Treatment of children with favorable histology Wilms tumor with extrapulmonary metastases: A report from the COG studies AREN0533 and AREN03B2 and NWTSG study NWTS-5

BACKGROUND

Patients with stage IV favorable histology Wilms tumor (FHWT) with extrapulmonary metastases (EPM) constitute a small subset of patients with FHWT. Because of their rarity and heterogeneity, optimal FHWT treatment is not well understood. Children's Oncology Group protocol AREN0533 assigned patients with FHWT and EPM to intensified chemotherapy, regimen M, after initial DD-4A chemotherapy. To improve understanding of prognostic factors and best therapies, experiences of patients with EPM on AREN0533, as well as on protocols AREN03B2 and NWTS-5, were reviewed.

METHODS

Combined outcomes for patients with EPM from NWTS-5, AREN0533, and AREN03B2 were determined. Those treated on AREN0533 were compared with those treated on NWTS-5. Prognostic factors were explored in the pooled cohort.

RESULTS

Forty-seven patients with FHWT with EPM enrolled on AREN0533, 37 enrolled on NWTS-5, and 64 were followed only on AREN03B2. The pooled cohort of all 148 patients demonstrated a 4-year event-free survival (EFS) of 77.3% (95% CI, 70.8-84.4) and 4-year overall survival of 88.9% (95% CI, 83.9-94.2). Four-year EFS of patients with EPM treated on AREN0533 was 76.0% (95% CI, 64.6-89.4) vs 64.9% (95% CI, 51.7-82.2) on NWTS-5; hazard ratio, 0.64, p = .26; no difference in overall survival was observed. Increasing linear age and slow incomplete lung response were associated with worse EFS in a pooled cohort.

CONCLUSIONS

Outcomes for patients with EPM are among the lowest for children with FHWT. Further trials with standardized surgical and radiation treatment to metastatic sites, and prospectively collected biologic and treatment details are needed.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov identifiers: NCT00379340, NCT00898365, and NCT00002611.

Prognostic impact of lymph node involvement and loss of heterozygosity of 1p or 16q in stage III favorable histology Wilms tumor: A report from Children's Oncology Group Studies AREN03B2 and AREN0532

INTRODUCTION

The prognostic impact of positive lymph nodes (LN+) and/or singular loss of heterozygosity (LOH) of 1p or 16q were assessed in children with stage III favorable histology Wilms tumor (FHWT) enrolled on AREN0532 or AREN03B2 alone.

PATIENTS AND METHODS

A total of 635 stage III FHWT vincristine/dactinomycin/doxorubicin (DD4A)-treated patients met inclusion criteria. Event-free survival (EFS) and overall survival are reported overall and by LN sampling, LN status, LOH 1p, LOH 16q, and a combination of LN status and singular LOH. Patients with unknown or positive combined LOH of 1p and 16q status and AREN03B2-only patients with unknown outcomes or treatment other than DD4A were excluded.

RESULTS

EFS did not differ by study, supporting pooling. Lack of LN sampling (hazard ratio [HR], 2.12; p = .0037), LN positivity (HR, 2.78; p = .0002), LOH 1p (HR, 2.18; p = .0067), and LOH 16q (HR, 1.72; p = .042) were associated with worse EFS. Compared with patients with both LN- and LOH-, those with negative nodes but positive LOH 1p or 16q and those with LN+ but LOH- for 1p or 16q had significantly worse EFS (HR, 3.05 and 3.57, respectively). Patients positive for both LN and LOH had the worst EFS (HR, 6.33; overall group factor, p < .0001).

CONCLUSION

Findings confirm LN+ status as an adverse prognostic factor amplified by presence of singular LOH 1p or 16q, supporting study of intensified therapy for patients with LN+ in combination with singular LOH in a prospective clinical trial.

Treatment and outcomes of clear cell sarcoma of the kidney: A report from the Children's Oncology Group studies AREN0321 and AREN03B2

BACKGROUND

On the fifth National Wilms Tumor Study, treatment for clear cell sarcoma of the kidney (CCSK) included combined vincristine, doxorubicin, cyclophosphamide, and etoposide (regimen I) plus radiation therapy (RT), yielding 5-year event-free survival (EFS) rates of 100%, 88%, 73%, and 29% for patients who had with stage I, II, III, and IV disease, respectively. In the Children's Oncology Group study AREN0321 of risk-adapted therapy, RT was omitted for stage I disease if lymph nodes were sampled, and carboplatin was added for stage IV disease (regimen UH-1). Patients who had stage II/III disease received regimen I with RT.

METHODS

Four-year EFS was analyzed for patients enrolled on AREN0321 and on those enrolled on AREN03B2 who received AREN0321 stage-appropriate chemotherapy.

RESULTS

Eighty-two patients with CCSK enrolled on AREN0321, 50 enrolled on AREN03B2 only. The 4-year EFS rate was 82.7% (95% confidence interval [CI], 74.8%-91.4%) for AREN0321 and 89.6% (95% CI, 81.3%-98.7%) for AREN03B2 only (p = .28). When combining studies, the 4-year EFS rates for patients who had stage I (n = 10), II (n = 47), III (n = 65), and IV (n = 10) disease were 90% (95% CI, 73.2%-100.0%), 93.4% (95% CI, 86.4%-100.0%), 82.8% (95% CI, 74.1%-92.6%), and 58.3% (95% CI, 34%-100.0%), respectively. There were no local recurrences among seven patients with stage I disease who were treated without RT. One stage I recurrence occurred in the brain, which was the most common site of relapse overall. Among patients with local stage III tumors, neither initial procedure type, margin status, nor lymph node involvement were prognostic.

CONCLUSIONS

Patients with stage I CCSK had excellent outcomes without local recurrences when treated without RT. Patients with stage IV disease appeared to benefit from a carboplatin-containing regimen, although their outcomes remained unsatisfactory. Further research is needed to improve outcomes for patients with advanced-stage disease (ClinicalTrials.gov identifiers NCT00335556 and NCT00898365).

Prohibitin is a prognostic marker and therapeutic target to block chemotherapy resistance in Wilms' tumor

Wilms' tumor is the most common type of childhood kidney cancer. To improve risk stratification and identify novel therapeutic targets for patients with Wilms' tumor, we used high-resolution mass spectrometry proteomics to identify urine tumor markers associated with Wilms' tumor relapse. We determined the urine proteomes at diagnosis of 49 patients with Wilms' tumor, non-Wilms' tumor renal tumors, and age-matched controls, leading to the quantitation of 6520 urine proteins. Supervised analysis revealed specific urine markers of renal rhabdoid tumors, kidney clear cell sarcomas, renal cell carcinomas as well as those detected in patients with cured and relapsed Wilms' tumor. In particular, urine prohibitin was significantly elevated at diagnosis in patients with relapsed as compared with cured Wilms' tumor. In a validation cohort of 139 patients, a specific urine prohibitin ELISA demonstrated that prohibitin concentrations greater than 998 ng/mL at diagnosis were significantly associated with ultimate Wilms' tumor relapse. Immunohistochemical analysis revealed that prohibitin was highly expressed in primary Wilms' tumor specimens and associated with disease stage. Using functional genetic experiments, we found that prohibitin was required for the growth and survival of Wilms' tumor cells. Overexpression of prohibitin was sufficient to block intrinsic mitochondrial apoptosis and to cause resistance to diverse chemotherapy drugs, at least in part by dysregulating factors that control apoptotic cytochrome c release from mitochondrial cristae. Thus, urine prohibitin may improve therapy stratification, noninvasive monitoring of treatment response, and early disease detection. In addition, therapeutic targeting of chemotherapy resistance induced by prohibitin dysregulation may offer improved therapies for patients with Wilms' and other relapsed or refractory tumors.

