Metastatic sites in stage IV and IVS neuroblastoma correlate with age, tumor biology, and survival

131I-MIBG followed by consolidation with busulfan, melphalan and autologous stem cell transplantation for refractory neuroblastoma

BACKGROUND

(131) I-metaiodobenzylguanidine (MIBG) produces a 37% response rate in relapsed/refractory neuroblastoma, and could be used to improve remission status prior to myeloablative chemotherapy with autologous stem cell transplant (ASCT). The purpose of our report was to evaluate safety and response with MIBG therapy followed by myeloablative busulfan and melphalan (BuMel) with ASCT in patients with refractory neuroblastoma.

METHODS

Retrospective chart review was done on patients treated with MIBG (18 mCi/kg) on Day 1 and ASCT on day 14. Six to eight weeks after MIBG, patients without progressive disease received IV busulfan on days -6 to -2 (target Css 700-900), melphalan (140 mg/m2 IV) on day -1, and ASCT on Day 0. Response and toxicity were evaluated after MIBG and again after myeloablative therapy.

RESULTS

Eight patients completed MIBG/ASCT followed by BuMel/ASCT. MIBG was well tolerated, with grade 3 or 4 non-hematologic toxicity limited to one patient with sepsis. Grade 3 mucositis occurred in six patients after BuMel/ASCT. One patient developed sinusoidal obstructive syndrome (SOS) and died 50 days post-ASCT following myeloablative conditioning. All patients engrafted neutrophils (median 16.5 days) and platelets (median 32 days) after BuMel, excluding the patient with SOS. After all therapy, there were three complete, two partial, and one minor response in seven evaluable patients.

CONCLUSIONS

MIBG at doses up to 18 mCi/kg can be safely administered 6 weeks prior to a BuMel consolidative regimen for refractory neuroblastoma. Preceding MIBG did not impair engraftment following BuMel. This regimen is being further evaluated in a Children's Oncology Group (COG) trial.

Critical role of STAT3 in IL-6-mediated drug resistance in human neuroblastoma

Drug resistance is a major cause of treatment failure in cancer. Here, we have evaluated the role of STAT3 in environment-mediated drug resistance (EMDR) in human neuroblastoma. We determined that STAT3 was not constitutively active in most neuroblastoma cell lines but was rapidly activated upon treatment with interleukin (IL)-6 alone and in combination with the soluble IL-6 receptor (sIL-6R). Treatment of neuroblastoma cells with IL-6 protected them from drug-induced apoptosis in a STAT3-dependent manner because the protective effect of IL-6 was abrogated in the presence of a STAT3 inhibitor and upon STAT3 knockdown. STAT3 was necessary for the upregulation of several survival factors such as survivin (BIRC5) and Bcl-xL (BCL2L1) when cells were exposed to IL-6. Importantly, IL-6-mediated STAT3 activation was enhanced by sIL-6R produced by human monocytes, pointing to an important function of monocytes in promoting IL-6-mediated EMDR. Our data also point to the presence of reciprocal activation of STAT3 between tumor cells and bone marrow stromal cells including not only monocytes but also regulatory T cells (Treg) and nonmyeloid stromal cells. Thus, the data identify an IL-6/sIL-6R/STAT3 interactive pathway between neuroblastoma cells and their microenvironment that contributes to drug resistance.

Mechanisms of the antitumor activity of human Vγ9Vδ2 T cells in combination with zoledronic acid in a preclinical model of neuroblastoma

Low expression of surface major histocompatibility complex (MHC) class I molecules and defects in antigen processing machinery make human neuroblastoma (NB) cells appropriate targets for MHC unrestricted immunotherapeutic approaches. Human T-cell receptor (TCR) Vγ9Vδ2 lymphocytes exert MHC-unrestricted antitumor activity and are activated by phosphoantigens, whose expression in cancer cells is increased by aminobisphosphonates. With this background, we have investigated the in vivo anti-NB activity of human Vγ9Vδ2 lymphocytes and zoledronic acid (ZOL). SH-SY-5Y human NB cells were injected in the adrenal gland of immunodeficient mice. After 3 days, mice received ZOL or human Vγ9Vδ2 T cells or both agents by intravenous administration once a week for 4 weeks. A significantly improved overall survival was observed in mice receiving Vγ9Vδ2 T cells in combination with ZOL. Inhibition of tumor cell proliferation, angiogenesis and lymphangiogenesis, and increased tumor cell apoptosis were detected. Vγ9Vδ2 T lymphocytes were attracted to NB-tumor masses of mice receiving ZOL where they actively modified tumor microenvironment by producing interferon-γ (IFN-γ), that in turn induced CXCL10 expression in NB cells. This study shows that human Vγ9Vδ2 T cells and ZOL in combination inhibit NB growth in vivo and may provide the rationale for a phase I clinical trial in patients with high-risk NB.

Genistein inhibits estradiol- and environmental endocrine disruptor-induced growth effects on neuroblastoma cells in vitro

The aim of this study was to examine the effect of genistein on human neuroblastoma cell proliferation induced by two common environmental endocrine disruptors, bisphenol A (BPA) and Di-2-ethylhexyl phthalate (DEHP), and to investigate its underlying mechanism. SK-N-SH human neuroblastoma cells were treated with E₂ (1 ng/ml), BPA (2 μg/ml) or DEHP (100 μM), with or without genistein (12.5 μM) in vitro. The number of viable cells was detected with an absorbance reader after 0, 24, 48 or 72 h treatment. The percentage of cells in different phases, and expression of Akt and its phosphorylation levels were also assessed by flow cytometry and western blot analysis at 72 h, respectively. The BPA and DEHP groups had a 30% higher number of viable cells compared to the non-treated group at 48 h (P<0.001). However, the cell numbers did not increase significantly in the groups with additional treatment with genistein (P>0.05 vs. control) and the same trend was observed at 72 h. The expression of phospho-Akt protein was increased in the groups treated with BPA or DEHP compared to the control group at 72 h (P<0.05), while no significant elevation in the expression of phospho-Akt was observed (P>0.05) in genistein-treated groups. Cells were arrested at the G₂/M phase by genistein. Similar effects were observed in the E₂ group with or without genistein treatment. Akt protein expression had no significant change among all the groups (P>0.05). In conclusion, estradiol- or environmental endocrine disruptor-induced proliferation of human neuroblastoma cells is effectively abolished by genistein, likely in a cell cycle- and Akt pathway-dependent manner.

Iodine-123 Metaiodobenzylguanidine Scintigraphy Scoring Allows Prediction of Outcome in Patients With Stage 4 Neuroblastoma: Results of the Cologne Interscore Comparison Study

Purpose

Radioiodinated metaiodobenzylguanidine (123I-mIBG) scintigraphy is an established imaging method in neuroblastoma. Semiquantitative scoring systems have been developed to assess the extent of disease and response to chemotherapy. We present the results of the comparison between the SIOPEN [International Society of Pediatric Oncology Europe Neuroblastoma Group] score and the modified Curie score.

Patients and Methods

We retrospectively analyzed 147 mIBG scans of 58 patients older than 1 year of age with stage 4 neuroblastoma from German Neuroblastoma Trial NB97 that were assessed according to the SIOPEN and the Curie scoring method. mIBG examinations were performed at diagnosis and after four and six cycles of chemotherapy.

Results

Scoring results were highly correlated between both methods, and interobserver reliability was excellent. A Curie score ≤ 2 and a SIOPEN score ≤ 4 (best cutoff) at diagnosis were correlated to significantly better event-free and overall survival compared with higher scores. After four cycles of chemotherapy, overall survival was significantly better for mIBG-negative patients compared with those with any residual mIBG-positive metastases. After six cycles of chemotherapy, there was no difference in survival between mIBG-negative patients and patients with residual mIBG-positive metastases. Patients without mIBG-positive metastases after four and six cycles of chemotherapy had a better overall survival, but late clearance of mIBG-positive metastases did not improve outcome.

Conclusion

Higher mIBG scores at diagnosis and occurrence of any residual mIBG-positive metastases after four cycles of chemotherapy predicted unfavorable outcome for patients with stage 4 neuroblastoma. Later clearance of metastases did not improve prognosis. The Curie and the SIOPEN score were equally reliable and predictive.

