Experience with International Neuroblastoma Staging System and Pathology Classification

A nationwide phase II study of delayed local treatment for children with high-risk neuroblastoma: The Japan Children's Cancer Group Neuroblastoma Committee Trial JN-H-11

PURPOSE

Survival rates of patients with high-risk neuroblastoma are unacceptable. A time-intensified treatment strategy with delayed local treatment to control systemic diseases has been developed in Japan. We conducted a nationwide, prospective, single-arm clinical trial with delayed local treatment. This study evaluated the safety and efficacy of delayed surgery to increase treatment intensity.

PATIENTS AND METHODS

Seventy-five patients with high-risk neuroblastoma were enrolled in this study between May 2011 and September 2015. Delayed local treatment consisted of five courses of induction chemotherapy (cisplatin, pirarubicin, vincristine, and cyclophosphamide) and myeloablative high-dose chemotherapy (melphalan, etoposide, and carboplatin), followed by local tumor extirpation with surgery and irradiation. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), response rate, adverse events, and surgical complications.

RESULTS

Seventy-five patients were enrolled, and 64 were evaluable (stage 3, n = 8; stage 4, n = 56). The estimated 3-year PFS and OS rates (95% confidence interval [CI]) were 44.4% [31.8%-56.3%] and 80.7% [68.5%-88.5%], resspectively. The response rate of INRC after completion of the treatment protocol was 66% (42/64; 95% CI: 53%-77%; 23 CR [complete response], 10 VGPR [very good partial response], and nine PR [partial response]). None of the patients died during the protocol treatment or within 30 days of completion. Grade 4 adverse effects, excluding hematological adverse effects, occurred in 48% of patients [31/64; 95% CI: 36%-61%]. Major Surgical complications were observed in 25% of patients [13/51; 95% CI: 14%-40%].

CONCLUSION

This study indicates that delayed local treatment is feasible and shows promising efficacy, suggesting that this treatment should be considered further in a comparative study of high-risk neuroblastoma.

Identification of immune-related signature with prognosis in children with stage 4 and 4S neuroblastoma

OBJECTIVE

Spontaneous regression of tumors is an attractive phenomenon that most commonly occurs in stage 4S neuroblastoma (NB). However, the mechanism underlying this phenomenon remains unclear.

METHODS

Datasets correlated with NB were downloaded from online public databases, the differentially expressed genes (DEGs) between stage 4 and 4S associated with immunity were identified, and functional enrichment analysis was utilized to explore the potential functions and signaling pathways of these DEGs. In addition, based on these DEGs, a prognostic signature was constructed and validated, and differences in immune cell infiltration were analyzed.

RESULTS

A total of 13 DEGs were finally identified, and functional enrichment analysis revealed that these DEGs were primarily enriched in the positive regulation of neuron differentiation and TGF-β signaling pathway. The signature successfully stratifies patients into two risk score groups and performs well in judging prognosis and predicting overall survival time. In addition, the prognostic value of the risk score calculated by the signature was independent of clinical factors. The results of immune cell infiltration showed that patients with a high infiltration of resting CD4 + memory T cells had a better prognosis, while plasma cells had a worse prognosis.

CONCLUSION

The results of the functional enrichment analysis of these identified DEGs suggested that these DEGs may be related to spontaneous regression of NB. In addition, the prognostic signature has the potential to create new risk stratification in patients with NB.

Integrative analysis with machine learning identifies diagnostic and prognostic signatures in neuroblastoma based on differentially DNA methylated enhancers between INSS stage 4 and 4S neuroblastoma

INTRODUCTION

Accumulating evidence demonstrates that aberrant methylation of enhancers is crucial in gene expression profiles across several cancers. However, the latent effect of differently expressed enhancers between INSS stage 4S and 4 neuroblastoma (NB) remains elusive.

METHODS

We utilized the transcriptome and methylation data of stage 4S and 4 NB patients to perform Enhancer Linking by Methylation/Expression Relationships (ELMER) analysis, discovering a differently expressed motif within 67 enhancers between stage 4S and 4 NB. Harnessing the 67 motif genes, we established the INSS stage related signature (ISRS) by amalgamating 12 and 10 distinct machine learning (ML) algorithms across 113 and 101 ML combinations to precisely diagnose stage 4 NB among all NB patients and to predict the prognosis of NB patients. Based on risk scores calculated by prognostic ISRS, patients were categorized into high and low-risk groups according to median risk score. We conducted comprehensive comparisons between two risk groups, in terms of clinical applications, immune microenvironment, somatic mutations, immunotherapy, chemotherapy and single-cell analysis. Ultimately, we empirically validated the differential expressions of two ISRS model genes, CAMTA2 and FOXD1, through immunochemistry staining.

RESULTS

Through leave-one-out cross-validation, in both feature selection and model construction, we selected the random forest algorithm to diagnose stage 4 NB, and Enet algorithm to develop prognostic ISRS, due to their highest average C-index across five NB cohorts. After validations, the ISRS demonstrated a stable predictive capability, outperforming the previously published NB signatures and several clinic variables. We stratified NB patients into high and low-risk group based on median risk score, which showed the low-risk group with a superior survival outcome, an abundant immune infiltration, a decreased mutation landscape, and an enhanced sensitivity to immunotherapy. Single-cell analysis between two risk groups reveals biologically cellular variations underlying ISRS. Finally, we verified the significantly higher protein levels of CAMTA2 and FOXD1 in stage 4S NB, as well as their protective prognosis value in NB.

CONCLUSION

Based on multi-omics data and ML algorithms, we successfully developed the ISRS to enable accurate diagnosis and prognostic stratification in NB, which shed light on molecular mechanisms of spontaneous regression and clinical utilization of ISRS.

