N-Myc gene amplification is a major prognostic factor in localized neuroblastoma: results of the French NBL 90 study. Neuroblastoma Study Group of the Société Francaise d'Oncologie Pédiatrique

Risk estimation in localized unresectable single copy MYCN neuroblastoma by the status of chromosomes 1p and 11q

In localized neuroblastoma, the identification of patients requiring intensive treatment is still difficult. We retrospectively analyzed data of 280 single copy MYCN stage 2 and 3 neuroblastoma patients with gross residual tumor after initial surgery. The 3-year-event free survival of the total group was 83+/-2%, and 3-year-overall survival was 92+/-2%. Patients < or=1.5 years had a better outcome than older children. Deletions/imbalances of chromosome 1p were found in 9/90 patients and were associated with a higher event rate but not with a higher death rate. Aberrations of chromosome 11q in 14/91 patients were correlated with a higher event and death rate. Multivariate analysis identified 1p aberrations as important for event free survival and 11q aberrations for overall survival.

Use of Chromogenic In Situ Hybridization to Identify MYCN Gene Copy Number in Neuroblastoma Using Routine Tissue Sections

Amplification of MYCN in neuroblastoma is associated with a poor prognosis. However, methods for estimating the number of MYCN genes based on pooled cells do not address copy number heterogeneity at the cell level and can underestimate or even miss amplification. MYCN copy number can be directly assessed by fluorescence in situ hybridization, but evaluation of tissue histology is next to impossible. We have used a chromogenic method for in situ hybridization (CISH) that enables determination of MYCN copy number using routine light microscopy on routinely processed paraffin sections. Of 41 cases studied, CISH identified 100% of the 18 cases that were determined to be amplified by other techniques and was more sensitive than Southern blotting or quantitative DNA polymerase chain reaction. Because the technique evaluates individual tumor cells, heterogeneity of MYCN copy number was apparent from cell to cell. When defined as 50% or greater variation in copy number between cells in amplified tumors, almost 30% of cases were scored as heterogeneous. Heterogeneity reflects different tumor clones and its role has likely been under-recognized and underestimated in neuroblastoma biology. CISH will provide a valuable tool to assess this phenomenon in conjunction with other morphologic parameters in neuroblastoma specimens, to further our understanding of the biology of this childhood tumor.

Liver involvement in neuroblastoma: the Memorial Sloan-Kettering Experience supports treatment reduction in young patients

BACKGROUND

We reviewed clinical and biologic findings in a series of infants with neuroblastoma (NB) in liver. The aim was to gain insights into improving therapy.

PATIENTS AND METHODS

Among 19 newly or recently diagnosed infants with NB in liver, 1987-2002, those with stage 4 involving bone received chemotherapy, while those without bone or extensive bone marrow (BM) involvement were observed or received limited treatment if NB caused life-threatening symptoms. We assessed results in the context of NB treatment risk stratification, which is based on age, stage, and selected biologic features (MYCN, ploidy, histology).

RESULTS

Six of eight infants with bone involvement became long-term event-free survivors including 1/2 with MYCN amplification and four who received only 4-6 cycles of chemotherapy; at the end of treatment, four infants had abnormalities in liver +/- the primary site, but these resolved. All 11 infants without bone lesions became long-term survivors with either no cytotoxic therapy or only one cycle of chemotherapy (+/- radiotherapy to liver), including four who had stage 4 and one stage 4S patient who still had NB in BM at age 15 months.

CONCLUSIONS

Treatment reduction should be considered for subsets of infants with non-MYCN-amplified widespread NB: stage 4 without bone or extensive BM involvement may not require cytotoxic therapy, stage 4S with symptomatic hepatomegaly may not require multiple cycles of chemotherapy, and classic stage 4 may do well with limited chemotherapy. Persistent liver abnormalities post-treatment may not require continued therapy to achieve a radiologic complete remission.

Neuroblastoma in southern Brazil: an 11-year study

The authors report on the incidence and clinical characteristics of neuroblastoma in southern Brazil. The aims of the study were to evaluate the age at diagnosis, tumor stage, MYCN status, and tumor histopathology, and to relate these factors to survival. All patients with neuroblastoma, 15 years old or younger (n = 125), admitted to the three major pediatric oncology hospitals in the state of Parana over a period of 11 years (between January 1990 and December 2000), were included in the analysis. All patients were followed for at least 5 years. In addition, a FISH evaluation for MYCN status was conducted in a subset of 34 tumors. Overall survival for tumor stages 1, 2, 3, and 4 was 100%, 72%, 59%, and 17%, respectively. Sixty-two percent (77/125) of all patients were older than 2 years; these represented 71% (57/80) of the patients with stage 4 disease. Children who presented with an unfavorable histopathology had a significantly worse prognosis (20% survival) than children with a favorable histopathology (67% survival). MYCN amplification was detected most commonly in stages 3 and 4 tumors (13/16). These data showed a delayed diagnosis of neuroblastoma in children in southern Brazil, and consequently survival was considerably lower in these patients.

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.

Chromogenic in situ hybridization-detected hotspot MYCN amplification associates with Ki-67 expression and inversely with nestin expression in neuroblastomas

Since neuroblastomas are intratumorally heterogeneous, the analysis of genetic and biologic features of randomly selected tumor specimen spots may lead to erroneous conclusions. Our purpose was therefore to construct an easily assessable and strictly defined strategy to unify the detection of various molecular markers in paraffin-embedded neuroblastoma samples. We selected tumor specimen spots of highest proliferation activity, that is, hotspots, for the analysis of MYCN amplification status and proliferation-associated molecular markers, such as nestin, which role in neuroblastoma specimens was evaluated for the first time. Using a chromogenic in situ hybridization (CISH) technique, we showed that patients with a MYCN copy number higher than six in anti-Ki-67-detected hotspots have significantly worse overall survival prognosis than patients with low MYCN copy numbers (P = 0.0006). The chosen cutoff value of six was shown to dichotomize MYCN-amplified neuroblastomas at least as specifically as Southern blot hybridization, in which amplification was defined by a copy number of > or = 10. Interestingly, we also detected without difficulty MYCN-amplified neuroblastic cells in bone marrow samples using the CISH technique. The proliferation activity, assessed with an anti-Ki-67-based proliferation index, was significantly higher in MYCN-amplified than in nonamplified hotspots. The proliferation indices of the hotspots had also a significant correlation with the prognosis (International Classification) and histological type, whereas the proliferation accelerator Id2 did not associate with any of the mentioned parameters. The expression of nestin associated inversely with MYCN amplification (P = 0.018), which challenges a previously suggested role of nestin in neuroblastomas. In summary, hotspot focusing provides a means of analyzing proliferation-associated markers in neuroblastomas, and together with the CISH detection of the MYCN copy number enables an easy and reliable examination of MYCN status in neuroblastomas.

