Parents' perceptions of randomization in pediatric clinical trials. Children Cancer Group.

OBJECTIVES: The purpose of this study was to investigate parents' knowledge and perceptions about randomization in clinical trials for children with cancer, and to determine whether parents' decisions were influenced by demographic factors, randomization circumstances, the clinical characteristics of the child with cancer, or a combination. MATERIALS AND METHODS: This study collected information from 192 parents of patients with various forms of childhood cancer who either accepted or refused randomization. A comparative case-control design was used. The Clinical Investigation Randomization Scale was administered to all participants. This scale included 32 questionnaire items (QIs) pertaining to randomization as well as a mixture of open-ended questions to obtain information about demographic and other factors. RESULTS: A predictor model was developed that accurately predicted acceptance or refusal of randomization 87% of the time. Demographic information was found to have less influence than expected on parents' decisions regarding randomization. Knowledge deficits were found among both groups of parents, those who accepted and those who refused randomization. CONCLUSIONS: What most distinguished parents who refused from those who accepted randomization was not their knowledge and information about randomized clinical trials. By far, the majority of QIs that accurately predicted acceptors and refusers involved parents' beliefs, values, and perceptions. Further research is needed to determine interventions that may enable the healthcare team to provide information and decisional support most effectively to improve the informed consent process.

Pharmacokinetics and pharmacodynamics of oral methotrexate and mercaptopurine in children with lower risk acute lymphoblastic leukemia: a joint children's cancer group and pediatric oncology branch study.

We prospectively assessed the pharmacokinetics of methotrexate, mercaptopurine, and erythrocyte thioguanine nucleotide levels in a homogenous population of children with lower risk acute lymphoblastic leukemia and correlated pharmacokinetic parameters with disease outcome. The maintenance therapy regimen included daily oral mercaptopurine (75 mg/m2) and weekly oral methotrexate (20 mg/m2). One hundred ninety-one methotrexate doses and 190 mercaptopurine doses were monitored in 89 patients. Plasma drug concentrations of both agents were highly variable. The area under the plasma concentration-time curve (AUC) of methotrexate ranged from 0.63 to 12 micromol*h/L, and the AUC of mercaptopurine ranged from 0.11 to 8 micromol*h/L. Drug dose, patient age, and duration of therapy did not account for the variability. Methotrexate AUC was significantly higher in girls than boys (P =.007). There was considerable intrapatient variability for both agents. Erythrocyte thioguanine nucleotide levels were also highly variable (range, 0 to 10 pmol/g Hgb) and did not correlate with mercaptopurine dose or AUC. A Cox regression analysis showed that mercaptopurine AUC was a marginally significant (P =.043) predictor of outcome, but a direct comparison of mercaptopurine AUC in the remission and relapsed patient groups failed to show a significant difference. Methotrexate and mercaptopurine plasma concentrations and erythrocyte thioguanine nucleotide levels were highly variable, but measurement of these pharmacokinetic parameters at the start of maintenance will not distinguish patients who are more likely to relapse.

Behavioral adjustment and social functioning of long-term survivors of childhood leukemia: parent and teacher reports.

Obtained parent and teacher reports of behavior and social competence for children who were survivors of acute lymphoblastic leukemia (ALL). At follow-up, children were 5-18 years of age, 48 months postdiagnosis, in first continuous remission, and off chemotherapy. Each child had been randomized to receive either 1,800 cGy whole brain radiation therapy (WBRT) plus intrathecal methotrexate (IT MTX), or IT MTX alone as central nervous system prophylaxis, and one of four chemotherapy regimens that varied in treatment intensity. Scores on standardized measures (CBCL-P/T and PIC) were generally similar to instrument norms. Parents, but not teachers, reported heightened child somatic concerns. There was no effect of WBRT or chemotherapy regimen on ratings of behavioral adjustment. Results indicate minimal psychosocial morbidity among long-term survivors of ALL and suggest that the stressful life events associated with cancer and its treatment do not cause significant behavioral or emotional difficulties.