Metabolomics-transcriptomics joint analysis: unveiling the dysregulated cell death network and developing a diagnostic model for high-grade neuroblastoma

High-grade neuroblastoma (HG-NB) exhibits a significantly diminished survival rate in comparison to low-grade neuroblastoma (LG-NB), primarily attributed to the mechanism of HG-NB is unclear and the lacking effective therapeutic targets and diagnostic model. Therefore, the current investigation aims to study the dysregulated network between HG-NB and LG-NB based on transcriptomics and metabolomics joint analysis. Meanwhile, a risk diagnostic model to distinguish HG-NB and LG-NB was also developed. Metabolomics analysis was conducted using plasma samples obtained from 48 HG-NB patients and 36 LG-NB patients. A total of 39 metabolites exhibited alterations, with 20 showing an increase and 19 displaying a decrease in HG-NB. Additionally, transcriptomics analysis was performed on NB tissue samples collected from 31 HG-NB patients and 20 LG-NB patients. Results showed that a significant alteration was observed in a total of 1,199 mRNAs in HG-NB, among which 893 were upregulated while the remaining 306 were downregulated. In particular, the joint analysis of both omics data revealed three aberrant pathways, namely the cAMP signaling pathway, PI3K-Akt signaling pathway, and TNF signaling pathway, which were found to be associated with cell death. Notably, a diagnostic model for HG-NB risk classification was developed based on the genes MGST1, SERPINE1, and ERBB3 with an area under the receiver operating characteristic curve of 0.915. In the validation set, the sensitivity and specificity were determined to be 75.0% and 80.0%, respectively.

Comparative epigenomics by machine learning approach for neuroblastoma

BACKGROUND

Neuroblastoma (NB) is the second most common pediatric solid tumor. Because the number of genetic mutations found in tumors are small, even in some patients with unfavorable NB, epigenetic variation is expected to play an important role in NB progression. DNA methylation is a major epigenetic mechanism, and its relationship with NB prognosis has been a concern. One limitation with the analysis of variation in DNA methylation is the lack of a suitable analytical model. Therefore, in this study, we performed a random forest (RF) analysis of the DNA methylome data of NB from multiple databases.

RESULTS

RF is a popular machine learning model owing to its simplicity, intuitiveness, and computational cost. RF analysis identified novel intermediate-risk patient groups with characteristic DNA methylation patterns within the low-risk group. Feature selection analysis based on probe annotation revealed that enhancer-annotated regions had strong predictive power, particularly for MYCN-amplified NBs. We developed a gene-based analytical model to identify candidate genes related to disease progression, such as PRDM8 and FAM13A-AS1. RF analysis revealed sufficient predictive power compared to other machine learning models.

CONCLUSIONS

RF is a useful tool for DNA methylome analysis in cancer epigenetic studies, and has potential to identify a novel cancer-related genes.

The Machine-Learning-Mediated Interface of Microbiome and Genetic Risk Stratification in Neuroblastoma Reveals Molecular Pathways Related to Patient Survival

Simple Summary

Neuroblastoma is a highly heterogeneous malignancy with a wide range of outcomes from spontaneous regression to fatal chemoresistant disease, as currently treated according to the risk stratification of the Children’s Oncology Group (COG), resulting in some high COG risk patients receiving excessive treatment, due to lacking predictors for treatment response. Here, we sought to complement COG risk classification by using the tumor intracellular microbiome, which is part of the tumor’s molecular signature. We determine that an intra-tumor microbial gene abundance score, namely M-score, separates the high COG-risk patients into two subpopulations (M_high and M_low) with higher accuracy in risk stratification than the current COG risk assessment, thus sparing a subset of high COG-risk patients from being subjected to traditional high-risk therapies.

Abstract

Currently, most neuroblastoma patients are treated according to the Children’s Oncology Group (COG) risk group assignment; however, neuroblastoma’s heterogeneity renders only a few predictors for treatment response, resulting in excessive treatment. Here, we sought to couple COG risk classification with tumor intracellular microbiome, which is part of the molecular signature of a tumor. We determine that an intra-tumor microbial gene abundance score, namely M-score, separates the high COG-risk patients into two subpopulations (M_high and M_low) with higher accuracy in risk stratification than the current COG risk assessment, thus sparing a subset of high COG-risk patients from being subjected to traditional high-risk therapies. Mechanistically, the classification power of M-scores implies the effect of CREB over-activation, which may influence the critical genes involved in cellular proliferation, anti-apoptosis, and angiogenesis, affecting tumor cell proliferation survival and metastasis. Thus, intracellular microbiota abundance in neuroblastoma regulates intracellular signals to affect patients’ survival.

Are There Any Limiting Factors of Minimally Invasive Adrenalectomy in Children? Over 20-Year Single-Center Experience

<b> Introduction:</b> Laparoscopic adrenalectomy is more widely recognized as a valuable treatment method for benign and malignant tumours. </br></br> <b>Aim:</b> This study reviews over 20-year experience with laparoscopic adrenalectomy in children in Central-West Poland. </br></br> <b>Materials and methods:</b> During the last 21 years, 5041 laparoscopic procedures were performed, among them 39 adrenalectomies in children aged from 2 days to 17 years. The following data were analysed: patient's age at diagnosis and surgery, lesion volume in CT/MRI examination, duration of surgery, the incidence of complication after surgery, and length of hospitalization. </br></br> <b>Results:</b> The volume of adrenal lesion visualized by CT or MRI before surgery varied from 0.5 cm3 up to 490 cm3, with a median of 14 cm3. As many as 80% of adrenalectomies allowed radical removal of the lesion and 92% of those procedures were performed without any complications. From all data analysed, only age, both at diagnosis and at surgery, was significantly lower in patients with a malignant lesion. </br></br> <b>Conclusions:</b> Laparoscopic adrenalectomy is a valuable method to use in paediatric patients for both benign and malignant adrenal lesions. However, in patients with malignant adrenal lesions it may be expected that the procedure will be more difficult due to the lower age and larger lesion size.

Identification of an Autophagy-Related Risk Signature Correlates With Immunophenotype and Predicts Immune Checkpoint Blockade Efficacy of Neuroblastoma

Neuroblastoma is one of the malignant solid tumors with the highest mortality in childhood. Targeted immunotherapy still cannot achieve satisfactory results due to heterogeneity and tolerance. Exploring markers related to prognosis and evaluating the immune microenvironment remain the major obstacles. Herein, we constructed an autophagy-related gene (ATG) risk model by multivariate Cox regression and least absolute shrinkage and selection operator regression, and identified four prognostic ATGs (BIRC5, GRID2, HK2, and RNASEL) in the training cohort, then verified the signature in the internal and external validation cohorts. BIRC5 and HK2 showed higher expression in MYCN amplified cell lines and tumor tissues consistently, whereas GRID2 and RNASEL showed the opposite trends. The correlation between the signature and clinicopathological parameters was further analyzed and showing consistency. A prognostic nomogram using risk score, International Neuroblastoma Staging System stage, age, and MYCN status was built subsequently, and the area under curves, net reclassification improvement, and integrated discrimination improvement showed more satisfactory prognostic predicting performance. The ATG prognostic signature itself can significantly divide patients with neuroblastoma into high- and low-risk groups; differentially expressed genes between the two groups were enriched in autophagy-related behaviors and immune cell reactions in gene set enrichment analysis (false discovery rate q -value < 0.05). Furthermore, we evaluated the relationship of the signature risk score with immune cell infiltration and the cancer-immunity cycle. The low-risk group was characterized by more abundant expression of chemokines and higher immune checkpoints (PDL1, PD1, CTLA-4, and IDO1). The risk score was significantly correlated with the proportions of CD8+ T cells, CD4+ memory resting T cells, follicular helper T cells, memory B cells, plasma cells, and M2 macrophages in tumor tissues. In conclusion, we developed and validated an autophagy-related signature that can accurately predict the prognosis, which might be meaningful to understand the immune microenvironment and guide immune checkpoint blockade.