Oncogene amplification in the proximal part of chromosome 6 in rat endometrial adenocarcinoma as revealed by combined BAC/PAC FISH, chromosome painting, zoo-FISH, and allelotyping

The inbred BDII rat is a valuable experimental model for the genetic analysis of endometrial adenocarcinoma (EAC). One common aberration detected by comparative genomic hybridization in rat EAC was gain/amplification affecting the proximal part of rat chromosome 6 (RNO6). We applied rat and mouse chromosome painting probes onto tumor cell metaphase preparations in order to detect and characterize gross RNO6 aberrations. In addition, the RNO6q11-q16 segment was analyzed by fluorescence in situ hybridization with probes representing 12 cancer-related genes in the region. The analysis revealed that seven tumors contained large RNO6-derived homogeneously staining regions (HSRs) in addition to several normal or near-normal RNO6 chromosomes. Five tumors (two of which also had HSRs) exhibited a selective increase of the RNO6q11-q16 segment, sometimes in conjunction with moderate amplification of one or a few genes. Most commonly, the amplification affected the region centered around band 6q16 and included the Mycn, Ddx1, and Rrm2 genes. A second region, centering around Slc8a1 and Xdh, also was affected by gene amplification but to a lesser extent. The aberrations in the proximal part of RNO6 were further analyzed using allelotyping of microsatellite markers in all tumors from animals that were heterozygous in the proximal RNO6 region. We could detect allelic imbalance (AI) in 12 of 20 informative tumors, 6 of which were in addition to those already analyzed by molecular cytogenetic methods as described. Our findings suggest that increase/amplification of genes in this chromosome region contribute to the development of this hormone-dependent tumor.

Amplification of a chromatin remodeling gene, Rsf-1/HBXAP, in ovarian carcinoma

A genomewide technology, digital karyotyping, was used to identify subchromosomal alterations in ovarian cancer. Amplification at 11q13.5 was found in three of seven ovarian carcinomas, and amplicon mapping delineated a 1.8-Mb core of amplification that contained 13 genes. FISH analysis demonstrated amplification of this region in 13.2% of high-grade ovarian carcinomas but not in any of low-grade carcinomas or benign ovarian tumors. Combined genetic and transcriptome analyses showed that Rsf-1 (HBXAPalpha) was the only gene that demonstrated consistent overexpression in all of the tumors harboring the 11q13.5 amplification. Patients with Rsf-1 amplification or overexpression had a significantly shorter overall survival than those without. Overexpression of Rsf-1 gene stimulated cell proliferation and transform nonneoplastic cells by conferring serum-independent and anchorage-independent growth. Furthermore, Rsf-1 gene knockdown inhibited cell growth in OVCAR3 cells, which harbor Rsf-1 amplification. Taken together, these findings indicate an important role of Rsf-1 amplification in ovarian cancer.

Expression of p53, or targeting towards EGFR, enhances the oncolytic potency of conditionally replicative adenovirus against neuroblastoma

BACKGROUND

Advanced stage and relapsing neuroblastoma (NB) has a poor prognosis with frequent treatment failures, warranting new treatment options and enhanced local tumor control. Treatment with conditionally replicative adenoviruses (CRAds) has shown effectiveness in various preclinical cancer models, but has not yet been evaluated for local control of NB. Here, we tested the efficacy of the CRAd AdDelta24 and of two AdDelta24 derivatives against NB. Derivative AdDelta24-425S11 infects cells deficient in coxsackie/adenovirus receptor (CAR) via the epidermal growth factor receptor (EGFR). Derivative AdDelta24-p53 expresses the tumor suppressor protein p53 to promote oncolysis.

METHODS

Expression of CAR and EGFR, and p53 pathway and DNA damage responses were analyzed in six NB cell lines and two xenografts derived from primary NB using immunohistochemistry, reporter gene transactivation, Western blot and fluorescence-activated cell sorting (FACS) analysis. Efficacy of AdDelta24, AdDelta24-425S11 and AdDelta24-p53 against NB was evaluated in vitro by cell viability analysis and in vivo by monitoring subcutaneous xenograft tumor growth in mice and by histological analysis of treated tumors.

RESULTS

Neuroblastoma cell lines were sensitive to oncolysis by AdDelta24, with a higher susceptibility of those with functional p53 and intact DNA damage responses. Compared to AdDelta24, AdDelta24-p53 exhibited enhanced oncolytic potency on all NB cell lines independent of their p53 status and AdDelta24-425S11 was more effective against CAR-low IGR-NB8 cells. Moreover, five daily intratumoral injections of 10(8) plaque-forming units (pfu) of AdDelta24-p53 or AdDelta24-425S11 into subcutaneous IGR-NB8 and IGR-N91 xenografts at an advanced tumor stage yielded significant tumor growth delays (TGD). In contrast, at this dose, AdDelta24 did not cause significant TGD of neuroblastoma xenografts. Injection of AdDelta24-p53 was associated with extensive cell lysis, apoptotic cell death, and fibrous fascicles in the tumors.

CONCLUSION

CRAds expressing p53 and targeted towards EGFR appear promising new agents for local control in the treatment of neuroblastoma.

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.

Clinical features of molecular pathology of solid tumours in childhood

The outlook for children with cancer has improved substantially over the past 20 years, with over three-quarters of children now surviving in the long term. Better use of existing cytotoxic drugs and supportive care have made large contributions, but some of the improvement in survival is due to a greater knowledge of childhood cancer at the cellular and molecular levels. As in leukaemias, several childhood solid tumours carry balanced chromosomal translocations, resulting in fusion genes that encode chimeric proteins with new oncogenic properties. Many of these fusion genes, and other genetic aberrations are tumour specific and are related to outcome. Tumour biology now plays an important part in identifying appropriate treatment through more accurate diagnoses and new risk stratifications based on molecular markers.

Association of HER-2 overexpression with prognosis in nonsmall cell lung carcinoma: a metaanalysis

BACKGROUND

Prognostic implications of overexpression of the HER-2 gene in nonsmall cell lung carcinoma (NSCLC) are a matter of controversy. Many conflicting results have been reported from different laboratories.

METHODS

A metaanalysis of published studies was performed for this quantitative review of the effects of HER-2 overexpression on survival among patients with NSCLC. Of 44 articles initially selected, 20 articles fulfilled eligibility criteria. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on survival differences (the survival rate among patients without HER-2 overexpression minus the survival rate among patients with HER-2 overexpression) at endpoints of 1 years, 3 years, and 5 years after resection of NSCLC.

RESULTS

In total, 2579 patients were included in the final analysis. Overall, HER-2 positivity differed according to histologic type and included 38% of patients with adenocarcinoma, 16% of patients with squamous cell carcinoma, and 18% of patients with large cell carcinoma (P < 0.0001). The combined survival differences in patients with NSCLC at 1 year, 3 years, and 5 years, respectively, were 2.7% (95% confidence interval [95% CI], 1.3-6.7%; P = 0.1787), 15.2% (95% CI, 5.8-24.5%; P = 0.0015), and 16.4% (95% CI, 7.9-14.8%; P = 0.0001), suggesting significant poorer survival at 3 years and 5 years among patients with HER-2 overexpression. In patients with adenocarcinoma, the combined survival difference at 5 years was 26.0% (95% CI, 16.0-36.1%; P < 0.0001), suggesting a particularly strong survival impact for HER-2 overexpression.