RNAi-mediated stathmin suppression reduces lung metastasis in an orthotopic neuroblastoma mouse model

Metastatic neuroblastoma is an aggressive childhood cancer of neural crest origin. Stathmin, a microtubule destabilizing protein, is highly expressed in neuroblastoma although its functional role in this malignancy has not been addressed. Herein, we investigate stathmin's contribution to neuroblastoma tumor growth and metastasis. Small interfering RNA (siRNA)-mediated stathmin suppression in two independent neuroblastoma cell lines, BE(2)-C and SH-SY5Y, did not markedly influence cell proliferation, viability or anchorage-independent growth. In contrast, stathmin suppression significantly reduced cell migration and invasion in both the neuroblastoma cell lines. Stathmin suppression altered neuroblastoma cell morphology and this was associated with changes in the cytoskeleton, including increased tubulin polymer levels. Stathmin suppression also modulated phosphorylation of the actin-regulatory proteins, cofilin and myosin light chain (MLC). Treatment of stathmin-suppressed neuroblastoma cells with the ROCKI and ROCKII inhibitor, Y-27632, ablated MLC phosphorylation and returned the level of cofilin phosphorylation and cell invasion back to that of untreated control cells. ROCKII inhibition (H-1152) and siRNA suppression also reduced cofilin phosphorylation in stathmin-suppressed cells, indicating that ROCKII mediates stathmin's regulation of cofilin phosphorylation. This data demonstrates a link between stathmin and the regulation of cofilin and MLC phosphorylation via ROCK. To examine stathmin's role in neuroblastoma metastasis, stathmin short hairpin RNA (shRNA)\luciferase-expressing neuroblastoma cells were injected orthotopically into severe combined immunodeficiency-Beige mice, and tumor growth monitored by bioluminescent imaging. Stathmin suppression did not influence neuroblastoma cell engraftment or tumor growth. In contrast, stathmin suppression significantly reduced neuroblastoma lung metastases by 71% (P<0.008) compared with control. This is the first study to confirm a role for stathmin in hematogenous spread using a clinically relevant orthotopic cancer model, and has identified stathmin as an important contributor of cell invasion and metastasis in neuroblastoma.

Establishment and characterization of xenograft models of human neuroblastoma bone metastasis

OBJECTS

To improve the therapy of advanced neuroblastoma (NB), it is critical to develop animal models that mimic NB bone metastases. Unlike the human disease, NB xenograft models rarely metastasize spontaneously to bone from the orthotopic site of primary tumor growth.

METHODS

Single-cell suspensions of SY5Y, KCNR NB cells were injected directly into the femur of nude mice. Radiological and histological analyses and immunohistochemistry analyses were performed to characterize these osseous NB models. SY5Y and KCNR result in osteolytic responses.

RESULTS

We have detected osteoprotegerin, receptor activator of nuclear factor kappa B ligand, parathyroid hormone-related protein, and endothelin-1, proteins associated with bone growth and osteolysis, and C-X-C chemokine receptor type 4 (CXCR4) involved in tumor growth and tumor cell migration in the NB cells grown in the bone.

CONCLUSIONS

These animal models can be used to study biological interactions, pathways, and potential therapeutic targets and also to evaluate new agents for treatment and prevention of NB bone metastasis.

Pediatric primary and metastatic neuroblastoma: MRI findings: pictorial review

Magnetic resonance imaging (MRI) has become one of the most valuable modalities for initial and follow-up imaging of suspected or known neuroblastoma (NBL) owing to its excellent inherent contrast, lack of ionizing radiation and multiplanar imaging capability. Importantly, NBL has a variable appearance on different imaging modalities, and this is particularly pertinent to MRI. MRI is a cornerstone for management of NBL, providing essential information at initial presentation regarding diagnosis, staging, resectability and relation to vital structures. It can also define the extent of residual disease after surgical resection or assess the efficacy of treatment. Follow-up MRI is frequently performed to ensure sustained complete remission or to monitor known residual disease. This pictorial review article aims to provide the reader with a concise, yet comprehensive, collection of MR images of primary and metastatic NBL lesions with relevant correlation with other imaging modalities.

Malignant liver tumors

Malignant tumors of the liver comprise a relatively small fraction of the total number of pediatric malignancies. However, these tumors can be a significant cause of morbidity and mortality, and there have been significant therapeutic gains during the past few decades through advances in systemic therapy and surgical treatment. Even in patients with advanced local disease, complete resection is now a possibility because of improvements in liver transplantation techniques. In this review, we will discuss the staging and treatment of common malignant tumors of the liver.

Pediatrics: diagnosis of neuroblastoma

Neuroblastoma is the most common pediatric extracranial soft-tissue tumor, accounting for approximately 8% of childhood malignancies. Its prognosis is widely variable, ranging from spontaneous regression to fatal disease despite multimodality therapy. Multiple imaging and clinical tests are needed to accurately assess patient risk with risk groups based on disease stage, patient age, and biological tumor factors. Approximately 60% of patients with neuroblastoma have metastatic disease, most commonly involving bone marrow or cortical bone. Metaiodobenzylguanidine (mIBG) scintigraphy plays an important role in the assessment of neuroblastoma, allowing whole-body disease assessment. mIBG is used to define extent of disease at diagnosis, assess disease response during therapy, and detect residual and recurrent disease during follow-up. mIBG is highly sensitive and specific for neuroblastoma, concentrating in >90% of tumors. mIBG was initially labeled with (131)I, but (123)I-mIBG yields higher quality images at a lower patient radiation dose. (123)I-mIBG (AdreView; GE Healthcare, Arlington Heights, IL) was approved for clinical use in children by the Food and Drug Administration in 2008 and is now commercially available throughout the United States. The use of single-photon emission computed tomography and single-photon emission computed tomography/computed tomography in (123)I-mIBG imaging has improved certainty of lesion detection and localization. Fluorodeoxyglucose positron-emission tomography has recently been compared with mIBG and found to be most useful in neuroblastomas which fail to or weakly accumulate mIBG.

Lithocholic bile acid selectively kills neuroblastoma cells, while sparing normal neuronal cells

Aging is one of the major risk factors of cancer. The onset of cancer can be postponed by pharmacological and dietary anti-aging interventions. We recently found in yeast cellular models of aging that lithocholic acid (LCA) extends longevity. Here we show that, at concentrations that are not cytotoxic to primary cultures of human neurons, LCA kills the neuroblastoma (NB) cell lines BE(2)-m17, SK-n-SH, SK-n-MCIXC and Lan-1. In BE(2)-m17, SK-n-SH and SK-n-MCIXC cells, the LCA anti-tumor effect is due to apoptotic cell death. In contrast, the LCA-triggered death of Lan-1 cells is not caused by apoptosis. While low concentrations of LCA sensitize BE(2)-m17 and SK-n-MCIXC cells to hydrogen peroxide-induced apoptotic cell death controlled by mitochondria, these LCA concentrations make primary cultures of human neurons resistant to such a form of cell death. LCA kills BE(2)-m17 and SK-n-MCIXC cell lines by triggering not only the intrinsic (mitochondrial) apoptotic cell death pathway driven by mitochondrial outer membrane permeabilization and initiator caspase-9 activation, but also the extrinsic (death receptor) pathway of apoptosis involving activation of the initiator caspase-8. Based on these data, we propose a mechanism underlying a potent and selective anti-tumor effect of LCA in cultured human NB cells. Moreover, our finding that LCA kills cultured human breast cancer and rat glioma cells implies that it has a broad anti-tumor effect on cancer cells derived from different tissues and organisms.

Phase I study of vincristine, irinotecan, and ¹³¹I-metaiodobenzylguanidine for patients with relapsed or refractory neuroblastoma: a new approaches to neuroblastoma therapy trial

PURPOSE

(131)I-metaiodobenzylguanidine (MIBG) is a targeted radiopharmaceutical with activity in patients with relapsed or refractory neuroblastoma. Irinotecan is a known radiosensitizer with activity in neuroblastoma. This phase I study aimed to determine the recommended phase 2 dose of MIBG together with fixed doses of vincristine and irinotecan.

