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Biomedical subjects

Barbara Hero

Publications and source records attributed to Barbara Hero.

At least 19 recordsLinked to original sources
PubMed2008

Treatment of neuroblastoma-related opsoclonus-myoclonus-ataxia syndrome with high-dose dexamethasone pulses.

Opsoclonus-myoclonus-ataxia-syndrome (OMS) represents a rare neuroblastoma-associated paraneoplastic syndrome that commonly results in neurologic deficits despite tumor resection and immunosuppressive therapy. We describe the response of five such children to high-dose dexamethasone pulses including two patients in whom previous glucocorticoids, rituximab, and cytostatic drugs were not successful. All patients had MYCN non-amplified tumors that were detected 1 to 7 months after the onset of the OMS or ataxia. This treatment resulted in a good partial response in three and in complete remission in two patients. Our results show that dexamethasone pulses are likely to be useful for both, first-line- and salvage-therapy for OMS-patients.

Adrenal Gland Neoplasms↗
PubMed2006

Classification of neuroblastoma patients by published gene-expression markers reveals a low sensitivity for unfavorable courses of MYCN non-amplified disease.

Currently, Pubmed lists 385 marker genes for neuroblastoma outcome. Using a customized neuroblastoma-microarray, we evaluated the prognostic impact of the gene-expression pattern of 349 of these candidates (90.6%) in 127 neuroblastoma patients with divergent outcome. By significance analysis of microarrays (SAM) and both uncorrected and Bonferroni-corrected ANOVA, 166/349 (47.5%), 218/349 (62.5%) and 128/349 (36.4%) candidates showed significant differential expression between patients with contrasting outcome. By Prediction Analysis for Microarrays (PAM), a 38-gene-classifier was derived from all markers, which classified patients outcome with an overall accuracy of 78.5%. However, patients with unfavorable outcome of MYCN non-amplified disease were largely misclassified (accuracy: 35%), suggesting that these courses are not identified by current marker genes.

Analysis of Variance↗
PubMed2006

Customized oligonucleotide microarray gene expression-based classification of neuroblastoma patients outperforms current clinical risk stratification.

PURPOSE: To develop a gene expression-based classifier for neuroblastoma patients that reliably predicts courses of the disease. PATIENTS AND METHODS: Two hundred fifty-one neuroblastoma specimens were analyzed using a customized oligonucleotide microarray comprising 10,163 probes for transcripts with differential expression in clinical subgroups of the disease. Subsequently, the prediction analysis for microarrays (PAM) was applied to a first set of patients with maximally divergent clinical courses (n = 77). The classification accuracy was estimated by a complete 10-times-repeated 10-fold cross validation, and a 144-gene predictor was constructed from this set. This classifier's predictive power was evaluated in an independent second set (n = 174) by comparing results of the gene expression-based classification with those of risk stratification systems of current trials from Germany, Japan, and the United States. RESULTS: The first set of patients was accurately predicted by PAM (cross-validated accuracy, 99%). Within the second set, the PAM classifier significantly separated cohorts with distinct courses (3-year event-free survival [EFS] 0.86 +/- 0.03 [favorable; n = 115] v 0.52 +/- 0.07 [unfavorable; n = 59] and 3-year overall survival 0.99 +/- 0.01 v 0.84 +/- 0.05; both P < .0001) and separated risk groups of current neuroblastoma trials into subgroups with divergent outcome (NB2004: low-risk 3-year EFS 0.86 +/- 0.04 v 0.25 +/- 0.15, P < .0001; intermediate-risk 1.00 v 0.57 +/- 0.19, P = .018; high-risk 0.81 +/- 0.10 v 0.56 +/- 0.08, P = .06). In a multivariate Cox regression model, the PAM predictor classified patients of the second set more accurately than risk stratification of current trials from Germany, Japan, and the United States (P < .001; hazard ratio, 4.756 [95% CI, 2.544 to 8.893]). CONCLUSION: Integration of gene expression-based class prediction of neuroblastoma patients may improve risk estimation of current neuroblastoma trials.

Biomarkers, Tumor↗
PubMed2006

Loss of caspase-8 expression does not correlate with MYCN amplification, aggressive disease, or prognosis in neuroblastoma.