CONCLUSIONS

A significant, unfavorable prognostic effect of HER-2 overexpression in NSCLC was evident from the metaanalysis. However, because several studies that found no significant difference were excluded by the current eligibility criteria, caution is needed in interpreting the results.

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.

Detection of Neuroblastoma Cells in Bone Marrow and Peripheral Blood by Different Techniques

PURPOSE

Detection of metastatic tumor cells in bone marrow (BM) and peripheral blood (PB) of children with neuroblastoma is crucial for prognosis and planning of therapy. Aims of this large descriptive repeated survey were to evaluate the diagnostic accuracy of different techniques in diagnostic samples obtained at several disease course time points and to correlate positive results with patient clinical features and outcome.

EXPERIMENTAL DESIGN

BM aspirates, trephine biopsies, PB, and peripheral blood stem cell (PBSC) samples from Italian children with neuroblastoma were analyzed by morphological and histologic techniques, as well as by immunocytochemistry (IC) for disialoganglioside GD(2) and reverse transcription-PCRs (RT-PCRs) for tyrosine hydroxylase (TH) and pgp9.5 genes. The diagnostic odd ratio (DOR) was used to measure the accuracy of the different techniques.

RESULTS

A total of 2,247 evaluations were done on 561 BM, 265 PB, and 69 PBSC samples from 247 patients. IC showed the best accuracy. Whereas TH RT-PCR accuracy was satisfactory, that of pgp9.5 was very low. Positive results obtained by IC in BM and PB samples at diagnosis from stage 1, 2, and 3 patients correlated with unfavourable outcome. No correlation was found between positive results obtained by IC or TH RT-PCR in BM, PB, and PBSC samples from stage 4 patients and their outcome.

CONCLUSIONS

Because of its elevated diagnostic accuracy, IC may represent a useful adjunct to conventional morphological techniques, especially in view of its potential prognostic role in patients with localized disease. Longitudinal multicenter studies are warranted to definitely establish the clinical usefulness of TH RT-PCR.

[Prognosis of neuroblastoma in childhood. Methods of assessment and clinical use]

Neuroblastoma and its benign counterpart, ganglioneuroma, are pediatric neuroblastic tumors arising in the sympathetic nervous system from neural-crest cells. Neuroblastoma, the most common extra-cranial solid tumour during childhood, is unique for its broad spectrum of clinical virulence from spontaneous remission to rapid and fatal progression despite intensive multimodality therapy. To a large extent, outcome could be predicted by the stage of disease and the age at diagnosis. However, a number of molecular events in neuroblastoma tumors, accounting for the variability of outcome and response to therapy, have been identified over the past decades. Among these, MYCN amplification is the most relevant prognostic factor and was the first genetic marker, in paediatric oncology, to be included in clinical strategies as a guide for therapeutic decision. This has allowed the most suitable intensity of therapy to be delivered according to a risk-stratified strategy, from observation to megadose chemotherapy with stem cell transplantation. Recent advances in understanding the biology and genetics of neuroblastoma will ultimately allow to select poor-risk patients for appropriate future biologically based therapies.

[Neonatal localized neuroblastoma: 52 cases treated from 1990 to 1999]

Neuroblastoma is the most frequent tumor observed in the newborn. The aim of this study was to review clinical features, treatment and outcome of newborns diagnosed with a localized neuroblastoma.

POPULATION AND METHODS

Data from 52 cases treated according to the NBL 90 and 94 protocols between 1990 and 1999 in 18 French centers of pediatric oncology were analyzed.

RESULTS

The median age at diagnosis was 12 days (range 0-28) with antenatal detection in 14 patients (27%). Tumor location was abdominal in 40 patients (adrenal in 20 of the 40), thoracic in eight, pelvic in three, and cervical in one. N-myc amplification was observed in one out of 40 evaluable cases. The size of the primary tumor was less than 5 cm in 25 cases, between 5 and 10 cm in 25 and more than 10 cm in two. Dumbbell tumor was observed in seven, of whom five had neurological deficit. One child died from hemorrhage after fine needle biopsy during diagnostic procedure. Primary surgical resection was attempted in 37 infants, of whom two died of surgery related complications and three had nephrectomy. Tumor was deemed as unresectable in 14 patients, and primary chemotherapy was given followed by surgical excision in 12. One of them died a few days after the beginning of chemotherapy. As a whole, continuous complete remission was achieved in 48 children, four of them after relapse. Overall survival was 92% with a median follow-up of 46 months (0-113 months).

CONCLUSION

The excellent prognosis of localized NB in neonates needs very restrictive surgical indications, with well-established anatomic and imaging criteria. Indeed, chemotherapy based on weight and managed by expert teams should allow to perform surgical excision in safer conditions for unresectable tumors.

Localized pelvic neuroblastoma: excellent survival and low morbidity with tailored therapy--the 10-year experience of the French Society of Pediatric Oncology

PURPOSE

To assess the results and morbidity of treatment of children with localized pelvic neuroblastoma (NB).

PATIENTS AND METHODS

All consecutive cases of localized pelvic NB registered in the French multicenter prospective studies NBL90 and NBL94 between 1990 and 1999 were reviewed. Resectability was decided on the basis of clinical and radiologic evaluation. In unresectable tumors, primary chemotherapy (combinations of carboplatin-etoposide and vincristine-cyclophosphamide-doxorubicine) was administered before surgery.

RESULTS

Forty-seven children (with 26 resectable tumors and 21 unresectable) were included in this study. At the end of treatment, 31 children were in complete remission (66%). Long-term neurologic sequelae were observed in seven patients (15%), directly attributable to surgery in three cases. After a median follow-up of 48 months (range, 13 to 129 months), 44 patients are alive. Six children experienced local relapse; four of these children achieved subsequent remission. The projected overall survival and event-free survival (EFS) rates at 5 years are, respectively, 93% +/- 4% and 84% +/- 5%. Survival of children treated with preoperative chemotherapy are similar to those treated by primary surgery (80% and 88% respectively). The extent of surgical resection seemed to have no influence on the outcome (EFS rates 76% and 89% in case of gross residue and complete resection or microscopic residue, respectively).

CONCLUSION

Our data confirm the excellent survival of localized pelvic NBs. Considering the efficacy of preoperative chemotherapy, patients with pelvic NB should be carefully screened for primary surgery. The risk of neurologic impairment during radical excision should be balanced with the good survival of children with minimal residual disease.