Inhibition of fatty acid synthesis induces differentiation and reduces tumor burden in childhood neuroblastoma

Many metabolic pathways, including lipid metabolism, are rewired in tumors to support energy and biomass production and to allow adaptation to stressful environments. Neuroblastoma is the second deadliest solid tumor in children. Genetic aberrations, as the amplification of the MYCN-oncogene, correlate strongly with disease progression. Yet, there are only a few molecular targets successfully exploited in the clinic. Here we show that inhibition of fatty acid synthesis led to increased neural differentiation and reduced tumor burden in neuroblastoma xenograft experiments independently of MYCN-status. This was accompanied by reduced levels of the MYCN or c-MYC oncoproteins and activation of ERK signaling. Importantly, the expression levels of genes involved in de novo fatty acid synthesis showed prognostic value for neuroblastoma patients. Our findings demonstrate that inhibition of de novo fatty acid synthesis is a promising pharmacological intervention strategy for the treatment of neuroblastoma independently of MYCN-status.

Predictors of differential response to induction therapy in high-risk neuroblastoma: A report from the Children's Oncology Group (COG)

BACKGROUND

Induction chemotherapy plays an important role in the management of patients with high-risk neuroblastoma. Predictors of response to induction therapy are largely lacking. We sought to describe clinical and biological features associated with induction response.

METHODS

Patients from four consecutive COG high-risk trials were included. Response was evaluated by the 1993 International Neuroblastoma Response Criteria. The primary end-point was end-induction partial response (PR) or better. Univariate analyses were performed to compare response as a function of clinical or biologic predictors. A multivariate logistic regression model using significant predictors from univariate analyses was constructed to model PR or better.

RESULTS

The analytic cohort included 1242 patients. End-induction response ≥PR was significantly associated with higher event-free and overall survival. Baseline factors associated with ≥PR included age <18 months (87.4% with ≥PR vs. 78.7% if older; p = 0.0103), International Neuroblastoma Staging System non-stage 4 (89.0% vs. 78.4% if stage 4; p = 0.0016), MYCN amplification (85.5% vs. 77.1% if non-amplified; p = 0.0006), 1p loss of heterozygosity (LOH; 85.6% vs. 76.0% if no LOH; p = 0.0085), no 11q LOH (84.8% vs. 70.9% if 11q LOH; p = 0.0004) and high mitosis-karyorrhexis index (MKI; 84.5% vs. 77.5% if low-intermediate MKI; p = 0.0098). On multivariable analysis (n = 407), the absence of 11q LOH was the only factor that remained significantly associated with ≥PR (odds ratio: 1.962 vs. 11q LOH; 95% confidence interval 1.104-3.487; p = 0.0216).

CONCLUSIONS

Improved end-induction response in high-risk neuroblastoma is associated with longer survival. Patients with 11q LOH are less likely to respond to induction therapies and should be prioritised for novel approaches in future trials.

The Evolution of Risk Classification for Neuroblastoma

Neuroblastoma is a tumor with great clinical heterogeneity. Patients in North America are risk-stratified using a number of features including age at diagnosis, disease stage, tumor histology, MYCN status (amplified versus nonamplified), and tumor cell ploidy. In this paper, we review the evidence for utilizing these features in the risk classification of neuroblastic tumors. Additionally, we review the clinical and biologic criteria used by various cooperative groups to define low, intermediate, and high-risk disease populations in clinical trials, highlighting the differences in risk classification internationally. Finally, we discuss the development of the International Neuroblastoma Risk Group classification system, designed to begin worldwide standardization of neuroblastoma pretreatment risk classification and allow comparison of clinical trials conducted through different cooperative groups.

Natural Killer-Derived Exosomal miR-186 Inhibits Neuroblastoma Growth and Immune Escape Mechanisms

In neuroblastoma, the interplay between immune cells of the tumor microenvironment and cancer cells contributes to immune escape mechanisms and drug resistance. In this study, we show that natural killer (NK) cell-derived exosomes carrying the tumor suppressor microRNA (miR)-186 exhibit cytotoxicity against MYCN-amplified neuroblastoma cell lines. The cytotoxic potential of these exosomes was partly dependent upon expression of miR-186. miR-186 was downregulated in high-risk neuroblastoma patients, and its low expression represented a poor prognostic factor that directly correlated with NK activation markers (i.e., NKG2D and DNAM-1). Expression of MYCN, AURKA, TGFBR1, and TGFBR2 was directly inhibited by miR-186. Targeted delivery of miR-186 to MYCN-amplified neuroblastoma or NK cells resulted in inhibition of neuroblastoma tumorigenic potential and prevented the TGFβ1-dependent inhibition of NK cells. Altogether, these data support the investigation of a miR-186-containing nanoparticle formulation to prevent tumor growth and TGFβ1-dependent immune escape in high-risk neuroblastoma patients as well as the inclusion of ex vivo-derived NK exosomes as a potential therapeutic option alongside NK cell-based immunotherapy.Significance: These findings highlight the therapeutic potential of NK cell-derived exosomes containing the tumor suppressor miR-186 that inhibits growth, spreading, and TGFβ-dependent immune escape mechanisms in neuroblastoma.