Low numbers of CSF blasts at diagnosis do not predict for the development of CNS leukemia in children with intermediate-risk acute lymphoblastic leukemia: a Childrens Cancer Group report.

PURPOSE: This study was designed to evaluate the effect on CNS relapse (CNSR) and overall relapse rates of blast cells in the CSF containing < or = 5 cells/microL at the time of diagnosis of intermediate-risk acute lymphoblastic leukemia (ALL) in children entered onto a large randomized multicenter prospective therapeutic trial (Childrens Cancer Group [CCG]-105). PATIENTS AND METHODS: We studied outcome in terms of CNSR and event-free survival (EFS) in 1,544 patients who successfully completed remission-induction therapy and had been randomized to one of four systemic chemotherapy regimens and to one of two CNS prophylaxis regimens. We compared outcome between 1,450 patients who had varying degrees of pleocytosis but no blasts in the CSF at diagnosis (blast-negative group) with 94 who had blasts detected in the CSF after cytocentrifugation but had a total CSF WBC count of < or = 5/microL (blast-positive group). RESULTS: No statistically significant differences in overall CNSR or EFS rates were observed between the two groups and no differences were found when analyzed according to age or WBC count at diagnosis, sex, or type of CNS prophylaxis (intrathecal [IT] methotrexate [MTX] alone v IT MTX plus 18 Gy cranial irradiation [CXRT]). CONCLUSION: In intermediate-risk ALL, there was no significant difference in CNSR and systemic relapse rates after standard presymptomatic CNS therapy between patients with a CSF WBC count < or = 5/microL and those without identifiable blasts in the CSF. These findings suggest that certain approaches to therapy, such as that used in this study, may eliminate the need for any additional special treatment directed at this subset of patients with CSF blasts.

Epidemiological characteristics of childhood acute lymphocytic leukemia. Analysis by immunophenotype. The Childrens Cancer Group.

While a number of epidemiological studies of childhood acute lymphocytic leukemia (ALL) have been conducted, separate analysis of risk factors for ALL subtypes has generally not been possible. We report the results of an analysis of data obtained from parents of children with ALL (and a control group of children without cancer), linked to a clinical database. Cases were classified into four ALL subtypes, and odds ratios (OR) were determined for each subtype for a broad range of factors. Numerous significant associations were found, some across all subtypes and others that were subtype-specific. Factors with elevated and/or significant ORs included: (i) for common ALL (n = 286): Down syndrome; family history (FH) of bone/joint diseases; postnatal jaundice; birthweight; MMR vaccination; exposure to gases and insecticides; and parental occupational exposure to insecticides. (ii) for pre-B ALL (n = 38): FH of gastrointestinal, hematological or bone/joint diseases, or allergy; cat ownership; exposure to solvents, fumes, petroleum products, cleaning agents and farm animals; and parental exposure to farm animals, fumes and solvents; (iii) for T-cell ALL (n = 158): FH of gastrointestinal disorders, maternal age, male gender, and parental occupational exposure to metals; (iv) for null-cell ALL (n = 65): FH of congenital heart disorders; measles; and parental occupational exposure to fumes, metals or solvents. This analysis should be considered as a hypothesis-generating process for future case-control interview studies.

Blasts in CSF with a normal cell count do not justify alteration of therapy for acute lymphoblastic leukemia in remission: a Childrens Cancer Group study.

PURPOSE: The Childrens Cancer Group (CCG) requires both a CSF WBC count of more than five cells per microliter and demonstration of blast cells in the cytocentrifuge specimen to support a diagnosis of CNS relapse. We reviewed the CSF examinations of patients with intermediate-risk acute lymphoblastic leukemia (ALL) to determine the clinical significance of blast cells reported in the cytocentrifuge when the total CSF cell count was normal. PATIENTS AND METHODS: Children treated on CCG-105 for ALL had CSF examinations every 12 weeks during maintenance therapy. The outcome of children who had a positive CSF cytocentrifuge examination without an elevated CSF WBC count was compared with that of children who did not have any CSF blast cells observed. RESULTS: Sixty-four patients had 81 CSF examinations with blast cells and a normal cell count. By Cox life-table regression analysis, patients with blasts had a different disease-free survival (DFS) distribution, with relapses tending to occur earlier (P = .008). However, the DFS for these patients was 63% +/- 9.6% at 5 years from the time of the abnormal cytocentrifuge result as compared with 69% +/- 1.5% for 1,490 children who did not have blasts in their CSF. This difference is not significant. CONCLUSION: Blast cells were infrequently identified in cytocentrifuge preparations of CSF when the cell count was normal. The majority of patients in whom such an event was observed have not experienced a subsequent relapse as measured by life-table analysis at 5 years. The data do not justify changing or augmenting therapy based on cytocentrifuge results alone.