Inactivation of caspase-8 because of aberrant gene methylation has been associated with amplification of the MYCN oncogene and aggressive disease in neuroblastoma, suggesting that caspase-8 may function as tumor suppressor. However, the prognostic effect of caspase-8 in neuroblastoma has remained obscure. Therefore, we investigated caspase-8 expression and its correlation with established prognostic markers and survival outcome in a large cohort of neuroblastoma patients. Here, we report that loss of caspase-8 protein expression occurs in the majority (75%) of neuroblastoma and is not restricted to advanced disease stages. Surprisingly, no correlation was observed between caspase-8 expression and MYCN amplification. Similarly, ectopic expression of MYCN or antisense-mediated down-regulation of MYCN had no effect on caspase-8 expression in neuroblastoma cell lines. In addition, caspase-8 expression did not correlate with other variables of high-risk disease (e.g., 1p36 aberrations, disease stage, age at diagnosis, or tumor histology). Most importantly, loss of caspase-8 protein had no effect on event-free or overall survival in the overall study population or in distinct subgroups of patients. By revealing no correlation between caspase-8 expression and MYCN amplification or other established variables of aggressive disease, our findings in a large cohort of neuroblastoma patients show that inactivation of caspase-8 is not a characteristic feature of aggressive neuroblastoma. Thus, our study provides novel insight into the biology of this tumor, which may have important clinical implications.

Alstrom Syndrome↗
PubMed2006

Differential expression of neuronal genes defines subtypes of disseminated neuroblastoma with favorable and unfavorable outcome.

PURPOSE: Identification of molecular characteristics of spontaneously regressing stage IVS and progressing stage IV neuroblastoma to improve discrimination of patients with metastatic disease following favorable and unfavorable clinical courses. EXPERIMENTAL DESIGN: Serial analysis of gene expression profiles were generated from five stage IVS and three stage IV neuroblastoma. Differential expression of candidate genes was evaluated by real-time quantitative reverse transcription-PCR in 76 pretreatment tumor samples (stage IVS n=27 and stage IV n=49). Gene expression-based outcome prediction was determined by Prediction Analysis for Microarrays using 38 tumors as a training set and 38 tumors as a test set. RESULTS: Comparison of serial analysis of gene expression profiles from stage IV and IVS neuroblastoma revealed approximately 500 differentially expressed transcripts. Genes related to neuronal differentiation were observed more frequently in stage IVS tumors as determined by associating transcripts to Gene Ontology annotations. Forty-one candidate genes were evaluated by quantitative reverse transcription-PCR and 18 were confirmed to be differentially expressed (P<or=0.001). Classification of patients according to expression patterns of these 18 genes using Prediction Analysis for Microarrays discriminated two subgroups with significantly differing event-free survival (96+/-6% versus 40+/-8% at 3 years; P<0.0001) and overall survival (100% versus 72+/-7% at 3 years; P=0.0003). This classifier was the only independent covariate marker in a multivariate analysis considering the variables stage, age, MYCN amplification, and gene signature. CONCLUSIONS: Spontaneously regressing and progressing metastatic neuroblastoma differ by specific gene expression patterns, indicating distinct levels of neuronal differentiation and allowing for an improved risk estimation of children with disseminated disease.

Child, Preschool↗
PubMed2006

Loss in chromosome 11q identifies tumors with increased risk for metastatic relapses in localized and 4S neuroblastoma.

PURPOSE: To improve risk prediction in neuroblastoma and to specify the type of a possible relapse, alterations in the long arm of chromosome 11 were analyzed. EXPERIMENTAL DESIGN: A representative cohort of 611 neuroblastomas was investigated for deletion events in distal chromosome 11q using interphase fluorescence in situ hybridization. RESULTS: Alterations in 11q were found in 159 of 611 tumors in the whole cohort (26%) and were associated with stage 4 disease (P < 0.001) and age at diagnosis of >2.5 years (P < 0.001). Event-free survival and overall survival were significantly poorer for patients with 11q loss in the whole cohort (event-free survival and overall survival, P < 0.001) and in different subsets: neuroblastoma without MYCN amplification (MNA) (event-free survival and overall survival, P < 0.001), with MNA (event-free survival, P = 0.03; overall survival, P = 0.02), and MYCN-nonamplified stage 1, 2, 3, and 4S tumors with and without del 1p (event-free survival and overall survival, P < 0.001). In stage 4, the 11q status did not discriminate outcome. By multivariate analysis, the 11q status proved prognostic for event-free survival in the whole cohort (P = 0.008; hazard ratio, 1.573) and in the subgroup of stages 1, 2, 3, and 4S without MNA (P < 0.001; hazard ratio, 3.534). Moreover, 11q alterations were strongly correlated with the occurrence of metastatic relapses (P < 0.001). CONCLUSION: In addition to the current risk stratification, the status of 11q enables the identification of patients with an increased risk for relapses in general and metastatic relapses in particular.

