Jed G. Nuchtern

The International Neuroblastoma Risk Group (INRG) Staging System: An INRG Task Force Report

PURPOSE The International Neuroblastoma Risk Group (INRG) classification system was developed to establish a consensus approach for pretreatment risk stratification. Because the International Neuroblastoma Staging System (INSS) is a postsurgical staging system, a new clinical staging system was required for the INRG pretreatment risk classification system. METHODS To stage patients before any treatment, the INRG Task Force, consisting of neuroblastoma experts from Australia/New Zealand, China, Europe, Japan, and North America, developed a new INRG staging system (INRGSS) based on clinical criteria and image-defined risk factors (IDRFs). To investigate the impact of IDRFs on outcome, survival analyses were performed on 661 European patients with INSS stages 1, 2, or 3 disease for whom IDRFs were known. RESULTS In the INGRSS, locoregional tumors are staged L1 or L2 based on the absence or presence of one or more of 20 IDRFs, respectively. Metastatic tumors are defined as stage M, except for stage MS, in which metastases are confined to the skin, liver, and/or bone marrow in children younger than 18 months of age. Within the 661-patient cohort, IDRFs were present (ie, stage L2) in 21% of patients with stage 1, 45% of patients with stage 2, and 94% of patients with stage 3 disease. Patients with INRGSS stage L2 disease had significantly lower 5-year event-free survival than those with INRGSS stage L1 disease (78% +/- 4% v 90% +/- 3%; P = .0010). CONCLUSION Use of the new staging (INRGSS) and risk classification (INRG) of neuroblastoma will greatly facilitate the comparison of risk-based clinical trials conducted in different regions of the world.

Laparoscopic evaluation of the pediatric inguinal hernia-a meta-analysis

BACKGROUND/PURPOSE For over 50 years there has been debate over how to manage the contralateral groin in children who present with a unilateral inguinal hernia. Many preoperative and intraoperative tools to diagnose a contralateral patent processus vaginalis or true inguinal hernia have been described. In 1992 laparoscopy was introduced as a new diagnostic test. Although multiple series have assessed this new tool, none of them have been able to statistically show that laparoscopy is effective in assessing the contralateral groin. By combining all published studies and using the technique of meta-analysis, intraoperative laparoscopy can be shown to be effective in diagnosing a contralateral patent processus vaginalis in children undergoing unilateral inguinal herniorrhaphy. METHODS All available studies of children with a unilateral hernia who had exploration of the contralateral groin by laparoscopy were reanalyzed. Sensitivity and specificity of laparoscopy was determined using open exploration or development of a metachronous hernia as the gold standard. RESULTS Nine hundred sixty-four patients were suitable for analysis. A contralateral hernia was seen on laparoscopy in 376 patients. All of these patients underwent open contralateral exploration. A patent processus vaginalis or true hernia sac was found in 373. The sensitivity of laparoscopy was 99.4% (95% confidence interval 97.87 to 99.91). Five hundred eighty-eight patients had a laparoscopy with negative results. Sixty-two of these patients then had open contralateral exploration. In one case, a patent processus vaginalis was found; the other 61 patients underwent exploration with negative results. In the remaining 526 laparoscopy-negative patients, follow-up (1 month to 3 years) was used to see if a contralateral hernia developed. A metachronous hernia developed in one of the 526 patients. The specificity of laparoscopy was 99.5% (95% confidence interval 98.39 to 99.87). Laparoscopy added an average of 6 minutes to the surgical time and was accurate regardless of the technique. There were two minor complications related to laparoscopy and no deaths. CONCLUSIONS Laparoscopy may be the ideal tool to diagnose a contralateral patent processus vaginalis intraoperatively. It is sensitive, specific, fast, and safe. Although the presence of a patent processus does not imply that the patient will go on to develop a metachronous hernia, identifying and ligating a patent processus should certainly prevent the development of an indirect inguinal hernia.