Abstract 4888: Human PGBD5 DNA transposase promotes site-specific oncogenic mutations in rhabdoid tumors

Genomic rearrangements are a hallmark of childhood solid tumors, but their mutational causes remain poorly understood. Here, we identify the piggyBac transposable element derived 5 (PGBD5) gene as an enzymatically active human DNA transposase expressed in the majority of rhabdoid tumors, a lethal childhood cancer. Using assembly-based whole-genome DNA sequencing, we observed previously unknown somatic genomic rearrangements in primary human rhabdoid tumors. These rearrangements were characterized by deletions and inversions involving PGBD5-specific signal (PSS) sequences at their breakpoints, with some recurrently targeting tumor suppressor genes, leading to their inactivation. PGBD5 was found to be physically associated with human genomic PSS sequences that were also sufficient to mediate PGBD5-induced DNA rearrangements in rhabdoid tumor cells. We found that ectopic expression of PGBD5 in primary human cells was sufficient to promote penetrant cell transformation in vitro and in immunodeficient mice in vivo. This activity required specific catalytic residues in the PGBD5 transposase domain, as well as end-joining DNA repair, and induced distinct structural rearrangements, involving PSS-associated breakpoints, similar to those found in primary human rhabdoid tumors. Thus, PGBD5 defines a distinct class of oncogenic mutators and induces site-specific somatic DNA rearrangements in human cancer.

Citation Format: Anton G. Henssen, Richard Koche, Jiali Zhuang, Eileen Jiang, Casie Reed, Amy Eisenberg, Eric Still, Elias Rodríguez-Fos, Santiago Gonzalez, Montserrat Puiggròs, Andrew N. Blackford, Christopher E. Mason, Elisa de Stanchina, Mithat Gönen, Anne-Katrin Emde, Minita Shah, Kanika Arora, Catherine Reeves, Nicholas D. Socci, Elizabeth Perlman, Cristina R. Antonescu, Charles W. Roberts, Hanno Steen, Elizabeth Mullen, Stephen P. Jackson, David Torrents, Zhiping Weng, Scott A. Armstrong, Alex Kentsis. Human PGBD5 DNA transposase promotes site-specific oncogenic mutations in rhabdoid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4888. doi:10.1158/1538-7445.AM2017-4888

PGBD5 promotes site-specific oncogenic mutations in human tumors

Genomic rearrangements are a hallmark of human cancers. Here, we identify the piggyBac transposable element derived 5 (PGBD5) gene as encoding an active DNA transposase expressed in the majority of childhood solid tumors, including lethal rhabdoid tumors. Using assembly-based whole-genome DNA sequencing, we found previously undefined genomic rearrangements in human rhabdoid tumors. These rearrangements involved PGBD5-specific signal (PSS) sequences at their breakpoints and recurrently inactivated tumor-suppressor genes. PGBD5 was physically associated with genomic PSS sequences that were also sufficient to mediate PGBD5-induced DNA rearrangements in rhabdoid tumor cells. Ectopic expression of PGBD5 in primary immortalized human cells was sufficient to promote cell transformation in vivo. This activity required specific catalytic residues in the PGBD5 transposase domain as well as end-joining DNA repair and induced structural rearrangements with PSS breakpoints. These results define PGBD5 as an oncogenic mutator and provide a plausible mechanism for site-specific DNA rearrangements in childhood and adult solid tumors.

Abstract 3004: Comparison of somatic alterations in the genome and transcriptome of 1,705 pediatric leukemia and solid tumors: a report from the Children’s Oncology Group (COG) - NCI TARGET Project

To discover common and sub-type specific somatic alterations affecting key biological processes in pediatric cancers, we analyzed point mutations, copy number alterations, gene fusions and structural alterations detected from paired tumor-normal whole genome sequencing (n=655), whole exome sequencing (n=1,108), and RNA-seq data (n=913) of 1,705 leukemia and solid tumors. Our cohort consists of 693 B-lineage Acute Lymphoblastic Leukemia (B-ALL), 264 T-ALL, 211 Acute Myeloid Leukemia (AML), 318 Neuroblastoma (NBL), 128 Wilms Tumor (WT), and 91 Osteosarcoma (OS) with a median mutation rate of 0.28-0.58 per Mb. We identified 130 potential driver genes based on significance of variant recurrence and pathogenicity within each cancer type and across all cancer types. Seventy-two (55%) driver genes were significant in one cancer type, thirty eight were significant in &gt; 1 leukemia subtype, thirteen (NRAS, WT1, MYCN, PTEN, TP53, KRAS, RB1, ATRX, PTPN11, MLLT1, BCOR, SETD2, NF1) were significant in both leukemia and solid tumor while the remaining seven (MGA, SF3B1, ASXL1, BCORL1, STAG2, ACTB, NIPBL) were significant only in pan-cancer analysis. The number of mutated driver genes per sample ranged from 0.8 in WT to 5.8 in T-ALL, lower when considering only point mutations (from 0.3 in NBL to 3.1 in T-ALL). The most frequently mutated biological processes affecting both leukemia and solid tumor were transcription factors (56% of samples), cell cycle (41%), epigenetic regulators (36%), Ras signaling (21%), PI-3K (11%), and the MYC complex (7%). By contrast, the JAK signaling pathway was mutated only in leukemia (16%) while mutations in the NOTCH signaling pathway were exclusive to T-ALL (77%).

Aberrant transcription may also affect the normal function of a driver gene. For example, the RAS signaling pathway was mutated in B-ALL (35%), T-ALL (15%), AML (37%) and NBL (4.3%). Aside from the known KRAS 4a isoform found in all cancer types, we discovered two novel KRAS isoforms present in 71.1% of B-ALL, 67.9% of T-ALL, 71.3% of AML and 3.0% of NBL but not in WT or OS. Allele-specific expression (ASE) was detected in 205 (6.8%) of 3,016 expressed somatic mutations, and 97% (32 out of 33) of truncation mutations on autosomes exhibit reduced expression of the mutant allele likely due to nonsense mediated decay. Two ASE mutations, WT1 D447N in a cytogenetically normal AML and JAK2 D873N in a B-ALL, were selected for single-cell sequencing and successfully validated.

Only 44% of our driver genes match those identified in adult cancer. This, coupled with our finding that point mutations only accounted for 48% of the driver alterations, may provide new insight into the design of precision treatment for pediatric cancer. Our presented data will be made public at NCI’s Genome Data Commons (gdc.cancer.gov) and can be explored on our ProteinPaint data portal (pecan.stjude.org).

Citation Format: Xiaotu Ma, Yu Liu, Yanling Liu, Michael Edmonson, Charles Gawad, Xin Zhou, Yongjin Li, Michael Rusch, John Easton, Mark Wilkinson, Leandro C. Hermida, Sean Davis, Malcolm Smith, Jaime Guidry Auvil, Paul Meltzer, Ching C. Lau, Elizabeth Perlman, John M. Maris, Soheil Meshinchi, Stephen P. Hunger, Daniela S. Gerhard, Jinghui Zhang. Comparison of somatic alterations in the genome and transcriptome of 1,705 pediatric leukemia and solid tumors: a report from the Children’s Oncology Group (COG) - NCI TARGET Project [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3004. doi:10.1158/1538-7445.AM2017-3004

Abstract 708: Prohibitin is a prognostic marker of treatment failure and therapeutic target to block chemotherapy resistance in Wilms tumor

Wilms tumor (WT) is the most common kidney tumor of children. Over the last three decades, clinical trials employing multi-modality therapies have resulted in overall survival of greater than 90% for patients with low-risk disease. In spite of these advances, treatment of patients with advanced, anaplastic, and relapsed Wilms tumors remains challenging, with substantial rates of treatment failure and death. To improve risk stratification and identify novel therapeutic targets, we used high-accuracy mass spectrometry urine proteomics to identify urine tumors markers associated with relapsed WT and non-WT renal tumors. We measured urine proteomes at diagnosis of 54 patients with renal WT, clear cell sarcoma, rhabdoid tumor, and age-matched controls, leading to the quantitation of 6,519 urine proteins. In particular, we identified specific urine WT markers, including those that were enriched in patients with relapsed WT, such as mitochondrial regulators prohibitin and DAD1, β-catenin antagonist DACT2, and DNA repair factor SUN1. Using a specific enzyme-linked immunosorbent assay (ELISA) developed to measure urine prohibitin in an independent cohort of 139 WT and control samples, we found that urine prohibitin concentrations over 1000 ng/mL were significantly associated with the risk of disease relapse, with an odds ratio of relapse of 153 and receiver operating characteristic area under the curve of 0.77 (95% confidence interval of 0.64-0.99). Immunohistochemical tumor analysis revealed that prohibitin was highly expressed in primary Wilms tumor specimens. Importantly, using loss- and gain-of-function genetic experiments, we found that prohibitin was required for the growth and survival of Wilms tumor cells, and its overexpression conferred concomitant resistance to vincristine, doxorubicin and actinomycin D. Consistent with prohibitin’s functions in mitochondria, we are using BH3 profiling to elucidate specific intrinsic apoptotic dependencies in distinct subsets of refractory Wilms tumors, as a prelude to rational combination blockade of chemotherapy resistance, such as blockade of BCL2 dependence using venetoclax. In all, the use of urine prohibitin measurements may improve initial therapy stratification, and enable monitoring of response to therapy and early detection of relapse. In addition, therapeutic targeting of chemotherapy resistance induced by prohibitin overexpression may offer improved therapies for patients with relapsed or refractory Wilms tumors.

