H. Ekert

Outcome prediction in childhood acute lymphoblastic leukaemia by molecular quantification of residual disease at the end of induction

Methods to detect and quantify minimal residual disease (MRD) after chemotherapy for acute lymphoblastic leukaemia (ALL) could improve treatment by identifying patients who need more or less intensive therapy. We have used a clone-specific polymerase chain reaction to detect rearranged immunoglobulin heavy-chain gene from the leukaemic clone, and quantified the clone by limiting dilution analysis. MRD was successfully quantified, by extracting DNA from marrow slides, from 88 of 181 children with ALL, who had total leucocyte counts below 100 x 10(9)/L at presentation and were enrolled in two clinical trials, in 1980-84 and 1985-89. Leukaemia was detected in the first remission marrow of 38 patients, in amounts between 6.7 x 10(-2) and 9.9 x 10(-7) cells; 26 of these patients relapsed. Of 50 patients with no MRD detected, despite study of 522-496,000 genomes, only 6 relapsed. The association between MRD detection and outcome was significant for patients in each trial. In the first trial, patients relapsed at all levels of detected MRD, whereas in the later trial, in which treatment was more intensive and results were better, the extent of MRD was closely related to the probability of relapse (5 of 5 patients with > 10(-3) MRD, 4 of 10 with 10(-3) to 2 x 10(-5), 0 of 3 with levels below 2 x 10(-5), and 2 of 26 with no MRD detected). Early quantification of leukaemic cells after chemotherapy may be a successful strategy for predicting outcome and hence individualizing treatment in childhood ALL, because the results indicate both in-vivo drug sensitivity of the leukaemia and the number of leukaemic cells that remain to be killed by post-induction therapy.

Cognitive and academic outcome following cranial irradiation and chemotherapy in children: a longitudinal study.

Cranial irradiation therapy (CRT) and chemotherapy are associated with neurobehavioural deficits. Many studies have investigated late effects of these treatments, but few have evaluated changes in abilities over time. This study employed a longitudinal design to map abilities following these treatments. Three groups of children were studied: Group 1 (n = 35): children treated with CRT (18 Gy) + chemotherapy, aged 5 years or less at time of diagnosis; Group 2 (n = 19): children treated with chemotherapy alone, aged 5 years or less at time of diagnosis; Group 3 (n = 35): healthy children. All children were aged 7–13 years at time of initial assessment, with no pre-diagnosis history of neurologic, developmental, or psychiatric disorder. Intellectual and educational abilities were evaluated twice: T1, not less than 2 years post-treatment, and T2, 3 years later. Group 1 achieved poorest results at T1, with comparison groups performing similarly. At T2 group differences were maintained. For verbal skills differences remained stable. Group 1 exhibited deterioration on non-verbal and processing tasks, while comparison groups showed improved abilities. Group 1 exhibited increases in literacy skills, with educational intervention predicting progress. Results suggest cumulative deficits in non-verbal and information processing skills for children treated with CRT + chemotherapy, with other deficits remaining relatively stable over time. Improved literacy skills suggest that gains can occur with remediation.

Intellectual, educational, and behavioural sequelae after cranial irradiation and chemotherapy.

Cognitive and educational sequelae are inconsistently reported in children treated with cranial irradiation for acute lymphoblastic leukaemia. This study investigated differences in these skills after cranial irradiation, controlling the effects of chemotherapy and psychosocial factors. Three groups were evaluated: 100 children diagnosed with acute lymphoblastic leukaemia and treated with cranial irradiation and chemotherapy; 50 children diagnosed with acute lymphoblastic leukaemia or other cancers and treated with chemotherapy alone; and a healthy control group of 100 children. Children in the clinical groups stopped treatment at least two years before evaluation and had no history of relapse. Children were aged between 7 and 16 at the time of assessment. Evaluation included cognitive, educational, and behavioural measures. Analyses found that children receiving cranial irradiation and chemotherapy performed more poorly than non-irradiated groups on intellectual and educational tests, with verbal and attentional deficits most pronounced. Children receiving chemotherapy alone performed similarly to controls, suggesting such treatment is not associated with adverse neurobehavioural sequelae.

Risk factors for intellectual and educational sequelae of cranial irradiation in childhood acute lymphoblastic leukaemia.

Long-term cognitive and educational sequelae have been inconsistently reported in children who received cranial irradiation (CRT) to prevent central nervous system (CNS) disease in acute lymphoblastic leukaemia (ALL). This study investigates a large and representative sample of survivors of ALL and compares them with non-irradiated survivors of cancer and healthy control children to determine the effect of CRT on cognitive and educational ability. Three groups of children were studied: Group 1 (n=100) survivors of ALL treated with chemotherapy and CRT, group 2 (n=50) children with a variety of malignancies treated with chemotherapy alone, group 3(n=100) healthy children. Cognitive and educational abilities of these groups were evaluated using standardised psychometric techniques. Significant differences in cognitive and educational abilities were found between the children in group 1 (chemotherapy + CRT) and the two control groups, with the children receiving CRT performing less well in a range of tests. Greatest differences were detected for tasks dependent on language function including verbal IQ, reading and spelling. Within group 1 a younger age at treatment (less than 5 years) and a higher dose of CRT (24 Gy vs 18 Gy) were predictive of poor long-term outcome for cognitive and education ability. In contrast, children who received chemotherapy alone, with or without intrathecal methotrexate, performed similarly to healthy controls. No gender differences were detected for these measures.

