Amy E. Armstrong

A Children's Oncology Group and TARGET initiative exploring the genetic landscape of Wilms tumor

We performed genome-wide sequencing and analyzed mRNA and miRNA expression, DNA copy number, and DNA methylation in 117 Wilms tumors, followed by targeted sequencing of 651 Wilms tumors. In addition to genes previously implicated in Wilms tumors (WT1, CTNNB1, AMER1, DROSHA, DGCR8, XPO5, DICER1, SIX1, SIX2, MLLT1, MYCN, and TP53), we identified mutations in genes not previously recognized as recurrently involved in Wilms tumors, the most frequent being BCOR, BCORL1, NONO, MAX, COL6A3, ASXL1, MAP3K4, and ARID1A. DNA copy number changes resulted in recurrent 1q gain, MYCN amplification, LIN28B gain, and MIRLET7A loss. Unexpected germline variants involved PALB2 and CHEK2. Integrated analyses support two major classes of genetic changes that preserve the progenitor state and/or interrupt normal development.

Late Effects in Pediatric High-risk Neuroblastoma Survivors after Intensive Induction Chemotherapy Followed by Myeloablative Consolidation Chemotherapy and Triple Autologous Stem Cell Transplants

Multimodal treatment in high-risk neuroblastoma has modestly improved survival; limited data exist on the late effects from these regimens. We report the sequelae of treatment incorporating 3 consecutive cycles of high-dose therapy and autologous stem cell transplants (ASCTs) without the use of total body irradiation (TBI). We reviewed the medical records of 61 patients treated on or following the Chicago Pilot 2 protocol between 1991 and 2008. Of the 25 patients who are alive (41%), 19 had near complete data to report. Specific treatment modalities and therapy-related side effects were collected. Fourteen of these 19 patients (74%) received 3 cycles of high-dose therapy with ASCT; follow-up occurred over a median of 13.9 years (range, 5.8 to 18.8 y). The majority of late effects were endocrine-related, including growth failure, hypothyroidism, and hypogonadism. Patients also developed secondary neoplasms and skeletal deformities. The most frequent sequela was hearing loss, seen in 17/19 patients. We found a high prevalence of various late effects in survivors of high-risk neuroblastoma using a non–TBI-based regimen including 3 cycles of high-dose therapy with ASCTs. As current treatment regimens recommend tandem ASCT without TBI, it is imperative that we understand and monitor for the sequelae from these modalities.

Treatment of neuroblastoma in congenital central hypoventilation syndrome with a PHOX2B polyalanine repeat expansion mutation: New twist on a neurocristopathy syndrome

Neuroblastoma in patients with congenital central hypoventilation syndrome (CCHS) as part of a neurocristopathy syndrome is a rare finding and has only been associated with paired‐like homeobox 2b (PHOX2B) non‐polyalanine‐repeat‐expansion mutations. To the best of our knowledge, we report the first case of a child with CCHS and Hirschsprung disease who had a PHOX2B polyalanine‐repeat‐expansion mutation (PARM) (genotype 20/33) and developed high‐risk neuroblastoma. We further describe his treatment including chemotherapy and therapeutic I131‐metaiodobenzylguanidine. This case highlights the need to consider neuroblastoma in patients with CCHS and the longest PHOX2B PARMs and to individualize treatment based on co‐morbidities. Pediatr Blood Cancer

Irinotecan and temozolomide for treatment of neuroblastoma in a patient with renal failure on hemodialysis

Renal failure is a rare complication of neuroblastoma or its therapy. To our knowledge, no reports describe treatment of children with neuroblastoma with chemotherapy in the setting of renal failure and maintenance hemodialysis. We report a 6‐year‐old child with high‐risk neuroblastoma who developed renal failure requiring long‐term hemodialysis. She was subsequently treated with 13 cycles of intravenous irinotecan 20 mg/m2/day and oral temozolomide 100 mg/m2/day for 5 days before disease progression without any dose adjustments, transfusions, febrile neutropenia or diarrhea. This case demonstrates that irinotecan and temozolomide can be safely administered in children with renal failure requiring hemodialysis. Pediatr Blood Cancer 2014;61:949–950.

Proximal Hypospadias and a Novel WT1 Variant: When Should Genetic Testing Be Considered?

