Catherine Cullinane

Vascular Endothelial Growth Factor: A Therapeutic Target for Tumors of the Ewing's Sarcoma Family

Purpose: We have reported previously that intratumoral microvessel density (MVD) is a significant prognostic indicator of event-free survival in the Ewings sarcoma family of tumors (ESFT). Here, the angiogenic growth factor expression profile and its relationship with MVD has been investigated in ESFT. Experimental Design and Results: Using ESFT model systems, the potential of these factors as therapeutic targets has been evaluated. A significant correlation (P = 0.02) was observed between vascular endothelial growth factor (VEGF) expression and MVD, consistent with the hypothesis that VEGF regulates the development of microvessels in ESFT. There was no correlation between MVD and any of the other growth factors studied. All six ESFT cell lines studied produced and secreted VEGF; five of six cell lines also secreted placental growth factor, one cell line (A673) at high levels. Tumor conditioned medium induced proliferation of human umbilical vein endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was heterogeneous across the cell lines. Both receptor tyrosine kinase inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor receptor-β, and fibroblast growth factor receptor 1) and SU5416 (targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF (bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d), rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg twice weekly). Conclusions: These data suggest that VEGF is the single most important regulator of angiogenesis in ESFT and may be exploited for therapeutic advantage.

Comprehensive Genetic and Histopathologic Study Reveals Three Types of Neuroblastoma Tumors

PURPOSE To determine the relationship between multiple genetic features, tumor morphology, and prognosis in neuroblastoma. PATIENTS AND METHODS The genetic alterations and morphologic features that underpin three histopathologic risk classifications were analyzed in 108 neuroblastoma patients. Tumors were subdivided into four groups based on the three most frequent and prognostically significant genetic alterations (17q gain, 1p deletion, and MYCN amplification), and all other genetic, morphologic, and clinical data were analyzed with respect to these groups. RESULTS Our analyses identify three nonoverlapping tumor types with distinct genetic and morphologic features, defined here as types 1, 2, and 3. Type 1 tumors show none of the three significant genetic alterations and have good prognosis. Both type 2 (17q gain only or 17q gain and 1p del) and type 3 (17q gain, 1p del, and MYCN amplification) tumors progress. However, these tumor types are distinguished clinically by having significantly different median age at diagnosis and median progression-free survival (PFS). Multivariate analysis indicates that 17q gain is the only independent prognostic factor among all genetic, histopathologic, and clinical factors analyzed. Among histopathologic risk systems, the International Neuroblastoma Pathology Classification was the best predictor of PFS. CONCLUSION Our results indicate that specific combinations of genetic changes in neuroblastoma tumors contribute to distinct morphologic and clinical features. Furthermore, the identification of two genetically and morphologically distinct types of progressing tumors suggests that possibilities for different therapeutic regimens should be investigated.

Identification of candidate genes involved in neuroblastoma progression by combining genomic and expression microarrays with survival data

Identifying genes, whose expression is consistently altered by chromosomal gains or losses, is an important step in defining genes of biological relevance in a wide variety of tumour types. However, additional criteria are needed to discriminate further among the large number of candidate genes identified. This is particularly true for neuroblastoma, where multiple genomic copy number changes of proven prognostic value exist. We have used Affymetrix microarrays and a combination of fluorescent in situ hybridization and single nucleotide polymorphism (SNP) microarrays to establish expression profiles and delineate copy number alterations in 30 primary neuroblastomas. Correlation of microarray data with patient survival and analysis of expression within rodent neuroblastoma cell lines were then used to define further genes likely to be involved in the disease process. Using this approach, we identify >1000 genes within eight recurrent genomic alterations (loss of 1p, 3p, 4p, 10q and 11q, 2p gain, 17q gain, and the MYCN amplicon) whose expression is consistently altered by copy number change. Of these, 84 correlate with patient survival, with the minimal regions of 17q gain and 4p loss being enriched significantly for such genes. These include genes involved in RNA and DNA metabolism, and apoptosis. Orthologues of all but one of these genes on 17q are overexpressed in rodent neuroblastoma cell lines. A significant excess of SNPs whose copy number correlates with survival is also observed on proximal 4p in stage 4 tumours, and we find that deletion of 4p is associated with improved outcome in an extended cohort of tumours. These results define the major impact of genomic copy number alterations upon transcription within neuroblastoma, and highlight genes on distal 17q and proximal 4p for downstream analyses. They also suggest that integration of discriminators, such as survival and comparative gene expression, with microarray data may be useful in the identification of critical genes within regions of loss or gain in many human cancers.

