Augmented expression of MYC and/or MYCN protein defines highly aggressive MYC-driven neuroblastoma: a Children's Oncology Group study.

BACKGROUND: MYCN amplification with subsequent MYCN protein overexpression is a powerful indicator of poor prognosis of neuroblastoma patients. Little is known regarding the prognostic significance of the homologous MYC protein expression in neuroblastoma. METHODS: Immunostaining for MYCN and MYC protein was performed on 357 undifferentiated/poorly differentiated neuroblastomas. Results were analysed with other prognostic markers. RESULTS: Sixty-seven (19%) tumours were MYCN(+), 38 (11%) were MYC(+), and one(0.3%) had both proteins(+). MYCN(+) tumours and MYC(+) tumours were more likely diagnosed in children>18months with stage4-disease. MYCN(+) tumours were associated with amplified MYCN, Unfavourable Histology (UH), and High-MKI (Mitosis-Karyorrhexis Index). MYC(+) tumours were also frequently UH but not associated with MYCN amplification, and more likely to have low-/intermediate-MKI. Favourable Histology patients without MYC/MYCN expressions exhibited the best survival (N=167, 89.7±5.5% 3-year EFS, 97.0±3.2% 3-year OS), followed by UH patients without MYC/MYCN expressions (N=84, 63.1±13.6% 3-year EFS, 83.5±9.4% 3-year OS). MYCN(+)patients and MYC(+)patients had similar and significantly low (P<0.0001) survivals (46.2±12.0% 3-year EFS, 63.2±12.1% 3-year OS and 43.4±23.1% 3-year EFS, 63.5±19.2% 3-year OS, respectively). Notably, the prognostic impact imparted by MYC expression was independent from other markers. CONCLUSIONS: In this series, ∼30% of neuroblastomas had augmented MYCN or MYC expression with dismal survivals. Prospective study of MYC/MYCN protein expression signature as a new biomarker for high-risk neuroblastomas should be conducted.

Preferential amplification of the paternal allele of the N-myc gene in human neuroblastomas.

Genomic imprinting plays a role in influencing the parental origin of genes involved in cancer-specific rearrangements. We have analysed 22 neuroblastomas with N-myc amplification to determine the parental origin of the amplified N-myc allele and the allele that is deleted from chromosome 1p. We analysed DNA from neuroblastoma patients and their parents, using four polymorphisms for 1p and three for the N-myc amplicon. We determined that the paternal allele of N-myc was preferentially amplified (12 out of 13 cases; P = 0.002). However, the paternal allele was lost from 1p in six out of ten cases, consistent with a random distribution (P > 0.2). These results suggest that parental imprinting influences which N-myc allele is amplified in neuroblastomas, but it does not appear to affect the 1p allele that is deleted in the cases that we have examined.

Segmental chromosomal alterations have prognostic impact in neuroblastoma: a report from the INRG project.

BACKGROUND: In the INRG dataset, the hypothesis that any segmental chromosomal alteration might be of prognostic impact in neuroblastoma without MYCN amplification (MNA) was tested. METHODS: The presence of any segmental chromosomal alteration (chromosome 1p deletion, 11q deletion and/or chromosome 17q gain) defined a segmental genomic profile. Only tumours with a confirmed unaltered status for all three chromosome arms were considered as having no segmental chromosomal alterations. RESULTS: Among the 8800 patients in the INRG database, a genomic type could be attributed for 505 patients without MNA: 397 cases had a segmental genomic type, whereas 108 cases had an absence of any segmental alteration. A segmental genomic type was more frequent in patients >18 months and in stage 4 disease (P<0.0001). In univariate analysis, 11q deletion, 17q gain and a segmental genomic type were associated with a poorer event-free survival (EFS) (P<0.0001, P=0.0002 and P<0.0001, respectively). In multivariate analysis modelling EFS, the parameters age, stage and a segmental genomic type were retained in the model, whereas the individual genetic markers were not (P<0.0001 and RR=2.56; P=0.0002 and RR=1.8; P=0.01 and RR=1.7, respectively). CONCLUSION: A segmental genomic profile, rather than the single genetic markers, adds prognostic information to the clinical markers age and stage in neuroblastoma patients without MNA, underlining the importance of pangenomic studies.

Criteria for evaluation of disease extent by (123)I-metaiodobenzylguanidine scans in neuroblastoma: a report for the International Neuroblastoma Risk Group (INRG) Task Force.