Somatostatin receptors in non-endocrine tumours

The presence of cellular somatostatin receptors, particularly of subtype 2, has been reported in a large number of human primary non-neuroendocrine tumours, such as breast and colon cancer. Our aim was to evaluate whether subtype 2 expression may represent a prognostic factor in these tumours, and if the exact determination of its expression might help to identify patients eligible for a new treatment modality based on somatostatin analogues. Large groups of neuroblastomas as well as breast and colon cancers were studied for subtype 2 expression. In the two latter groups the expression of subtype 2 was evaluated both in tumour and in the corresponding normal tissue from the same patient, to correctly evaluate any modification of subtype 2 mRNA expression in cancer. Subtype 2 mRNA expression was measured with accurate quantitative retro transcription-polymerase chain reaction procedures (first, by competitive polymerase chain reaction and then, by real-time assays). When possible, results of mRNA measurement were compared with in vitro (in situ hybridisation and immunohistochemistry) and in vivo (octreoscan) demonstration of subtype 2 expression in the same patients. Our results seem to suggest the hypothesis that subtype 2 may represent a marker of cell differentiation in certain tumours, such as neuroblastoma, and another instance may be represented by breast and colon cancer. Beside this, the question whether subtype 2 may have an active role in inhibiting cancer cell proliferation, stays open.

Localised and unresectable neuroblastoma in infants: excellent outcome with low-dose primary chemotherapy

The purpose of this study was to evaluate the efficacy of low-dose chemotherapy in infants with localised and unresectable neuroblastoma (NB). All consecutive infants with localised NB and no N-myc amplification were eligible in the SFOP-NBL 94 study. Primary tumour was deemed as unresectable according to imaging data showing any risk of immediate resection. Diagnostic procedures and staging were conducted according to INSS recommendations. For children, provided that they had no threatening symptom (i.e. vital risk or dumb-bell NB with neurologic deficit), chemotherapy consisted in low-dose cyclophosphamide (5 mg⁻¹kg day⁻¹ × 5 days) and vincristine (0.05 mg kg⁻¹ at day 1)–CV and repeated one to three times every 2 weeks until surgical excision can be safely performed. No postoperative treatment was given. Between January 1995 and December 1999, 134 consecutive infants with localised NB were registered in the study, of whom 39 had an unresectable NB without N-myc amplification. Among them 28 had no threatening symptom and received CV according to the protocol. Objective response was observed in 14 (50%) and the other 14 were given second-line chemotherapy because of no response. Surgery was attempted in 38 patients including 14 after CV alone, leading to complete resection in 23. Relapses occurred in four patients all local. Survival and event-free survival were 100 and 90±5% with a median follow-up of 55 months (range 33–93). In conclusion primary low-dose chemotherapy without anthracyclines is efficient in about half of the infants presenting with an unresectable NB and no N-myc amplification, allowing excellent survival rates without jeopardising their long-term outcome even for nonresponding patients who received standard regimen.

Overexpression of the amplified Pip4k2β gene from 17q11–12 in breast cancer cells confers proliferation advantage

Gene amplification is common in solid tumors and is associated with adverse prognosis, disease progression, and development of drug resistance. A small segment from chromosome 17q11-12 containing the HER-2/Neu gene is amplified in about 25% of breast cancer. HER-2/Neu amplification is associated with adverse prognosis and may predict response to chemotherapy and hormonal manipulation. Moreover, HER-2/Neu amplification may select patients for anti-HER-2/Neu-based therapy with Herceptin. We and others recently described a common sequence element from the HER-2/Neu region that was amplified in breast cancer cells. In addition, most, if not all, of the amplified genes from this region display overexpression. This raises the intriguing possibility that genes immediately adjacent to HER-2/Neu may influence the biological behavior of breast cancer carrying HER-2/Neu amplification and serve as rational targets for therapy. By extracting sequence information from public databases, we have constructed a contig in bacterial artificial chromosomes (BACs) that extends from HER-2/Neu to a phosphotidylinositol phosphate kinase (PIPK), Pip4k2beta from 17q11-12. Although a role of PI-3-kinase and AKT in cancer biology has been previously described, PIPK has not been previously implicated. We show that Pip4k2beta, initially known as Pip5k2beta, is amplified in a subset of breast cancer cell lines and primary breast cancer samples that carry HER-2/Neu amplification. Out of eight breast cancer cell lines with HER-2/Neu amplification, three have concomitant amplification of the Pip4k2beta gene--UACC-812, BT-474 and ZR-75-30. Similarly, two out of four primary breast tumors with HER-2/Neu amplification carry Pip4k2beta gene amplification. Intriguingly, one tumor displays an increase in the gene copy number of Pip4k2beta that is significantly more than that of HER-2/Neu. Moreover, dual color FISH reveals that amplified Pip4k2beta gene may exist in a distinct structure from that of HER-2/Neu in ZR-75-30 cell line. These studies suggest that Pip4k2beta may reside on an amplification maximum distinct from that of HER-2/Neu and serve as an independent target for amplification and selective retention. Pip4k2beta amplification is associated with overexpression at the RNA and protein level in breast cancer cell lines. Stable expression of Pip4k2beta in breast cancer cell lines with and without HER-2/Neu amplification increases cell proliferation and anchorage-independent growth. The above observations implicate Pip4k2beta in the development and/or progression of breast cancer. Our study suggests that Pip4k2beta may be a distinct target for gene amplification and selective retention from 17q11-12.

Localized cervical neuroblastoma: prevention of surgical complications

OBJECTIVES

The purpose of this study focused on cervical neuroblastoma (NB) was to assess the prognosis, define the most suitable methods of investigation, and evaluate risk factors for complications following primary surgery.

METHODS

Between 1990 and 1999, we conducted two consecutive prospective multicentric studies (NBL90 and NBL94) on localized NB. Because the first study (1990-1994) found surgery-related morbidity and mortality, several surgical risk factors (i.e. adhesion to major vessels, size, friability, and dumb bell tumor) were defined and used prospectively as criteria of resectability in the second study (1994-1999).

RESULTS

Of 617 cases included in the two studies, 43 involved cervical NB including 17 cervicothoracic tumors. With a median follow-up of 4 years, overall survival and event-free survival rates were 91 and 81%, respectively with no significant difference between cervical or cervicothoracic NB. Seventeen patients were included in the second study; surgery was used as the first line treatment in 11. Full pre-operative work-up was performed in eight patients, demonstrating one or more risk factors in three. The remaining three patients underwent emergency surgery with no pre-operative work-up or only ultrasound: two developed serious complications. All three patients presenting documented risk factors developed post-operative complications versus only two of the eight patients who presented no risk factor (n = 5) or were inadequately evaluated (n = 3) (P = 0.06). None of the five patients in whom full work-up demonstrated no risk factor had post-operative complications (P = 0.02).

CONCLUSIONS

Cervical neuroblastoma has a favorable prognosis. Surgery is the treatment of choice but there is a risk of complications. Appropriate pre-operative work-up is mandatory to evaluate resectability. The surgical risk factors defined for our second study seem to be significant predictors of post-operative complications.