Adolescent↗
PubMed2006

Oligonucleotide array-based comparative genomic hybridization (aCGH) of 90 neuroblastomas reveals aberration patterns closely associated with relapse pattern and outcome.

The study of genomic alterations in neuroblastoma is of particular importance since several cytogenetic markers proved to be closely associated with the clinical phenotype. To disclose patterns of gains and losses, we performed high-resolution oligonucleotide array-based comparative genomic hybridization (aCGH). A total cohort of 90 patients was classified into 6 subsets according to tumor stage and outcome: Stages 1-3+ (with event), Stage 1-3- (no event), Stage 4+/-, and Stage 4S+/-. The aberration patterns in Stages 1-3- and 4S- tumors differed from all other groups as they were predominantly characterized by losses (3, 4, 14, X) and gains (7, 17) of whole chromosomes. However, 59/65 (91%) tumors of Stages 1-3+ or Stage 4 revealed numerous structural copy number alterations (sCNA). While deletions in chromosomes 1, 3, and 11 discriminated outcome in Stage 4, there were no specific sCNA that distinguished tumor stage within the subgroup of unfavorable tumors. sCNA in 1p, 3p, 11q, 17q, or MYCN amplification (MNA) was seen among 22/24 patients who died, 10/12 with metastatic relapses, and 5/9 with local recurrences. Detailed breakpoint analyses on chromosomes 1, 3, 11, and 17 disclosed preferred breaking areas, although breakpoints were not identical. Amplifications were found in 18 patients and involved 2p24 (MYCN) and other segments of chromosome 2, as well as regions on chromosome arms 6q, 12q, and 17q. One single feature in 21q21.1 (BU678720, without known function yet) attracted particular attention since five patients showed a homozygous loss of this sequence.

Chromosome Aberrations↗
PubMed2006

Intensified external-beam radiation therapy improves the outcome of stage 4 neuroblastoma in children > 1 year with residual local disease.

BACKGROUND AND PURPOSE: In neuroblastoma, the value of radiation therapy in high-intensive first-line treatment protocols is still not exactly known but radiation-associated long-term effects need to be considered. The impact of external-beam radiation therapy (EBRT) on event-free (EFS) and overall survival (OS) of stage 4 neuroblastoma patients of the NB97 trial was analyzed. PATIENTS AND METHODS: The authors retrospectively analyzed data of 110 stage 4 neuroblastoma patients > or = 1 year who underwent induction therapy and high-dose chemotherapy with stem cell transplantation without relapse. Intensified local EBRT (36 Gy) of the residual tumor volume was reserved for patients with residual viable tumor documented by MRI and corresponding metaiodobenzylguanidine (MIBG) uptake. RESULTS: 13 patients who received EBRT for local residual disease had similar outcome (3-year EFS 85 +/- 10%, 3-year OS 92 +/- 7%) as 74 patients without any MIBG residual (3-year EFS 61 +/- 6%, 3-year OS 75 +/- 6%). Outcome was worse in 23 children without EBRT to residual primary (3-year EFS 25 +/- 10%, 3-year OS 51 +/- 11%). Separate analysis of 14 patients with isolated localized residual disease found far better outcome of eight patients with EBRT (3-year EFS 100%, 3-year OS 100%) compared to six patients without EBRT (3-year EFS 20 +/- 18%, 3-year OS 20 +/- 18%). Multivariate analysis identified EBRT as influential on EFS (hazard ratio 0.27) and OS (hazard ratio 0.17) in addition to MYCN amplification and presence of primary tumor site MIBG residual. CONCLUSION: EBRT appeared effective in high-intensive treatment of stage 4 neuroblastoma. It seems to compensate the disadvantage of incomplete response to induction chemotherapy. These retrospective results need confirmation by a prospective randomized trial.

Child↗
PubMed2006

Favorable outcome of triploid neuroblastomas: a contribution to the special oncogenesis of neuroblastoma.