BACKGROUND: Neuroblastoma is an embryonic tumour of the sympathetic nervous system, metastatic in half of the patients at diagnosis, with a high preponderance of osteomedullary disease, making accurate evaluation of metastatic sites and response to therapy challenging. Metaiodobenzylguanidine (mIBG), taken into cells via the norepinephrine transporter, provides a sensitive and specific method of assessing tumour in both soft tissue and bone sites. The goal of this report was to develop consensus guidelines for the use of mIBG scans in staging, response assessment and surveillance in neuroblastoma. METHODS: The International Neuroblastoma Risk Group (INRG) Task Force, including a multidisciplinary group in paediatric oncology of North and South America, Europe, Oceania and Asia, formed a subcommittee on metastatic disease evaluation, including expert nuclear medicine physicians and oncologists, who developed these guidelines based on their experience and the medical literature, with approval by the larger INRG Task Force. RESULTS: Guidelines for patient preparation, radiotracer administration, techniques of scanning including timing, energy, specific views, and use of single photon emission computed tomography are included. Optimal timing of scans in relation to therapy and for surveillance is reviewed. Validated semi-quantitative scoring methods in current use are reviewed, with recommendations for use in prognosis and response evaluation. CONCLUSIONS: Metaiodobenzylguanidine scans are the most sensitive and specific method of staging and response evaluation in neuroblastoma, particularly when used with a semi-quantitative scoring method. Use of the optimal techniques for mIBG in staging and response, including a semi-quantitative score, is essential for evaluation of the efficacy of new therapy.

Consensus criteria for sensitive detection of minimal neuroblastoma cells in bone marrow, blood and stem cell preparations by immunocytology and QRT-PCR: recommendations by the International Neuroblastoma Risk Group Task Force.

Disseminating disease is a predictive and prognostic indicator of poor outcome in children with neuroblastoma. Its accurate and sensitive assessment can facilitate optimal treatment decisions. The International Neuroblastoma Risk Group (INRG) Task Force has defined standardised methods for the determination of minimal disease (MD) by immunocytology (IC) and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) using disialoganglioside G(D2) and tyrosine hydroxylase mRNA respectively. The INRG standard operating procedures (SOPs) define methods for collecting, processing and evaluating bone marrow (BM), peripheral blood (PB) and peripheral blood stem cell harvest by IC and QRT-PCR. Sampling PB and BM is recommended at diagnosis, before and after myeloablative therapy and at the end of treatment. Peripheral blood stem cell products should be analysed at the time of harvest. Performing MD detection according to INRG SOPs will enable laboratories throughout the world to compare their results and thus facilitate quality-controlled multi-centre prospective trials to assess the clinical significance of MD and minimal residual disease in heterogeneous patient groups.

International consensus for neuroblastoma molecular diagnostics: report from the International Neuroblastoma Risk Group (INRG) Biology Committee.

Neuroblastoma serves as a paradigm for utilising tumour genomic data for determining patient prognosis and treatment allocation. However, before the establishment of the International Neuroblastoma Risk Group (INRG) Task Force in 2004, international consensus on markers, methodology, and data interpretation did not exist, compromising the reliability of decisive genetic markers and inhibiting translational research efforts. The objectives of the INRG Biology Committee were to identify highly prognostic genetic aberrations to be included in the new INRG risk classification schema and to develop precise definitions, decisive biomarkers, and technique standardisation. The review of the INRG database (n=8800 patients) by the INRG Task Force finally enabled the identification of the most significant neuroblastoma biomarkers. In addition, the Biology Committee compared the standard operating procedures of different cooperative groups to arrive at international consensus for methodology, nomenclature, and future directions. Consensus was reached to include MYCN status, 11q23 allelic status, and ploidy in the INRG classification system on the basis of an evidence-based review of the INRG database. Standardised operating procedures for analysing these genetic factors were adopted, and criteria for proper nomenclature were developed. Neuroblastoma treatment planning is highly dependant on tumour cell genomic features, and it is likely that a comprehensive panel of DNA-based biomarkers will be used in future risk assignment algorithms applying genome-wide techniques. Consensus on methodology and interpretation is essential for uniform INRG classification and will greatly facilitate international and cooperative clinical and translational research studies.

SPARC enhances tumor stroma formation and prevents fibroblast activation.