Citation Format: Michael Vincent Ortiz, Melissa Burns, Amy Eisenberg, Saima Ahmed, Lyvia Gaewsky, Gary Bradwin, Paolo Cifani, Anton Henssen, Ian Macarthur, Michael LaQuaglia, Anthony Letai, Arlene Naranjo, Samantha Gadd, Yueh-Yun Chi, Jeffrey Dome, Elizabeth Perlman, Elizabeth Mullen, Hanno Steen, Alex Kentsis. Prohibitin is a prognostic marker of treatment failure and therapeutic target to block chemotherapy resistance in Wilms tumor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 708. doi:10.1158/1538-7445.AM2017-708

Abstract 1103: Human tumorigenesis induced by endogenous DNA transposase

Recent cancer genome surveys have revealed extremely low rates of coding gene mutations in distinct tumor subtypes, suggesting that alternative mechanisms must contribute to their pathogenesis. Transposons are mobile genetic elements that are found in all living organisms, including humans where they occupy nearly half of the genome. Their mobilization can cause structural rearrangements in normal and cancer cells. However, it remains unknown whether transposition is a cause of cellular transformation or merely a bystander effect of dysregulated gene expression. Here, we report that PGBD5, a recently characterized human gene related to the piggyBac transposase from the cabbage looper moth, is aberrantly expressed in rhabdoid tumors, medulloblastoma, acute leukemias, and some sarcomas and carcinomas. Ectopic expression of PGBD5 in non-transformed primary human cells is sufficient to induce anchorage independence in vitro and penetrant tumor formation in immunodeficient mice in vivo. PGBD5 expression is sufficient to induce genomic mobilization of engineered DNA transposons in human cells, and purified recombinant PGBD5 exhibits transposase domain-dependent endonuclease activity in vitro. Flanking-sequence exponential anchored PCR and massively parallel sequencing of DNA transposon integrations revealed distinct activity on piggyBac-like inverted terminal repeats, and preference for specific euchromatic human genomic loci. This enables mapping of structural rearrangements of endogenous human transposable elements in primary human tumor genomes, some of which target genes involved in cellular transformation. We find that PGBD5 transposase-induced cell transformation is associated with morphologic de-differentiation, induction of distinct Polycomb gene expression programs and structural chromatin remodeling, consistent with its epigenetic control. These findings reveal an unanticipated mechanism of human tumorigenesis, genomic plasticity and structural alterations of non-coding regulatory genomic loci in human cancer.

Citation Format: Anton Henssen, Amy Eisenberg, Eileen Jiang, Elizabeth Henaff, Richard Koche, Melissa Burns, Julianne R. Carson, Gouri Nanjangud, Eric Still, Jorge Gandara, Paolo Cifani, Avantika Dhabaria, Xiaodong Huang, Elisa de Stanchina, Elizabeth Mullen, Hanno Steen, Elizabeth Perlman, Jeffrey Dome, Cristina Antonescu, Cedric Feschotte, Christopher E. Mason, Alex Kentsis. Human tumorigenesis induced by endogenous DNA transposase. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1103. doi:10.1158/1538-7445.AM2015-1103

TP53 mutational status is a potential marker for risk stratification in Wilms tumour with diffuse anaplasia

PURPOSE

The presence of diffuse anaplasia in Wilms tumours (DAWT) is associated with TP53 mutations and poor outcome. As patients receive intensified treatment, we sought to identify whether TP53 mutational status confers additional prognostic information.

PATIENTS AND METHODS

We studied 40 patients with DAWT with anaplasia in the tissue from which DNA was extracted and analysed for TP53 mutations and 17p loss. The majority of cases were profiled by copy number (n = 32) and gene expression (n = 36) arrays. TP53 mutational status was correlated with patient event-free and overall survival, genomic copy number instability and gene expression profiling.

RESULTS

From the 40 cases, 22 (55%) had TP53 mutations (2 detected only after deep-sequencing), 20 of which also had 17p loss (91%); 18 (45%) cases had no detectable mutation but three had 17p loss. Tumours with TP53 mutations and/or 17p loss (n = 25) had an increased risk of recurrence as a first event (p = 0.03, hazard ratio (HR), 3.89; 95% confidence interval (CI), 1.26-16.0) and death (p = 0.04, HR, 4.95; 95% CI, 1.36-31.7) compared to tumours lacking TP53 abnormalities. DAWT carrying TP53 mutations showed increased copy number alterations compared to those with wild-type, suggesting a more unstable genome (p = 0.03). These tumours showed deregulation of genes associated with cell cycle and DNA repair biological processes.

CONCLUSION

This study provides evidence that TP53 mutational analysis improves risk stratification in DAWT. This requires validation in an independent cohort before clinical use as a biomarker.

Prognostic implications of gain of 1q in favorable histology Wilms tumor: A report from the Children’s Oncology Group

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Background: Wilms tumor is the most common childhood renal tumor. While the majority of patients with favorable histology Wilms Tumor (FHWT) have good outcomes, many patients still experience recurrence and death from disease. This study’s goal was to determine if chromosome 1q gain is associated with event-free (EFS) and overall survival (OS) in FHWT. Methods: Unilateral FHWT samples were obtained from patients enrolled on National Wilms Tumor Study-4 and Pediatric Oncology Group 9046, “A Molecular Genetic analysis of Wilms Tumor.” 1q gain, 1p loss, and 16q loss were determined using multiplex ligation-dependent probe amplification (MLPA). Results: The eight-year EFS was 87% (95% CI 82%, 91%) for the entire cohort of 212 patients. Tumors of 58/212 patients (27%) displayed 1q gain. A strong relationship between 1q gain and 1p/16q loss was observed. The eight-year EFS was 76% (95% CI 63%, 85%) for those with 1q gain and 93% (95% CI 87%, 96%) for those lacking 1q gain (p=0.0024). The eight-year OS was 89% (95% CI 78%, 95%) for those with 1q gain, and 98% (95% CI 94%, 99%) for those lacking 1q gain (p=0.0075). Gain of 1q did not correlate with disease stage (p=0.16). After stratification for stage, 1q gain was associated with a significant increase in the risk of failure (risk ratio estimate: 2.72, p=0.0089). Conclusions: Gain of 1q is associated with inferior EFS and OS in FHWT and may provide a new and valuable prognostic marker to stratify therapy for patients with FHWT. A confirmatory study is necessary before this biomarker is incorporated into risk stratification schema of future therapeutic studies.

Genome-based outcome prediction in MYCN nonamplified high-risk neuroblastoma

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Background: Less than 40% of children with high-risk neuroblastoma achieve long-term survival, and at diagnosis, it is not possible to identify patients who will be cured. Microarray studies have proposed expression signatures associated with outcome within high-risk cohorts. However, integrating this technology as a clinical test has been difficult, in part due to the lack of available frozen tissue and high quality RNA. The nCounter overcomes this obstacle, using formalin-fixed paraffin embedded tissue (FFPE). Our objective is to test the correlation of a previously published “ultra high-risk” microarray gene signature developed in the MYCN nonamplified high-risk population (Asgharzadeh et al, J Natl Cancer Inst, 2006) with the gene expression signature obtained with the nCounter (NanoString Technologies) using RNA isolated from FFPE MYCN nonamplified high-risk neuroblastoma samples. Methods: FFPE tumor samples linked to clinical outcome data were obtained from 6 collaborative institutions. Tumor content of each sample was assessed morphologically. RNA was isolated using the RNeasy FFPE-kit. Customized probes corresponding to the candidate genes were designed by NanoString. Hybridization reactions were performed in duplicate using 100 ng of RNA. Positive and negative control probes and housekeeping probes were included in every reaction and were used to normalize data for differences in purification, hybridization, and capture efficiencies Results: Forty-two MYCN nonamplified high-risk neuroblastoma samples were analyzed by the nCounter. The cohort 5-year event-free survival and overall survival were 44.6 +/- 8.0% and 53.8 +/- 8.4% respectively. Highly degraded RNA (RIN ~ 1.5-2.8) was obtained. Unsupervised clustering and principle components analysis on normalized expression data showed differential expression of most of the genes with clustering of cases depending upon outcome (FDR = 0.05). Conclusions: Our results demonstrate that the nCounter can yield gene expression profiles that are similar to microarray gene signatures. Further investigation of the clinical utility the nCounter technology to prognosticate outcome in patients with high-risk neuroblastoma is warranted.