There is a well-known association between patient outcome and tumor ploidy in neuroblastoma. To date, however, most clinical trials have not used this parameter for therapy stratification. Using conventional cytogenetics and fluorescence in situ hybridization (FISH), we investigated 36 tumors in terms of ploidy and chromosome 1 copy number (polysomy). In addition, interphase FISH for polysomy was performed on a second cohort of 440 neuroblastomas, together with the status of 1p, MYCN, and 11q. The main goals were as follows: (1) to assess the reliability of FISH to determine ploidy; (2) to illustrate associations between somy 1 and clinical/biologic factors; and (3) to investigate the role of somy 1 for predicting outcome. The comparison between karyotyping and FISH in the smaller cohort revealed 86% consistency between ploidy and polysomy (31/36). According to FISH, trisomic tumors in the second cohort showed structural chromosomal aberrations less frequently compared to di-/tetrasomic tumors (15 vs. 60%, P < 0.001). The portion of trisomic neuroblastomas was higher in stages 1, 2, and 4S versus stages 3 and 4 (55 vs. 24%, P < 0.001) and in children 18 months or younger versus those older than 18 months (55 vs. 19%, P < 0.001). Prognosis was significantly better for trisomic tumors versus di-/tetrasomic in the whole cohort [event-free (EFS) and overall survival (OS), P < 0.001]. In the subgroup without abnormalities of other molecular markers, EFS of trisomic neuroblastomas was better (P = 0.048), but was most likely due to an unequal stage distribution. In further subgroups, in terms of age and stage, significance between the somy groups was not reached, neither for EFS nor OS. The multivariate analyses including age, stage, chromosomal markers, and somy 1 confirmed the lack of independent prognostic power for the copy number of chromosome 1. This study demonstrates the following: (1) FISH is a practical alternative to other more labor-intensive techniques for determining ploidy; (2) trisomic tumors correlate with younger age at diagnosis, localized stage, and the lack of structural alterations; and (3) polysomy is not an independent prognostic marker. The sharp decline of trisomic tumors after the age of 18 months supports the idea of different genetic tumor entities.

Age of Onset↗
PubMed2005

Opsoclonus myoclonus syndrome in neuroblastoma a report from a workshop on the dancing eyes syndrome at the advances in neuroblastoma meeting in Genoa, Italy, 2004.

Opsoclonus-myoclonus syndrome (OMS) is a rare neurologic syndrome that, in children, associates with neuroblastoma in more than half of the cases. The etiology of this condition is thought to be immune mediated, but, though immunosuppressive therapies may ameliorate the acute symptoms, no effective treatment to prevent the common neuropsychologic sequelae has been established. This paper summarizes the results obtained at the 2004 Advances in Neuroblastoma Research meeting, providing status of the art information on immune pathogenesis, clinical features, acute and chronic neurologic manifestations, current and novel therapeutic approaches. It is emphasized that, due to the rarity of OMS in general and neuroblastoma-associated OMS in particular, international collaborations are needed to better define the pathogenesis and therapy of this disease, propose common evaluation criteria and identify new treatment modalities.

Humans↗
PubMed2005

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.

Adolescent↗
PubMed2005

Surface-binding autoantibodies to cerebellar neurons in opsoclonus syndrome.

Childhood opsoclonus-myoclonus syndrome can occur with or without associated neuroblastoma. An autoimmune pathogenesis has been discussed for both forms. We show here that the majority of children with opsoclonus-myoclonus syndrome (10/14) have autoantibodies binding to the surface of isolated rat cerebellar granular neurons. In some patients, these antibodies are masked by IgG binding to ubiquitous surface antigens, which could be removed by preincubation with the nonneuronal control cell line HEK 293. A newly introduced competitive binding assay showed that the surface binding is directed against the same autoantigen in different patients. Therefore, we hypothesize that opsoclonus-myoclonus syndrome may be the result of an autoimmune process against a neuronal surface protein.

Antigens, Surface↗
PubMed2005

Lacking immunocytological GD2 expression in neuroblastoma: report of 3 cases.