Renal medullary carcinoma: Prolonged remission with chemotherapy, immunohistochemical characterisation and evidence of bcr/abl rearrangement

BACKGROUND Renal medullary carcinoma (RMC), an extremely rare tumour of the kidney, carries a dismal prognosis, with no reports to date of significant response to chemotherapy or radiotherapy. A case of this tumour in a male child, who showed a dramatic response to chemotherapy, is described. PROCEDURE A detailed histological evaluation of the tumour and cytogenetic analysis using fluorescent in situ hybridisation (FISH) was carried out. The child was treated with multiagent chemotherapy, followed by abdominal radiotherapy. RESULTS A detailed histopathological and immunohistochemical portrait of this tumour is described, and FISH studies confirmed the presence of a bcr/abl rearrangement. The child obtained complete radiological remission following chemotherapy, although he later relapsed and died of progressive disease despite further attempts at treatment with chemotherapy. CONCLUSIONS Although there are no previous reports of response of this tumour to chemotherapy, this case illustrates that treatment of this disease is justified. The responses of other cases to similar drug regimens would be of interest to confirm whether the encouraging response described for this case could be reproduced. Cytogenetic analysis of other cases of RMC may clarify whether the abnormalities seen in this case are typical.

Breakpoint position on 17q identifies the most aggressive neuroblastoma tumors

Gain of chromosome arm 17q is a powerful prognostic factor in neuroblastoma, and the distribution of 17q breakpoints suggests that the dosage of one or more genes in 17q22–23 to 17qter is critical for tumor progression. To identify the smallest region of 17q gain, we used eight probes to map translocation breakpoints in 48 primary neuroblastoma tumors. We identified at least five different breakpoints, all localized within the proximal part of 17q (from D17Z1 to MPO). The shortest region of gain identified by these probes extends from MPO (17q23.1) to 17qter. Surprisingly, we found that breakpoints localized proximal to ERBB2 (17q12) were associated with significantly better patient survival than breakpoints localized distal to ERBB2. Breakpoints localized distal to ERBB2 identified patients with a particularly poor prognosis, higher mitotic karyorrhectic index, and stage 4 disease. This implies that breakpoint position on 17q is a discriminative factor within this prognostically poor group of patients. This result also suggests that the biological effect of 17q gain during neuroblastoma progression has a complex basis. We propose that this involves dosage alterations of genes localized on both sides of the 17q breakpoints, with a gene or genes mapping between 17cen and 17q12 acting to suppress progression, and a gene or genes mapping between 17q23.1 and 17qter acting to promote tumor progression.

Ploidy and karyotype complexity are powerful prognostic indicators in the Ewing's sarcoma family of tumors: A study by the United Kingdom Cancer Cytogenetics and the Children's Cancer and Leukaemia Group

Ewings sarcoma family tumors (ESFT) are characterized by the presence of EWSR1‐ETS fusion genes. Secondary chromosome changes are frequently described, although their clinical significance is not clear. In this study, we have collected and reviewed abnormal karyotypes from 88 patients with primary ESFT and a rearrangement of 22q12. Secondary changes were identified in 80% (70/88) of tumors at diagnosis. Multivariate analysis showed a worse overall and relapse free survival (RFS) for those with a complex karyotype (overall survival, P = 0.005; RFS, P = 0.04), independent of metastatic disease. Univariate survival analysis showed that a chromosome number above 50 or a complex karyotype was associated with a worse overall survival (>50 chromosomes, P = 0.05; complex karyotype, P = 0.04). There was no association between type of cytogenetic abnormality and the presence of metastatic disease at diagnosis. Univariate and multivariate survival analysis of a small subgroup with trisomy 20 indicated that trisomy 20 was associated with a worse overall and RFS. There was no difference in outcome associated with other recurrent trisomies (2, 5, 7, 8, or 12) or the common recurrent secondary structural rearrangements (deletions of 1p36, 9p12, 17p13, and 16q, and gain of 1q), although numbers were small. These data demonstrate the continued value of cytogenetics as a genome‐wide screen in ESFT and illustrates the potential importance of secondary chromosome changes for stratification of patients for risk. Specifically, karyotype complexity appears to be a powerful predictor of prognosis, and the presence of trisomy 20 may be a marker of a more aggressive subset of this group.

EWS-FLI1 fusion transcripts identified in patients with typical neuroblastoma.