Tumor growth is influenced by interactions between malignant cells and the tumor stroma. Although the normal host microenvironment is nonpermissive for neoplastic progression, tumor-reactive stroma, characterized by the presence of activated fibroblasts, promotes neoplastic growth and metastasis. Secreted protein, acidic and rich in cysteine (SPARC) is a matricellular glycoprotein that is capable of inhibiting the growth of several different types of cancer. Recently, we reported that SPARC also impairs the growth of xenografts comprised of 293 cells. In this study, we show that in addition to enhancing stroma formation, SPARC prevents fibroblast activation in 293 xenografts, suggesting that the anti-cancer effects of SPARC may be due, at least in part, to the formation of tumor stroma that is not supportive of tumor growth. In vitro, 3T3 fibroblasts cocultured with SPARC-transfected 293 cells remain negative for alpha-smooth muscle actin, whereas wild-type 293 cells induce fibroblast activation. Moreover, activation of 3T3 cells and primary fibroblasts by transforming growth factor beta is blocked by SPARC treatment. We also demonstrate that SPARC significantly increases basic fibroblast growth factor-induced fibroblast migration in vitro, indicating that it may recruit host fibroblasts to the tumor stroma. Taken together, our results suggest that in addition to blocking angiogenesis, SPARC may inhibit tumor growth by promoting the assembly of stroma that is non-permissive for tumor progression.

Evidence for an age cutoff greater than 365 days for neuroblastoma risk group stratification in the Children's Oncology Group.

PURPOSE: In the Children's Oncology Group, risk group assignment for neuroblastoma is critical for therapeutic decisions, and patients are stratified by International Neuroblastoma Staging System stage, MYCN status, ploidy, Shimada histopathology, and diagnosis age. Age less than 365 days has been associated with favorable outcome, but recent studies suggest that older age cutoff may improve prognostic precision. METHODS: To identify the optimal age cutoff, we retrospectively analyzed data from the Pediatric Oncology Group biology study 9047 and Children's Cancer Group studies 321p1-p4, 3881, 3891, and B973 on 3,666 patients (1986 to 2001) with documented ages and follow-up data. Twenty-seven separate analyses, one for each different age cutoff (adjusting for MYCN and stage), tested age influence on outcome. The cutoff that maximized outcome difference between younger and older patients was selected. RESULTS: Thirty-seven percent of patients were younger than 365 days, and 64% were > or = 365 days old (4-year event-free survival [EFS] rate +/- SE: 83% +/- 1% [n = 1,339] and 45% +/- 1% [n = 2,327], respectively; P < .0001). Graphical analyses revealed the continuous nature of the prognostic contribution of age to outcome. The optimal 460-day cutoff we selected maximized the outcome difference between younger and older patients. Forty-three percent were younger than 460 days, and 57% were > or = 460 days old (4-year EFS rate +/- SE: 82% +/- 1% [n = 1,589] and 42% +/- 1% [n = 2,077], respectively; P < .0001). Using a 460-day cutoff (assuming stage 4, MYCN-amplified patients remain high-risk), 5% of patients (365 to 460 days: 4-year EFS 92% +/- 3%; n = 135) fell into a lower risk group. CONCLUSION: The prognostic contribution of age to outcome is continuous in nature. Within clinically relevant risk stratification, statistical support exists for an age cutoff of 460 days.

RNA expression of the WT1 gene in Wilms' tumors in relation to histology.

BACKGROUND: On the basis of accumulating data, the recently isolated WT1 gene is a Wilms' tumor gene and a putative tumor suppressor gene. These findings include expression in developing fetal kidney, intragenic deletions in tumors, and germline mutations in predisposed individuals. Wilms' tumors, which exhibit a broad range of differentiation, are composed of three cell types: blastema, epithelium, and stroma. PURPOSE: The purpose of this study was to investigate the relationship between WT1 gene expression and histologic composition in Wilms' tumors in an effort to elucidate how the WT1 gene functions in proliferation of these histologic components. METHODS: We used Northern blot hybridization to study WT1 gene expression by messenger RNA (mRNA) accumulation in 20 tumors of varying histology and in adjacent uninvolved kidney tissue. In two patients, tumors were also compared before and after therapy. RESULTS: Tumors that were predominantly blastemal expressed high amounts of WT1 mRNA, whereas predominantly stromal tumors expressed either low or undetectable amounts. Blastemal tumors that were predominantly poorly differentiated expressed WT1 mRNA at higher levels than those that were more well differentiated. Although we expected that a putative tumor suppressor gene like WT1 would generally be expressed at lower levels in tumor than in normal kidney, this was true only in predominantly stromal cells. One of the two patients studied before and after therapy had a dramatic response to therapy accompanied by a decline in WT1 gene expression and disappearance of blastemal and epithelial elements. CONCLUSIONS: A correlation was observed between WT1 gene expression and histology of the tumors. Level of expression was inversely related to the degree of differentiation in blastemal tumors and in the patient with a dramatic response to therapy. These results, in conjunction with the observation that WT1 mRNA is abundant in normal fetal kidney, suggest that WT1 gene expression is related to kidney development, especially in differentiation of blastemal components. IMPLICATIONS: Further studies to search for alterations of the WT1 gene in tumors and to identify regulatory factors in gene expression will increase understanding of the role of this gene in normal development and tumorigenesis.