Immunocytological bone marrow assessment for contamination with neuroblastoma cells is based on their characteristic GD2 surface staining. Neuroblastoma without GD2 expression have been rarely and only after antibody therapy reported. Conventional cytology was performed using Pappenheim staining. For immunocytology, the APAAP method was utilized with the 14G2a anti-GD2 mouse monoclonal antibody. 7 x 10(5) cells on cytospin preparations were investigated. In 2003, 288 bone marrow samples from 191 neuroblastoma patients were investigated by cytology and immunocytology. Three cases demonstrated GD2 negativity on cytologically unambiguous neuroblastoma cells. Two female cases (94 and 37 months of age) with stage 4 neuroblastoma had GD2 expressing neuroblastoma cells in bone marrow at diagnosis. At 2nd relapse 25 and 23 months after diagnosis and 8 months and 12 months after anti-GD2 antibody treatment (ch14.18), the bone marrow infiltrating neuroblastoma cells lacked GD2 staining. The third patient, a 63-month-old girl with bone marrow replacement by neuroblastoma cells showed at diagnosis a mixture of GD2-unstained tumor clumps and very weakly stained neuroblastoma cells. Neuroblastoma cells may lack GD2 expression at diagnosis and at recurrence. This observation has diagnostic and therapeutic implications.

Antibodies, Monoclonal↗
PubMed2005

Esthesioneuroblastoma in childhood and adolescence. Better prognosis with multimodal treatment?

BACKGROUND AND PURPOSE: Only 3% of all malignant intranasal tumors are esthesioneuroblastomas (ENB) and only 20% of these rare neuroectodermal tumors are diagnosed up to 20 years of age. Radiotherapy and surgery are established treatment modalities for these patients, but the role of chemotherapy, especially in a multimodal approach, is not well defined. To investigate the influence of radio- and chemotherapy, the treatment and course of the disease in children and adolescents with ENB were analyzed retrospectively. PATIENTS AND METHODS: 19 unselected patients (nine male and ten female) diagnosed with ENB < or = 20 years of age were included in this analysis. Median age at diagnosis was 14.0 years (range, 5-20 years). The tumors were Kadish stage B in 4/19 patients and stage C in 15/19 patients. 17 patients underwent surgery, either without further therapy (n = 4), followed by radiotherapy (n = 1) or as part of multimodal regimens (n = 12). Two patients received radio- and chemotherapy without surgery. Complete resection (R0) was achieved in 15 out of 17 patients with surgery including all five patients with preoperative chemotherapy due to unresectable primary at diagnosis. RESULTS: The 5-year overall survival (OS) for the whole group was 73% +/- 12% and the 5-year event-free survival (EFS) 55% +/- 13%. None of the four patients with stage B experienced tumor progression so far, whereas seven out of 15 patients with stage C did (5-year EFS 47% +/- 14%; not significant). Patients with Kadish stage C and multimodal treatment strategies combing surgery, chemo- and radiotherapy had a significantly better outcome than patients with stage C and less than three treatment modalities (65% +/- 17% vs. 20% +/- 18%; p = 0.02). CONCLUSION: These data indicate a benefit of multimodal treatment regimens combining surgery, chemo- and radiotherapy for pediatric patients with ENB Kadish stage C. Chemotherapy appears to improve resectability, EFS, and OS. Radiotherapy is an integral part in the management of children and young adolescents with ENB in Kadish stage B and C.

Adolescent↗
PubMed2005

Myeloablative megatherapy with autologous stem-cell rescue versus oral maintenance chemotherapy as consolidation treatment in patients with high-risk neuroblastoma: a randomised controlled trial.

BACKGROUND: Myeloablative megatherapy is commonly used to improve the poor outlook of children with high-risk neuroblastoma, yet its role is poorly defined. We aimed to assess whether megatherapy with autologous stem-cell transplantation could increase event-free survival and overall survival compared with maintenance chemotherapy. METHODS: 295 patients with high-risk neuroblastoma (ie, patients with stage 4 disease aged older than 1 year or those with MYCN-amplified tumours and stage 1, 2, 3, or 4S disease or stage 4 disease and <1 year old) were randomly assigned to myeloablative megatherapy (melphalan, etoposide, and carboplatin) with autologous stem-cell transplantation (n=149) or to oral maintenance chemotherapy with cyclophosphamide (n=146). The primary endpoint was event-free survival. Secondary endpoints were overall survival and the number of treatment-related deaths. Analyses were done by intent to treat, as treated, and treated as randomised. FINDINGS: Intention-to-treat analysis showed that patients allocated megatherapy had increased 3-year event-free survival compared with those allocated maintenance therapy (47% [95% CI 38-55] vs 31% [95% CI 23-39]; hazard ratio 1.404 [95% CI 1.048-1.881], p=0.0221), but did not have significantly increased 3-year overall survival (62% [95% CI 54-70] vs 53% [95% CI 45-62]; 1.329 [0.958-1.843], p=0.0875). Improved 3-year event-free survival and 3-year overall survival were also recorded for patients given megatherapy in the as-treated group (n=212) and in the treated-as-randomised group (n=145). Two patients died from therapy-related complications during induction treatment. No patients given maintenance therapy died from acute treatment-related toxic effects. Five patients given megatherapy died from acute complications related to megatherapy. INTERPRETATION: Myeloablative chemotherapy with autologous stem-cell transplantation improves the outcome for children with high-risk neuroblastoma despite the raised risk of treatment-associated death.