Analysis of the risk factor for the poor prognosis of localized neuroblastoma after the surgical

Neuroblastoma is a unique malignancy in infants often presenting with either localized or metastatic disease. The study was carried out to explore the risk stratification of the poor prognosis for patients underwent surgical treatment.60 patients diagnosed with neuroblastoma were primarily enrolled in the study from April 2008 to April 2016. All the patients underwent surgical treatment and received 5-year follow-up. Clinical variables, including age, International Neuroblastoma Staging System (INSS) stage, tumor size and site, histology, and MYCN status were retrospectively analyzed, and EFS was chosen as the endpoint.The median age of patients was 8.2 months and average follow-up period was 40.2 ± 8.6 months. Among 60 patients, complete remission was achieved in 35 patients and partial remission in 14 subjects. Poor prognosis including patient death and tumor progression were overserved in 11 patients. Cox multifactor regression analysis revealed that age, histology and MYCN status had significant prognostic effect on event-free survival (EFS) rate for neuroblastoma patients underwent surgical treatment.In our study, we identified a series of prognostic factors including age, histology, and MYCN status predicting the prognosis of neuroblastoma patients after surgical treatment.

Neuroblastoma

Neuroblastoma is one of the most common solid tumors in children and has a diverse clinical behavior that largely depends on the tumor biology. Neuroblastoma exhibits unique features, such as early age of onset, high frequency of metastatic disease at diagnosis in patients over 1 year of age and the tendency for spontaneous regression of tumors in infants. The high-risk tumors frequently have amplification of the MYCN oncogene as well as segmental chromosome alterations with poor survival. Recent advanced genomic sequencing technology has revealed that mutation of ALK, which is present in ~10% of primary tumors, often causes familial neuroblastoma with germline mutation. However, the frequency of gene mutations is relatively small and other aberrations, such as epigenetic abnormalities, have also been proposed. The risk-stratified therapy was introduced by the Japan Neuroblastoma Study Group (JNBSG), which is now moving to the Neuroblastoma Committee of Japan Children's Cancer Group (JCCG). Several clinical studies have facilitated the reduction of therapy for children with low-risk neuroblastoma disease and the significant improvement of cure rates for patients with intermediate-risk as well as high-risk disease. Therapy for patients with high-risk disease includes intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy. The JCCG aims for better cures and long-term quality of life for children with cancer by facilitating new approaches targeting novel driver proteins, genetic pathways and the tumor microenvironment.

Effects of the Cessation of Mass Screening for Neuroblastoma at 6 Months of Age: A Population-Based Study in Osaka, Japan

Background

In 2004, the Japanese government halted the 6-month mass screening program for neuroblastoma. We investigated whether its cessation had led to an increase not only in mortality due to this disease but also in the incidence of advanced-stage disease among older children.

Methods

Study subjects were neuroblastoma patients retrieved from the population-based Osaka Cancer Registry. Trends of incidence and mortality from neuroblastoma were analyzed by calendar year and birth cohort. Prognostic factors, including stage and v-myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog (MYCN) oncogene status, were compared before and after the cessation of mass screening.

Results

Age-standardized incidence rates in 2005–2009 (the cessation period of mass screening; 11.1 per million) were similar to those in 1975–1979 (the pre-screening period; 8.6 per million). Age-standardized mortality rates tended to decrease from 1975–1979 (4.0 per million) to 2005–2009 (2.7 per million) in parallel with the improvement in survival. Analysis by birth cohort indicated that the mortality rates in 2004–2005 (after cessation) for children 0–4 years of age were lower than those in 1975–1979 (O:E ratio 0.25; 95% confidence interval, 0.03–0.90). For children 1–9 years of age, there was a not significant difference in the distribution of stage, MYCN oncogene status, and DNA ploidy between 1991–2003 (the mass screening period) and 2004–2008 (after cessation).

Conclusions

The cessation of mass screening for neuroblastoma does not appear to have increased mortality due to this disease or incidence of advanced-stage disease among older children.

Nifurtimox reduces N-Myc expression and aerobic glycolysis in neuroblastoma

Neuroblastoma is one of the most common solid tumors in childhood and usually accompanied with poor prognosis and rapid tumor progression when diagnosed with amplification of the proto-oncogene N-Myc. The amplification of N-Myc has major influence on the maintenance of aerobic glycolysis, also known as the Warburg effect. This specific switch in the conversion of pyruvate to lactate instead of the conversion of pyruvate to acetyl-coenzyme A even in the presence of oxygen has important benefits for the tumor, e.g. increased production of enzymes and enzyme substrates that are involved in tumor progression, angiogenesis and inhibition of apoptosis. The antiprotozoal drug nifurtimox, which is generally used for the treatment of infections with the parasitic protozoan Trypanosoma cruzi, has been reported to have cytotoxic properties in the therapy of neuroblastoma. However, its action of mechanism has not been described in detail yet. The presented in vitro study on the neuroblastoma cell lines LA-N-1, IMR-32, LS and SK-N-SH shows an increased production of oxidative stress, a reduced lactate dehydrogenase enzyme activity and reduced lactate production after nifurtimox treatment. Furthermore, nifurtimox leads to reduced mRNA and protein levels of the proto-oncogene protein N-Myc. Thus, the current work gives new insights into the effect of nifurtimox on tumor metabolism revealing a shifted glucose metabolism from production of lactate to oxidative phosphorylation and a reduced expression of the major molecular prognostic factor in neuroblastoma N-Myc, presenting nifurtimox as a possible adjuvant therapeutic agent against (high risk) neuroblastoma.

The neuroblastoma and ganglion components of nodular ganglioneuroblastoma are genetically similar: evidence against separate clonal origins

Nodular ganglioneuroblastoma is characterized by a macroscopic nodule of neuroblastoma within a ganglioneuromatous component. These two components have been considered to originate from separate clones, with the neuroblastoma clone accounting for the clinical behavior of nodular ganglioneuroblastoma. In order to investigate the clonal origin of the cellular components (neuroblasts, ganglion cells, and Schwann cells) of nodular ganglioneuroblastoma, paraffin-embedded tumor samples from eight cases were analyzed by single nucleotide polymorphism array and in situ hybridization. DNA was extracted separately from neuroblastomatous and ganglioneuromatous areas. By in situ hybridization, MYCN gain (4-10 gene copies/nucleus) was detected in 7/8 neuroblastoma samples. In ganglioneuromatous regions, gains were also detected in ganglion cells but not in Schwann cells. Single-nucleotide polymorphism array studies identified chromosome losses (11q and 14q) and gains (12, 13q, 17q and 18q) in the neuroblastoma component, whereas the ganglioneuromatous component showed fewer or no genetic alterations. There were no unique copy number changes distinguishing nodular ganglioneuroblastoma from other subtypes of neuroblastoma. By in situ hybridization, ganglion cells but not Schwann cells showed the same alterations detected in neuroblasts. Thus, neuroblasts and ganglion cells in nodular ganglioneuroblastoma are genetically related and may arise from the same clone. In contrast, the Schwann cells have a different origin and may be derived from a non-neoplastic neural crest precursor. Our results suggest that the clinical behavior of nodular ganglioneuroblastoma cannot be explained by the presence of separate clones with distinct genetic signatures.