Genetic staging of unresectable or metastatic neuroblastoma in infants: a Pediatric Oncology Group study.

BACKGROUND: Current staging systems for unresectable or metastatic neuroblastoma do not reliably predict responses to chemotherapy in infants under 1 year of age. Previous studies have indicated that the DNA content, or ploidy, of malignant neuroblasts can discriminate between good and poor responders in this group of patients, but the clinical utility of ploidy assessment has remained in question. PURPOSE: We tested, in a prospective nonrandomized study, the hypothesis that neuroblast ploidy could be used as the sole guide for treatment selection in infants with unresectable or metastatic tumors and could differentiate between those who would respond to our previous standard regimen and those who would benefit from an immediate switch to another therapy. METHODS: One hundred seventy-seven infants were enrolled in this trial. Five of these infants were subsequently excluded (two ineligible, two lacking ploidy information, and one protocol violation); therefore, 172 patients were included in the study. One hundred thirty infants with hyperdiploid tumors (DNA index > 1.0; better prognosis in retrospective studies) were treated with a well-tolerated regimen of cyclophosphamide (150 mg/m2 per day orally or intravenously on days 1-7) and doxorubicin (35 mg/m2 intravenously on day 8). Forty-two infants with diploid tumors (DNA index = 1.0; worse prognosis in retrospective studies) received cisplatin (90 mg/m2 intravenously on day 1) and teniposide (100 mg/ m2 intravenously on day 3) after an initial course of cyclophosphamide plus doxorubicin. Statistical end points were response and long-term survival. In addition, we assessed within each ploidy group (i.e., patients with hyperdiploid tumors and those with diploid tumors) the prognostic significance of NMYC gene copy number, tumor stage, and other variables commonly measured in this disease. RESULTS: Of the 127 assessable infants with hyperdiploid tumors, 115 (91%) had complete responses--85 after receiving five courses of cyclophosphamide plus doxorubicin and 30 after receiving further therapy including cisplatin plus teniposide. The 3-year survival estimate for the entire hyperdiploid group was 94% (95% confidence interval [CI] = 89%-98%). Nineteen (46%) of 41 assessable infants with diploid tumors were complete responders. The overall 3-year survival estimate for this group was 55% (95% CI = 39%-70%). Prognostic factor analysis indicated that NMYC gene amplification and an elevated serum lactate dehydrogenase level were statistically significant markers of higher risk disease within the diploid group (two-sided P values of .005 and .003, respectively). Only NMYC was predictive in the hyperdiploid group (P = .003). CONCLUSION: Use of a prognostic staging system based on tumor cell ploidy, augmented with the NMYC gene copy number and serum level of lactate dehydrogenase, would very likely improve the treatment of infants with unresectable or metastatic neuroblastoma. Patients with diploid tumors characterized by an amplified NMYC locus represent a particularly unfavorable risk group that may benefit from innovative new therapies.

Lack of correlation of N-myc gene amplification with prognosis in localized neuroblastoma: a Pediatric Oncology Group study.