EXPERIMENTAL DESIGN

Patients 1 to 30 years old with relapsed or refractory neuroblastoma and MIBG-avid tumors were eligible. All patients had autologous hematopoietic stem cells (PBSC) available and met standard phase I organ function requirements. Irinotecan (20 mg/m(2)/dose IV) was given on days 0 to 4 and 7 to 11, with vincristine (1.5 mg/m(2) IV) on days 0 and 7. MIBG was given on day 1 following a 3 + 3 phase I dose escalation design starting at 8 mCi/kg MIBG. PBSCs were administered at dose level 8 mCi/kg for prolonged myelosuppression and for all patients at 12 mCi/kg or more.

RESULTS

Twenty-four patients evaluable for dose escalation (median age, 6.7 years; range, 1.9-26.8 years) received 1 (n = 17), 2 (n = 5), or 3 (n = 2) cycles of therapy. Myelosuppression and diarrhea were the most common toxicities. Two of 6 patients at the 18 mCi/kg dose level had dose-limiting toxicity (DLT), including one with protocol-defined DLT with prolonged mild aspartate aminotransferase elevation. Eighteen mCi/kg was the recommended phase 2 dose. Six additional patients were treated at 18 mCi/kg, with one additional DLT. Responses (2 complete and 4 partial responses) occurred in 6 of 24 (25%) evaluable patients.

CONCLUSIONS

MIBG is tolerable and active at 18 mCi/kg with standard doses of vincristine and irinotecan.

Preclinical models of pediatric solid tumors (neuroblastoma) and their use in drug discovery

Neuroblastoma is the most common pediatric abdominal solid tumor. This aggressive embryonal malignancy of neural crest origin has a peak age of onset of 22 months, and accounts for ~11% of all pediatric cancers and 15% of all pediatric cancer deaths. With current treatment protocols, including high-dose chemotherapy with autologous stem cell transplantation, radiation, and surgery, ~80% of high-risk patients go into remission, although the majority relapse and succumb to therapy-resistant tumors. Long-term survival rates (>5 years) are <50%. Mouse models of neuroblastoma provide clinically relevant tools for studying the growth and metastasis of this aggressive malignancy, and for testing the efficacy of potentially novel therapeutics in vivo. This unit describes an orthotopic murine model of neuroblastoma using cultured human cells that closely mimics the clinical condition in terms of the bulky intra-abdominal tumors and other aspects of metastatic disease. Also described are methods for in vivo imaging and monitoring of tumor growth, and procedures for necropsy and tumor preservation for pathological analysis.

The role of neoadjuvant chemotherapy in children with malignant solid tumors

Pediatric surgeons play a critical role in diagnosing, staging, and treating malignant solid tumors in children. Over the years, the surgical management of the primary tumor site has evolved from an aggressive en-bloc resection at diagnosis to a more tailored surgical approach, often affecting definitive local control after the delivery of neoadjuvant therapy, as currently directed by many solid tumor protocols. In fact, inappropriate upfront resection can lead to unnecessary short- and long-term morbidity, an incomplete resection, and may be associated with a delay in the initiation of the systemic chemotherapy that is critical to the treatment of gross or occult metastatic disease. Therefore, it is important for the pediatric surgeon, as a member of the multidisciplinary team involved in the care of these children, to understand the indications for and implications of neoadjuvant therapy in the treatment of pediatric solid tumors. Here we review the current management of childhood solid tumors focusing on the role of neoadjuvant therapy.

Didymin induces apoptosis by inhibiting N-Myc and upregulating RKIP in neuroblastoma

Neuroblastomas arise from the neural crest cells and represent the most common solid tumors outside the nervous system in children. The amplification of N-Myc plays a primary role in the pathogenesis of neuroblastomas, whereas acquired mutations of p53 lead to refractory and relapsed cases of neuroblastomas. In this regard, dietary compounds which can target N-Myc and exert anticancer effects independent of p53 status acquire significance in the management of neuroblastomas. Hence, we investigated the anticancer properties of the flavonoid didymin in neuroblastomas. Didymin effectively inhibited proliferation and induced apoptosis irrespective of p53 status in neuroblastomas. Didymin downregulated phosphoinositide 3-kinase, pAkt, Akt, vimentin, and upregulated RKIP levels. Didymin induced G(2)/M arrest along with decreasing the levels of cyclin D1, CDK4, and cyclin B1. Importantly, didymin inhibited N-Myc as confirmed at protein, mRNA, and transcriptional level by promoter-reporter assays. High-performance liquid chromatography analysis of didymin-treated (2 mg/kg b.w.) mice serum revealed effective oral absorption with free didymin concentration of 2.1 μmol/L. Further in vivo mice xenograft studies revealed that didymin-treated (2 mg/kg b.w.) animals had significant reductions in tumors size compared with controls. Didymin strongly inhibited the proliferation (Ki67) and angiogenesis (CD31) markers, as well as N-Myc expression, as revealed by the histopathologic examination of paraffin-embedded section of resected tumors. Collectively, our in vitro and in vivo studies elucidated the anticancer properties and mechanisms of action of a novel, orally active, and palatable flavonoid didymin, which makes it a potential new approach for neuroblastoma therapy (NANT) to target pediatric neuroblastomas.

Phase II study of oral capsular 4-hydroxyphenylretinamide (4-HPR/fenretinide) in pediatric patients with refractory or recurrent neuroblastoma: a report from the Children's Oncology Group

PURPOSE

To determine the response rate to oral capsular fenretinide in children with recurrent or biopsy proven refractory high-risk neuroblastoma.

EXPERIMENTAL DESIGN

Patients received 7 days of fenretinide: 2,475 mg/m(2)/d divided TID (<18 years) or 1,800 mg/m(2)/d divided BID (≥18 years) every 21 days for a maximum of 30 courses. Patients with stable or responding disease after course 30 could request additional compassionate courses. Best response by course 8 was evaluated in stratum 1 (measurable disease on CT/MRI ± bone marrow and/or MIBG avid sites) and stratum 2 (bone marrow and/or MIBG avid sites only).

RESULTS

Sixty-two eligible patients, median age 5 years (range 0.6-19.9), were treated in stratum 1 (n = 38) and stratum 2 (n = 24). One partial response (PR) was seen in stratum 2 (n = 24 evaluable). No responses were seen in stratum 1 (n = 35 evaluable). Prolonged stable disease (SD) was seen in 7 patients in stratum 1 and 6 patients in stratum 2 for 4 to 45+ (median 15) courses. Median time to progression was 40 days (range 17-506) for stratum 1 and 48 days (range 17-892) for stratum 2. Mean 4-HPR steady-state trough plasma concentrations were 7.25 μmol/L (coefficient of variation 40-56%) at day 7 course 1. Toxicities were mild and reversible.

CONCLUSIONS

Although neither stratum met protocol criteria for efficacy, 1 PR + 13 prolonged SD occurred in 14/59 (24%) of evaluable patients. Low bioavailability may have limited fenretinide activity. Novel fenretinide formulations with improved bioavailability are currently in pediatric phase I studies.

Imaging neuroblastoma: what the radiologist needs to know

Neuroblastoma is the most common extracranial solid malignancy in children. The tumor has variable biological behavior that can be predicted by patient age, genetic features, tumor biology and extent of disease at diagnosis. Factors chosen by various cooperative groups to define risk of treatment failure have been non-uniform. Therefore, historically, it has been difficult to compare outcomes across clinical trials performed around the world. This has hindered the advancement of treatment strategies to improve survival of these patients. The International Neuroblastoma Risk Group (INRG) was established in 2004 to develop a consensus approach to pretreatment risk stratification. The result was the development of the INRG Staging System (INRGSS) which relies on imaging-defined risk factors (IDRFs) that are determined before surgery or other therapy. With the application of the INRGSS the radiologist's role in staging children with neuroblastoma is increased. This review provides an overview of the INRGSS and the IDRFs.

Prognostic value of the stage 4S metastatic pattern and tumor biology in patients with metastatic neuroblastoma diagnosed between birth and 18 months of age

PURPOSE

Patients with neuroblastoma younger than 12 months of age with a 4S pattern of disease (metastases limited to liver, skin, bone marrow) have better outcomes than infants with stage 4 disease. The new International Neuroblastoma Risk Group (INRG) staging system extends age to 18 months for the 4S pattern. Our aim was to determine which prognostic features could be used for optimal risk classification among patients younger than 18 months with metastatic disease.