Brief unconscious sedation for painful pediatric oncology procedures. Intravenous methohexital with appropriate monitoring is safe and effective.

PURPOSE: We report here our experience in using intravenous methohexital (MHX), an ultrashort-acting barbiturate, for brief unconscious sedation of pediatric oncology outpatients undergoing painful, invasive procedures. METHODS: Following published monitoring guidelines for deep pediatric sedation, 1.0 mg/kg MHX was administered immediately before the procedure, 1% xylocaine was given locally, and MHX was additionally titrated to maintain minimal response to pain during the procedure. Clinical data reported here were gathered retrospectively from permanent medical records. RESULTS: Data reported here represent 132 evaluable consecutive procedures in 33 patients ranging in age from 1.6 to 20.5 years. Patients underwent an average of 4 +/- 3 procedures and received a mean total MHX dose per procedure of 5.8 +/- 2.1 mg/kg. The mean length of time from start of sedation to full arousability was 30 +/- 12 min. Twenty-three (17.4%) procedures were associated with clinically insignificant decreases in diastolic blood pressure or heart rate below resting normal ranges for age. Eight (6.1%) procedures in six patients were associated with minor complications requiring no intervention, such as transient behavioral changes, transient myoclonus, and minimal stridor. Five procedures (3.8%) in five patients required simple suctioning to manage secretions. Only two procedures (1.5%) in two patients required brief bag-mask ventilation plus suctioning for suspected laryngospasm. None required intubation. No differences in clinical features or MHX doses were noted for patients with, as compared to those without, complications. All procedures were completed with a satisfactory level of sedation. CONCLUSIONS: Our experience indicates that MHX, with appropriate monitoring as described here, is a safe and effective agent for use in pediatric oncology outpatient sedation programs.

Prevention of CNS disease in intermediate-risk acute lymphoblastic leukemia: comparison of cranial radiation and intrathecal methotrexate and the importance of systemic therapy: a Childrens Cancer Group report.

PURPOSE: This study (Childrens Cancer Group [CCG]-105) was designed in part to determine in a prospective randomized trial whether intrathecal methotrexate (IT MTX) administered during induction, consolidation, and maintenance could provide protection from CNS relapse equivalent to that provided by cranial radiation (CXRT) in children with acute lymphoblastic leukemia (ALL) and intermediate-risk features. PATIENTS AND METHODS: We randomized 1,388 children with intermediate-risk ALL to the two CNS regimens. They received either IT MTX at intervals throughout their course of therapy or CXRT (18 Gy) during consolidation with IT MTX during induction, consolidation, and delayed intensification. Systemic therapy was randomized to one of four treatment regimens derived from a regimen used by CCG in recent studies for this patient population and three more intensive regimens based on the Berlin-Frankfurt-Munster trials. RESULTS: Life-table estimates at 7 years show a 93% and 91% CNS relapse-free survival rate for the CXRT and IT MTX groups, respectively. The corresponding event-free survival (EFS) rates are 68% and 64%. The differences are not significant. Patients who received more intensive systemic therapy had a 94% CNS relapse-free survival rate on either CXRT or IT MTX, while patients who received standard systemic therapy had 90% and 80% rates for CXRT and IT MTX, respectively (P < .0001). Patients less than 10 years of age who received CXRT or IT MTX had 72% and 71% EFS rates if they received more intensive systemic therapy. Patients 10 years or older who received CXRT had an improved EFS (61% v 53%) with a more intensive systemic program. This was primarily due to fewer bone marrow relapses (P = .04). CONCLUSIONS: IT MTX during induction, consolidation, and maintenance provides protection from CNS relapse in patients with intermediate-risk ALL equivalent to that provided by CXRT if more intensive systemic therapy is given. The CNS relapse rate with either CXRT or IT MTX is in part dependent on the associated systemic therapy. For intermediate-risk patients less than 10 years of age, IT MTX with an intensified systemic regimen provided CNS prophylaxis comparable to that provided by CXRT, whereas older patients had fewer systemic relapses if they received CXRT.