Advances in the diagnosis and treatment of neuroblastoma

Neuroblastoma, a childhood neoplasm arising from neural crest cells, is characterized by a diversity of clinical behavior ranging from spontaneous remission to rapid tumor progression and death. To a large extent, outcome can be predicted by the stage of disease and the age at diagnosis. However, the molecular events responsible for the variability in response to treatment and the rate of tumor growth remain largely unknown. Over the past decade, transformation-linked genetic changes have been identified in neuroblastoma tumors that have contributed to the understanding of tumor predisposition, metastasis, treatment responsiveness, and prognosis. The Children's Oncology Group recently developed a Neuroblastoma Risk Stratification System that is currently in use for treatment stratification purposes, based on clinical and biologic factors that are strongly predictive of outcome. This review discusses the current risk-based treatment approaches for children with neuroblastoma and recent advances in biologic therapy.

Identification of genes that are regulated transcriptionally by Myc in childhood tumors

BACKGROUND

Amplification of the N-myc oncogene is associated with adverse outcomes in the common childhood tumor, neuroblastoma. Because the transforming properties of Myc are related to its ability to modulate gene expression, the authors used cDNA microarrays to identify potential Myc target genes.

METHODS

Expression levels of 4608 genes were analyzed in a series of neuroblastoma cell lines. Identical analyses were performed in a panel of medulloblastoma cell lines to identify c-Myc targets and to determine the extent to which N-Myc targets and c-Myc targets were shared. Comparisons were made between cell lines with high levels versus low levels of Myc protein expression.

RESULTS

Array analyses yielded 121 genes with increased expression levels (>or= 1.65-fold) and 9 genes with decreased expression levels in N-Myc-expressing versus nonexpressing cell lines. Many of these were newly identified targets of biologic interest. Fifty percent of the N-Myc targets (60 of 121) were mutual c-Myc targets. A significant correlation between the level of N-myc and selected target gene expression was demonstrated independently in 27 neuroblastoma tumor samples and in an N-myc-inducible cell line system.

CONCLUSIONS

A number of diverse pathways are modulated by N-Myc in neuroblastoma. Although, overall, there was significant correlation between myc and target transcript expression among cohorts of tumors, great variability in levels of target expression was seen among individual tumor samples, and this biologic heterogeneity in the levels of target gene expression may offer insight into differences in the clinical behavior of neuroblastoma and may prove to be of prognostic significance in the future.

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.

Neuroblastoma in adolescents

BACKGROUND

Less than 5% of neuroblastomas are diagnosed in adolescent patients. Previous studies of patients who were treated with less intensive chemotherapy regimens relative to currently available regimens suggested that adolescents survived longer than younger children, and this finding was related to a lack of myc-N amplification. Those reports prompted the authors to study a cohort of adolescent patients who had been included in more recent trials.

METHODS

The authors investigated the presentation, treatment, and outcome in 28 adolescent patients who were enrolled in studies of the French Society of Pediatric Oncology during the period from 1987 to 1999 and who were older than age 10 years at the time they were diagnosed with neuroblastoma. The results were used to compare this subpopulation with a control group of children.

RESULTS

None of the six patients with Stage I-II disease either developed recurrent disease or died. At 5 years, disease progression was high (progression-free survival [PFS], 28%) for the 9 adolescents with Stage III disease, but so was survival (overall survival [OS], 86%). The 13 adolescent patients with metastatic neuroblastoma had very poor outcomes (PFS, 18%; OS, 27%). Despite intensive therapy, advanced neuroblastoma appeared to carry a poorer prognosis in adolescent patients compared with children, although patients with Stage III disease had a more indolent course. No difference was found between adolescent patients and children regarding the clinical presentation, treatment schedule, or doses and tolerance of chemotherapy. The incidence of elevated urinary catecholamine metabolite secretion was lower in adolescents compared with children.

CONCLUSIONS

Adolescent patients with advanced neuroblastoma had less favorable outcomes compared with children, even if survival in adolescents with Stage III disease seemed longer.

Curability of recurrent disseminated disease after surgery alone for local-regional neuroblastoma using intensive chemotherapy and anti-G(D2) immunotherapy

PURPOSE

A reluctance to treat local-regional neuroblastoma by surgery alone derives partly from concern that if widespread neuroblastoma develops, the chance for cure is small, and partly from hope that mild chemotherapy will prevent relapse. The authors report on a series of patients who had distant recurrences after surgery alone for local-regional neuroblastoma.

METHODS

Seven patients treated with surgery alone for local-regional neuroblastoma had widespread relapses 2.5 to 25 (median 7) months later and were treated at Memorial Sloan-Kettering Cancer Center (MSKCC). During the period of this study (1995-1999), MSKCC patients with high-risk neuroblastoma received the N7 protocol (dose-intensive chemotherapy, immunotherapy with the anti-G(D2) 3F8 antibody, targeted radiotherapy using 131I-3F8, local radiotherapy) if they had assessable disease, or 3F8 plus granulocyte-macrophage colony-stimulating factor (GM-CSF) followed by 13-cis-retinoic acid if they were in remission after treatment elsewhere.

RESULTS

Five patients were in complete remission 3 years 11 months to 7 years 4 months from the start of retrieval therapy, including three who received all of their N7 treatment of relapsed neuroblastoma at MSKCC, one who received two cycles of chemotherapy elsewhere before starting N7, and one who was referred for 3F8/GM-CSF because of neuroblastoma cells in pretransplantation bone marrow.

CONCLUSIONS

The encouraging survival results of our cohort are consistent with the concept that surgery alone for local-regional neuroblastoma might be beneficial to the overall neuroblastoma population because many patients will never need chemotherapy (and will therefore be spared its potential toxicities), and most of those who do have widespread relapses are likely to be cured with contemporary treatments.

Quality assessment of genetic markers used for therapy stratification

PURPOSE

Therapy stratification based on genetic markers is becoming increasingly important, which makes commitment to the highest possible reliability of the involved markers mandatory. In neuroblastic tumors, amplification of the MYCN gene is an unequivocal marker that indicates aggressive tumor behavior and is consequently used for therapy stratification. To guarantee reliable and standardized quality of genetic features, a quality-assessment study was initiated by the European Neuroblastoma Quality Assessment (ENQUA; connected to International Society of Pediatric Oncology) Group.

MATERIALS AND METHODS

One hundred thirty-seven coded specimens from 17 tumors were analyzed in 11 European national/regional reference laboratories using molecular techniques, in situ hybridization, and flow and image cytometry. Tumor samples with divergent results were re-evaluated.

RESULTS

Three hundred fifty-two investigations were performed, which resulted in 23 divergent findings, 17 of which were judged as errors after re-evaluation. MYCN analyses determined by Southern blot and in situ hybridization led to 3.7% and 4% of errors, respectively. Tumor cell content was not indicated in 32% of the samples, and 11% of seemingly correct MYCN results were based on the investigation of normal cells (eg, Schwann cells). Thirty-eight investigations were considered nonassessable.