METHODS

Event-free survival (EFS) and overall survival were analyzed by log-rank tests, Cox models, and survival tree regression for 656 infants with stage 4S neuroblastoma younger than 12 months of age and 1,019 patients with stage 4 disease younger than 18 months of age in the INRG database.

RESULTS

Unfavorable biologic features were more frequent in infants with stage 4 disease than in infants with 4S tumors and higher overall in those age 12 to 18 months (although not different for stage 4 v 4S pattern). EFS was significantly better for infants younger than 12 months with 4S pattern than with stage 4 disease (P < .01) but similar for toddlers age 12 to 18 months with stage 4 versus 4S pattern. Among 717 patients with stage 4S pattern, patients age 12 to 18 months had worse EFS than those age younger than 12 months (P < .01). MYCN, 11q, mitosis-karyorrhexis index (MKI), ploidy, and lactate dehydrogenase were independently statistically significant predictors of EFS and more highly predictive than age or metastatic pattern. MYCN, 11q, MKI, histology, and 1p were combined in a survival tree for improved risk stratification.

CONCLUSION

Tumor biology is more critical than age or metastatic pattern for prognosis of patients age younger than 18 months with metastatic neuroblastoma and should be considered for risk stratification.

Role of positron emission tomography-computed tomography in staging and early chemotherapy response evaluation in children with neuroblastoma

BACKGROUND

To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome.

PATIENTS AND METHODS

Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial 18F-flourodeoxygl ucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent I-131 meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid tumors criteria. Response on PET-CT was assessed using percentage improvement in lesion to background SUV ratio, taking a value of 50% as cut-off. Final outcome based on follow-up ranging from 6 to 43 months (mean 18.8 months) served as reference.

RESULTS

All 17 patients showed increased FDG uptake at the primary site. Seven of the 17 patients (41.2%) showed metastasis. Lymph nodes were the most common site of metastatic disease followed by bone, bone marrow, lung and meninges. For response evaluation, change in the size of the primary tumor was noted in 11/17 (64.7%) patients on CT. Treatment response was noted in 12/17 patients (70.6%) on PET-CT. Eleven out of 17 (65%) patients showed response in both CT and PET-CT. Five out of 17 patients showed no response in both. Discordant findings on CT and PET were noted in one (5.9%) patient where PET showed response but no response was seen on CT. Two patients with initial response but with distant metastases expired during follow-up.

CONCLUSION

PET-CT has potential in the initial staging of NB. PET-CT also appears to be a good modality for response assessment in patients with moderate and high FDG uptake on the baseline scan. However, no significant beneficial effect was seen in patients with low baseline FDG uptake.

Targeting p53-null neuroblastomas through RLIP76

The search for p53-independent mechanism of cancer cell killing is highly relevant to pediatric neuroblastomas, where successful therapy is limited by its transformation into p53-mutant and a highly drug-resistant neoplasm. Our studies on the drug-resistant p53-mutant as compared with drug-resistant p53 wild-type neuroblastoma revealed a novel mechanism for resistance to apoptosis: a direct role of p53 in regulating the cellular concentration of proapoptotic alkenals by functioning as a specific and saturable allosteric inhibitor of the alkenal-glutathione conjugate transporter, RLIP76. The RLIP76-p53 complex was showed by both immunoprecipitation analyses of purified proteins and immunofluorescence analysis. Drug transport studies revealed that p53 inhibited both basal and PKCα-stimulated transport of glutathione conjugates of 4HNE (GSHNE) and doxorubicin. Drug resistance was significantly greater for p53-mutant as compared with p53 wild-type neuroblastoma cell lines, but both were susceptible to depletion of RLIP76 by antisense alone. In addition, inhibition of RLIP76 significantly enhanced the cytotoxicity of cisplatin. Taken together, these studies provide powerful evidence for a novel mechanism for drug and apoptosis resistance in p53-mutant neuroblastoma, based on a model of regulation of p53-induced apoptosis by RLIP76, where p53 is a saturable and specific allosteric inhibitor of RLIP76, and p53 loss results in overexpression of RLIP76; thus, in the absence of p53, the drug and glutathione-conjugate transport activities of RLIP76 are enhanced. Most importantly, our findings strongly indicate RLIP76 as a novel target for therapy of drug-resistant and p53-mutant neuroblastoma.

¹²³I-MIBG scintigraphy/SPECT versus ¹⁸F-FDG PET in paediatric neuroblastoma

PURPOSE

To analyse different uptake patterns in (123)I-MIBG scintigraphy/SPECT imaging and (18)F-FDG PET in paediatric neuroblastoma patients.

METHODS

We compared 23 (123)I-MIBG scintigraphy scans and 23 (18)F-FDG PET scans (mean interval 10 days) in 19 patients with a suspected neuroblastic tumour (16 neuroblastoma, 1 ganglioneuroblastoma, 1 ganglioneuroma and 1 opsomyoclonus syndrome). SPECT images of the abdomen or other tumour-affected regions were available in all patients. Indications for (18)F-FDG PET were a (123)I-MIBG-negative tumour, a discrepancy in (123)I-MIBG uptake compared to the morphological imaging or imaging results inconsistent with clinical findings. A lesion was found by (123)I-MIBG scintigraphy and/or (18)F-FDG PET and/or morphological imaging.

RESULTS

A total of 58 suspicious lesions (mean lesion diameter 3.8 cm) were evaluated and 18 were confirmed by histology and 40 by clinical follow-up. The sensitivities of (123)I-MIBG scintigraphy and (18)F-FDG PET were 50% and 78% and the specificities were 75% and 92%, respectively. False-positive results (three (123)I-MIBG scintigraphy, one (18)F-FDG PET) were due to physiological uptake or posttherapy changes. False-negative results (23 (123)I-MIBG scintigraphy, 10 (18)F-FDG PET) were due to low uptake and small lesion size. Combined (123)I-MIBG scintigraphy/(18)F-FDG PET imaging showed the highest sensitivity of 85%. In 34 lesions the (123)I-MIBG scintigraphy and morphological imaging findings were discrepant. (18)F-FDG PET correctly identified 32 of the discrepant findings. Two bone/bone marrow metastases were missed by (18)F-FDG PET.

CONCLUSION

(123)I-MIBG scintigraphy and (18)F-FDG PET showed noticeable differences in their uptake patterns. (18)F-FDG PET was more sensitive and specific for the detection of neuroblastoma lesions. Our findings suggest that a (18)F-FDG PET scan may be useful in the event of discrepant or inconclusive findings on (123)I-MIBG scintigraphy/SPECT and morphological imaging.

Clinical significance of interleukin (IL)-6 in cancer metastasis to bone: potential of anti-IL-6 therapies

Metastatic events to the bone occur frequently in numerous cancer types such as breast, prostate, lung, and renal carcinomas, melanoma, neuroblastoma, and multiple myeloma. Accumulating evidence suggests that the inflammatory cytokine interleukin (IL)-6 is frequently upregulated and is implicated in the ability of cancer cells to metastasize to bone. IL-6 is able to activate various cell signaling cascades that include the STAT (signal transducer and activator of transcription) pathway, the PI3K (phosphatidylinositol-3 kinase) pathway, and the MAPK (mitogen-activated protein kinase) pathway. Activation of these pathways may explain the ability of IL-6 to mediate various aspects of normal and pathogenic bone remodeling, inflammation, cell survival, proliferation, and pro-tumorigenic effects. This review article will discuss the role of IL-6: 1) in bone metabolism, 2) in cancer metastasis to bone, 3) in cancer prognosis, and 4) as potential therapies for metastatic bone cancer.