Targeting of GD2‐positive tumor cells by human T lymphocytes engineered to express chimeric T‐cell receptor genes

Genetic engineering of human T lymphocytes to express tumor antigen‐specific chimeric immune receptors is an attractive means for providing large numbers of effector cells for adoptive immunotherapy while bypassing major mechanisms of tumor escape from immune recognition. We have applied this strategy to the targeting of a GD2‐positive tumor, neuroblastoma, which is the commonest extracranial solid tumor of childhood. Chimeric immune receptors were generated by joining an extracellular antigen‐binding domain derived from either of the 2 ganglioside GD2‐specific antibodies sc7A4 and sc14.G2a to a cytoplasmic signaling domain. The variable domains of hybridoma antibody 14.G2a were cloned and selected using a phage display approach. Upon coincubation with GD2‐expressing tumor cell targets, human T lymphocytes transduced with recombinant retroviruses encoding chimeric receptors based on sc14.G2a, but not sc7A4, secreted significant levels of cytokines in a pattern comparable to the cytokine response obtained by engagement of the CD3 receptor. T cells transduced with the sc14.G2a‐based chimeric T‐cell receptors also displayed specific lysis of GD2‐positive neuroblastoma cells, which was blocked in the presence of monoclonal antibody 14.G2a. In the absence of nonspecific stimulation of transduced cells, their functionality declined over time and antigenic stimulation of the chimeric receptor alone did not induce commitment to proliferation. These results support the feasibility of redirecting human T lymphocytes to a tumor‐associated ganglioside epitope but emphasize that successful chimeric receptor‐mediated adoptive immunotherapy will require additional strategies that overcome functional inactivation of gene‐modified primary T lymphocytes.

Meta-analysis of the risk of metachronous hernia in infants and children

BACKGROUND Inguinal herniorrhaphy is the most common general surgical procedure performed in children. The presence of a contralateral patent processus vaginalis forms the basis of the recommendation for contralateral exploration in patients undergoing unilateral herniorrhaphy. However, a patent processus vaginalis does not necessarily go on to become a clinically apparent inguinal hernia. METHODS All published pediatric series, in which patients underwent unilateral inguinal hernia repair and were evaluated for the development of a metachronous hernia, were included. The incidence of and risk factors associated with development a metachronous hernia were evaluated with meta-analysis. RESULTS There were 15,310 patients ranging in age from birth to 16 years, including premature infants. Of these, 1,062 patients (7%) developed a metachronous hernia. Gender and age were not risk factors. There was an 11% risk of metachronous hernia if the original hernia was on the left side, a risk that was 50% greater than if the original hernia was on the right. Of patients who developed a metachronous hernia, 90% did so within 5 years. The complication rate of metachronous hernia was 0.5%. CONCLUSION There is no role for routine contralateral groin exploration. High-risk infants and children, especially those who undergo left inguinal herniorrhaphy, may benefit from contralateral groin exploration. If a patent processus vaginalis is found, it should be ligated. Patients who do not undergo contralateral groin exploration should be followed up for 5 years.

Diagnostic Yield of Clinical Tumor and Germline Whole-Exome Sequencing for Children With Solid Tumors.

Importance Whole-exome sequencing (WES) has the potential to reveal tumor and germline mutations of clinical relevance, but the diagnostic yield for pediatric patients with solid tumors is unknown. Objective To characterize the diagnostic yield of combined tumor and germline WES for children with solid tumors. Design Unselected children with newly diagnosed and previously untreated central nervous system (CNS) and non-CNS solid tumors were prospectively enrolled in the BASIC3 study at a large academic childrens hospital during a 23-month period from August 2012 through June 2014. Blood and tumor samples underwent WES in a certified clinical laboratory with genetic results categorized on the basis of perceived clinical relevance and entered in the electronic health record. Main Outcomes and Measures Clinical categorization of somatic mutations; frequencies of deleterious germline mutations related to patient phenotype and incidental medically-actionable mutations. Results Of the first 150 participants (80 boys and 70 girls, mean age, 7.4 years), tumor samples adequate for WES were available from 121 patients (81%). Somatic mutations of established clinical utility (category I) were reported in 4 (3%) of 121 patients, with mutations of potential utility (category II) detected in an additional 29 (24%) of 121 patients. CTNNB1 was the gene most frequently mutated, with recurrent mutations in KIT, TSC2, and MAPK pathway genes (BRAF, KRAS, and NRAS) also identified. Mutations in consensus cancer genes (category III) were found in an additional 24 (20%) of 121 tumors. Fewer than half of somatic mutations identified were in genes known to be recurrently mutated in the tumor type tested. Diagnostic germline findings related to patient phenotype were discovered in 15 (10%) of 150 cases: 13 pathogenic or likely pathogenic dominant mutations in adult and pediatric cancer susceptibility genes (including 2 each in TP53, VHL, and BRCA1), 1 recessive liver disorder with hepatocellular carcinoma (TJP2), and 1 renal diagnosis (CLCN5). Incidental findings were reported in 8 (5%) of 150 patients. Most patients harbored germline uncertain variants in cancer genes (98%), pharmacogenetic variants (89%), and recessive carrier mutations (85%). Conclusions and Relevance Tumor and germline WES revealed mutations in a broad spectrum of genes previously implicated in both adult and pediatric cancers. Combined reporting of tumor and germline WES identified diagnostic and/or potentially actionable findings in nearly 40% of newly diagnosed pediatric patients with solid tumors.