ALK amplification and protein expression predict inferior prognosis in neuroblastomas

BACKGROUND

ALK gene has been identified as a major neuroblastoma (NBL) predisposition gene. But ALK gene copy number and protein expression in ganglioneuroblastoma (GNBL) and ganglioneuroma (GN) are poorly described in the literature. Furthermore, there are controversies on the correlation between ALK protein expression and clinical outcome in NBL.

METHODS

We evaluated MYCN/ALK gene copy number by fluorescence in situ hybridization (FISH) and detected ALK protein expression by immunohistochemistry (IHC) in 188 NBL, 52 GNBL and 6 GN samples and analyzed their association with clinical outcome of the patients.

RESULTS

Although ALK gene copy number increase is a recurrent genetic aberration of neuroblastic tumors (NTs) (39.1%, 96/246), ALK amplification was only present in three NBLs (1.2%, 3/246). The frequency of ALK positivity in NBL (50.5%, 51/101) was significantly higher than in GNBL (22.6%, 7/31) and in GN (0.0%, 0/4) (P<0.05). In addition, ALK positivity also significantly correlates with MYCN/ALK gene copy number increases (P<0.05). Kaplan-Meier survival analysis indicated that MYCN/ALK amplification is correlated with decreased overall survival in NBL. A better prognosis trend was observed in patients with MYCN/ALK gain tumors compared with those with MYCN/ALK normal tumors. Furthermore, ALK positivity significantly correlated with inferior survival in NBL (P=0.044).

CONCLUSION

ALK positivity in NTs correlated with advanced tumor types and MYCN/ALK gene copy number increases. ALK positivity predicts inferior prognosis in NBL and IHC is a simplified strategy to screen ALK positivity in clinical practice.

Evaluation of morphological/immunohistochemical versus nuclear medicine imaging modalities in detecting metastatic bone and/or marrow deposits in neuroblastoma patients

BACKGROUND & PURPOSE

In planning diagnostic or follow-up investigational strategies, neuroblastoma (NB) metastatic deposits in bone and/or bone marrow (BM) should be detected as early as possible. Therefore, all investigational detection tools should be conducted simultaneously for precise staging. However, because of the financial conditions in our developing countries and in view of the cost/benefit relationship, the question is, can one detection tool only become satisfactory and replacing others? The purpose of our study is to compare simultaneous results of bone and metaiodobenzylguanidine (MIBG) scans versus BM biopsies with immunohistochemical (IHC) staining; in detecting bone and/or BM metastatic deposits in NB patients.

MATERIAL AND METHODS

This study included 138 NB patients; 46 were de novo and 92 were under follow-up. They were subjected to bilateral BM biopsies, IHC staining (using NSE McAb) and Tc-99m methylene diphosphonate (Tc-99m MDP) bone scan (BS). Only 57/138 patients were, in addition, subjected to I-131 MIBG scan.

RESULTS

Matched results between IHC-stained BM sections and bone scans (BSs) 107/138 (77.5%) were higher than the un-matched ones 31/138 (22.5%). There was a moderate agreement between the two methods in all studied cases (Kappa=0.538) and it was higher among de novo (Kappa=0.603) than follow-up group (Kappa=0.511). Among the 31 un-matched results, the most frequent (17/31) were due to the presence of minute amount of infiltrating NB cells that could be detected by IHC-stained BM sections and not by BSs. The less frequent (12/31) were due to the presence of metastatic deposits outside pelvic bones that could be detected by BSs and not by IHC-stained BM sections mainly in the follow-up cases (11/12) rather than de novo cases (1/12). The matched results between IHC-stained BM sections and MIBG scans 54/57 (94.7%) were higher than the un-matched ones 3/57 (5.3%). The agreement between the two methods was higher among de novo (Kappa=1.000) than follow-up group (Kappa=0.847). The agreement between IHC-stained BM sections and MIBG scans was substantial (Kappa=0.890) while that between IHC-stained BM sections and BSs was moderate (Kappa=0.538).

CONCLUSIONS

We suggest a step-wise strategy to be applied, at least in developing countries, in approaching de novo and follow-up NB cases for detecting bone and/or BM metastatic deposits. This strategy might be beneficial if it is considered during application of NB guide-lines for diagnosis and follow-up.

Metastatic neuroblastoma mimicking infantile hemangioma

Many lesions can masquerade as deep infantile hemangioma, the most common tumor of infancy. We describe an infant with infantile hemangioma and concomitant metastatic subcutaneous neuroblastoma mimicking deep hemangioma. The patient presented at 8 months of age with 3 superficial infantile hemangiomas as well as 3 subcutaneous masses. History, physical examination, and ultrasonography of the deep lesions were consistent with subcutaneous hemangioma. New masses appeared at 10 months of age that prompted biopsy; histopathology demonstrated metastatic neuroblastoma. Deviation from the predictable clinical features of a deep infantile hemangioma should prompt consideration for other causes of a subcutaneous mass in infancy, including metastatic neuroblastoma.

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.

Reconstitution of Schwannian stroma in neuroblastomas using human bone marrow stromal cells

The Schwannian stroma in neuroblastomas is related to patient prognosis. There is debate surrounding the origin of Schwannian stroma in neuroblastomas: one theory is that the Schwann cells are derived from neoplastic cells, and the other is that they arise from normal cells surrounding the neuroblastoma. We examined whether human bone marrow stromal cells (hBMSCs) or human mesenchymal stem cells (hMSCs) could differentiate into Schwann cells in neuroblastomas. hBMSCs or hMSCs along with enhanced green fluorescent protein (EGFP) were injected into xenotransplanted neuroblastomas in nonobese diabetic mice with severe combined immunodeficiency and the resulting tumors were analyzed using immunohistochemistry. HBMSCs and hMSCs were co-cultured with neuroblastoma cells, and the induction of Schwann cell-specific molecules, S100beta and Egr-2, was monitored. S100beta-positive Schwannian stroma was observed only in neuroblastomas containing either hBMSCs or hMSCs, but not in neuroblastomas lacking these cells. Double staining with anti-S100 and anti-EGFP antibodies showed that S100-positive cells in neuroblastomas were also EGFP-positive. By contrast, hBMSCs did not develop into Schwann cells in Ewing's sarcoma, demonstrating that differentiation of transplanted hBMSCs or hMSCs into Schwann cells occurs specifically in neuroblastomas. Both S100beta and Egr-2 were expressed in hBMSCs or hMSCs co-cultured with neuroblastoma cells. HBMSCs or hMSCs may contribute to the formation of human tumor stroma. The Schwannian stroma of neuroblastomas appears to be derived from nonneoplastic stromal cells rather than neuroblastoma cells, further clarifying its developmental origins.