Guidelines for imaging and staging of neuroblastic tumors: consensus report from the International Neuroblastoma Risk Group Project

Neuroblastoma is an enigmatic disease entity; some tumors disappear spontaneously without any therapy, while others progress with a fatal outcome despite the implementation of maximal modern therapy. However, strong prognostic factors can accurately predict whether children have "good" or "bad" disease at diagnosis, and the clinical stage is currently the most significant and clinically relevant prognostic factor. Therefore, for an individual patient, proper staging is of paramount importance for risk assessment and selection of optimal treatment. In 2009, the International Neuroblastoma Risk Group (INRG) Project proposed a new staging system designed for tumor staging before any treatment, including surgery. Compared with the focus of the International Neuroblastoma Staging System, which is currently the most used, the focus has now shifted from surgicopathologic findings to imaging findings. The new INRG Staging System includes two stages of localized disease, which are dependent on whether image-defined risk factors (IDRFs) are or are not present. IDRFs are features detected with imaging at the time of diagnosis. The present consensus report was written by the INRG Imaging Committee to optimize imaging and staging and reduce interobserver variability. The rationales for using imaging methods (ultrasonography, magnetic resonance imaging, computed tomography, and scintigraphy), as well as technical guidelines, are described. Definitions of the terms recommended for assessing IDRFs are provided with examples. It is anticipated that the use of standardized nomenclature will contribute substantially to more uniform staging and thereby facilitate comparisons of clinical trials conducted in different parts of the world.

Detection of MYCN DNA in the cerebrospinal fluid for diagnosing isolated central nervous system relapse in neuroblastoma

We present the case of a 1-year-old female with stage-4 neuroblastoma with MYCN amplification; she was treated with five chemotherapy courses, resulting in normalization of elevated serum levels of tumor markers. Complete remission was achieved after allogeneic hematopoietic stem-cell transplantation with reduced-intensity conditioning. Nine months later, however, the tumor relapsed in the central nervous system (CNS). The serum and cerebrospinal fluid (CSF) levels of the tumor markers were normal, but the MYCN copy number was high only in the CSF DNA, suggesting an isolated CNS recurrence. The MYCN copy number in the CSF DNA was reflective of response to treatment.

Prognostic impact of MYCN, DDX1, TrkA, and TrkC gene transcripts expression in neuroblastoma

BACKGROUND

The aims of this study were to define the mRNA expression profiles of MYCN, DDX1, TrkA, and TrkC in biopsy tumor samples from 64 Brazilian patients with neuroblastomas of different risk stages and to correlate altered expression with prognostic values.

PROCEDURE

Patients were retrospectively classified into low- (n = 11), intermediate- (n = 18), and high-risk (n = 35) groups using standard criteria. The mRNA levels of the above genes were measured by quantitative real-time polymerase chain reaction. Univariate analyses were performed and survival curves were plotted by the Kaplan-Meier method.

RESULTS

Of the 64 patients, 53% were female and 62.5% were older than 18 months. The 5-year overall survival (OS) for the entire cohort was 40.3%, with inferior median OS in patients identified in the intermediate- and high-risk groups. A significant difference in OS with respect to TrkA mRNA expression was found for the high-risk group vs. either the low- or intermediate-risk groups (P < 0.01, log rank test). Within the intermediate-risk group, neuroblastoma patients with positive TrkA mRNA expression had better clinical outcomes than patients with no TrkA transcript expression (P = 0.004). Another difference in OS was only found between the intermediate- and high-risk groups (P < 0.027, log rank test). No significant correlation of mRNA expression and survival outcome could be detected for the MYCN, DDX1.

CONCLUSIONS

Positive expression of TrkA mRNA may be a clinically useful addition to the current risk classification system, allowing the identification of NB tumors with favorable prognosis.

Vorinostat increases expression of functional norepinephrine transporter in neuroblastoma in vitro and in vivo model systems

PURPOSE

Histone deacetylase (HDAC) inhibition causes transcriptional activation or repression of several genes that in turn can influence the biodistribution of other chemotherapeutic agents. Here, we hypothesize that the combination of vorinostat, a HDAC inhibitor, with (131)I-meta-iodobenzylguanidine (MIBG) would lead to preferential accumulation of the latter in neuroblastoma (NB) tumors via increased expression of the human norepinephrine transporter (NET).

EXPERIMENTAL DESIGN

In vitro and in vivo experiments examined the effect of vorinostat on the expression of NET, an uptake transporter for (131)I-MIBG. Human NB cell lines (Kelly and SH-SY-5Y) and NB1691-luc mouse xenografts were employed. The upregulated NET protein was characterized for its effect on (123)I-MIBG biodistribution.

RESULTS

Preincubation of NB cell lines, Kelly, and SH-SY-5Y, with vorinostat caused dose-dependent increases in NET mRNA and protein levels. Accompanying this was a corresponding dose-dependent increase in MIBG uptake in NB cell lines. Four- and 2.5-fold increases were observed in Kelly and SH-SY-5Y cells, respectively, pretreated with vorinostat in comparison to untreated cells. Similarly, NB xenografts, created by intravenous tail vein injection of NB1691-luc, and harvested from nude mice livers treated with vorinostat (150 mg/kg i.p.) showed substantial increases in NET protein expression. Maximal effect of vorinostat pretreatment in NB xenografts on (123)I-MIBG biodistribution was observed in tumors that exhibited enhanced uptake in vorinostat-treated [0.062 ± 0.011 μCi/(mg tissue-dose injected)] vs. -untreated mice [0.022 ± 0.003 μCi/(mg tissue-dose injected); P < 0.05].

CONCLUSIONS

The results of our study provide preclinical evidence that vorinostat treatment can enhance NB therapy with (131)I-MIBG.

Neuroblastoma with primary pleural involvement: an unusual presentation

Neuroblastomas are the most common neoplasms in infants. We report a 10-month-old who was diagnosed with thoracic neuroblastoma, with imaging showing unusual primary extension into the pleura, which might have an adverse staging and prognostic significance.

Parotid metastasis from adrenal neuroblastoma

Neuroblastomas are the most common extracranial solid malignancy in children. In contrast, salivary gland tumors are uncommon in children, accounting for only 1% of all pediatric neoplasms. Parotid metastases are rare; only two cases of parotid metastases from neuroblastomas have been reported with an emphasis on the pathology. We present a case of a parotid metastasis from a neuroblastoma with in-depth description and discussion of its ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) appearances.

Retroperitoneal neoplasms within the perirenal space in infants and children: differentiation of renal and non-renal origin in enhanced CT images

PURPOSE

To retrospectively demonstrate the specific CT findings of retroperitoneal neoplasms to diagnosis and differential diagnosis renal and non-renal tumors within the perirenal space in infants and children.

MATERIALS AND METHODS

We retrospectively reviewed the clinical data and CT images of 42 consecutive patients with surgically and pathologically proven retroperitoneal neoplasms within the perirenal space. The patients were divided into renal tumors group (n=16) and non-renal tumors group (n=26). The former included nephroblastoma (n=15) and renal lymphoma (n=1), while the latter included neuroblastoma (n=12), retroperitoneal teratoma (n=6), adrenal ganglioneuroma (n=4), retroperitoneal lymphoma (n=2), ectopic pheochromocytoma (n=1) and adrenal cortical carcinoma (n=1). The clinical information of these patients and the major CT imaging findings which were related to lesion localization in the two groups were compared and statistically analyzed using Pearson Chi-Square Test and Risk Estimate.

RESULTS

The mean diameter of tumors was 9.82±6.13 cm (n=42 range: 2.3-3 2cm). The demographic data and chief clinical symptoms between the renal tumor group and the non-renal tumor group showed no statistically significant differences (P>0.05). 30.8% (8/26) of non-renal tumor patients presented elevated urinary vanillylmandelic acid (VMA) level, while no patient showed elevated VMA in renal tumor group (P<0.05). Some CT imaging signs of the renal tumors including "crescent sign" (odds ratio, OR=52), "beak sign" (OR=84), "embedded organ sign" (OR=84), and "prominent feeding artery sign" (OR=36) showed significantly higher incidence when compared to the non-renal tumors (P<0.001). The sign of "renal displacement and renal axis rotation" (OR=0.059) was seen in 23 of 26 (88.5%) non-renal tumors, but in only 5 of 16 (31.3%) renal tumors (P<0.001). The sign of "extra-renal central plane of tumor" (OR=0.038) was displayed in 24 of 26 (92.3%) non-renal tumors, but in only 5 of 16 (31.3%) renal tumors (P<0.001). The CT findings such as "pseudocapsule" (OR=38.5), "necrosis and cystic change" (OR=11.2), "vascularity" (OR=16.867), "distant metastasis" (OR=5.96), and "inferior vena cava tumor thrombus" which were thought to be characteristic of renal tumors were observed with significant higher incidence in renal tumors group than in the non-renal tumors group (P<0.05); while CT signs of "irregular mass" (OR=0.045) and "intratumoral calcifications" (OR=0.065) were observed with lower incidence in renal tumors group than in the non-renal tumors group (P<0.05).