Evaluation of diagnostic performance of CT for detection of tumor thrombus in children with Wilms tumor: a report from the Children's Oncology Group

BACKGROUND

Pre-operative assessment of intravascular extension of Wilms tumor is essential to guide management. Our aim is to evaluate the diagnostic performance of multidetector CT in detection of tumor thrombus in Wilms tumor.

PROCEDURE

The study population was drawn from the first 1,015 cases in the AREN03B2 study of the Children's Oncology Group. CT scans of children with (n = 62) and without (n = 111) tumor thrombus at nephrectomy were independently reviewed by two radiologists, blinded to patient information. Doppler sonography results were obtained from institutional radiology reports, as Doppler requires real-time evaluation. The diagnostic performance of CT and Doppler for detection of tumor thrombus was determined using nephrectomy findings as reference standard.

RESULTS

In the primary nephrectomy group, tumor thrombus detection sensitivity, specificity of CT was 65.6, 84.8%, and Doppler was 45.8, 95.7%, respectively. In this group, sensitivity of CT, Doppler for detection of cavoatrial thrombus was 84.6 and 70.0%, respectively. In the secondary nephrectomy group, tumor thrombus detection sensitivity, specificity of CT was 86.7, 90.6%, and Doppler was 66.7, 100.0%, respectively. In this group, sensitivity of CT, Doppler for detection of cavoatrial thrombus was 96.0 and 68.8%, respectively. Pre-operative Doppler evaluation performed in 108/173 cases, detected 3 cases with intravenous extension (2 in renal vein, 1 in IVC at renal vein level) that were missed at CT.

CONCLUSIONS

CT can accurately identify cavoatrial tumor thrombus that will impact surgical approach. Routine Doppler evaluation, after CT has already been performed, is not required in Wilms tumor.

Risk factors for end stage renal disease in non-WT1-syndromic Wilms tumor

PURPOSE

We assessed risk factors for end stage renal disease in patients with Wilms tumor without known WT1 related syndromes. We hypothesized that patients with characteristics suggestive of a WT1 etiology (early onset, stromal predominant histology, intralobar nephrogenic rests) would have a higher risk of end stage renal disease due to chronic renal failure. We predicted a high risk of end stage renal disease due to progressive bilateral Wilms tumor in patients with metachronous bilateral disease.

MATERIALS AND METHODS

End stage renal disease was ascertained in 100 of 7,950 nonsyndromic patients enrolled in a National Wilms Tumor Study during 1969 to 2002. Risk factors were evaluated with cumulative incidence curves and proportional hazard regressions.

RESULTS

The cumulative incidence of end stage renal disease due to chronic renal failure 20 years after Wilms tumor diagnosis was 0.7%. For end stage renal disease due to progressive bilateral Wilms tumor the incidence was 4.0% at 3 years after diagnosis in patients with synchronous bilateral Wilms tumor and 19.3% in those with metachronous bilateral Wilms tumor. For end stage renal disease due to chronic renal failure stromal predominant histology had a HR of 6.4 relative to mixed (95% CI 3.4, 11.9; p<0.001), intralobar rests had a HR of 5.9 relative to no rests (95% CI 2.0, 17.3; p=0.001), and Wilms tumor diagnosis at less than 24 months had a HR of 1.7 relative to 24 to 48 months and 2.8 relative to greater than 48 months (p=0.003 for trend).

CONCLUSIONS

Metachronous bilateral Wilms tumor is associated with high rates of end stage renal disease due to surgery for progressive Wilms tumor. Characteristics associated with a WT1 etiology markedly increased the risk of end stage renal disease due to chronic renal failure despite the low risk in non-WT1 syndromic cases overall.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : I. THE SPECIFIC ANTIGENS OF SHIGELLA PARADYSENTERIAE (FLEXNER)

1. Methods for the isolation of the specific antigens of Types V, W, Z, and Newcastle Shigella paradysenteriae are given. 2. The physical, chemical, toxic, and immunological properties of these substances are described.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : II. THE CHEMICAL DEGRADATION OF THE SPECIFIC ANTIGEN OF TYPE Z SHIGELLA PARADYSENTERIAE (FLEXNER)

The chemical and enzymatic dissociation of the specific antigen of Type Z Shigella paradysenteriae has been studied. The chemical, toxic, and serological properties of the products of degradation have been investigated. The nature of the toxic component has been discussed.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : III. ANTIBODY RESPONSE IN MAN FOLLOWING THE ADMINISTRATION OF THE SPECIFIC ANTIGEN OF TYPE V SHIGELLA PARADYSENTERIAE (FLEXNER)

1. Volunteers have been immunized with the purified specific antigen of Type V Shigella paradysenteriae (Flexner). The subjects developed a high titer of bacterial agglutinins and mouse-protective antibodies. The agglutinin titer fell moderately after a period of 6 months. The subjects responded fairly well to a small recall dose of the antigen. 2. Two individuals from a group of 10 injected with the specific polysaccharide obtained from Type V organisms responded with an increase in bacterial agglutinins. Mouse-protective antibodies were demonstrable in the one serum tested.

AN IMMUNOLOGICAL AND ELECTROPHORETIC COMPARISON OF THE ANTIBODY TO C POLYSACCHARIDE AND THE C-REACTIVE PROTEIN OF ACUTE PHASE SERUM

1. Studies of the precipitation reaction of C polysaccharide with C protein, and of C polysaccharide with C antibody are reported. The similarity between these two systems in this respect is demonstrated. 2. The differences between C protein and C antibody are emphasized. The differences between this protein and antibodies in general have been reported previously by others. 3. Electrophoretic studies show that C antibody is in the gamma globulin fraction of serum whereas C protein migrates with the alpha₁ globulin fraction of acute phase protein.

Use of radionuclide bone scans in multicenter clinical trials: Opportunities for quality improvement

e17534

Background: Radionuclide bone scans are widely utilized to screen for osseous metastases given their high sensitivity for detection of metastatic disease. However, the variance in image quality can significantly impact the diagnostic interpretation. Methods: Prospective assessment of image quality on 478 digital and hard copy planar bone scans received as part of several multi-center clinical trials was completed using a two reviewer paradigm. To improve image quality, the following steps were taken: an Internal Image Quality Task Committee was formed, a comprehensive training program for all internal quality control reviewers was completed, and a site qualification process was initiated prior to site selection and/or subject enrollment with direct feedback to the sites. Results: Significant image quality issues potentially limiting the diagnostic interpretation of the radionuclide scans were initially identified in 21% of the submitted radionuclide bone scans. Quality issues were based on: technical factors, poor imaging technique, and subject factors which could not be corrected. A discordance rate of 4.3% among the two reviewers was also measured. After institution of the above steps, the net result was a 58% decrease in the quality control issues that were previously identified. The most significant improvements occurred on the basis of the site qualification process where sites changed from sending hard copy to digital images and there was direct feedback from the Imaging Core Lab to the sites to correct identified issues. Conclusions: Image quality of bone scans in multicenter clinical trials can be improved with direct communication coupled with a site qualification process prior to subject enrollment. We suspect these quality improvements will impact event driven endpoints that rely on the accurate assessment of bone lesions. We further suspect this level of quality control will continue to increase in importance as technology evolves to include hybrid scanning techniques such as SPECT/CT. This parallels our experience in the level of quality control and site qualification required for deployment of FDG-PET imaging in multicenter clinical trials.

[Table: see text]

Dose-intensified compared with standard chemotherapy for nonmetastatic Ewing sarcoma family of tumors: a Children's Oncology Group Study

PURPOSE

The Ewing sarcoma family of tumors (ESFT) is a group of malignant tumors of soft tissue and bone sharing a chromosomal translocation affecting the EWS locus. The Intergroup INT-0091 demonstrated the superiority of a regimen of vincristine, cyclophosphamide, doxorubicin (VDC), and dactinomycin alternating with ifosfamide and etoposide (IE) over VDC for patients with nonmetastatic ESFT of bone. The goal of this study was to determine whether a dose-intensified regimen of VDC alternating with IE would further improve the outcome for patients with nonmetastatic ESFT of bone or soft tissue.