Deregulated minichromosomal maintenance protein MCM7 contributes to oncogene driven tumorigenesis

Minichromosomal maintenance protein 7 (MCM7) is an essential component of the replication helicase complex (MCM2-7) required for DNA replication. Although this function is highly conserved among eukaryotes, additional functions for the MCM molecules continue to be described. Minichromosomal maintenance protein 7 is a marker for proliferation and is upregulated in a variety of tumors including neuroblastoma, prostate, cervical and hypopharyngeal carcinomas. To further investigate the general role of MCM7 in tumorigenesis, we generated a mouse model with deregulated MCM7 expression targeted to the basal layer of the epidermis using the keratin 14 (K14) promoter (K14.MCM7). When subjected to a two-stage chemical carcinogenesis protocol (dimethylbenz[α]anthracene (DMBA) initiation with 12-ortho-tetradecanoylphorbol-13-acetate promotion), K14.MCM7 mice showed significantly increased incidence and prevalence of tumor development relative to controls. Furthermore, within 40 weeks of treatment over 45% K14.MCM7 mice exhibited tumors that had converted to squamous cell carcinomas versus none in the control group. As predicted from previous skin carcinogenesis studies using DMBA as the initiating agent, Ras mutations where found in more than 90% of tumors isolated from K14.MCM7 mice. Whereas previous studies have shown that MCM7 is useful as a proliferation marker, our data suggest that deregulated MCM7 expression actively contributes to tumor formation, progression and malignant conversion.

Phosphorylation of Thr-178 and Thr-184 in the TAK1 T-loop Is Required for Interleukin (IL)-1-mediated Optimal NFκB and AP-1 Activation as Well as IL-6 Gene Expression

TAK1 (transforming growth factor-β-activated kinase 1), a mitogen-activated protein kinase kinase kinase, is activated by various cytokines, including interleukin-1 (IL-1). However, the precise regulation for TAK1 activation at the molecular level is still not fully understood. Here we report that dual phosphorylation of Thr-178 and Thr-184 residues within the kinase activation loop of TAK1 is essential for TAK1-mediated NFκB and AP-1 activation. Once co-overexpressed with TAB1, TAK1 mutant with alanine substitution of these two residues fails to activate IKKβ-mediated NFκB and JNK-mediated AP-1, whereas TAK1 mutant with replacement of these two sites with acidic residues acts like the TAK1 wild type. Consistently, TAK1 mutant with alanine substitution of these two residues severely inhibits IL-1-induced NFκB and AP-1 activities, whereas TAK1 mutant with replacement of these two sites with acidic residues slightly enhances IL-1-induced NFκB and AP-1 activities compared with the TAK1 wild-type. IL-1 induces the phosphorylation of endogenous TAK1 at Thr-178 and Thr-184. Reconstitution of TAK1-deficient mouse embryo fibroblast cells with wild-type TAK1 or a TAK1 mutant containing threonine 178 and 184 to alanine mutations revealed the importance of these two sites in IL-1-mediated IKK-NFκB and JNK-AP-1 activation as well as IL-1-induced IL-6 gene expression. Our finding is the first report that substitution of key serine/threonine residues with acidic residues mimics the phosphorylated state of TAK1 and renders TAK1 active during its induced activation.

A prospective study of expectant observation as primary therapy for neuroblastoma in young infants: A children's oncology group study