Incidence of Neuroblastoma After a Screening Program

Purpose

A significant increase in the incidence of neuroblastoma occurred among a 5-year birth cohort (May 1989 to April 1994) during an active urinary screening program for its early detection. We examined the postscreening incidence of neuroblastoma in the subsequent 5-year birth cohort (May 1994 to April 1999), with follow-up to 2002, to determine whether the incidence remained increased.

Patients and Methods

We reviewed institutional records of patients diagnosed with neuroblastoma during the period from 1994 to 2002 who were born in 1994 to 1999 in the province of Quebec, as well as in the state of Minnesota and the province of Ontario, regions that had served as controls during the screening interval. We calculated and compared incidence rates during the 1994 to 2002 time period.

Results

For the 5-year birth cohort as a whole, the rate of newly diagnosed neuroblastoma was higher in Quebec than in the control populations of Minnesota and Ontario (standardized incidence ratio, 1.34; 95% CI, 1.03 to 1.70). However, in years 4 and 5 of the interval, population-based incidence declined to the same levels as those seen in the control areas.

Conclusion

The institution of a urinary screening program for neuroblastoma led to increased awareness of the diagnosis and an elevated rate of diagnosis even after the completion of the screening evaluation. However, this halo effect was transient, with diagnostic rates subsequently decreasing within the range seen in control populations.

A technique for excision of abdominal and pelvic neuroblastomas

INTRODUCTION

As neuroblastomas usually envelope major vessels, excision poses a significant technical problem.

PATIENTS AND METHODS

Over a 22-year period, 234 infants and children have undergone attempted surgical excision of abdominal or pelvic neuroblastomas using a consistent surgical approach. This entails a systematic dissection of the involved vessels prior to removal of the tumour.

RESULTS

Macroscopically complete or near complete tumour clearance was achieved in 89% of cases. Three aortic injuries occurred which required repair.

CONCLUSIONS

The described technique is safe and reproducible and allows tumour clearance in the majority of affected children.

Peripheral neuroblastic tumours in eastern Denmark 1972?2002

The peripheral neuroblastic tumour group includes neuroblastoma, ganglioneuroblastoma and ganglioneuroma. Neuroblastoma is the most common extracranial solid tumour of childhood. We have evaluated the histological presentation, MYCN gene status, and clinical course of peripheral neuroblastic tumours diagnosed and treated in eastern Denmark from 1972-2002. 125 patients were diagnosed with peripheral neuroblastic tumour during this 30-year period. The histological material was reviewed and classified into three categories in accordance with the Shimada system: unfavourable histology, favourable histology, and benign tumours. MYCN status was determined by fluorescent in situ hybridization (FISH) on paraffin sections from the primary tumour. Clinical information was obtained from hospital records. Diagnostic likelihood ratios in the two groups were calculated to compare the ability of MYCN status and histological classification to predict 5-year outcome. 41 tumours showed unfavourable histology, 30 tumours showed favourable histology, 11 were benign, and 43 were unclassifiable due to limited amounts of primary tumour, bad preservation or inaccessibility of the primary tumour necessitating metastatic tumour biopsy for diagnosis. Unfavourable histology was associated with widespread disease (p<0.001). The overall 5-year survival rate was 45%, which correlates well with the European survival rate reported for this time period. The 5-year survival rate in the unfavourable group was 30% as compared to 100% in the favourable histology group (p<0.001). The survival rate in the unclassifiable group was 13%. 26% of the neuroblastomas were MYCN amplified. MYCN amplification was associated with undifferentiated histology, a histological subtype of the unfavourable histology group (p<0.001). For unfavourable histology the positive diagnostic likelihood ratio was 2.9 as compared to 4.7 for MYCN amplification. The study has confirmed the prognostic significance of the Shimada system in the peripheral neuroblastic tumour group in a retrospective material, and has also demonstrated the prognostic superiority of MYCN compared to histological classification, thus reducing the necessary amounts of tumour tissue.

MYCN gene amplification is a powerful prognostic factor even in infantile neuroblastoma detected by mass screening

MYCN is the most powerful prognostic factor in cases of older children. However, how MYCN is related to the prognosis of infantile cases is not clear. A mass screening program was carried out by measuring urinary catecholamine metabolites (VMA and HVA) from 6-month-old infants. Of 2084 cases detected by the screening program, MYCN amplification (MNA) was examined by Southern blot analyses in 1533 cases from 1987 to 2000. Of the 1533 cases examined, 1500 (97.8%) showed no MNA, 20 cases (1.3%) showed MNA from three to nine copies, and 13 (0.8%) cases showed more than 10 copies. The 4-year overall survival rates of these three groups (99, 89 and 53%, respectively) were significantly different (P<0.001), indicating that MYCN copy number correlates with the prognosis. Cases with MNA more than 10 copies were more advanced than those without amplification (stage III, IV vs I, II, IVs; P<0.001). Patients with MNA more than 10 copies had significantly higher serum levels of neuron-specific-enolase (NSE) and ferritin than non-amplified patients (P=0.049, P=0.025, respectively). MYCN amplification was strongly correlated with a poor prognosis in infantile neuroblastoma cases. Therefore, for the selection of appropriate treatment, an accurate determination of MNA is indispensable.

Prognostic Value of International Neuroblastoma Pathology Classification in Localized Resectable Peripheral Neuroblastic Tumors: A Histopathologic Study of Localized Neuroblastoma European Study Group 94.01 Trial and Protocol

Purpose

To assess the prognostic value of clinical, biologic, and morphologic data in peripheral neuroblastic tumors, International Neuroblastoma Staging System (INSS) stages 2A and 2B MYCN nonamplified, a multinational protocol entitled Localized Neuroblastoma European Study Group trial 94.01, with a trial of surgery as the only treatment, was initiated in 1995. We present the prognostic value of the revised International Neuroblastoma Pathology Classification (INPC) applied to the patients included in this protocol until its closure in 1999.