METHODS

Patients with previously untreated, nonmetastatic ESFT of bone or soft tissue were eligible. They were randomly assigned to receive standard doses of VDC/IE over 48 weeks or a dose-intensified regimen of VDC/IE over 30 weeks.

RESULTS

Four hundred seventy-eight patients met eligibility requirements: 231 patients received the standard regimen; 247 patients received the intensified regimen. The 5-year event-free survival (EFS) and overall survival rates for all eligible patients were 71.1% (95% CI, 67.7% to 75.0%) and 78.6% (95% CI, 74.6% to 82.1%), respectively. There was no significant difference (P = .57) in EFS between patients treated with the standard (5-year EFS, 72.1%; 95% CI, 65.8% to 77.5%) or intensified regimen (5-year EFS, 70.1%; 63.9% to 75%). Patients with soft tissue tumors accounted for 20% of the study population; there was no difference in outcome between patients with soft tissue and bone primary sites.

CONCLUSION

Dose escalation of alkylating agents as tested in this trial did not improve the outcome for patients with nonmetastatic ESFT of bone or soft tissue.

Speech production variability in fricatives of children and adults: results of functional data analysis

This study investigates token-to-token variability in fricative production of 5 year olds, 10 year olds, and adults. Previous studies have reported higher intrasubject variability in children than adults, in speech as well as nonspeech tasks, but authors have disagreed on the causes and implications of this finding. The current work assessed the characteristics of age-related variability across articulators (larynx and tongue) as well as in temporal versus spatial domains. Oral airflow signals, which reflect changes in both laryngeal and supralaryngeal apertures, were obtained for multiple productions of /h s z/. The data were processed using functional data analysis, which provides a means of obtaining relatively independent indices of amplitude and temporal (phasing) variability. Consistent with past work, both temporal and amplitude variabilities were higher in children than adults, but the temporal indices were generally less adultlike than the amplitude indices for both groups of children. Quantitative and qualitative analyses showed considerable speaker- and consonant-specific patterns of variability. The data indicate that variability in /s/ may represent laryngeal as well as supralaryngeal control and further that a simple random noise factor, higher in children than in adults, is insufficient to explain developmental differences in speech production variability.

Treatment of Wilms tumor relapsing after initial treatment with vincristine, actinomycin D, and doxorubicin. A report from the National Wilms Tumor Study Group

OBJECTIVE

We evaluated the use of alternating cycles of cyclophosphamide/etoposide and carboplatin/etoposide in children entered on National Wilms Tumor Study (NWTS)-5 who were diagnosed between August 1, 1995 and May 31, 2002 and who relapsed after chemotherapy with vincristine, actinomycin D, and doxorubicin (VAD) and radiation therapy (DD-4A).

PATIENTS AND METHODS

One hundred three patients who relapsed or had progressive disease after initial VAD chemotherapy and radiation therapy were registered on stratum C of the NWTS-5 Relapse protocol. Twelve patients were not evaluable: five due to insufficient data, six due to major protocol violations, and one for refusal of therapy. Among the 91 remaining patients, 14 with stage V Wilms tumor (WT), 1 with contralateral relapse, and 16 who did not achieve a complete response (CR) to the initial three-drug chemotherapy were not included in this analysis. Relapse treatment included alternating courses of the drug pairs cyclophosphamide/etoposide and carboplatin/etoposide, surgery, and radiation therapy.

RESULTS

The outcomes of 60 patients were analyzed. The lung was the only site of relapse for 33 patients; other sites of relapse included the operative bed, the abdomen, and liver. Four-year event-free survival (EFS) and overall survival (OS) were 42.3 and 48.0% respectively for all patients and were 48.9 and 52.8% for those who relapsed in the lungs only. Thrombocytopenia was the most frequent toxicity.

CONCLUSION

These results demonstrate that approximately one-half of children with unilateral WT who relapse after initial treatment with VAD and radiation therapy can be successfully retreated.

Patient weight and event-free survival for children under 2 years of age at diagnosis with favorable histology Wilms tumor

20002

Background: Over- and underweight have been associated with excess mortality in certain childhood cancers. The impact of the child’s weight at diagnosis on event-free survival (EFS) in favorable histology Wilms tumor (FH WT) is unknown. Methods: Patients with FH WT under 2 years of age at enrolment on NWTS-5 were included. This age group was analyzed by body weight in kilograms because body mass index (BMI) norms do not exist for individuals less than 2 years old. Outcomes by BMI for children older than 2 years of age with FH WT will be analyzed separately. CDC 2000 growth charts were used. Patients were stratified for risk based on stage and chemotherapy protocol [EE4A = vincristine/dactinomycin] [DD4A = vincristine/doxorubicin/ actinomycin]. A univariate analysis of the relationship of weight-for-age and EFS was calculated. A Cox proportional hazards model was fitted for EFS examining four subsets of weight-for-age by percentiles: a) less than 5%, b) 5–9.9%, c) 90–94.9% and d) more than 95% and adjusting for risk/treatment groups via stratification. Results: 594 patients met the study criteria. 567 had weights recorded. Median follow-up was 4.7 years. 10% of patients had a weight for age percentile of 5.6 or below and 10% had a weight percentile of 94.1 or above. A univariate analysis of the relationship of weight-for-age and EFS showed no relationship (p=0.40, log-rank test). A Cox proportional hazards model, stratified by risk/treatment groups, showed that low or high weight-for-age was not predictive of outcome (p=0.24). Conclusions: There was no evidence that low or high weight-for-age was predictive for EFS among patients less than 2 years old with FH WT. There were more patients with lower or higher weight than would be expected.

[Table: see text]

No significant financial relationships to disclose.

Treatment of Wilms tumor relapsing after initial treatment with vincristine and actinomycin D: a report from the National Wilms Tumor Study Group

PURPOSE

NWTS-5 was a multi-institutional clinical trial for patients less than 16 years of age at diagnosis with specific renal neoplasms who were diagnosed between August 1, 1995 and May 31, 2002. A uniform approach to the treatment of patients with relapse was employed.

PATIENTS AND METHODS

Seventy-two patients who relapsed after immediate nephrectomy (stages I and II), initial chemotherapy with vincristine (VCR) and actinomycin D and no radiation therapy were registered on stratum B of the NWTS-5 relapse protocol. Four patients were not evaluable: one due to insufficient data and three due to major protocol violations. Among the 68 remaining patients, one who was 19 years of age at initial diagnosis of Wilms tumor, five with bilateral Wilms tumor at diagnosis, three who developed a contralateral relapse, and one with persistent disease were not included in this analysis. Relapse treatment included surgical excision, when feasible, radiation therapy and alternating courses of VCR, doxorubicin and cyclophosphamide and etoposide and cyclophosphamide.

RESULTS

The outcomes of 58 patients were analyzed. The lung was the only site of relapse for 31 patients. Event-free survival 4 years after relapse was 71.1% and 4-year overall survival was 81.8% for all patients and were 67.8 and 81.0% for those who relapsed only to their lungs. The most frequent toxicities were hematological.

CONCLUSIONS

These results demonstrate that a significant proportion of children with Wilms tumor who relapse after initial treatment with VCR and actinomycin D can be successfully re-treated.

Rhabdoid tumor of the kidney in the National Wilms' Tumor Study: age at diagnosis as a prognostic factor

PURPOSE

The objective of this study is to determine prognostic factors in rhabdoid tumor of the kidney (RTK), including both demographic and treatment variables.

PATIENTS AND METHODS

A total of 142 patients studied on National Wilms' Tumor Studies 1, 2, 3, 4, and 5 were analyzed. Patients were enrolled between the years 1969 and 2002. Variables examined included sex, age of diagnosis, tumor stage, presence of CNS lesions, as well as treatment variables, including the use of doxorubicin and/or radiotherapy (RT).

RESULTS

No survival differences were observed between males and females, between those treated with or without doxorubicin, or with or without RT. Patients with tumors of lower stage had an overall survival rate of 41.8%, whereas, tumors of higher stage were associated with a 15.9% survival (P < .001). A highly significant difference in survival was noted when patients were stratified according to age of diagnosis. Survival at 4 years in infants under 6 months of age at diagnosis was 8.8%, whereas, survival in patients 2 years of age or older was 41.1% (P < .0001). Stratification into intermediate age brackets demonstrated a strong correlation of increasing survival with increasing age at diagnosis. All patients with a CNS lesion, except one, died.

