Multidisciplinary management of pediatric low-grade gliomas.

Low-grade gliomas comprise a heterogeneous group of tumors accounting for 30% to 40% of all primary central nervous system (CNS) neoplasms in the pediatric population. Management of these patients has evolved significantly over the past 2 decades, the present emphasis being on surgery. Adjuvant therapies, such as radiation and/or chemotherapy are generally withheld until symptomatic or radiographic progression is evident. The goal of surgery is gross total resection, while preserving maximal neurologic function. The goal of radiation and chemotherapy is to provide symptom and tumor control with minimal acute and late toxicities. Chemotherapy has the additional goal of deferring radiation to allow maximal development and maturation of the child's CNS. The incorporation of these 3 modalities into the overall care of the pediatric low-grade glioma patient involves the multidisciplinary input of the neurosurgeon, radiation oncologist, and pediatric neuro-oncologist both at time of diagnosis and throughout the course of their disease.

Oral methotrexate for recurrent brain tumors in children: a Pediatric Oncology Group study.

PURPOSE: Children with recurrent or progressive central nervous system (CNS) tumors have an unfavorable prognosis. Based on Pediatric Oncology Group (POG) institutional pilot data, low-dose oral methotrexate (MTX) was studied. METHODS: Eight dosages of MTX 7.5 mg/m2 every 6 hours were administered on a weekly schedule for as long as 18 months. Patients in six different brain tumor strata were accrued. RESULTS: The response rates (complete or partial responses) were as follows: astrocytoma 2 of 10, malignant glioma 1 of 19, medulloblastoma 0 of 18, brainstem tumor 0 of 12, ependymoma 1 of 7, and miscellaneous histologic types 0 of 12. The main toxicities, mucositis, myelosuppression, and hepatic transaminase elevation were considered tolerable. CONCLUSION: Low-dose oral MTX showed no significant activity against malignant glioma, medulloblastoma, brainstem tumors, and miscellaneous histologic types. Indeterminate but low response rates were observed in children with astrocytoma and ependymoma. This regimen will not be recommended for front-line therapy.

Topotecan for the treatment of recurrent or progressive central nervous system tumors - a pediatric oncology group phase II study.

Topotecan was studied as a 72 h infusion given every 3 weeks. Treatment began at a dose of 1.0 mg/m2/day and was increased to 1.25 mg/m2/day after the first 6 patients tolerated this higher dose without excessive toxicities. Eighty-eight evaluable children were accrued in 6 strata. There were no complete nor partial responses. Twenty subjects had stable disease (astrocytoma 5/11, malignant glioma 5/13, medulloblastoma 0/12, brain stem tumor 4/19, ependymoma 5/17, and miscellaneous histologies 1/16). Two patients (astrocytoma, ependymoma) completed the maximum 18 topotecan courses. The remaining 68 children developed progressive disease within 2 months. Myelosuppression was the main toxicity. Grade 4 leukopenia, neutropenia, anemia, and thrombocytopenia were observed in 18, 32, 5, and 23 participants, respectively. It was concluded that topotecan as given according to this schedule showed insufficient activity to promote it to frontline protocol usage.

Cyclophosphamide for the treatment of progressive low-grade astrocytoma: a Pediatric Oncology Group phase II Study.

PURPOSE: Results of a phase II trial of cyclophosphamide (CPM) for children with progressive low-grade astrocytoma are reported. PATIENTS AND METHODS: Fifteen patients with a median age of 39 months (range, 2 to 71) were included in this study. The tumors of 11 children were located in the optic pathway, hypothalamus, or thalamus. Four courses of intravenous CPM 1.2 g/m2 were administered every 3 weeks during the upfront window portion of this protocol. Subsequently, chemotherapy was to continue with CPM, vincristine, and carboplatin for 2 years. RESULTS: By study design, the first 14 patients were centrally reviewed after completion of the initial 4 CPM courses. Toxicity was primarily hematologic. One patients had a complete response, 8 had stable disease, and 5 had progressive disease (PD). The excessive number of children with PD prompted study closure. CONCLUSION: CPM as used in this protocol showed insufficient activity against astrocytoma to justify further patient accrual.

Hyperfractionated irradiation and concurrent cisplatin in brain stem tumors: a Pediatric Oncology Group pilot study (9139).