Neurobehavioural sequelae following cranial irradiation and chemotherapy in children: an analysis of risk factors.

Neurobehavioural deficits are commonly reported following treatment for childhood cancers. This study examined the impact of cranial irradiation (CRT) and chemotherapy in children, aiming to identify factors detrimental to long-term outcome. The study compared survivors of acute lymphoblastic leukemia (ALL), treated with CRT and chemotherapy (CRT group: n = 100), survivors of cancers treated with chemotherapy only (n = 50) and healthy controls (n = 100) for intelligence, academic achievement, information processing, learning, and executive function. CRT and chemotherapy in combination were associated with reduced intelligence, educational skill, immediate memory, processing speed, and executive function. Children treated with chemotherapy alone exhibited subtle information processing deficits. Within the CRT group, younger age at treatment was predictive of deficits in non-verbal ability, educational skills and executive functions. High dose CRT was associated with poorer information processing and lower arithmetic ability.

Autologous bone marrow rescue in the treatment of advanced tumors of childhood

High‐dose multiagent chemotherapy followed by autologous marrow rescue was used in the treatment of 13 patients with Stage III or IV childhood tumors. Encouraging results are being obtained in abdominal lymphoma (1/3 complete remissions (CR)); rhabdomyosarcoma (2/4 CR); and retinoblastoma (1/2 CR). In neuroblastoma, the results are disappointing, with only one of four patients in CR; this patient developed a lymphoma associated with Epstein‐Barr virus infection. Marrow reconstitution was obtained in 11 patients, with recovery of neutrophils to >0.5 × 109/liter between six and 30 days and platelet recovery to >50 × 109/liter between seven and 38 days. Investigations on the numbers of cells or committed granulocyte precursors (CFU‐cs) infused and parameters of hematologic recovery show poor correlation and suggest that a more accurate and reliable assay for the predictability of cryopreserved marrow to reconstitute marrow function within a reasonable time is necessary. Nonhematologic toxicities of high‐dose multiagent chemotherapy are the principal dose‐limiting factors.

Impairments of Attention Following Treatment With Cranial Irradiation and Chemotherapy in Children

Neurobehavioral impairments are frequently reported following treatment for childhood cancers, with cranial irradiation (CRT). This study investigated attention and information processing skills, predicting that these skills would be impaired due to the vulnerability of cerebral white matter in early childhood. Three treatment groups were studied: (i) CRT+chemotherapy (n = 35); (ii) chemotherapy alone (n = 19); (iii) healthy children (n = 35). All children were aged 9 to 16 years at time of assessment, with no pre-diagnosis history of neurologic, developmental, or psychiatric disorder. Children were administered a series of tasks measuring processing speed and sustained, selective, and shifting attention. For children treated with CRT + chemo, results identified residual deficits in processing speed for complex tasks, selective and shifting attention. In contrast, processing speed was intact for simple tasks, and there was no clear evidence of deterioration in performance over time, as might be expected in the presence of a sustained attention deficit. Children treated with chemotherapy alone demonstrated generally intact attentional skills. However, this group did record an increasing number of attentional lapses over time on tasks tapping sustained attention skills.

Hemophagocytic reticulosis A case report with investigations of immune and white cell function

A 5‐month‐old child with hemophagocytic reticulosis is described. Investigations revealed a grossly defective PHA response of the patients lymphocytes which improved with chemotherapy. Defective glucose oxidation by phagocytosing cells and low IgA levels were demonstrated at diagnosis and have persisted despite chemotherapy. HL‐A typing and chromosome studies did not reveal maternal lymphocytes in the childs circulation. The patient was treated with vinblastine and prednisolone and remains well after 11 months of treatment.

The role of platelets in fibrinolysis. Studies on the plasminogen activator and anti-plasmin activity of platelets.

Inhibition of plasmin and activation of plasminogen by platelet‐poor plasma, intact, lysed and thrombin‐aggregated platelet‐rich plasma, and washed platelets was studied by means of fibrin‐agar plates. No significant activation of plasminogen by platelets could be demonstrated. Maximal inhibition of plasmin occurred after 2–3 hr incubation with either platelet‐rich or platelet‐poor plasma; in each case the kinetics of the reaction were suggestive of non‐competitive inhibition. Platelets showed both adsorbed and intrinsic anti‐plasmin activity, but the latter was equivalent to only about 1% of the total plasma activity.

Results of Treatment of 18 Children With Hodgkin Disease With MOPP Chemotherapy as the Only Treatment Modality

Eighteen children with Hodgkin disease (16 previously untreated; two relapsed) were treated with MOPP chemotherapy (nitrogen mustard, vincristine, prednisone, procarbazine) only. Ten had clinical stage I and II disease, four had stage III, and four had stage IV. In ten patients, the clinical stage was confirmed by staging laparotomy. Six courses of MOPP were given to eight stage I and II patients and two stage IV patients. Between 7 and 12 courses were given to two stage I and II, and six stage III and IV patients. Dose reduction of 75-50% was required in 13% and delay of treatment in 22% of the first six courses of MOPP. Hematologic toxicity, minor and major viral infections, and nausea and vomiting were the major complications. Complete remission (CR) was obtained in 17 patients. Of these 17, there has been one death in CR, and one relapse. Sixteen patients have discontinued treatment and have been observed off treatment for 8 months to 7.5 years. The actuarial disease-free survival with a median follow-up of 28 months is 80% and overall survival is 92%.