Multiple copies of N-myc proto-oncogene are only rarely detected in localized neuroblastomas (NBs), and the prognostic relevance of amplification in this subset of patients is not clear. We analyzed a series of 850 children with NB admitted to a Pediatric Oncology Group NB Biology Study and identified six patients with localized NBs harboring N-myc gene amplification. Three patients whose tumors showed favorable histology by Shimada classification and low-risk histological features according to the Joshi classification have remained disease-free, whereas two of three patients with unfavorable histology tumors have developed recurrent disease. Although earlier studies have indicated that N-myc amplification is associated with diploid DNA content, flow cytometric analysis revealed that only two of the localized tumors contained stem lines with diploid DNA content. Loss of chromosome 1p was not detected by fluorescence in situ hybridization in the two tumors examined. N-myc protein was detected by immunohistochemical studies in four of the five NBs analyzed. However, N-myc protein was not visualized in one of the tumors with stroma-rich histology, and Western blot analysis revealed only low levels of N-myc protein expression in another NB with favorable histology. These studies indicate that the presence of N-myc amplification in localized NBs does not necessarily portend an adverse outcome. Furthermore, the biological features of this subset of N-myc-amplified NBs appear to differ from those of more advanced N-myc-amplified tumors.

Differential expression of N-myc in phenotypically distinct subclones of a human neuroblastoma cell line.

Neuroblastomas are malignant childhood neoplasms that arise from derivatives of the neural crest. We report the characterization of a new neuroblastoma cell line, designated NBL-W, derived from the primary tumor of a patient with stage IVS disease (S. L. Cohn, C. V. Herst, H. S. Maurer, and S. T. Rosen, J. Clin. Oncol., 5: 1441-1444, 1987) according to the criteria of Evans [A. E. Evans, G. J. D'Angio, and J. Randolf, Cancer (Phila.), 27: 374-378, 1971]. Neurite-bearing (N) and substrate-adherent (S) cell lines have been subcloned from the parent line. N and S cells can interconvert, and both cell types label with the neural crest cell surface marker antibody, HNK-1. Cells in the subcloned lines and in the parent line have been shown by Southern blot analysis to contain approximately 100 copies of the N-myc gene. Cytogenetic analysis shows a homogeneously staining region present on chromosome 19. Although these subclones are of identical genotype, the S cells express lower amounts of N-myc mRNA and protein as compared to the N cells. N cells express several neuronal proteins including the neurotransmitter-processing enzymes tyrosine hydroxylase and dopamine beta-hydroxylase, the neuronal intermediate filament proteins peripherin and NF66/alpha-internexin, and the neural cell adhesion molecule. S cells generally lack neuronal markers but express the mesenchymal intermediate filament protein vimentin, and a small subset of the S cells express glial fibrillary acidic protein. Some S cells were labeled weakly with neural cell adhesion molecule antibody; others were negative. S cells did not express the glial marker S-100 or a melanocyte marker, tyrosinase. Thus, S cells express the neural crest marker HNK-1 but do not express a set of antigens characteristic of any known cell type derived from the neural crest. These results are consistent with the suggestion that differential N-myc expression may be involved in the interconversion of N and S cells but indicate that the S cell phenotype need not represent a highly differentiated neural crest derivative.

Schwann cell-conditioned medium inhibits angiogenesis.

Neuroblastomas are biologically heterogeneous tumors that consist of two main cell populations: neuroblastic/ganglionic cells and Schwann cells. The amount of Schwannian stroma strongly impacts prognosis, and favorable outcome is associated with tumors that are Schwannian stroma rich/stroma dominant. At the present time, there is controversy regarding the origin of Schwann cells in neuroblastoma tumors. However, recent studies have suggested that the Schwann cells in mature neuroblastoma tumors may be normal cells that produce soluble substances that enhance the survival and differentiation of neuroblastoma cell lines. Previously, we reported that in neuroblastoma, high vascular index correlated with clinically aggressive disease. In contrast, tumors with favorable histology and abundant Schwannian stroma had low tumor vascularity. As a first step toward investigating whether Schwann cells also play a role in inhibiting angiogenesis in neuroblastoma tumors, we examined the ability of conditioned medium collected from normal human Schwann cells to affect basic fibroblast growth factor- and vascular endothelial growth factor-induced endothelial cell proliferation and migration and in vivo angiogenesis. In vitro angiogenesis assays were also performed with conditioned medium collected from Schwann cells derived from a Schwannian stroma-dominant neuroblastoma tumor. Our results indicate that Schwann cells derived from either adult nerve or tumor tissue produce a potent inhibitor(s) of angiogenesis. Expression studies revealed tissue inhibitor of metalloproteinase (TIMP)-2 in conditioned medium collected from both normal and tumor-derived Schwann cells. In addition, TIMP-2 was detected in the cytoplasm of Schwann cells and ganglion cells in stroma-rich/stroma-dominant neuroblastoma tumors by immunohistochemistry studies. We postulate that the low level of vascularity and more benign clinical behavior of Schwannian stroma-rich/stroma-dominant neuroblastoma tumors result from the Schwann cell production of TIMP-2 and/or other inhibitors of angiogenesis.