Materials and Methods

A total of 120 neuroblastic tumors from trial patients were reviewed by the European International Society of Pediatric Oncology neuroblastoma pathology panel and assigned to a favorable or unfavorable prognostic category according to the INPC guidelines. Overall survival and relapse-free survival (RFS) were estimated by the Kaplan-Meier method and compared by the log-rank test.

Results

A total of 115 of 120 patients were assessable and were assigned to the favorable (90 patients; 78.3%) or unfavorable (25 patients; 21.7%) category. The 60-month survival rate was 97.7% in favorable patients compared with 73.8% in unfavorable patients (P = .0002). RFS analysis showed a 60-month relapse rate of 13.4% and 32% in favorable and unfavorable patients (P < .025), respectively. Statistical analysis demonstrated a significant association of unfavorable INPC category and high lactate dehydrogenase level (P < .045).

Conclusion

This European study shows for the first time that the INPC prognostic categorization has a significant impact on outcome prediction in INSS stage 2 localized peripheral neuroblastic tumors.

Histopathological features of pretreatment neuroblastoma are of limited clinical significance following adjustment for clinical and biological marker status

Neuroblastic tumours are morphologically classified into broad categories according to defined criteria, with further histopathological features described which may provide prognostic information, such as calcification, mitotic rate and the mitoses-karyorrhexis index; these may be combined with patient age and other factors to indicate high-risk and low-risk groups. However, recently, a range of biological molecular markers have proved to be of major prognostic importance in neuroblastic tumours, including MYCN amplification, 1p deletion, and 17q gain. It is therefore hypothesised that traditional histopathological features are now of limited clinical significance after adjustment for known clinical and biological pregnostic markers. Evidence to evaluate this hypothesis was obtained via a literature search to identify studies reporting on prognostic significance of histopathological features in multivariate analysis after adjustment for biological marker status. Thirteen studies were included of which four (1642 subjects) reported an independent effect of histopathological findings, whereas nine (2385 subjects) reported no significant independent effect. All four studies examining both MYCN and other markers such as 1p, 11q or 17q status, reported no significant independent effect of histological parameters. Histopathological diagnosis remains the gold standard for the diagnosis and evaluation of paediatric tumours but in the evolving era of molecular evaluation of tumours, the role of traditional morphological assessments is likely to become increasingly obsolete, and diagnostic paediatric pathology departments must respond to the changing understanding of the biological basis of childhood malignancies towards routinely providing both diagnostic and molecular prognostic data from these small samples.

Reactive oxygen species: Biological stimuli of neuroblastoma cell response

Reactive oxygen species play a critical role in differentiation, proliferation and apoptosis acting as 'second messengers' able to regulate sulphydryl groups in signaling molecules as protein kinase C, a family of isoenzymes involved in many cellular responses and implicated in cell transformation. Neuroblastoma is characterised by the production of oxygen intermediates and L-buthionine-S,R-sulfoximine, a glutathione-depleting agent that has been tested in the clinics, exploits this biological peculiarity to induce cell death. The latter process is mediated by the oxidative activation of PKC delta which might be involved also in the production of reactive oxygen species, thus amplifying the apoptotic cascade.

Gene profiling of high risk neuroblastoma

Neuroblastoma, a cancer of young children, is well known for its diverse pattern of presentation. Approximately one-half of children have localized tumors that can be cured with surgery alone. The remaining children have widespread metastatic disease or quite large, aggressive, localized tumors. These children have a poor long-term survival rate of approximately 30%. We review the prognostically significant histologic and molecular features of high risk neuroblastoma and propose an algorithm to dissect further the differentially expressed genes that define the phenotype of this disease. Over the past 25 years, much effort has gone into establishing reliable prognostic indicators of high risk disease. For neuroblastoma, age, stage, and histopathology have time and again correlated well with outcomes. Chromosomal number, or ploidy, and amplification of the MYCN oncogene have proved to be equally as important and are commonly used to stratify patient risk. Other potentially lucrative markers include chromosome 1p deletion, chromosome 17q gain, receptor tyrosine kinases A and B (trk-A, trk-B), CD44, CXCR4, and multidrug resistance associated protein (MRP). With the onset of new technology, expression microarrays are now being used to profile advanced-stage neuroblastoma on a larger scale. Genes particular to cell cycle control, DNA/RNA replication, ribosomal synthesis, neuronal differentiation, and intracellular/extracellular signal transduction have been identified through differential expression analysis. We present our research on the MYCN transcription factor and target gene, MCM7, to show the utility of this approach.

Characterization of karyotypic events and evolution in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is cytogenetically characterized by a number of non-random events. However, knowledge is limited concerning the timing of occurrence and inter-action of many of these events.

METHODS

Karyotypic patterns were obtained from a study group of 49 NB tumors that had been analyzed by conventional cytogenetics combined with FISH and in some instances SKY.

RESULTS

All chromosomes were involved in a numerical and structural aberration in at least one tumor. There was a positive correlation between the occurrence of MYCN and del(1p) and between del(1p) and 17q. Aberrations involving chromosomes X, 3, 19, and del(1p) could be considered early events, whereas those involving chromosomes 9, 13, 15, 18, 20, and 21 were often late events.

CONCLUSIONS

This study suggests that the karyotypic patterns characterizing NB are complex. There are aberrations that can be grouped into early or late karyotypic events, but others, such as gain of 17q, are variable.

Positional gene expression analysis identifies 12q overexpression and amplification in a subset of neuroblastomas

Neuroblastoma is a heterogeneous disease with variable clinical behaviors. Unique molecular features are associated with clinically relevant subgroups. We performed a comprehensive microarray gene expression analysis of 95 neuroblastomas in an effort to define clinically important molecular subtypes. A subset of tumors overexpressed several contiguous genes located at 12q13 approximately q15 and were studied further. By microarray, 5 of 95 neuroblastomas had overexpression of genes mapped to 12q13.1 approximately q15, suggesting an amplification event in this region. Positional expression mapping identified the narrowest region of overlap containing 21 genes, with 11 genes overexpressed in all five cases. Fluorescence in situ hybridization demonstrated 3 neuroblastomas with more than a 10-fold increase in 12q gene copies and 9 with 3- to 5-fold increases. Amplification and overexpression of genes at 12q13 approximately q15 were observed in a small subset of neuroblastomas. Although amplification of 12q has been previously reported in neuroblastoma cell lines, this is the first demonstration in tumor samples, and it defines a distinct subset that has not been described previously. The expressed genes mapped closely to the complex amplicon reported in sarcomas, and they identify critical genes and pathways affected by 12q gene amplification.