Adolescent↗
PubMed2004

Consolidation treatment with chimeric anti-GD2-antibody ch14.18 in children older than 1 year with metastatic neuroblastoma.

PURPOSE: Antibody treatment is considered tolerable and potentially effective in the therapy of neuroblastoma. We have analyzed stage 4 neuroblastoma patients older than 1 year who underwent consolidation treatment with the chimeric monoclonal anti-GD2-antibody ch14.18. PATIENTS AND METHODS: Stage 4 patients older than 1 year who completed initial treatment without event were eligible. ch14.18 was scheduled in a dose of 20 mg/m2/d during 5 days in six cycles every 2 months. Patients who did not receive ch14.18 served as controls. RESULTS: Of 334 assessable patients, 166 received ch14.18, 99 received a 12-month low-dose maintenance chemotherapy (MT) instead, and 69 had no additional treatment. During 695 ch14.18 cycles, fever (55% of cycles), abnormal C-reactive protein without infection (35%), cough (24%), rash (22%), and pain (16%) were the main side effects. Univariate analysis found similar event-free survival (EFS) for the three groups (3-year EFS, 46.5% +/- 4.1%, 44.4% +/- 4.9%, 37.1% +/- 5.9% for patients treated with antibody ch14.18, MT, and no additional therapy, respectively; log-rank test, P =.314). For overall survival (OS), ch14.18 treatment (3-year OS, 68.5% +/- 3.9%) was superior to MT (3-year OS, 56.6% +/- 5.0%) or no additional therapy (3-year OS, 46.8% +/- 6.2%; log-rank test, P =.018). Separate univariate analysis of patients with autologous stem-cell transplantation revealed no difference between patients with ch14.18 treatment and no additional consolidation. Multivariate analysis failed to demonstrate an advantage of antibody treatment for EFS and OS. CONCLUSION: Consolidation treatment of stage 4 neuroblastoma with ch14.18 was associated with considerable but manageable side effects. Compared with oral maintenance chemotherapy and no consolidation treatment, ch14.18 had no clear impact on the outcome of patients.

Adolescent↗
PubMed2004

The tumor-associated antigen PRAME is universally expressed in high-stage neuroblastoma and associated with poor outcome.

PURPOSE: The tumor-associated antigen PRAME, a potential candidate for immunotherapeutic targeting, is frequently expressed in a variety of cancers. However, no information about its presence in neuroblastoma is available to date. We therefore evaluated and quantified PRAME expression in a considerable number of neuroblastoma tumors and assessed its impact on the outcome of patients. EXPERIMENTAL DESIGN: Qualitative analysis of PRAME expression was assessed by reverse transcription (RT)-PCR screening of 94 patients with primary neuroblastoma. The same cohort was used for semiquantitative determination of transcript levels by Northern blotting, comparing the signal intensities of patients with those of testis total RNA. For more precise quantification of PRAME expression, real-time RT-PCR was performed in 88 patients of the above cohort and 7 additional patients, thus leaving a total of 101 patients that were analyzed with either method. Furthermore, association with tumor stage, age of patients at diagnosis, and MYCN amplification was determined as well as the prognostic impact of PRAME expression. RESULTS: RT-PCR screening detected PRAME expression in 93% of primary neuroblastoma and 100% of patients with advanced disease. Furthermore, RT-PCR and Northern blot analysis showed a highly significant association of PRAME expression with both higher tumor stage (P < 0.01) and the age of patients at diagnosis (P < 0.01). Finally, precise quantification of PRAME expression by quantitative real-time reverse transcription-PCR displayed significant impact on the outcome of patients. CONCLUSIONS: PRAME expression in neuroblastoma is extraordinarily common and was universally seen in patients with advanced-stage disease in our study. Furthermore, significant impact of PRAME expression on the outcome of patients was shown. Thus, PRAME may present a particularly attractive target for immunotherapeutic strategies in neuroblastoma.

Adolescent↗