CONCLUSION

This study demonstrated the importance of revealing the difficulties and limitations for each technique and problems in interpreting results, which are crucial for therapeutic decisions. Moreover, it led to the formulation of guidelines that are applicable to all kinds of tumors and that contain the standardization of techniques, including the exact determination of the tumor cell content. Finally, the group has developed a common terminology for molecular-genetic results.

Oncogenes in melanoma

Transformation of normal melanocytes into melanoma cells is accomplished by the activation of growth stimulatory pathways, typically leading to cellular proliferation, and the inactivation of apoptotic and tumor suppressor pathways. Small molecule inhibitors of proteins in the growth stimulatory pathways are under active investigation, and their application to melanoma patients would represent a new treatment strategy to inhibit cell proliferation or induce cell death. We provide a general overview of the mechanisms of oncogene activation and the functions of oncogenes. Lastly, we review oncogenic events in melanoma.

Malignant abdominal masses in children: quick guide to evaluation and diagnosis

A palpable mass in the abdomen of a child is a serious finding. In this article the authors present their single-institution experience of how these malignancies present and their distribution by age and diagnosis. The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms' tumor, hepatoblastoma, lymphoma, and germ cell tumors. This article provides the busy general pediatrician with some guidelines of how to proceed after discovering a suspiciousmass.

MYCN gene overrepresentation detected in primary neuroblastoma tumour cells without amplification

Neuroblastoma is the most frequent solid extracranial neoplasm of childhood, with a median age of presentation of under 2 years. This tumour is highly malignant in patients older than 12 months of age with metastatic disease. Clinical studies have confirmed that amplification of the MYCN proto-oncogene is one of the best prognostic indicators of poor outcome. Approximately 30% of neuroblastoma tumours present MYCN amplification at diagnosis. Far less is known about the incidence and consequences of overrepresentation of the gene due to duplication or rearrangement of the chromosome arm in which the gene is situated. This study has analysed 110 neuroblastomas by FISH and has detected a gain of 1-3 copies per cell of MYCN in 8% of MYCN-non-amplified tumours. In these primary tumours, cells gained small numbers of additional MYCN genes by two mechanisms: formation of an isochromosome 2p, or an unbalanced translocation involving the short arm of chromosome 2 (with MYCN) and various partner chromosomes. Quantitative RT-PCR showed three- to seven-fold elevated MYCN expression in three tumours. Although the follow-up time to date is still short, clinical outcome suggests that low-level overexpression of the MYCN gene does not enhance tumour aggressiveness and rapidity of disease progression, as is often seen in neuroblastoma with MYCN amplification. It is hypothesized that the small elevation in MYCN expression could alter the regulation of apoptosis, as has been shown in experimental models.

Chronic neuroblastoma

BACKGROUND

An indolent course is associated with neuroblastoma (NB) in adolescents and adults. In the current study, the authors analyzed this phenomenon in a large series of children with metastatic NB.

METHODS

The authors studied 38 patients who were diagnosed with NB in the first decade of life and had metastatic disease 5 years or more from diagnosis.

RESULTS

The median age at diagnosis was 3 years 10 months. MYCN was amplified in 2 of 28 patients tested. Of 30 patients with classic Stage 4 NB, 9 had a late first recurrence of disease (4.3-13 years from diagnosis). Of eight patients who had atypical cases at diagnosis (one isolated mandibular lesion, two Stage 4-N, five non-Stage 4), six had a late first distant recurrence of disease (4 years 11 months-38 years 8 months). Nineteen patients were off therapy continuously for 3 years or more before disease recurred a first or second time. Myeloablative therapy was used to consolidate a first or second response in 27 patients. High-dose conventional therapy helped to achieve a second remission of disease in 9 of 20 patients assessable for response of first recurrence but achieved no major responses of second or third relapse in 10 of 11 patients. The combination of anti-G(D2) immunotherapy and/or cis-retinoic acid, targeted radiotherapy, and multiple cycles of chemotherapy with modest toxicity helped prolong survival. Twelve patients survive at 5 years 6 months+ to 19 years 4 months+ from diagnosis (median, 6 years 10 months+), including four with complete remission of disease; 10 received anti-G(D2) immunotherapy after recurrence. The other 26 patients died of disease (n = 22) or toxicity (n = 4) at 5 years-41 years 5 months from diagnosis (median, 6 years 5 months).

CONCLUSIONS

The concept of indolent or smoldering NB should not be limited to adolescents/adults. The expanding repertoire of anti-NB treatments, including biologic therapies and chemotherapy regimens of modest toxicity, can convert childhood NB into a chronic disease with prolonged survival after recurrence.

Detection of N-myc amplification by FISH in immature areas of fixed neuroblastomas: more efficient than Southern blot/PCR

N-myc amplification is a major prognostic factor in neuroblastomas and is systematically investigated by Southern blot or polymerase chain reaction (PCR). A retrospective study of N -myc amplification has been carried out using fluorescence in situ hybridization (FISH) in 97 fixed neuroblastomas. For each tumour, FISH was performed on the area that contained the most immature neuroblasts. Among these 97 neuroblastomas, 16 were amplified and 12 were not interpretable. FISH was not interpretable in six cases. All neuroblastomas with N-myc amplification detected by Southern blot/PCR were amplified with FISH, except three that were not interpretable. Four tumours that were not interpretable in Southern blot/PCR contained more than five copies of N-myc by FISH: one was aneuploid and three were truly amplified, containing more than ten copies of N-myc. Among these three patients, two died in a short time of their tumours. Ten cases were not amplified by Southern blot/PCR and showed more than five copies by FISH: four were aneuploid and two showed heterogeneous amplification, with a few cells clearly amplified whereas most were not. Four cases were amplified, of which two patients died of their tumours. This study confirms that when applied to the most immature areas of fixed neuroblastomas, FISH displayed a higher sensitivity than molecular techniques (p < 0.001) and could detect heterogeneous amplification. FISH could therefore become an important complementary procedure in assessing prognosis in neuroblastomas.

Classifying the medulloblastoma: insights from morphology and molecular genetics

Significant advances in the treatment of the medulloblastoma (MB) have been made in the last 30 years, reducing mortality by 2-fold. Further improvements in the cure rate require an increased understanding of the biology of MBs, and this will translate into refinements in their classification. Scrutiny of the cytological variation found among MBs has recently led to the concept of the anaplastic MB, which overlaps the large-cell variant and appears to share its poor prognosis. In contrast, the MB with extensive nodularity, a distinctive nodular/desmoplastic variant occurring in infants, has a better outcome than most MBs in these young patients. Building on cytogenetic studies that have drawn attention to abnormalities on chromosome 17 in over a third of MBs, research shows non-random losses on chromosomes 8, 9, 10, 11 and 16, and gains on chromosomes 1, 7 and 9. Overexpression of ErbB2 receptors and losses on chromosome 17p have been proposed as independent indicators of aggressive behaviour, while high TrkC receptor expression indicates a favourable outcome. There is a strong association between anaplastic/large-cell tumours and MYC amplification, which has previously been linked with aggressive disease, but associations between abnormalities on chromosome 17 and anaplastic/large-cell MBs and between abnormalities in the shh/PTCH pathway and the desmoplastic variant are more controversial. Classification of the MB histopathologically and according to profiles of molecular abnormalities will help both to rationalize approaches to therapy, increasing the cure rate and reducing long-term side-effects, and to suggest novel treatments.