Improved outcome with delayed intensification for children with acute lymphoblastic leukemia and intermediate presenting features: a Childrens Cancer Group phase III trial.

PURPOSE: The Berlin-Frankfurt-Munster (BFM) 76/79 trial of acute lymphoblastic leukemia (ALL) in children produced impressive disease-free survival (DFS) rates with a protocol that began with 8 weeks of intensive therapy, followed by 8 weeks of maintenance therapy, and then another 6 weeks of intensive treatment. The current study was conducted to determine the relative contributions of each of these periods of intense therapy on the DFS rates of ALL patients with intermediate presenting features. In addition, due to concerns regarding the toxicity of CNS irradiation, we compared cranial irradiation (CXRT) with intrathecal methotrexate (IT MTX) administered during induction and consolidation to IT MTX during all phases of the treatment program. PATIENTS AND METHODS: Between May 1983 and April 1989, more than 1,600 children with ALL and intermediate presenting features, as defined by the Childrens Cancer Group (CCG), were entered into a randomized trial that tested four systemic therapy regimens and two CNS programs. RESULTS: The results with a median follow-up of 57 months show that systemic regimens with a delayed intensification (Delint) phase of therapy had a 5-year event-free survival (EFS) rate of 73% compared with the control regimen EFS rate of 61% (p = .006). For children less than 10 years of age, standard three-drug induction and Delint produced a 77% 5-year EFS. IT MTX during all phases of therapy provided CNS protection comparable to the CXRT regimen in children less than 10 years of age. Children 10 years of age or older appear to have a better EFS rate with intensive induction, Delint, and CXRT. CONCLUSION: Delint improves the EFS rate of children with ALL and intermediate presenting features. Maintenance IT MTX can be safely substituted for CXRT for presymptomatic CNS therapy in children with intermediate-risk characteristics less than 10 years of age.

CNS prophylaxis of childhood leukemia: what are the long-term neurological, neuropsychological, and behavioral effects?

Current medical treatments for childhood acute lymphoblastic leukemia (ALL) have improved the outlook to where more than 50% can be expected to survive five years or more. The use of CNS prophylaxis has contributed in a significant way to these improved survival statistics by reducing the likelihood of CNS relapses. The literature relating to the potential adverse psychological consequences of CNS prophylaxis, which include cranial radiation therapy (CRT), is reviewed and analyzed. The majority of published papers of children in first remission report that CNS prophylaxis, which include both CRT and intrathecal methotrexate, results in a variety of learning problems in many children who were younger than age 5 when treated. The available literature on the social, emotional, and educational sequelae of childhood ALL is also reviewed.

An overview of cancer in children in the 1980s.

Multidisciplinary teams, therapeutic research, and large successful clinical trials have led to the exciting improved survival outlook in pediatric oncology. The development of sophisticated supportive care measures and the identification of significant prognostic variables within disease categories have dramatically altered the management and outcome for many children with cancer. Prolonged survival has focused attention on the quality of life and strategies to enable these children and their families to cope effectively with chronic, life-threatening illness. Research is ongoing on several fronts: to find innovative treatment approaches for children who currently have a poorer prognosis, to minimize or prevent acute and late toxicities by modifying treatment plans so less intensive treatment can be given to patients with a low risk of disease recurrence, and to increase our understanding of the epidemiology and etiology of childhood cancer. With the continued efforts of researchers in the laboratory and at the bedside, prevention of these catastrophic diseases may some day become a reality.