CONCLUSION

The "crescent sign", "beak sign", "embedded kidney sign" and "renal arteries feeding" are the most specific CT signs suggestive of renal tumors and distinguish them from non-renal origin tumors within the perirenal space. Other CT signs, such as "pseudocapsule", "hypervascular tumors" and "Inferior vena cava tumor thrombus", when present, tumors of renal origin are strongly suggested. On the other hand, CT signs of "irregular mass", "intratumoral calcifications", and associated elevated urinary vanillylmandelic acid strongly suggest the non-renal tumors.

Whole neuraxis irradiation to address central nervous system relapse in high-risk neuroblastoma

BACKGROUND

As systemic control of high-risk neuroblastoma (NB) has improved, relapse in the central nervous system (CNS) is an increasingly recognized entity that carries a grim prognosis. This study describes the use of craniospinal irradiation (CSI) for CNS relapse and compares outcomes to patients who received focal radiotherapy (RT).

METHODS

A retrospective query identified 29 children with NB treated at Memorial Sloan-Kettering Cancer Center since 1987 who received RT for CNS relapse. At CNS relapse, 16 patients received CSI (median dose, 2160cGy), and 13 received focal RT. Of those who underwent CSI, 14 (88%) received intra-Ommaya (IO) radioimmunotherapy (RIT); one patient in the non-CSI cohort received IO-RIT.

RESULTS

Patient characteristics were similar between the groups. Time to CNS relapse was 20 and 17 months for the CSI and non-CSI cohorts, respectively. At a median follow-up of 28 months, 12 patients (75%) in the CSI group are alive without CNS disease, including two patients with isolated skeletal relapse. Another patient is alive without disease after a brain relapse was retreated with RT. Three patients died-one with no NB at autopsy, one of CNS disease, and one of systemic disease. The two patients who died of NB did not receive IO-RIT. All 13 patients in the non-CSI cohort died at a median of 8.8 months.

CONCLUSIONS

Low-dose CSI together with IO-RIT provides durable CNS remissions and improved survival compared with focal RT and conventional therapies. Further evaluation of long-term NB survivors after CSI is warranted to determine the treatment consequences for this cohort.

Neurological complications of neuroblastic tumors: experience of a single center

AIM

This study aims to evaluate the prevalence and clinical characteristics of neurological complications in patients with newly diagnosed neuroblastic tumors (NT).

PATIENTS AND METHOD

Hospital file search was performed in patients with NT, and neurological complications, clinical, and treatment features were analyzed.

RESULTS

Out of 523 patients with NT, 19 patients had Horner's syndrome, 9 patients had opsoclonus-myoclonus-ataxia syndrome (OMA), 11 patients had central nervous system (CNS) involvement, and 49 patients had spinal cord compression (SCC) at diagnosis. During follow-up, seven more patients had CNS metastases. Survival rates were poor in patients with CNS involvement; all died at a median of 7.9 months after diagnosis. The neurological symptoms and signs of patients with SCC were mild, moderate, and severe in 13, 9, and 22 patients, respectively. Sphincter deficiency and sensory loss were diagnosed in 52.3% and 43.2% of patients. The neurological deficits of 11/17 patients who had symptoms less than 4 weeks were completely resolved or improved. The incidence of sequelae after laminectomy, radiotherapy, and chemotherapy were 46.2%, 66.6%, and 13.6%, respectively.

CONCLUSION

The prevalence rates of Horner's syndrome, OMA, CNS metastasis, and SCC were found to be 3.6%, 1.8%, 2.2%, and 9.4%, respectively. Metastasis to the CNS indicated a very poor prognosis. No differences in neurological improvement in patients with SCC were found between those treated with radiotherapy, laminectomy, or chemotherapy alone, but laminectomy and radiotherapy caused significant late sequelae. Early diagnosis and proper management is critical to avoid long-term sequelae in patients with SCC.

Compartmental intrathecal radioimmunotherapy: results for treatment for metastatic CNS neuroblastoma

Innovation in the management of brain metastases is needed. We evaluated the addition of compartmental intrathecal antibody-based radioimmunotherapy (cRIT) in patients with recurrent metastatic central nervous system (CNS) neuroblastoma following surgery, craniospinal irradiation, and chemotherapy. Twenty one patients treated for recurrent neuroblastoma metastatic to the CNS, received a cRIT-containing salvage regimen incorporating intrathecal (131)I-monoclonal antibodies (MoAbs) targeting GD2 or B7H3 following surgery and radiation. Most patients also received outpatient craniospinal irradiation, 3F8/GMCSF immunotherapy, 13-cis-retinoic acid and oral temozolomide for systemic control. Seventeen of 21 cRIT-salvage patients are alive 7-74 months (median 33 months) since CNS relapse, with all 17 remaining free of CNS neuroblastoma. One patient died of infection at 22 months with no evidence of disease at autopsy, and one of lung and bone marrow metastases at 15 months, and one of progressive bone marrow disease at 30 months. The cRIT-salvage regimen was well tolerated, notable for myelosuppression minimized by stem cell support (n = 5), and biochemical hypothyroidism (n = 5). One patient with a 7-year history of metastatic neuroblastoma is in remission from MLL-associated secondary leukemia. This is significantly improved to published results with non-cRIT based where relapsed CNS NB has a median time to death of approximately 6 months. The cRIT-salvage regimen for CNS metastases was well tolerated by young patients, despite their prior history of intensive cytotoxic therapies. It has the potential to increase survival with better than expected quality of life.

Comparison of iodine-123 metaiodobenzylguanidine (MIBG) scan and [18F]fluorodeoxyglucose positron emission tomography to evaluate response after iodine-131 MIBG therapy for relapsed neuroblastoma

PURPOSE

Children with relapsed neuroblastoma have poor survival. It is crucial to have a reliable method for evaluating functional response to new therapies. In this study, we compared two functional imaging modalities for neuroblastoma: metaiodobenzylguanidine (MIBG) scan for uptake by the norepinephrine transporter and [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake for glucose metabolic activity.

PATIENTS AND METHODS

Patients enrolled onto a phase I study of sequential infusion of iodine-131 ((131)I) MIBG (NANT-2000-01) were eligible for inclusion if they had concomitant FDG-PET and MIBG scans. (131)I-MIBG therapy was administered on days 0 and 14. For each patient, we compared all lesions identified on concomitant FDG-PET and MIBG scans and gave scans a semiquantitative score.

RESULTS

The overall concordance of positive lesions on concomitant MIBG and FDG-PET scans was 39.6% when examining the 139 unique anatomic lesions. MIBG imaging was significantly more sensitive than FDG-PET overall and for the detection of bone lesions (P < .001). There was a trend for increased sensitivity of FDG-PET for detection of soft tissue lesions. Both modalities showed similar improvement in number of lesions identified from day 0 to day 56 scan and in semiquantitative scores that correlated with overall response. FDG-PET scans became completely negative more often than MIBG scans after treatment.

CONCLUSION

MIBG scan is significantly more sensitive for individual lesion detection in relapsed neuroblastoma than FDG-PET, though FDG-PET can sometimes play a complementary role, particularly in soft tissue lesions. Complete response by FDG-PET metabolic evaluation did not always correlate with complete response by MIBG uptake.

Neuroimaging patterns of central nervous system metastases in neuroblastoma: report of 2 recent cases and literature review

The authors describe imaging patterns of intracranial metastases in 2 children with grade 4 neuroblastoma. Central nervous system metastases from neuroblastoma are extremely rare and may involve the cerebral parenchyma, leptomeninges, or dura. Cerebral parenchymal metastases can be cystic with mural nodules or solid with hemorrhagic elements. The first patient in our study had multiple cystic parenchymal metastases with calcific mural nodules, while the second patient developed solid hemorrhagic parenchymal metastatic lesions along with extensive leptomeningeal and dural deposits. Central nervous system involvement in both patients occurred within a time span ranging from 12 to 14 months from the time of initial diagnosis.