Objective:To demonstrate that expectant observation of young infants with small adrenal masses would result in excellent event-free and overall survival. Background:Neuroblastoma is the most common malignant tumor in infants, and in young infants, 90% of neuroblastomas are located in the adrenal gland. Although surgical resection is standard therapy, multiple observations suggest that expectant observation could be a safe alternative for infants younger than 6 months who have small adrenal masses. Methods:A prospective study of infants younger than 6 months with small adrenal masses and no evidence of spreading beyond the primary tumor was performed at participating Childrens Oncology Group institutions. Parents could choose observation or immediate surgical resection. Serial abdominal sonograms and urinary vanillylmandelic acid and homovanillic acid measurements were performed during a 90-week interval. Infants experiencing a 50% increase in the volume of the mass, urine catecholamine values, or an increase in the homovanillic acid to vanillylmandelic acid ratio greater than 2, were referred for surgical resection. Results:Eighty-seven eligible patients were enrolled: 83 elected observation and 4 chose immediate surgery. Sixteen observational patients ultimately had surgery; 8 had International Neuroblastoma Staging System stage 1 neuroblastoma, 2 had higher staged neuroblastoma (2B and 4S), 2 had low-grade adrenocortical neoplasm, 2 had adrenal hemorrhage, and 2 had extralobar pulmonary sequestration. The 2 patients with adrenocortical tumors were resected because of a more than 50% increase in tumor volume. The 3-year event-free survival for a neuroblastoma event was 97.7 ± 2.2% within the entire cohort of patients (n = 87). The 3-year overall survival was 100%, with a median follow-up of 3.2 years. Eighty-one percent of patients on the observation arm were spared resection. Conclusions:Expectant observation of infants younger than 6 months with small adrenal masses led to excellent event-free survival and overall survival while avoiding surgical intervention in a large majority of the patients.

Aurora A is a negative prognostic factor and a new therapeutic target in human neuroblastoma

We studied expression of the Aurora A gene and its clinical significance in a cohort of neuroblastoma patients. In addition, we investigated the antitumor activity of MLN8054, a novel small-molecule inhibitor of Aurora A kinase, on cultured NB cell lines in vitro. Aurora A mRNA expression was assessed by quantitative real-time PCR in tumor tissue specimens from 67 patients at diagnosis and in 9 human neuroblastoma cell lines. Western blot assays for Aurora A protein were done on tumor tissue of 53 patients. The results were correlated with various prognostic factors of neuroblastoma. Aurora A mRNA and protein expression were identified in 9 of 9 neuroblastoma cell lines. Overexpression of Aurora A mRNA in neuroblastoma tumor tissue is associated with high risk (P = 0.019), high-stage (International Neuroblastoma Staging System III and IV) tumors (P = 0.007), unfavorable histology (P = 0.007), MYCN amplification (P = 0.017), disease relapse (P = 0.019), and decreased progression-free survival (P < 0.0001) but not correlated with the age at diagnosis (P = 0.877). Similarly, Aurora A protein expression also significantly correlated with high risk (P = 0.011), high stage (P = 0.0028), unfavorable histology (P = 0.0006), MYCN amplification (P = 0.0029), and disease relapse (P = 0.044). Small interfering RNA–mediated knockdown of the endogenous Aurora A gene causes a proliferation defect and enhances chemosensitivity in human neuroblastoma cell lines. In support of these observations, the Aurora A kinase inhibitor, MLN8054, markedly inhibited growth of cultured neuroblastoma cell lines through an apoptosis-dependent pathway. Overexpression of Aurora A is associated with disease progression in neuroblastoma. Inhibition of this kinase is a promising modality for neuroblastoma treatment. [Mol Cancer Ther 2009;8(8):2461–9]

Nonoperative initial management versus silon chimney for treatment of giant omphalocele

Giant omphalocele is a major clinical challenge for pediatric surgeons. Whereas small- to medium-sized defects can be repaired primarily, larger omphaloceles cannot be closed at birth because the liver and small bowel have lost the right of domain to the abdomen. Two divergent strategies have evolved for treating these giant defects: (1) use of a silon chimney with gradual reduction of the contents of the sac, and (2) initial nonoperative management (epithelialization) of the omphalocele followed by repair of the residual ventral hernia. In an 18-year retrospective study, we have reviewed our experience with these treatment methods. Ninety-four infants underwent treatment for omphalocele between 1975 and 1993. Primary closure (PC) was possible in 55 patients, silon chimney (SC) was used in 15, and 7 had nonoperative management (NM) with epithelialization. In the remaining 17 infants, surgery was believed to be inappropriate because of the lethality of their associated anomalies. Major (but potentially survivable) anomalies were present in 26% of PC, 13% of SC, and 71% of the NM group patients. The majority of the liver was present in 73% of SC- and 86% of NM-treated omphaloceles. There was a decrease in length of stay, time to enteral feeding, and mortality over the 18-year period. However, those patients whose defects could not be closed primarily had consistently longer hospital stays. This was particularly true for the SC patients. The decreased use of total parenteral nutrition seems to reflect a shift from SC to NM rather than a decrease in the interval to full enteral feeding in any given treatment group over time.(ABSTRACT TRUNCATED AT 250 WORDS)