[Statutory pediatric informations available for anticancer drugs: inventory and proposals]

Paediatric medicines are often prescribed off label because appropriate clinical and pharmacological studies have not been conducted in children. A European directive is being written to promote the development of paediatric medicines through incentives to pharmaceutical companies, as is already the case in the US.

METHOD

In order to evaluate the status of anticancer drugs, we analyzed the paediatric information available in the Vidal 2000 dictionary for cytotoxic chemotherapy.

RESULTS

Among the 76 products, 48 were currently used to treat children with cancer. An indication for paediatric use was described in only 29% of them. Paediatric use was mentioned in the posology chapter in 56% of cases, and in the warning or contra-indication chapter in 17% of cases. Ten products (21%) were devoid of paediatric information.

DISCUSSION

The paucity of this official paediatric information contrasts with the number of clinical and pharmacological studies that have been conducted and published by paediatric oncology societies and groups. Indeed, almost 80% of children with cancer are treated using prospective therapeutic research protocols. In conclusion, anticancer medicines have been evaluated in children, but official paediatric information is poor. This situation can be significantly improved with the literature currently available. On the other hand, prospective clinical studies are needed to better define the optimal dose in children under one year of age, to evaluate long-term sequelae in cured patients and to provide appropriate galenic forms for oral chemotherapy.

CONCLUSION

Incentives are urgently needed to facilitate access to therapeutic innovations in oncology and their development in children with cancer.

Primary neuroblastoma of the maxillary sinus

Although neuroblastoma is the most common of extracranial solid tumors of childhood and infancy, we report the first case of an isolated neuroblastoma of a paranasal sinus. A 15-year-old girl with a right maxillary sinus mass was asymptomatic except for persistent epiphora. Computed tomography and magnetic resonance imaging scans showed that the mass extended into the nasal cavity, encroached on the lamina papyracea, and obstructed the nasofrontal duct. An extensive workup revealed no evidence of systemic disease. The patient underwent right craniofacial resection. Immunohistochemistry and electronmicroscopic findings were consistent with conventional neuroblastoma. Fluorescence in situ hybridization analysis was performed with probes selected to demonstrate genetic alterations associated with neuroblastoma. Studies revealed deletion of chromosome arm 1p, gain of chromosome 17, and normal N-myc gene copy number. In summary, the tumor exhibited morphologic features and genetic alterations more consistent with those of neuroblastoma than with those of esthesioneuroblastoma.

Experience with International Neuroblastoma Staging System and Pathology Classification

The International Neuroblastoma Staging System and Pathology Classification were proposed in 1988 and in 1999, respectively, but their clinical value has not yet been fully studied in new patients. Six hundred and forty-four patients with neuroblastoma treated between January 1995 and December 1999 were analysed by these classifications. The 4-year overall survival rate of patients <12 months of age with INSS stages 1, 2A, 2B, 3 and 4S disease was 98.5%, which was significantly higher than the 73.1% rate in stage 4 patients <12 months (P<0.0001). When patients were > or = 12 months, the 4-year overall survival rate of patients with neuroblastoma at 1, 2A, 2B and 3 stages was 100% and that of patients at stage 4 was 48.5% (P<0.0001). As to the International Neuroblastoma Pathology Classification histology, the 4-year overall survival rate was 98.8% in patients with favourable histology and 60.7% in those with unfavourable histology in the <12 months group (P<0.0001). In the > or = 12 months group, the 4-year oral survival of patients with favourable histology was 95.3% and that of patients with unfavourable histology was 50.6% (P<0.0001). Among biological factors, MYCN amplification, DNA diploidy and 1p deletions were significantly associated with poor prognosis in patients <12 months, as were MYCN amplification and DNA diploidy in patients > or = 12 months of age. Multivariate analysis showed that the INSS stage (stage 4 vs other stages) and International Neuroblastoma Pathology Classification histology (unfavourable vs favourable) were significantly and independently associated with the survival of patients undergoing treatment, stratified by age, stage and MYCN amplification (P=0.0002 and P=0.0051, respectively).

Quantification of MYCN, DDX1, and NAG gene copy number in neuroblastoma using a real-time quantitative PCR assay

Amplification of the proto-oncogene MYCN is a strong adverse prognostic factor in neuroblastoma patients in all tumor stages. The status of the MYCN gene has become an important factor in clinical decision making and therapy stratification. Consequently, fast and accurate assessment of MYCN gene copy number is of the utmost importance and the use of two independent methods to determine MYCN status is recommended. For these reasons we have developed and evaluated a real-time quantitative PCR (Q-PCR) assay as an alternative for time-consuming Southern blot analysis (SB), and as a second independent technique in parallel with fluorescence in situ hybridization (FISH) analysis. Advantages of Q-PCR are a large dynamic range of quantification, no requirement for post-PCR sample handling and the need for very small amounts of starting material. The accuracy of the assay was illustrated by measurement of MYCN single gene copy changes in DNA samples of two patients with 2p deletion and duplication, respectively. Two different detection chemistries i.e., a sequence specific TaqMan probe and a generic DNA binding dye SYBR Green I were evaluated and shown to yield similar results. Also, two different calculation methods for copy number determination were used i.e., the kinetic method and the comparative C(T) method, and shown to be equivalent. In total, 175 neuroblastoma samples with known MYCN status, as determined by FISH and/or SB, were examined. Q-PCR data were highly concordant with FISH and SB data. In addition to MYCN copy number evaluation, DDX1 and NAG gene copy numbers were determined using a similar Q-PCR strategy. Survival analysis pointed out that DDX1 and/or NAG amplification has no additional adverse effect on prognosis.

Galanin and galanin receptor expression in neuroblastic tumours: correlation with their differentiation status

Neuroblastoma and its benign differentiated counterpart, ganglioneuroma, are paediatric neuroblastic tumours arising in the sympathetic nervous system. Their broad spectrum of clinical virulence is mainly related to heterogeneous biologic background and tumour differentiation. Neuroblastic tumours synthesize various neuropeptides acting as neuromodulators. Previous studies suggested that galanin plays a role in sympathetic tissue where it could be involved in differentiation and development. We investigated the expression and distribution of galanin and its three known receptors (Gal-R1, Gal-R2, Gal-R3) in 19 samples of neuroblastic tumours tissue by immunohistochemistry, in situ hybridization and fluorescent-ligand binding. This study provides clear evidence for galanin and galanin receptor expression in human neuroblastic tumours. The messengers coding for galanin, Gal-R1 and -R3 were highly expressed in neuroblastoma and their amount dramatically decreased in ganglioneuroma. In contrast, Gal-R2 levels remained unchanged. Double labelling studies showed that galanin was mainly co-expressed with its receptors whatever the differentiation stage. In neuroblastic tumours, galanin might promote cell-survival or counteract neuronal differentiation through the different signalling pathways mediated by galanin receptors. Finally, our results suggest that galanin influences neuroblastoma growth and development as an autocrine/paracrine modulator. These findings suggest potential critical implications for galanin in neuroblastic tumours development.