CONCLUSION

Age at diagnosis is a highly significant prognostic factor for survival of children with RTK. Infants have a dismal prognosis, whereas, older children have a more favorable outcome. Higher tumor stage and presence of a CNS lesion were both factors predictive of a poor survival rate.

Loss of heterozygosity for chromosomes 1p and 16q is an adverse prognostic factor in favorable-histology Wilms tumor: a report from the National Wilms Tumor Study Group

PURPOSE

To determine if tumor-specific loss of heterozygosity (LOH) for chromosomes 1p or 16q is associated with a poorer prognosis for children with favorable-histology (FH) Wilms tumor entered on the fifth National Wilms Tumor Study (NWTS-5).

PATIENTS AND METHODS

Between August 1995 and June 2002, 2,021 previously untreated children with FH or anaplastic Wilms tumor, clear-cell sarcoma of the kidney (CCSK) or malignant rhabdoid tumor of the kidney (RTK), were treated with stage- and histology-specific therapy. Their tumors were assayed for LOH for polymorphic DNA markers on chromosomes 1p and 16q. ResultsLOH for 1p or 16q was rarely observed in CCSK (n = 90) or RTK (n = 22). The relative risk (RR) of relapse for patients with FH stage I to IV tumors with LOH, stratified by stage, was 1.56 for LOH 1p (P = .01) and 1.49 for LOH 16q (P = .01), whereas the RR of death was 1.84 (P = .03) and 1.44 (P = .15), respectively. When the effects of LOH for both regions were considered jointly among patients with stage I to II FH disease, the risks of relapse and death were increased for LOH 1p only (RR = 2.2, P = .02 for relapse; RR = 4.0, P = .02 for death), for LOH 16q only (RR = 1.9, P = .01 and RR = 1.4, P = .60) and for LOH for both regions (RR = 2.9, P = .001 and RR = 4.3, P = .01) in comparison with patients with LOH at neither locus. The risks of relapse and death for patients with stage III to IV FH tumors were increased only with LOH for both regions (RR = 2.4, P = .01 and RR = 2.7, P = .04).

CONCLUSION

Tumor-specific LOH for both chromosomes 1p and 16q identifies a subset of FH Wilms tumor patients who have a significantly increased risk of relapse and death. LOH for these chromosomal regions can now be used as an independent prognostic factor together with disease stage to target intensity of treatment to risk of treatment failure.

[Kidney tumors in childhood]

Types of renal tumors arising in children are different from those occurring in adults. Nephroblastoma is the most common (85%) with a clinical outcome which has dramatically improved in the last 30 years. Current classifications are aimed at better adaptation of treatment to each individual case, reducing iatrogenic complications without impairing total cure. Amongst entities which have been recently described or are better known we can find juvenile carcinoma associated with Xp11.2 translocation, renal medullary carcinoma, metanephric tumors, etc. Role of molecular cytogenetics is increasing for classification (and treatment) and this should always be kept in mind when dealing a fresh specimen of childhood renal tumor.

Treatment outcomes in adults with favorable histologic type Wilms tumor—an update from the National Wilms Tumor Study Group

PURPOSE

To describe the clinical outcomes in adults with favorable histologic type (FH) Wilms tumor (WT) registered in the National Wilms Tumor Studies (NWTS) 4-5. We also describe the results of patients treated in the "modern era" (1979-2001) with surgical staging, central pathology review and stage-appropriate multimodality treatment.

METHODS AND MATERIALS

Twenty-three adult patients (> or =16 years of age) with FHWT after central pathology review were registered on NWTS 4-5. The tumor stage distribution was Stage I in 5, Stage II in 8, Stage III in 6, and Stage IV in 4 patients. All patients underwent primary nephrectomy followed by multiagent chemotherapy and/or radiotherapy (RT). All patients underwent tumor stage-based chemotherapy that generally followed existing NWTS Group (NWTSG) protocols. To analyze the outcomes of adult patients treated in the "modern era," the data from this report were combined with the data from 22 patients with FHWT previously reported in 1990 by the NWTSG.

RESULTS

The 5-year relapse-free survival, overall survival, and disease-specific survival (DSS) rate was 77.3%, 82.6%, and 95.7%, respectively, for patients registered in the NWTS 4-5 protocols. Three patients (13%) died of chemotherapy-induced hepatic venoocclusive disease. For a total of 45 adults with FHWTs treated in the "modern era," the overall survival rate was 82%. The survival rate for those with Stage I, II, III, and IV disease was 100%, 92%, 70%, and 73%, respectively. Of the 12 Stage I-II patients treated with two drugs and no RT, the survival rate was 100%. The survival rate for Stage III and IV patients treated with three drugs and RT was 63% and 70%, respectively.

CONCLUSION

The results of this report demonstrate that adults with FHWT treated with a multimodality approach similar to NWTSG protocols have good survival. We recommend that all adult patients be treated with stage-appropriate combined modality therapy, and furthermore, be entered in current Children's Oncology Group WT protocols so that coherent data can be gathered for this relatively rare tumor. Finally, all patients should be monitored for signs and symptoms of hepatic venoocclusive disease.

Mucinous cancers have fewer genomic alterations than more common classes of breast cancer

Mucinous cancers of the breast are distinguished histologically by their abundant pools of mucin and low degree of nuclear pleomorphism. Relative to the more common breast cancers of no distinctive type (ductal carcinoma), mucinous cancers have a relatively favorable prognosis. In a study of chromosomal changes in mucinous cancers, we evaluated the extent of loss of heterozygosity (LOH) at chromosomal regions commonly deleted in usual infiltrating ductal carcinoma, including markers on chromosomal arms 1p, 1q, 3p, 6q, 8p, 9p, 11p, 11q, 13q, 16q, 17p, and 17q. Remarkably, we found an average frequency of LOH of only 1.9 of these 12 chromosomal arms in 18 cases of mucinous carcinoma, compared to an average frequency of LOH of 6.4 of these same chromosomal arms in cases of infiltrating ductal cancer. In three of the 18 cases of mucinous carcinoma studied, including one case with regional lymph node metastases, no LOH was seen at any of the 12 chromosomal regions studied. We considered the possibility of other chromosomal loci being more commonly affected in mucinous cancers and conducted comparative genomic hybridization on six of the cases. These studies demonstrated a low overall frequency of genomic copy number changes (mean of 3.1 changes per case) and failed to reveal any other chromosomal locus with frequent losses that had not been evaluated by microsatellite analysis. Together, these data indicate that mucinous cancers of the breast do not have the extensive genomic alterations that are typically found in more common variants of breast cancer. Thus, mucinous cancers most likely have less genetic instability than most other forms of breast cancer and the molecular pathogenesis of this form of breast cancer is likely to be substantially different than that of usual ductal breast cancer.

A genome-wide screen for normally methylated human CpG islands that can identify novel imprinted genes

DNA methylation is a covalent modification of the nucleotide cytosine that is stably inherited at the dinucleotide CpG by somatic cells, and 70% of CpG dinucleotides in the genome are methylated. The exception to this pattern of methylation are CpG islands, CpG-rich sequences that are protected from methylation, and generally are thought to be methylated only on the inactive X-chromosome and in tumors, as well as differentially methylated regions (DMRs) in the vicinity of imprinted genes. To identify chromosomal regions that might harbor imprinted genes, we devised a strategy for isolating a library of normally methylated CpG islands. Most of the methylated CpG islands represented high copy number dispersed repeats. However, 62 unique clones in the library were characterized, all of which were methylated and GC-rich, with a GC content >50%. Of these, 43 clones also showed a CpG(obs)/CpG(exp) >0.6, of which 30 were studied in detail. These unique methylated CpG islands mapped to 23 chromosomal regions, and 12 were differentially methylated regions in uniparental tissues of germline origin, i.e., hydatidiform moles (paternal origin) and complete ovarian teratomas (maternal origin), even though many apparently were methylated in somatic tissues. We term these sequences gDMRs, for germline differentially methylated regions. At least two gDMRs mapped near imprinted genes, HYMA1 and a novel homolog of Elongin A and Elongin A2, which we term Elongin A3. Surprisingly, 18 of the methylated CpG islands were methylated in germline tissues of both parental origins, representing a previously uncharacterized class of normally methylated CpG islands in the genome, and which we term similarly methylated regions (SMRs). These SMRs, in contrast to the gDMRs, were significantly associated with telomeric band locations (P =.0008), suggesting a potential role for SMRs in chromosome organization. At least 10 of the methylated CpG islands were on average 85% conserved between mouse and human. These sequences will provide a valuable resource in the search for novel imprinted genes, for defining the molecular substrates of the normal methylome, and for identifying novel targets for mammalian chromatin formation.