We present a novel phenotypic presentation of a WT1 variant identified on a custom DSD gene panel. We present a case of an infant with proximal hypospadias, penoscrotal transposition, and bilaterally descended testes found to have a clinically significant WT1 gene alteration on a customized disorder of sex development genetic panel in which 62 genes associated with 46, XY disorders of sex development were evaluated. This diagnosis led to early screening for and diagnosis and treatment of Wilms tumor. Patients with proximal hypospadias are not routinely evaluated by genetic testing, and when initial hormonal analyses are within normal ranges for a typical male patient, the genital atypia is usually attributed to an isolated anatomic abnormality. There is no consensus among urologists, endocrinologists, or geneticists regarding when genetic testing is warranted in these patients or the extent of genetic testing that should be pursued. However, given advances in genetic testing and the discovery of more genetic variants, the genetic evaluation of infants with proximal hypospadias should be considered on an individual patient basis. Only with continued evaluation and the identification of further genetic variants can we establish future parameters for genetic evaluation in patients with proximal hypospadias and more appropriately counsel patients and their families regarding the implications of these variants.

The Impact of High-resolution HLA-A, HLA-B, HLA-C, and HLA-DRB1 on Transplant-related Outcomes in Single-unit Umbilical Cord Blood Transplantation in Pediatric Patients.

Current practice for selecting donor units for umbilical cord blood transplant (UCBT) involves matching at HLA-A and HLA-B by low-resolution typing and the HLA-DRB1 allele by high-resolution (HR) typing. We retrospectively studied the impact of HR allele matching at HLA-A, HLA-B, HLA-C, and HLA-DRB1 on transplant-related outcomes in 60 single-unit UCBTs in pediatric patients with malignant and nonmalignant conditions. Five-year overall survival of our cohort was 71% (95% confidence interval, 58-81); 27% experienced primary graft failure. Applying HR typing, donor-recipient mismatch variability increased ranging from 1/8 to 8/8, however, no impact on primary graft failure, graft-versus-host disease or posttransplant infection was observed. UCBTs with ≥6/8 HR matches did have a better overall survival (P=0.04) and decreased transplant-related mortality (P=0.02) compared with <6/8 HR matches. Using standard HLA typing, we showed an increased incidence of acute graft-versus-host disease (grade II to IV) and decreased transplant-related mortality in comparing the matched (6/6) versus ⩽5/6 group (P=0.05 and 0.05, respectively). These data support the use of current guidelines for umbilical cord blood selection and encourage utilization of HR typing to select umbilical cord blood units matched at ≥6/8 especially when appropriate ≥5/6 units are available.

Prolonged response to sorafenib in a patient with refractory metastatic osteosarcoma and a somatic PDGFRA D846V mutation

Outcome for patients with metastatic or recurrent/refractory osteosarcoma remains poor. Responses to sorafenib, a multikinase inhibitor, have been seen in recurrent/refractory osteosarcoma, although specific biomarkers of response have not been described. We report a partial response in a 7‐year‐old with refractory osteosarcoma treated with sorafenib 200 mg twice daily. Toxicities included Common Terminology Criteria for Adverse Events Grade 2 skin toxicities and growth suppression. After 51 months of therapy, he suffered a recurrence. Tumor sequencing later revealed a PDGFRA D846V mutation that was not identified in the relapse specimen. This case demonstrates prolonged partial response to sorafenib and provides a potential biomarker for response.

Current Knowledge and Practice of Pediatric Providers in Umbilical Cord Blood Banking

More than 35 000 umbilical cord blood (UCB) transplants have been performed worldwide, prompting the development of private and public banks to collect and store UCB cells. We hypothesized that pediatricians, who are uniquely poised to discuss UCB banking (UCBB) during prenatal or sibling visits, rarely do so. Through distribution of a 26-question electronic survey to general and subspecialty pediatric providers, we assessed baseline knowledge and conversations about UCBB. A total of 473 providers completed the survey; only 22% of physicians ever discussed UCBB with expectant parents. The majority responded that autologous UCB transplants were indicated in malignant (73%) and nonmalignant (61%) conditions; however, these are rare indications. Providers practicing >10 years were more likely to address UCBB (P ≤ .001), whereas younger and female general pediatric providers were significantly less likely (P < .001). Overall, pediatric providers rarely speak to families about UCBB, and we believe that they can be better informed to its current clinical utility.