Primary pediatric neuroblastic tumors of the neck

Neuroblastic tumors are the third most common cause of solid tumors in early childhood. Cervical tumors account for only 5% of cases. In this report, we describe a series of four pediatric neuroblastic tumors of the neck. The histological diagnosis was ganglioneuroblastoma in three cases and neuroblastoma in one case. Presenting signs were solitary cervical mass in two cases and respiratory distress in association with Claude-Bernard Horner's syndrome in two cases. Mean age at presentation was 15 months. Cervical computed tomography scan and/or magnetic resonance imaging depicted calcifications within the tumor in 50% of cases and allowed accurate assessment of extension. Increased urine catecholamine levels were observed only in the patient with neuroblastoma. Scintigraphy with [131]iodine-methyliodobenzylguanidine demonstrated selective uptake by the tumor in two cases. Amplification of N-myc oncogene, a documented unfavorable prognostic sign, was not found in any case. Surgical treatment was performed in all patients. Neoadjuvant chemotherapy was performed in one case. All patients underwent regular surveillance. No evidence of recurrence has been observed with a mean follow-up period of 7 years.

Smallest region of overlapping deletion in 1p36 in human neuroblastoma: a 1 Mbp cosmid and PAC contig

In human neuroblastomas, the distal portion of 1p is frequently deleted, as if one or more tumor suppressor genes from this region were involved in neuroblastoma tumorigenesis. Earlier studies had identified a smallest region of overlapping deletion (SRO) spanning approximately 23 cM between the most distally retained D1S80 and by the proximally retained D1S244. In pursuit of generating a refined delineation of the minimally deleted region, we have analyzed 49 neuroblastomas of different stages for loss of heterozygosity (LOH) from 1pter to 1p35 by employing 26 simple sequence length polymorphisms. Fifteen of the 49 tumors (31%) had LOH; homozygous deletion was not detected. Seven tumors had LOH at all informative loci analyzed, and eight tumors showed a terminal or an interstitial allelic loss of 1p. One small terminal and one interstitial deletion defined a new 1.7 cM SRO, approximately 1 Mbp in physical length, deleted in all tumors between the retained D1S2731 (distal) and D1S2666 (proximal). To determine the genomic complexity of the deleted region shared among tumors, we assembled a physical map of the I Mbp SRO consisting predominantly of bacteriophage P1-derived artificial chromosome (PAC) clones. A total of 55 sequence-tagged site (STS) markers (23 published STSs and short tandem repeats and 32 newly identified STSs from the insert ends of PACs and cosmids) were assembled in a contig, resulting in a sequence-ready physical map with approximately one STS per 20 Kbp. Twelve genes (41BB, CD30, DFFA, DJ1, DR3, FRAP, HKR3, MASP2, MTHFR, RIZ, TNR2, TP73) previously mapped to 1p36 are localized outside this SRO. On the basis of this study, they would be excluded as candidate genes for neuroblastoma tumorigenesis. Ten expressed sequence tags were integrated in the contig, of which five are located outside the SRO. The other five from within the SRO may provide an entrance point for the cloning of candidate genes for neuroblastoma.

Amplification of oncogenes revisited: from expression profiling to clinical application

Regulatory or structural alterations of cellular oncogenes have been implicated in the causation of cancers. Amplification represents one of the major molecular pathways by which gene expression is constitutively enhanced above the level of physiologically normal variation. Consequently, the significance of oncogene amplification in tumorigenesis originally had emerged from expression profiling of tumor cells by oncogene arrays. Amplified oncogenes have been found associated with more aggressive tumor variants and in selected settings are clinical markers to determine patient prognosis.

Hyperfractionated low-dose radiotherapy for high-risk neuroblastoma after intensive chemotherapy and surgery

PURPOSE

To assess prognostic factors for local control in high-risk neuroblastoma patients treated with hyperfractionated 21-Gy total dose to consolidate remission achieved by dose-intensive chemotherapy and surgery.

PATIENTS AND METHODS

Patients with high-risk neuroblastoma in first remission received local radiotherapy (RT) totaling 21 Gy in twice-daily 1.5-Gy fractions. RT to the primary site followed dose-intensive chemotherapy and tumor resection; the target field encompassed the extent of tumor at diagnosis, plus 3-cm margins and regional lymph nodes. RT to distant sites followed radiologic evidence of response. Local failure was correlated with clinical factors (including other consolidative treatments) and biologic findings.

RESULTS

Of 99 consecutively irradiated patients followed for a median of 21.1 months from RT, 10 relapsed in or at margins of RT fields at 1 to 27 months (median, 14 months). At 36 months after RT, the probability of primary-site failure was 10.1% +/- 5.3%. No primary-site relapses occurred among the 23 patients whose tumors were excised at diagnosis, but there were three such relapses among the seven patients who were irradiated with evidence of residual disease in the primary site. Four of 18 patients with MYCN-amplified disease and serum lactate dehydrogenase greater than 1,500 U/L had local failures (23.4% +/- 10.7% risk at 18 months). Acute radiotoxicities were insignificant, but three of 35 patients followed for > or = 36 months had short stature from decreased growth of irradiated vertebra.

CONCLUSION

Hyperfractionated 21-Gy RT is well tolerated and, together with dose-intensive chemotherapy and surgery, may help in local control of high-risk neuroblastoma. Extending the RT field to definitively encompass regional nodal groups may improve results. Visible residual disease may warrant higher RT dosing. Patients with biologically unfavorable disease may be at increased risk for local failure. RT to the primary site may not be necessary when tumors are excised at diagnosis.

In vivo elimination of acentric double minutes containing amplified MYCN from neuroblastoma tumor cells through the formation of micronuclei

Neuroblastoma, the most common solid extracranial neoplasm in children, shows an appreciable variability in clinical evolution. Amplification of the MYCN oncogene in this tumor is detected in 25 to 30% of cases and is associated with poor clinical outcome. In this study, quantitative polymerase chain reaction and fluorescence in situ hybridization were used to determine MYCN amplification status in 46 neuroblastoma tumors. MYCN amplification was detected in tumors from 11 patients. Fluorescence in situ hybridization revealed the presence of micronuclei containing amplified MYCN sequences in 8 of the 11 tumors. Micronuclei are indicative of spontaneous elimination or loss of amplified sequences by tumor cells. Because the elimination of amplified sequences can be enhanced in vitro by specific drugs such as hydroxyurea, our observations suggest a new therapeutic strategy specifically targeted to cells with amplified genes.