Micropapillary serous carcinoma of the ovary has distinct patterns of chromosomal imbalances by comparative genomic hybridization compared with atypical proliferative serous tumors and serous carcinomas

Recent studies have subdivided serous borderline tumors into 2 categories: atypical proliferative serous tumors (APSTs), which have a relatively benign course, and micropapillary serous carcinomas (MPSCs), which behave like low-grade carcinoma. This study was undertaken to determine, using comparative genomic hybridization (CGH), whether cytogenetic changes support this hypothesis. Nine cases of APST, 10 of MPSC, and 11 of invasive serous carcinoma (SC) were analyzed by CGH. Tumor DNA was extracted from frozen or paraffin-embedded tissue from the primary ovarian tumor, using either sections with at least 70% tumor cells or tissue after relative enrichment by microdissection. Chromosomal imbalances were identified in 3 of 9 APST, 6 of 10 MPSC, and 11 of 11 SC. Three or more chromosomal imbalances were found in 0 of 9 APST, 4 of 10 MPSC, and 9 of 11 SC. Recurrent copy number alterations were grouped into 4 classes correlating with the different tumor types. Class I changes were present in APST and in MPSC or SC and included +8q (7 of 11 SC, 2 of 10 MPSC, 2 of 9 APST), -9p (5 of 11 SC, 0 of 10 MPSC, 1 of 9 APST), and +12 (+12p in 3/11 SC, +12 in 2 of 10 MPSC, +12 in 1 of 9 APST). Class II changes were found only in MPSC and SC, but not in APST. The most frequent examples were +3q (10 of 11 SC, 1 of 10 MPSC), -4q (5 of 11 SC, 1 of 10 MPSC), and -17p (5 of 11 SC, 1 of 10 MPSC). Class III changes were limited to SC, like -16q (7 of 11 SC) and -18q (6 of 11 SC). Class VI changes were unique to MPSC. Gain of 16p (3 of 10 MPSC) was the only aberration in this group. This aberration was not only unique to MPSC but was also the most frequent finding in MPSC. These data support the hypothesis that noninvasive serous tumors of the ovary can be subdivided into 2 categories: APST and MPSC. The number of imbalances in MPSC is substantially higher than in APST and lower than in SC. Some changes in MPSC are shared with SC and APST and others with SC only, suggesting that a subset of MPSC may represent a stage in progression from APST to SC. Other cases of MPSC with independent genetic alterations may represent another subset of tumors that are a distinct entity from APST and SC.

Metanephric stromal tumor: a rare benign pediatric renal mass

We report a rare case and description of a benign pediatric renal mass. To our knowledge, this tumor has never been described in urologic published reports. It is possible that the identification of this renal tumor could spare a child the toxic adjuvant chemotherapy that would be administered if confused with histologically similar tumors such as clear cell sarcoma of the kidney.

Treatment with nephrectomy only for small, stage I/favorable histology Wilms' tumor: a report from the National Wilms' Tumor Study Group

PURPOSE

Children younger than 24 months with small (< 550 g), favorable histology (FH) Wilms tumors (WTs) were shown in a pilot study to have an excellent prognosis when treated with nephrectomy only.

PATIENTS AND METHODS

A study of nephrectomy only for the treatment of selected children with FH WT was undertaken. Stringent stopping rules were designed to insure closure of the study if the true 2-year relapse-free survival rate was 90% or lower.

RESULTS

Seventy-five previously untreated children younger than 24 months with stage I/FH WTs for which the surgical specimen weighed less than 550 g were treated with nephrectomy only. Three patients developed metachronous, contralateral WT 1.1, 1.4, and 2.3 years after nephrectomy, and eight patients relapsed 0.3 to 1.05 years after diagnosis (median, 0.4 years; mean, 0.51 years). The sites of relapse were lung (n = 5) and operative bed (n = 3). The 2-year disease-free (relapse and metachronous contralateral WT) survival rate was 86.5%. The 2-year survival rate is 100% with a median follow-up of 2.84 years. The 2-year disease-free survival rate (excluding metachronous contralateral WT) was 89.2%, and the 2-year cumulative risk of metachronous contralateral WT was 3.1%.

CONCLUSION

Children younger than 24 months treated with nephrectomy only for a stage I/FH WT that weighed less than 550 g had a risk of relapse, including the development of metachronous contralateral WT, of 13.5% 2 years after diagnosis. All patients who experienced relapse on this trial are alive at this time. This approach will be re-evaluated in a clinical trial using a less conservative stopping rule.

ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor of extrapulmonary and pulmonary tissues with an unpredictable clinical course, occasional recurrences, and rare malignant transformation. Clonal abnormalities with rearrangements of chromosome of 2p23 and the ALK gene have been reported in a few cases. The purpose of this study is to investigate whether these are consistent abnormalities among IMTs or represent a distinct subset.

DESIGN

Formalin-fixed, paraffin-embedded archival tissue sections from 47 IMTs in 40 patients were immunostained with monoclonal antibodies against ALK and p80. Fluorescence in situ hybridization for ALK rearrangements was done on 22 IMTs from 19 patients. Findings were correlated with clinical features and outcome.

RESULTS

ALK positivity was observed in 17 of 47 IMTs (36%) and p80 positivity in 16 of 47 IMTs (34%). Fluorescence in situ hybridization showed ALK rearrangements in nine cases (47%), aneuploidy in three cases (16%), and no rearrangement in seven cases (37%). IMTs with ALK abnormalities by immunohistochemistry and/or fluorescence in situ hybridization originated in the abdomen/pelvis/retroperitoneum, chest, and extremities. The mean age was 6.6 years, with a male/female ratio of 1.3. 64% of patients had no evidence of disease at last follow-up, 45% had one or more recurrences, and 18% displayed histologic evidence of malignant transformation. The IMTs without ALK abnormalities occurred in older children, were more frequent in females, and had fewer recurrences. However, in this group of 40 patients, the differences between the groups with and without ALK abnormalities did not have statistical significance. Aneuploidy without ALK abnormalities was associated with malignant transformation in three of five cases.

CONCLUSIONS

Abnormalities of ALK and p80 and evidence of chromosomal rearrangements of 2p23 occur in a significant proportion of IMTs. These changes are most frequent in abdominal and pulmonary IMTs in the first decade of life and are associated with a higher frequency of recurrence. These findings confirm the neoplastic nature of a subset IMT with ALK abnormalities and suggest that aneuploid IMT is a subset with more aggressive clinical behavior.

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies.

Astronomical constraints on the cosmic evolution of the fine structure constant and possible quantum dimensions

We present measurements of absorption by the 21 cm hyperfine transition of neutral hydrogen toward radio sources at substantial look-back times. These data are used in combination with observations of rotational transitions of common interstellar molecules to set limits on the evolution of the fine structure constant: alpha/ alpha<3.5x10(-15) yr(-1), to a look-back time of 4.8 Gyr. In the context of string theory, the limit on the secular evolution of the scale factor of the compact dimensions, R, is &Rdot/ R<10(-15) yr(-1). Including terrestrial and other astronomical measurements places 2sigma limits on slow oscillations of R from the present to the epoch of cosmic nucleosynthesis, just seconds after the big bang, of DeltaR /R<10(-5).

Coexpression of hypoxia-inducible factor 1-alpha and vascular endothelial growth factor in Wilms' tumor

BACKGROUND/PURPOSE

Hypoxia-inducible factor 1 alpha (HIF-1alpha) is an important transcriptional factor responsible for regulating expression of the angiogenic cytokine, vascular endothelial growth factor (VEGF). Little information is available regarding factors involved in the hypoxic cascade, such as HIF or VEGF in Wilms' tumor. We concomitantly evaluate the expression of HIF-1alpha and VEGF in ex vivo human Wilms' tumor specimens.

