Wilms' tumor, an embryonic renal neoplasm diagnosed primarily in young children, can occur in either a noninheritable (sporadic) or a familial form, with the latter presenting earlier and more often at bilateral sites. Although familial Wilms' tumor is thought to develop through inherited and acquired mutational inactivation of the two alleles of predisposing tumor suppressor genes, only a small percentage of cases can be accounted for by mutations affecting the WT1 gene or linkage to the Beckwith-Weidemann syndrome of the BWS region on the short arm of chromosome 11. To find chromosomal regions that might contain genes important in the development of this disease, we used comparative genomic hybridization to analyze tumor specimens from familial cases for chromosomal regions that were consistently lost. Although inherited lesions of tumor suppressors are most often inactivating point mutations, accompanying somatic lesions in the malignant clones are often chromosomal deletions; therefore, consensus regions of loss in familial tumors are likely to harbor genes linked to familial predisposition. There were extensive genomic aberrations among the eight familial cases studied, with an average of 6.5 changes/tumor (range, 0-22). The most consistent findings with likely biological relevance were deletions of chromosomes 4 (consensus, 4q21-qter), 9 (consensus, 9p21-pter), 20p, and 3 (consensus, 3q12-q21). These regions have not been previously implicated in Wilms' tumor and may harbor novel genes that could aid attempts to understand the familial predisposition as well as the development and progression of these tumors.
Purpose: To determine in a prospective randomized trial the effect on survival, progression-free survival, and patterns of relapse of a decrease in the neuraxis radiation dose from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions in patients with newly diagnosed medulloblastoma between 3 and 21 years of age with low T stage (T1, T2 and T3A), minimal postoperative residual tumor, and no evidence of dissemination (Mo). Methods and Materials: Between June 1986 and November 1990, the Children's Cancer Group and the Pediatric Oncology Group randomized 126 patients in a two-arm study comparing the two different doses of neuraxis irradiation. In both arms, the posterior fossa received 5,400 cGy in 30 fractions. All patients were staged with myelography, postoperative lumbar cerebrospinal fluid cytology, and postoperative contrast-enhanced cranial computerized tomography to ensure no evidence of dissemination and no more than 1.5 cm3 residual tumor volume. Overall survival, progression-free survival, and patterns of recurrence were carefully monitored. Prospective endocrine and psychometric studies were performed to determine the benefit of decreasing the neuraxis radiation dose. Results: Following an interim analysis at a median time on study of 16 months, the study was closed, since a statistically significant increase was observed in the number of all relapses as well as isolated neuraxis relapses in patients randomized to the lower dose of neuraxis radiation. Conclusions: In patients with newly diagnosed medulloblastoma considered to have a good prognosis on the basis of low T stage, minimal residual tumor after at least subtotal resection, and no evidence of dissemination after thorough evaluation, there is an increased risk of early relapse associated with lowering the dose of neuraxis radiation from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions.
Medulloblastoma is a highly lethal disease when it recurs. Very few patients survive with conventional treatment. This study evaluated the use of high-dose carboplatin, thiotepa, and etoposide with autologous stem-cell rescue (ASCR) in patients with recurrent medulloblastoma.Chemotherapy consisted of carboplatin 500 mg/m2 (or area under the curve = 7 mg/mL x min via Calvert formula) on days -8, -7, and -6; and thiotepa 300 mg/m2 and etoposide 250 mg/m2 on days -5, -4, and -3; followed by ASCR on day 0. In addition to the study-prescribed therapy, 21 patients received other treatment: neurosurgical resection in seven, conventional chemotherapy in 17, and external-beam irradiation in 11 cases.Twenty-three patients with recurrent medulloblastoma, aged two to 44 years (median, 13 years) at ASCR, were treated. Three patients died of treatment-related toxicities within 21 days of ASCR; multiorgan system failure in two, and Aspergillus infection with venoocclusive disease in one. Seven of 23 patients (30%) are event-free survivors at a median of 54 months post-ASCR (range, 24 to 78 months). Kaplan-Meier estimates of event-free (EFS) and overall survival are 34% +/- 10% and 46% +/- 11%, respectively, at 36 months post-ASCR.This strategy may provide long-term survival for some patients with recurrent medulloblastoma.