Bin1 is linked to metastatic potential and chemosensitivity in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is the most common extracranial solid tumor in children. At the time of diagnosis, the tumor has metastasized in as many as 7 of 10 cases, and survival in high-risk patients remains poor. Accurate classification of high-risk patients is very important since this determines treatment plan, and although a consensus risk classification system has been established for NB, it contains few specific molecular markers that account for aggressive nature and metastatic potential of the tumor. Bin1 expression is reduced in breast, NB, and other cancer types and the reduction correlates with high-risk clinical features. Here we hypothesize that Bin1 has an inhibitory role in metastasis, and therefore decrease in its expression may be a marker of high-risk NB.

PROCEDURE

Initially, breast cancer and NB cell lines derived from metastasis were examined for Bin1 expression. Then, a stable Bin1-overexpressing NB cell line was created and evaluated for in vitro metastatic behaviors using anoikis, invasion, and migration assays, and chemoresponsiveness using MTT assay.

RESULTS

Reduced Bin1 was detected in all cancer cell lines examined, and forced Bin1 overexpression increased NB cell anoikis and enhanced the cell killing by doxorubicin. However, Bin1 overexpression did not significantly affect cell invasion, motility, or proliferation.

CONCLUSIONS

Bin1 appears to function as a metastasis suppressor and chemosensitizer in NB, and resistance to anoikis may be an important metastatic mechanism. Thus, Bin1 expression status could serve as a marker for metastatic potential and chemosensitivity thereby allowing for more accurate classifications of high-risk NB patients.

Prognostic significance of interleukin-6 single nucleotide polymorphism genotypes in neuroblastoma: rs1800795 (promoter) and rs8192284 (receptor)

PURPOSE

Neuroblastoma is a childhood cancer of the sympathetic nervous system and many patients present with high-risk disease. Risk stratification, based on pathology and tumor-derived biomarkers, has improved prediction of clinical outcomes, but overall survival (OS) rates remain unfavorable and new therapeutic targets are needed. Some studies suggest a link between interleukin (IL)-6 and more aggressive behavior in neuroblastoma tumor cells. Therefore, we examined the impact of two IL-6 single nucleotide polymorphisms (SNP) on neuroblastoma disease progression.

EXPERIMENTAL DESIGN

DNA samples from 96 high-risk neuroblastoma patients were screened for two SNP that are known to regulate the serum levels of IL-6 and the soluble IL-6 receptor, rs1800795 and rs8192284, respectively. The genotype for each SNP was determined in a blinded fashion and independent statistical analysis was done to determine SNP-related event-free survival (EFS) and OS rates.

RESULTS

The rs1800795 IL-6 promoter SNP is an independent prognostic factor for EFS and OS in high-risk neuroblastoma patients. In contrast, the rs8192284 IL-6 receptor SNP revealed no prognostic value.

CONCLUSIONS

The rs1800795 SNP [-174 IL-6 (G > C)] represents a novel and independent prognostic marker for both EFS and OS in high-risk neuroblastoma. Because the rs1800795 SNP [-174 IL-6 (G > C)] has been shown to correlate with production of IL-6, this cytokine may represent a target for development of new therapies in neuroblastoma.

Hyperfractionated low-dose (21 Gy) radiotherapy for cranial skeletal metastases in patients with high-risk neuroblastoma

PURPOSE

To present a large experience (73 patients) using a standard radiotherapy (RT) protocol to prevent relapse in cranial sites where measurable metastatic neuroblastoma (NB), an adverse prognostic marker, is common.

METHODS AND MATERIALS

High-risk NB patients with measurable cranial disease at diagnosis or residual cranial disease after induction therapy had those sites irradiated with hyperfractionated 21 Gy; a brain-sparing technique was used for an extensive field. The patients were grouped according to the response to systemic therapy. Thus, when irradiated, Group 1 patients were in complete remission and Group 2 patients had primary refractory disease. Follow-up was from the start of cranial RT.

RESULTS

At 3 years, the 39 Group 1 patients had a progression-free survival rate of 51%; control of cranial disease was 79%. Two relapses involved irradiated cranial sites. Two other patients relapsed in the irradiated cranial sites 6 and 12 months after a systemic relapse. At 3 years, the 34 Group 2 patients had a progression-free survival rate of 33%; control of cranial disease was 52%. Group 2 included 19 patients who had residual cranial (with or without extracranial) disease. The cranial sites showed major (n = 13), minor (n = 2), or no response (n = 4) to RT. Five patients had progression in the cranial RT field at 10-27 months. Group 2 also included 15 patients who had persistent NB in extracranial, but not cranial, sites. Of these 15 patients, 2 relapsed in the irradiated cranial sites and elsewhere at 8 and 14 months. Cranial RT was well tolerated, with no Grade 2 or greater toxicity.

CONCLUSION

Hyperfractionated 21-Gy cranial RT might help control NB and is feasible without significant toxicity in children.

Neuroblastoma cell death is induced by inorganic arsenic trioxide (As(2)O(3)) and inhibited by a normal human bone marrow cell-derived factor

Three phenotypically distinct cell types are present in human neuroblastomas (NB) and NB cell lines: I-type stem cells, N-type neuroblastic precursors, and S-type Schwannian/melanoblastic precursors. The stimulation of human N-type neuroblastoma cell proliferation by normal human bone marrow monocytic cell conditioned medium (BMCM) has been demonstrated in vitro, a finding consistent with the high frequency of bone marrow (BM) metastases in patients with advanced NB. Inorganic arsenic trioxide (As₂O₃), already clinically approved for the treatment of several hematological malignancies, is currently under investigation for NB. Recent studies show that As₂O₃ induces apoptosis in NB cells. We examined the impact of BMCM on growth and survival of As₂O₃-treated NB cell lines, to evaluate the response of cultured NB cell variants to regulatory agents. We studied the effect of BMCM on survival and clonogenic growth of eleven As₂O₃-treated NB cell lines grown in sparsely seeded, non-adherent, semi-solid cultures. As₂O₃ had a strong inhibitory effect on survival of all tested NB cell lines. BMCM augmented cell growth and survival and reversed the inhibitory action of As₂O₃ in all tested cell lines, but most strongly in N-type cells_. While As₂O₃ effectively reduced survival of all tested NB cell lines, BMCM effectively impacted its inhibitory action. Better understanding of micro-environmental regulators affecting human NB tumor cell growth and survival may be seminal to the development of therapeutic strategies and clinically effective agents for this condition.

Regression of orthotopic neuroblastoma in mice by targeting the endothelial and tumor cell compartments

BACKGROUND

High-risk neuroblastoma has an overall five-year survival of less than 40%, indicating a need for new treatment strategies such as angiogenesis inhibition. Recent studies have shown that chemotherapeutic drugs can inhibit angiogenesis if administered in a continuous schedule. The aim of this study was primarily to characterize tumor spread in an orthotopic, metastatic model for aggressive, MYCN-amplified neuroblastoma and secondarily to study the effects of daily administration of the chemotherapeutic agent CHS 828 on tumor angiogenesis, tumor growth, and spread.

METHODS

MYCN-amplified human neuroblastoma cells (IMR-32, 2 x 10(6)) were injected into the left adrenal gland in SCID mice through a flank incision. Nine weeks later, a new laparotomy was performed to confirm tumor establishment and to estimate tumor volume. Animals were randomized to either treatment with CHS 828 (20 mg/kg/day; p.o.) or vehicle control. Differences between groups in tumor volume were analyzed by Mann-Whitney U test and in metastatic spread using Fisher's exact test. Differences with p < 0.05 were considered statistically significant.

RESULTS

The orthotopic model resembled clinical neuroblastoma in respect to tumor site, growth and spread. Treatment with CHS 828 resulted in tumor regression (p < 0.001) and reduction in viable tumor fraction (p < 0.001) and metastatic spread (p < 0.05) in correlation with reduced plasma levels of the putative tumor marker chromogranin A (p < 0.001). These effects were due to increased tumor cell death and reduced angiogenesis. No treatment-related toxicities were observed.

CONCLUSION

The metastatic animal model in this study resembled clinical neuroblastoma and is therefore clinically relevant for examining new treatment strategies for this malignancy. Our results indicate that daily scheduling of CHS 828 may be beneficial in treating patients with high-risk neuroblastoma.