METHODS

Immunohistochemical analysis (IHC) utilizing a monoclonal human anti-HIF-1alpha or a polyclonal anti-VEGF antibody was performed on ex vivo specimens of Wilms' tumor (n = 18). Predominant tumor histologic subtype was divided equally between epithelial (n = 6), blastemal (n = 6), and mixed (n = 6). Specimens were scored on a predetermined scale for distribution (percent positive cells) and intensity of HIF-1alpha/VEGF expression within areas of tumor.

RESULTS

IHC analysis found that HIF-1alpha and VEGF were expressed in all Wilms' tumor specimens. Strong nuclear staining for HIF-1alpha was seen in all samples evaluated, (n = 18), mean score 2.7 (>50% cells exhibiting nuclear HIF-1alpha expression). Cytoplasmic staining for HIF-1alpha also was seen in 15 of 18 samples (83%). Distribution of VEGF was equivalent between blastemal and epthelial components, mean score 2.23 versus 2.35.

CONCLUSIONS

HIF-1alpha and one of its regulatory end-products, the angiogenic cytokine VEGF, are simultaneously expressed in human Wilms' tumor. In Wilms' tumor, intratumoral hypoxia may stimulate tumor conversion to the angiogenic phenotype and incite production of VEGF. Strategies targeting the hypoxic cascade ultimately may prove efficacious against Wilms' tumor.

Genomic aberrations in human hepatocellular carcinomas of differing etiologies

We sought to assess whether genetic abnormalities in hepatocellular carcinoma differed in geographic locations associated with different risk factors. Comparative genomic hybridization (CGH) was applied to the genome-wide chromosomal analysis in 83 tumor samples from four different geographic origins. Samples were obtained from regions that differed in aflatoxin exposure: China (Hong Kong with low aflatoxin exposure and Shanghai with moderate aflatoxin exposure), Japan, and the United States (negligible aflatoxin exposure). Cases from Hong Kong and Shanghai were all hepatitis B virus (HBV) related, those from Japan were hepatitis C virus related, and those from the United States were HBV negative. In parallel, the mutational pattern of the whole p53 gene (exons 1-11) was also investigated in these cases. CGH revealed a complex pattern of chromosomal gains and losses, with the commonest aberration in each geographic location being chromosome 1q copy number gain (38-60%). Shanghai cases displayed the highest number of total aberrations per sample, with significant copy losses on 4q (75%), 8p (70%), and 16q (65%). Hepatitis C virus-related samples from Japan had a characteristically high incidence of 11q13 gain. p53 mutation(s) was detected in 23% of Hong Kong cases, 40% of Shanghai, 31% of Japan, but only 6% of the United States cases. The "aflatoxin-associated" codon 249 mutation was, however, identified only in samples from China (13% Hong Kong and 20% Shanghai). This finding, together with the highly aberrant pattern of genetic changes detected in the Shanghai series, is suggestive of the genotoxic effects of aflatoxin being more broadly based. It is also likely that there is a synergistic effect of HBV infection and high aflatoxin exposure in promoting hepatocellular carcinoma development. It appears from our CGH study that individual risk factors are indeed associated with distinct genetic aberrations, although changes in 1q gain appear common to all.

Myogenin is a specific marker for rhabdomyosarcoma: an immunohistochemical study in paraffin-embedded tissues

Myogenin belongs to a group of myogenic regulatory proteins whose expression determines commitment and differentiation of primitive mesenchymal cells into skeletal muscle. The expression of myogenin has been demonstrated to be extremely specific for rhabdomyoblastic differentiation, which makes it a useful marker in the differential diagnosis of rhabdomyosarcomas (RMS) from other malignant small round cell tumors of childhood. Commercially available antibodies capable of detecting myogenin in routinely processed formalin-fixed paraffin-embedded (FFPE) tissue are now available. In this study, we evaluated myogenin expression using the monoclonal myf-4 antibody (Novocastra Labs) on FFPE in a large number of pediatric tumors in order to define the clinical utility of this marker. A total of 119 tumors were studied. These included 48 alveolar RMS (ARMS), 20 embryonal RMS (ERMS), one spindle cell RMS, 16 Ewing's sarcomas (ES), six nephroblastomas, two ectomesenchymomas, seven precursor hematopoietic neoplasms, five olfactory neuroblastomas, three neuroblastomas, six desmoplastic small round cell tumors, and five rhabdoid tumors. Distinct nuclear staining for myogenin was noted in all 69 RMS. Notably, the number of positive tumor cells differed between the ARMS and ERMS. In ARMS, the majority of tumor cells (75 to 100%) were positive, in contrast to ERMS, in which the positivity ranged from rare + to 25% in all but three tumors. Additionally, myogenin positivity was seen in two of two ectomesenchymomas and in two nephroblastomas with myogenous differentiation. All other tumors were clearly negative. Our results indicate that staining for myogenin is an extremely reliable and specific marker for rhabdomyoblastic differentiation. It gives consistent and easily interpretable results in routinely fixed tissues.

Absence of EWS/FLI1 fusion in olfactory neuroblastomas indicates these tumors do not belong to the Ewing's sarcoma family

The balanced reciprocal translocation t(11;22)(q24;q12) is a specific molecular marker for the Ewing's sarcoma family of tumors (ESFT). Based on the detection of this translocation in some olfactory neuroblastomas (ONBs), it has been proposed that ONBs also belong to the ESFT. Others have challenged this hypothesis; however, the rarity of ONBs, as well as the lack of molecular techniques that work reliably on formalin fixed tissue, have precluded the molecular analysis of a significant number of cases. We evaluated the immunophenotypic and molecular features of 17 paranasal small round neuroectodermal tumors using routinely fixed tissue. Probes localizing to 22q12 (EWS) and 11q24 (FLI-1) were used in a standard 2-color fluorescence in situ hybridization (FISH) assay to evaluate EWS/FLI1 fusion on the der(22). Sixteen tumors were mic-2 negative, whereas 1 tumor was mic-2 positive, compatible with ONB and ESFT, respectively. Thirteen of 15 ONBs could be evaluated by FISH, and all 13 were negative for the EWS/FLI1 fusion. Distinct fusion signals were identified in the single paranasal ESFT. Our findings indicate that ONBs lack the EWS/FLI1 fusion and are unrelated to the ESFT; however, true ESFTs may rarely occur as primary sinonasal tumors.

Neural innervation of the newborn exstrophic bladder: an immunohistochemical study

PURPOSE

Continence in bladder exstrophy is not always easy to attain. Some patients have a small noncontractile bladder while in others an adequate capacity bladder may not contract normally. Innervation of the detrusor determines its ability to contract. The exstrophic bladder during organogenesis does not store urine. Therefore, its requirements for contraction are limited and its innervation would potentially reflect this difference in function. The availability of specific immunostains allows better differentiation of the neural elements in tissue specimens. Our study focuses on myelinated nerves innervating the newborn exstrophic detrusor.

MATERIALS AND METHODS

Biopsies were obtained from the anterior wall of 10 newborn exstrophic bladders at the time of initial closure and compared to 10 newborn controls. Patient age at bladder closure ranged from 1 to 90 days (mean 22). Specimens were formalin fixed and paraffin embedded. Then 4 micro. thick sections were stained with S100, an immunostain that stains neural crest elements including Schwann's elements (myelinated nerve fibers). The entire tissue section was examined. Microscopic fields were sequentially examined with a morphometric system comprising a microscope, video camera and personal computer with a video frame grabber. The output image was displayed on a second monitor and the nerves in each field and numbers of fields in each section were counted. To be considered, fields had to have greater than 75% tissue coverage. The average number of nerves per field was compared between the exstrophic bladders and normal controls.

RESULTS

The average number of myelinated nerves per field in the newborn exstrophic bladders (0.13 per field) was significantly reduced compared to normal controls (1.25 per field) and statistically significant (p<0.001). This reduction in nerve fibers appeared to be due to lack of smaller fibers with preservation of larger fibers. There was no difference in innervation in cases closed at birth compared to those closed after month 1 of life.

CONCLUSIONS

The newborn exstrophic bladder has fewer myelinated nerve fibers than normal controls primarily due to reduction in the smaller fibers which may represent a maturational delay in the development of the exstrophic bladder. Another possible explanation may be degeneration of the fibers due to lack of bladder contraction but no indication of nerve degeneration was evident in our study. Followup studies of patients at various stages of reconstruction will determine the evolution of neural innervation in the exstrophic bladder.