The methodological advancement in microarray data analysis on the basis of false discovery rate (FDR) control, such as the q-value plots, allows the investigator to examine the FDR from several perspectives. However, when FDR control at the “customary" levels 0.01, 0.05, or 0.1 does not provide fruitful findings, there is little guidance for making the trade off between the significance threshold and the FDR level by sound statistical or biological considerations. Thus, meaningful statistical significance criteria that complement the existing FDR methods for large-scale multiple tests are desirable. Three statistical significance criteria, the profile information criterion, the total error proportion, and the guide-gene driven selection, are developed in this research. The first two are general significance threshold criteria for large-scale multiple tests; the profile information criterion is related to the recent theoretical studies of the connection between FDR control and minimax estimation, and the total error proportion is closely related to the asymptotic properties of FDR control in terms of the total error risk. The guide-gene driven selection is an approach to combining statistical significance and the existing biological knowledge of the study at hand. Error properties of these criteria are investigated theoretically and by simulation. The proposed methods are illustrated and compared using an example of genomic screening for novel Arf gene targets. Operating characteristics of q-value and the proposed significance threshold criteria are investigated and compared in a simulation study that employs a model mimicking a gene regulatory pathway. A guideline for using these criteria is provided. Splus/R code is available from the corresponding author upon request.
We studied the impact of gross total resection on progression-free survival (PFS) and postoperative morbidity in 40 children with locally advanced meduUoblastoma characterized by tumor invading the brain stem. These patients represented 40% of children treated for newly diagnosed meduUoblastoma at a pediatric oncology center over a 10-year period. All patients underwent aggressive initial surgical resection. Review of surgical and neuro-imaging findings documented gross total resection in 13 cases, near-total resection (< 1.5 cm2 residual tumor on imaging) in 14 cases, and subtotal resection (>than 50% resection with > 1.5 cm2 residual) in 13 cases. Overall, 85% of patients had a >90% resection. Subsequent therapy comprised craniospinal irradiation in all cases and chemotherapy on institutional or cooperative group protocols in 35 cases. At a median follow-up of 4 years, postirradiation PFS is 61% (SE = 10%). There was no difference in PFS for patients who underwent gross total resection compared to those with any detectable residual tumor (p > 0.70). The posterior fossa syndrome occurred in 25% of cases, and had no apparent relationship to the extent of resection (p > 0.5, exact test). In this series, true gross total resection was not associated with a PFS advantage when compared to strictly defined near-total and subtotal resection. Although there was no operative mortality, the frequency of the posterior fossa syndrome is of concern and emphasizes the need for careful consideration of the risk/benefit ratio in the surgical approach to this subgroup of patients.
<p>PDF file - 156K, Supplementary Fig. S1. Concentration-time plots of the first 72 hours after administration of the first vismodegib dose during Course 1 to the patients in the initial cohort: 6 received 85 mg/m2 (Figure A & B), and 7 received 170 mg/m2 (Figure C &D). Plasma concentrations of total vismodegib (A, C) and unbound vismodegib (B, D) were measured. Supplementary Fig S2. The relation between total vismodegib plasma concentrations and alpha-1-acid glycoprotein (AAGP) plasma concentrations in pediatric patients. The scatter plot includes all data from patients treated in this study. The solid line represents the best-fit line from linear regression analysis (R2= 0.38).</p>
BackgroundWe conducted a phase I study to estimate the maximum tolerated dose and describe the dose-limiting toxicities and pharmacokinetics of oral capecitabine rapidly disintegrating tablets given concurrently with radiation therapy to children with newly diagnosed brainstem or high-grade gliomas.