A phase I Pediatric Oncology Group Study was performed combining 7,020 cGy hyperfractionated irradiation (117 cGy twice daily separated by 6 h) with increasing concurrent doses of cisplatin given with the intent of radiosensitization as treatment for children with newly diagnosed brain stem tumors. Cisplatin was infused over 120 h on weeks 1, 3, and 5 during a 6-week radiotherapy course. The following cisplatin dose levels were studied: (1) 50 mg/m2/120 h, (2) 75 mg/m2/120 h and (3) 100 mg/m2/120 h. Sixteen of 17 children completed therapy. One child expired after 2 days of treatment secondary to massive intratumoral hemorrhage. At cisplatin dose level 3 (100 mg/m2/120 h), grade 2-4 myelosuppression was encountered in 3 of 5 evaluable patients. Otherwise, no other excessive toxicities, including renal and ototoxicity, were noted.

Hepatoblastoma characterized by trisomy 20 and double minutes.

Karyotypic study of two hepatoblastomas revealed trisomies for chromosome 20 and the presence of double minutes (dmin). These cases are the second and third examples of trisomy 20 in hepatoblastoma and are the first examples of dmins in this rare childhood tumor.

A dysmorphic child with myelodysplasia characterized by a duplication of 1q and multiple duplications of 3q.

Multiple inserted duplications of bands 3q21 through 3q27 and a duplication of the chromosome 1 long arm are reported in a karyotypically altered clone from a dysmorphic child with myelodysplasia.

Cardiopulmonary function in long-term survivors of childhood Hodgkin's lymphoma: a pilot study.

Twelve patients who had received mantle radiotherapy for Hodgkin's lymphoma during childhood underwent cardiopulmonary testing 7 years or more after the initial diagnosis and treatment. All but one patient had been asymptomatic. Results of echocardiography, pulmonary function tests, or exercise studies were abnormal in 9 of the 12 patients. Long-term follow-up of cardiopulmonary function will be important to determine the ultimate significance of these abnormalities. These potential complications must be considered in planning prospective therapeutic studies in children with Hodgkin's disease.

The capillary thrombometer and von Willebrand factor.

A modified capillary thrombometer was constructed to study the rate of thrombus formation using heparinized whole blood (2 U/ml) from 4 different groups of pigs: normal, heterozygous von Willebrand's disease (vWD), homozygous vWD, and platelet storage pool disease (SPD). The median thrombosis times for the 4 groups of pigs were: 5.3 min (range = 3.0-14), 31 min (range = 4.0-47), 55 min (range = 41-60), and 60 min (range = 15-60), respectively. Significant differences were demonstrated between all pig groups (p less than .01 - p less than .001), except between the homozygous vWD pigs and the SPD pigs (p = 0.8), both of which are clinical bleeders. Cryoprecipitate was infused into 3 pigs with homozygous vWD. Partial correction of the capillary thrombometer thrombosis time and the in vivo ear bleeding time was observed. Murine monoclonal antibodies to porcine von Willebrand factor were added to normal pig whole blood samples in the capillary thrombometer. Four of six antibodies prolonged the thrombosis time and had similar effects on the ear bleeding time. Using these monoclonal antibodies, an immunoperoxidase stain demonstrated plasmatic and platelet associated von Willebrand factor in sections of thrombi from the capillary thrombometer. These experiments confirm that von Willebrand factor is important to thrombus formation in the capillary thrombometer and that measurements by this instrument may relate to in vivo hemostasis as measured by the ear bleeding time.

The capillary thrombometer revisited.

A modified capillary thrombometer was constructed to study the rate of thrombus formation using heparinized whole blood (2 U/ml) obtained from normal adults (n = 22) and children (n = 20) and patients with hemophilia A (n = 10) or von Willebrand's disease (n = 8). The median thrombosis times were as follows: normal adults = 12.8 min (range = 4.5-26.0), normal children = 13.3 min (range = 5.7-29.0), patients with hemophilia A = 37.2 min (range = 20.0-60.0 min), and patients with von Willebrand's disease = 60.0 min (range = 37.2-60.0). Significant differences were demonstrated between all groups of subjects, except between normal adults and children. The capillary thrombometer appears to measure thrombus formation dependent on adequate Willebrand factor and platelets.

Bone marrow transplantation for diseases of childhood.

Bone marrow transplantation in childhood is an established treatment modality for aplastic anemia, the acute and chronic leukemias, and severe combined immune deficiency. Recently, experience with this treatment has also been favorable with small numbers of children who have Wiskott-Aldrich syndrome, several types of inherited storage diseases, Fanconi's anemia, thalassemia, infantile malignant osteopetrosis, and selected cases of lymphoma and other solid tumors. The psychosocial impact and financial costs of bone marrow transplantation can be substantial. Multi-institutional, prospective, randomized trials that would compare transplantation and conventional therapy are necessary to establish the indications and precise timing for this procedure. Further development of monoclonal antibodies, a better understanding of the histocompatibility antigen systems, and improvement in pretransplantation conditioning regimens should increase the spectrum of effectiveness for bone marrow transplantation in the coming years.