Is surgery necessary for incidentally discovered adrenal masses in children?

BACKGROUND

There are no guidelines that exist to direct the management of incidental adrenal masses (IAM) in children. The aim of this study was to determine if there is a subset of IAMs that could be safely observed.

METHODS

A retrospective analysis was conducted of all adrenal masses that were either resected or biopsied between 1990 and 2002 (n = 91) at the Hospital for Sick Children, Toronto. IAM was defined as a solitary adrenal mass discovered by either physical examination (n = 6; 23.1%) or diagnostic imaging for other indications (n = 20; 76.9%), without metastases or biochemical activity.

RESULTS

Twenty-six (28.6%) IAMs were detected (mean age, 4.6 years [range, antenatal to 17 years]; 11 boys, 15 girls). Pathologic diagnoses included neuroblastoma (n = 7), ganglioneuroma (n = 6), adrenocortical adenoma (n = 4), adrenal cyst/pseudocyst (n = 3), adrenal hemorrhage (n = 3), ganglioneuroblastoma (n = 1), nodular cortical hyperplasia (n = 1), and teratoma (n = 1). Eight masses were malignant (30.8%). Two of the 5 masses discovered on antenatal ultrasound scan were neuroblastoma. In comparing the benign with malignant lesions, there was no significant difference in mean size (4.8 cm v 4.3 cm; P =.57), radiologic characteristics, or mode of presentation. Benign lesions occurred more frequently in older children (mean age, 6.5 years v 1.3 years; P =.03).

CONCLUSIONS

Clear guidelines cannot be established to predict benign IAM in children. Given the high proportion of malignant lesions, we recommend that all pediatric IAMs should be resected.

Continuous versus intermittent administration of human endostatin in xenografted human neuroblastoma

PURPOSE

The authors examined whether recombinant human endostatin (rhEndostatin), an antiangiogenic agent, is effective against a human neuroblastoma cell line (designated TNB9) using a human neuroblastoma xenograft model and investigated whether continuous infusion is more effective than intermittent administration.

METHODS

In the first experiment, when tumors on the back of nude mice reached a weight of 90 to 95 mg, rhEndostatin, 10 mg/kg/d mouse weight, was administered subcutaneously to the mice (n = 5) every day for 10 consecutive days. In the second experiment, the same daily dose of rhEndostatin was administered continuously to the TNB9-bearing mice (n = 6) via subcutaneous infusion pumps for 3 consecutive days with total dose being 30% of that in the first experiment. Nestin and factor VIII expression levels were studied immunohistochemically to elucidate whether histologic evidence of the effects of rhEndostatin was present on day 4 in the second experiment.

RESULTS

In the first experiment, relative tumor weight in treated mice (n = 5) was significantly less than that in controls (n = 12) on day 2 only after treatment initiation (P <.05). The maximum inhibition rate (MIR) of TNB9 xenograft growth by rhEndostatin was 46.4%, indicating lack of efficacy. In the second experiment, the effects of rhEndostatin were much more marked than those in the first experiment, with an MIR of 60.7%. The mean relative tumor weight in the treated group (n = 6) in the second experiment was significantly less than that in controls (n = 10) on days 2, 4, and 6 (P <.01) as well as on days 8 and 10 (P <.05). Nestin staining in the endothelium of control tumors (n = 2) was marked, whereas it showed a loss of fibrillar structure in rhEndostatin-treated tumors (n = 2). The number of vessels immunostained with antifactor VIII antibody was markedly reduced in tumors (n = 2) from rhEndostatin-treated mice compared with that in tumors from control animals (n = 2).

CONCLUSIONS

Continuous administration of rhEndostatin resulted in more significant tumor regression than intermittent administration of the agent in the same model. This indicates that rhEndostatin, if administered in continuous fashion, could become an effective agent for treating patients with neuroblastoma in the future.

Current treatment and future directions in neuroblastoma

OBJECTIVE

The International Neuroblastoma Staging System (INSS) and Pathology Classification (INPC) were applied to analyze the results of treatment of 644 patients with neuroblastoma treated in Japan during the years from 1995 to 1999, and it was found that the pathology classification (INPC) showed the strongest relevance to prognosis compared to other factors such as stage, MYNC amplification, DNA ploidy and 1p-deletion. Current results of treatment for advanced neuroblastoma are still not satisfactory, so innovative therapeutic methods have been sought during the past 10 years.

METHODS

Prospects for irinotecan and recombinant human endostatin (rhEndostatin) were studied expertimentally and clinically.

RESULTS

Irinotecan is a water-soluble derivative of camptothecin, which is isolated from a Chinese tree, Camptotheca acuminata; Its effectiveness against neuroblastoma was confirmed by in vivo preclinical studies, and phase I clinical trials in Japan concluded the maximum tolerated dose of this agent is 160-180 mg/m2/day for 3 consecutive days, repeated after 25 days off. Phase II trials with this dose began, and we could obtain some encouraging results with the clinical use of irinotecan. rhEndostatin has been studied in in vivo experimental models. The action of rhEndostatin was quite different from those of other cytotoxic chemotherapeutic agents, and continuous administration of this substance showed a more marked anti-effect than its intermittent use.

CONCLUSION

Irinotecan appears to be promising when it is given to the patients neuroblastoma, whereas rhEndostatin needs to have more preclinical studies before it is used in patients.

Neuroblastoma: biology and molecular and chromosomal pathology

Neuroblastoma is the most frequently occurring solid tumour in children, with an incidence of 1.3 cases per 100000 children aged 0-14 years. Despite many advances during the past three decades, neuroblastoma has remained an enigmatic challenge to clinical and basic scientists. 20 years ago, the MYCN gene was found to be amplified in neuroblastomas, and research since then has focused on the search for other genetic markers. It has emerged that neuroblastoma cells, like cells of many other tumour types, often suffer from extensive, non-random genetic damage at multiple genetic loci. Elucidation of the exact molecular make-up of neuroblastomas will enable researchers to analyse how much specific markers, alone or in combination, can help to stratify disease in prospective studies; at present, stratification is based on age, stage, MYCN, and Shimada pathology. Neuroblastoma may be one of the first examples of the use of genetic tumour markers as a tool for defining tumour behaviour and to aid clinical staging.