotropic medications. CONCLUSION This study did not show any clinically meaningful differences in neurocognitive functioning between patients previously randomly assigned to IT methotrexate or triple IT therapy except for a small difference in processing speed in the IT methotrexate group.

Portal hypertension develops in a subset of children with standard risk acute lymphoblastic leukemia treated with oral 6-thioguanine during maintenance therapy.

6‐Thioguanine (TG) was recently studied to determine whether TG in maintenance therapy achieves better event free survival than 6‐mercaptopurine (MP) for standard risk acute lymphoblastic leukemia (ALL) on the clinical trial, CCG‐1952 (5/1996–1/2000). Veno‐occlusive disease was previously recognized as a complication of TG on CCG‐1952. We report a newly recognized pediatric complication of TG: splenomegaly and portal hypertension (PH) developing during maintenance or after completion of therapy.

Imatinib mesylate causes growth deceleration in pediatric patients with chronic myelogenous leukemia

Imatinib mesylate, a tyrosine kinase inhibitor, is used in the treatment of chronic myelogeneous leukemia (CML). Given its ease of administration and manageable side effects in adults, imatinib mesylate was introduced as therapy for pediatric CML. Recently published case reports describe growth deceleration in children treated with imatinib. This study details the growth phenotype of seven pediatric patients maintained in remission on imatnib mesylate over an extended period of time.

Meta-analysis of randomised trials comparing thiopurines in childhood acute lymphoblastic leukaemia

Mercaptopurine has been used in continuing treatment of childhood acute lymphoblastic leukaemia since the mid 1950s. Recent advances in the understanding of thiopurine pharmacology indicated that thioguanine (TG) might be more effective than mercaptopurine (MP). The US and UK cooperative groups began randomised thiopurine trials and agreed prospectively to a meta-analysis. All randomised trials of TG versus MP were sought, and data on individual patients were analysed by standard methods. Combining three trials (from US, UK and Germany), the overall event-free survival (EFS) was not significantly improved with TG (odds ratio (OR)=0.89; 95% confidence interval 0.78–1.03). Apparent differences in results between trials may be partly explained by the different types of patients studied. The larger treatment effect reported in males in the US trial was confirmed in the other trials. There was heterogeneity between sex/age subgroups (P=0.001), with significant EFS benefit of TG only observed for males aged <10 years old (OR=0.70; 0.58–0.84), although this did not result in a significant difference in overall survival (OR=0.83; 0.62–1.10). Additional toxicity occurs with TG. Mercaptopurine remains the standard thiopurine of choice, but further study of TG may be warranted to determine whether it could benefit particular subgroups.