Analysis of possible WT1 RNA processing in primary Wilms tumors.

WT1 RNA processing abnormalities have been suggested to play a role in the development of Wilms tumor by reports of editing at codon 280 in the rat WT1 transcript (codon 281 in humans) and aberrant splicing of exon 2 in WT1 transcripts from Wilms tumor xenograft cell lines. Both events result in a functionally changed WT1 protein and are potential mechanisms of altering normal protein function in the absence of WT1 DNA mutations. To determine whether either of these RNA processing events occurs in primary Wilms tumors, we analysed WT1 mRNA from 15 primary tumors. There was no evidence of WT1 RNA editing at codon 281, and only one primary tumor displayed aberrant splicing of exon 2. Sequence and Southern analysis of DNA from this tumor did not reveal any alteration in or around exon 2. These results suggest that neither RNA editing at codon 281 nor aberrant exon 2 splicing is a frequent mechanism of WT1 alteration during tumorigenesis.

Physical mapping of the DDX1 gene to 340 kb 5' of MYCN.

One of the most important prognostic factors in neuroblastoma is amplification of the MYCN gene, which is strongly associated with advanced stages of disease and a poor prognosis. Although the MYCN amplicon sometimes spans more than 1 Mb, no other consistently expressed sequences from the MYCN amplicon have been reported. However, DDX1, a gene encoding a DEAD box protein, was recently mapped to chromosome 2p24 and is frequently co-amplified with MYCN. Therefore, we performed genomic mapping with YACs to determine the physical relationship between DDX1 and MYCN, and whether DDX1 was contained within the core region of amplification. Based on YAC restriction mapping and content analysis, DDX1 maps 340 kb 5' of MYCN, outside the core domain of consistent amplification. Interestingly, we also determined by sequence analysis and detailed restriction mapping that G21, previously isolated as a 'neuroblastoma-specific' cDNA clone from an MYCN amplicon, is a partial cDNA of DDX1. Our data confirm that DDX1 is amplified in some but not all MYCN-amplified tumors, and that it is rearranged in other cases. This suggests that the co-amplification of DDX1 is due to its proximity to MYCN.

Altered expression of the MYCN oncogene modulates MRP gene expression and response to cytotoxic drugs in neuroblastoma cells.

We have recently shown a close correlation between expression of the Multidrug Resistance-associated Protein (MRP) gene and the MYCN oncogene and provided evidence that high MRP expression is a powerful independent predictor of poor outcome in neuroblastoma (Norris et al., New Engl. J. Med., 334, 231-238, 1996). The effect of MYCN down-regulation on MRP expression and response to cytotoxic drugs was investigated in NBL-S neuroblastoma cells transfected with MYCN antisense RNA constructs. Concomitant with MYCN down-regulation, the level of MRP expression was decreased in the NBAS-4 and NBAS-5 antisense transfectants. These cells demonstrated significantly increased sensitivity to the high affinity MRP substrates vincristine, doxorubicin, sodium arsenate and potassium antimony tartrate, but not to the poor MRP substrates, taxol or cisplatin. Similarly, transfection of full-length MYCN cDNA into SH-EP neuroblastoma cells resulted in increased MRP expression and significantly increased resistance specifically to MRP substrates. The results provide evidence for the MYCN oncogene influencing cytotoxic drug response via regulation of MRP gene expression. Our data also provide a link between the malignant and chemoresistant phenotypes of this childhood malignancy.

Prolonged N-myc protein half-life in a neuroblastoma cell line lacking N-myc amplification.

Genomic amplification of the oncogene N-myc is associated with rapid tumor progression and poor prognosis in patients with neuroblastoma (NB). However, 40% of NBs which lack N-myc amplification are also clinically aggressive. Factors other than N-myc copy number must therefore play a role in determining tumor progression in these NBs. We have established an unusual human NB cell line (NBL-S) from the primary tumor of a patient with rapidly progressive disease which lacks N-myc amplification. The doubling time in vitro (48 h) and the time from injection of 2 x 10(7) cells to detectable tumors in nude mice (46 days) in similar to NB cell lines with amplified N-myc. However, karyotype analysis reveals no evidence of double minutes (DMs), homogeneously staining regions (HSRs), or chromosome 1p deletions, features commonly seen in NB cell lines. The cells have the cell surface phenotype typical of N-myc amplified NB (HLA-A,B,C negative and HSAN 1.2 positive), and similar to other NB cell lines, N-myc RNA and protein are expressed. Interestingly, the half-life of the N-myc protein in NBL-S is prolonged (approximately 100 min) compared to the short N-myc protein half-life previously described in N-myc amplified NB cell lines (approximately 30 min). Because N-myc protein is thought to have a regulatory role, prolongation of the half-life of this protein may be an important factor in the regulation of growth in NBs which lack N-myc amplification and rapidly progress.