The t(11.22)(q24.q12) results in expression of a chimeric RNA product, EWS-FLI1. This RNA product is expressed in over 85% of tumours belonging to the Ewings family, and is increasingly used as a definitive characteristic of these tumours. In this study, we evaluated reverse transcriptase-polymerase chain (RT-PCR) for EWS-FLI1 fusion transcripts in 18 neurally derived small round cell tumours. These included six Ewings family tumours and 12 neuroblastomas. EWS-FLI1 fusion transcripts were identified in all six Ewings tumours, but also in two of the 12 neuroblastomas. One neuroblastoma contained the classic type 1 fusion transcript, and the second a type 1 transcript containing a 66 bp (base pair) insert that was not derived from the EWS or FLI1 gene. The presence of EWS-FLI1 fusion products in RNA extracted from primary neuroblastoma suggests the identification of EWS-FLI1 fusion transcripts is not pathognomonic for tumours of the Ewings family. The clinical significance of these fusion transcripts in neuroblastoma is not known.

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

PURPOSE To assess the prognostic value of clinical, biologic, and morphologic data in peripheral neuroblastic tumors, International Neuroblastoma Staging System (INSS) stages 2A and 2B MYCN nonamplified, a multinational protocol entitled Localized Neuroblastoma European Study Group trial 94.01, with a trial of surgery as the only treatment, was initiated in 1995. We present the prognostic value of the revised International Neuroblastoma Pathology Classification (INPC) applied to the patients included in this protocol until its closure in 1999. MATERIALS AND METHODS A total of 120 neuroblastic tumors from trial patients were reviewed by the European International Society of Pediatric Oncology neuroblastoma pathology panel and assigned to a favorable or unfavorable prognostic category according to the INPC guidelines. Overall survival and relapse-free survival (RFS) were estimated by the Kaplan-Meier method and compared by the log-rank test. RESULTS A total of 115 of 120 patients were assessable and were assigned to the favorable (90 patients; 78.3%) or unfavorable (25 patients; 21.7%) category. The 60-month survival rate was 97.7% in favorable patients compared with 73.8% in unfavorable patients (P = .0002). RFS analysis showed a 60-month relapse rate of 13.4% and 32% in favorable and unfavorable patients (P < .025), respectively. Statistical analysis demonstrated a significant association of unfavorable INPC category and high lactate dehydrogenase level (P < .045). CONCLUSION This European study shows for the first time that the INPC prognostic categorization has a significant impact on outcome prediction in INSS stage 2 localized peripheral neuroblastic tumors.

Relationship between histopathological features, MYCN amplification, and prognosis: A UKCCSG study

Histological sections from 231 patients with neuroblastoma were reviewed and morphological features and their relationship to age, stage, MYCN amplification (in 128 tumours by Southern analyses), and clinical outcome (based on Shimada risk grouping) determined. Stage 4 disease was associated with poorly differentiated and undifferentiated tumours (P = 0.001), an MKI of >2% (P< 0.001), and Shimada unfavourable histology (UHi) P< 0.0001. In univariate analysis MKI was significant in predicting a poorer relapse-free survival (RFS), low vs. intermediate and high (P< 0.001). Age, MYCN amplification, and Shimada UH also emerged as significant variables. There was a higher proportion of MYCN-amplified tumours with Shimada UH (P = 0.03), and this group had a decreased RFS (P = 0.002). In patients with Shimada FH, MYCN amplification did not significantly predict a poor prognosis. In those with stage 4 disease, Shimada classification was not significant in predicting survival (P = 0.97); the same was true for those over the age of 1 year (P = 0.66). In multivariate analysis, MYCN amplification and Shimada UH both emerged as independent prognostic factors. In conclusion, morphological features assigned some subsets of patients to prognostic risk groups. Most MYCN-amplified tumours have unfavourable histology and a poorer prognosis. However, in patients with stage 4 disease and those over the age of 1 year, other factors that may influence prognosis should be determined.

p53 is nuclear and functional in both undifferentiated and differentiated neuroblastoma.

Aberrant cytoplasmic sequestration has been reported as an alternative mechanism of p53 inactivation to mutation in neuroblastoma. We hypothesized that p53 localization and function in neuroblastoma is related to differentiation status. Eighty-two untreated and 24 paired pre and post-chemotherapy neuroblastomas were studied by immunocytochemistry for p53, p21WAF1, BAX, Bcl2 and Ki67. Predominantly nuclear p53 was detected in undifferentiated neuroblastoma, and both nuclear and cytoplasmic p53 in differentiating neuroblastoma. The nuclear p53 labeling index (LI) correlated with the Ki67 LI (r = 0.51, p