N-myc amplification in an infant with stage IVS neuroblastoma.

N-myc amplification is most frequently found in neuroblastoma from patients with stage III and IV disease. Recently a significant association between genomic amplification and poor prognosis has been demonstrated. The primary tumors studied from patients with stage IVS disease have reportedly had a single copy of N-myc, and these patients are alive without progressive disease. We report a patient with stage IVS neuroblastoma with N-myc amplification who developed widespread metastasis within 6 months of diagnosis. The same correlation between oncogene copy number and progressive disease that has been seen in those patients with stage II, III, and IV disease was seen in this patient with stage IVS neuroblastoma.

Tumor angiogenesis correlates with metastatic disease, N-myc amplification, and poor outcome in human neuroblastoma.

PURPOSE: To determine if the clinical outcome of children with neuroblastoma (NB) is correlated with the degree of tumor neovascularization and to assess the relationship of stage, N-myc copy number, and histology to angiogenesis. MATERIALS AND METHODS: The vascularity of primary untreated NB from 50 patients diagnosed at a single institution between 1984 and 1994 was evaluated. An image processor was used to analyze the tumor tissue area for each histologic slide of tumor, and a vascular index (VI) was calculated, where VI = total number of vessels/mm2 of tissue area. Tumors were classified histologically according to the criteria of Shimada et al (J Natl Cancer Inst 73:405-416, 1984), and N-myc copy number was determined by Southern blot analysis. RESULTS: We found that higher VI (> 4.0) in NB strongly correlated with widely disseminated disease (P = .006) and poor survival (P < .0001). VI more than 4.0 was also statistically associated with N-myc amplification (P = .02) and unfavorable histology (P = .02). Univariate analysis demonstrated that disease stage, tumor histology, and N-myc copy number were also predictive of outcome. Cox regression analysis showed that VI provided independent prognostic information. CONCLUSION: Our studies indicate that angiogenesis may play an important role in determining the biologic behavior of NB. Antiangiogenic therapy may prove to be effective in the treatment of children with highly vascular, widely disseminated NB.

Treatment and outcome of 83 children with intraspinal neuroblastoma: the Pediatric Oncology Group experience.

PURPOSE: To investigate whether the rate of neurologic recovery or the incidence of long-term sequelae differed for children with neuroblastoma (NB) initially treated with chemotherapy versus surgical decompression with laminectomy, we reviewed the Pediatric Oncology Group (POG) experience. PATIENTS AND METHODS: A retrospective review of children diagnosed with intraspinal NB registered on POG NB Biology Protocol 9047 was performed. Survival, neurologic outcome, and orthopedic sequelae were evaluated according to age of the patient at diagnosis, stage of disease, duration and severity of neurologic symptoms, and therapeutic intervention. RESULTS: Between May 1990 and January 1998, 83 children with intraspinal NB were entered onto the study. Five-year survival for this cohort of patients was 71% +/- 9%. Forty-three (52%) of the patients had neurologic symptoms at diagnosis. After treatment, six of 15 severely affected patients, who presented with paralysis, completely recovered neurologic function. Two of five patients with moderate deficits, consisting of paresis and bowel/bladder dysfunction, completely recovered neurologic function. Seventeen of 22 assessable children, who had mild symptoms comprised of paresis alone, fully recovered. Seven of 24 assessable patients who had undergone laminectomy developed scoliosis, whereas spinal deformities were only detected in one of 49 assessable patients managed without laminectomy (P =.001). CONCLUSION: The frequency of complete neurologic recovery in children with intraspinal NB inversely correlated with the severity of the presenting neurologic deficits. The rate of neurologic recovery was similar for patients treated with chemotherapy compared to those managed with laminectomy. Fewer orthopedic sequelae were observed in the children managed with chemotherapy than were seen in children managed with laminectomy.