Poor Survival for Infants WithMYCN-Amplified Metastatic Neuroblastoma Despite Intensified Treatment: The International Society of Paediatric Oncology European Neuroblastoma Experience

Purpose

To report the results of a prospective, nonrandomized European study on infants with neuroblastoma and MYCN gene amplification.

Patients and Methods

Infants with neuroblastoma (stage 2, 3, 4, and 4s) and MYCN gene amplification who were diagnosed between 1999 and 2004 were eligible for enrollment onto the study. After diagnosis, staging, and mandatory biologic studies, induction chemotherapy (IC) with conventional drugs was administered, followed by delayed surgery, megatherapy (busulfan-melphalan as a conditioning regimen), and local radiotherapy.

Results

Of the 46 infants enrolled onto the study, 35 infants were eligible; of these 35 infants, 97% had metastatic spread (24 infants had stage 4, and 10 infants had stage 4s). Two-year overall survival (OS) was 30% (SE, 0.08), with median survival time of 12 months, and 23 deaths due to disease. Two-year, event-free survival (EFS) was 29% (SE, 0.07). The treatment was well tolerated with no deaths as a result of toxicity or severe toxicity. Despite protocol adherence, 30% of the patients who were assessable for response to IC experienced disease progression or did not respond. Stage and high lactate dehydrogenase reached significance in the univariate analysis (P = .028 and .039, respectively for OS; and P = .05 and .031 respectively, for EFS). Ten of 16 patients who received megatherapy are still alive.

Conclusion

Although treatment was well tolerated, survival was poor and our IC failed to achieve a satisfactory response in 30% of our patients. New therapeutic approaches and more intense world-wide collaboration are needed to achieve a cure in this population.

Sensitivity of surveillance studies for detecting asymptomatic and unsuspected relapse of high-risk neuroblastoma

PURPOSE

Relapse-free survival (RFS) is a powerful measure of treatment efficacy. We describe the sensitivity of standard surveillance studies for detecting relapse of neuroblastoma (NB).

PATIENTS AND METHODS

The patients were in complete/very good partial remission of high-risk NB; routine monitoring revealed asymptomatic and, therefore, unsuspected relapses in 113 patients, whereas 41 patients had symptoms prompting urgent evaluations. Assessments every 2 to 4 months included computed tomography, iodine-131-metaiodobenzylguanidine (131)I-MIBG; through November 1999) or iodine-123-metaiodobenzylguanidine ((123)I-MIBG) scan, urine catecholamines, and bone marrow (BM) histology. Bone scan was routine through 2002.

RESULTS

(123)I-MIBG scan was the most reliable study for revealing unsuspected relapse; it had an 82% detection rate, which was superior to the rates with (131)I-MIBG scan (64%; P = .1), bone scan (36%; P < .001), and BM histology (34%; P < .001). Among asymptomatic patients, (123)I-MIBG scan was the sole positive study indicating relapse in 25 (27%) of 91 patients compared with one (4.5%) of 22 patients for (131)I-MIBG scan (P = .04) and 0% to 6% of patients for each of the other studies (P < .001). Patients whose monitoring included (123)I-MIBG scan were significantly less likely than patients monitored by (131)I-MIBG scan to have an extensive osteomedullary relapse and had a significantly longer survival from relapse (P < .001) and from diagnosis (P = .002). They also had significantly longer survival than patients with symptomatic relapses (P = .002).

CONCLUSION

(123)I-MIBG scan is essential for valid estimation of the duration of RFS of patients with high-risk NB. Without monitoring that includes (123)I-MIBG scan, caution should be used when comparing RFS between institutions and protocols.

Interleukin-6 in the bone marrow microenvironment promotes the growth and survival of neuroblastoma cells

Neuroblastoma, the second most common solid tumor in children, frequently metastasizes to the bone marrow and the bone. Neuroblastoma cells present in the bone marrow stimulate the expression of interleukin-6 (IL-6) by bone marrow stromal cells (BMSC) to activate osteoclasts. Here we have examined whether stromal-derived IL-6 also has a paracrine effect on neuroblastoma cells. An analysis of the expression of IL-6 and its receptor, IL-6R, in 11 neuroblastoma cell lines indicated the expression of IL-6 in 4 cell lines and of IL-6R in 9 cell lines. Treatment of IL-6R-positive cells with recombinant human IL-6 resulted in signal transducer and activator of transcription-3 and extracellular signal-regulated kinase-1/2 activation. Culturing IL-6R-positive neuroblastoma cells in the presence of BMSC or recombinant human IL-6 increased proliferation and protected tumor cells from etoposide-induced apoptosis, whereas it had no effect on IL-6R-negative tumor cells. In vivo, neuroblastoma tumors grew faster in the presence of a paracrine source of IL-6. IL-6 induced the expression of cyclooxygenase-2 in neuroblastoma cells with concomitant release of prostaglandin-E2, which increased the expression of IL-6 by BMSC. Supporting a role for stromal-derived IL-6 in patients with neuroblastoma bone metastasis, we observed elevated levels of IL-6 in the serum and bone marrow of 16 patients with neuroblastoma bone metastasis and in BMSC derived from these patients. Altogether, the data indicate that stromal-derived IL-6 contributes to the formation of a bone marrow microenvironment favorable to the progression of metastatic neuroblastoma.

Lung metastases in neuroblastoma at initial diagnosis: A report from the International Neuroblastoma Risk Group (INRG) project

BACKGROUND

Neuroblastoma is the most common extracranial pediatric solid cancer. Lung metastasis is rarely detected in children with newly diagnosed neuroblastoma. We aimed to describe the incidence, clinical characteristics, and outcome of patients with lung metastasis at initial diagnosis using a large international database.

PROCEDURE

The subset of patients from the International Neuroblastoma Risk Group database with INSS stage 4 neuroblastoma and known data regarding lung metastasis at diagnosis was selected for analysis. Clinical and biological characteristics were compared between patients with and without lung metastasis. Survival for patients with and without lung metastasis was estimated by Kaplan-Meier methods. Cox proportional hazards methods were used to determine the independent prognostic value of lung metastasis at diagnosis.

RESULTS

Of the 2,808 patients with INSS stage 4 neuroblastoma diagnosed between 1990 and 2002, 100 patients (3.6%) were reported to have lung metastasis at diagnosis. Lung metastasis was more common among patients with MYCN amplified tumors, adrenal primary tumors, or elevated lactate dehydrogenase (LDH) levels (P < 0.02 in each case). Five-year overall survival +/- standard error for patients with lung metastasis was 34.5% +/- 6.8% compared to 44.7% +/- 1.3% for patients without lung metastasis (P = 0.0002). However, in multivariable analysis, the presence of lung metastasis was not independently predictive of outcome.

CONCLUSIONS

Lung metastasis at initial diagnosis of neuroblastoma is associated with MYCN amplification and elevated LDH levels. Although lung metastasis at diagnosis was not independently predictive of outcome in this analysis, it remains a useful prognostic marker of unfavorable outcome.

Cutaneous mimickers of child abuse: a primer for pediatricians

The annual incidence of child abuse was estimated to be 2.8 million by the national incidence study conducted in the USA in 1993, which is a two-fold increase compared to 1986. Awareness of child abuse has been increasing since the 1960s. Although most victims of child abuse present with cutaneous lesions, many genuine skin diseases may appear as non-accidental injuries which, if not recognized, may lead to misdiagnosis of child abuse. Here, we review the most common cutaneous mimickers of child abuse in order to increase awareness of these disorders and reduce erroneous diagnosis of child abuse.

Radiolabeled metaiodobenzylguanidine for the treatment of neuroblastoma

INTRODUCTION

Neuroblastoma is the most common pediatric extracranial solid cancer. This tumor is characterized by metaiodobenzylguanidine (MIBG) avidity in 90% of cases, prompting the use of radiolabeled MIBG for targeted radiotherapy in these tumors.

METHODS

The available English language literature was reviewed for original research investigating in vitro, in vivo and clinical applications of radiolabeled MIBG for neuroblastoma.

RESULTS

MIBG is actively transported into neuroblastoma cells by the norepinephrine transporter. Preclinical studies demonstrate substantial activity of radiolabeled MIBG in neuroblastoma models, with (131)I-MIBG showing enhanced activity in larger tumors compared to (125)I-MIBG. Clinical studies of (131)I-MIBG in patients with relapsed or refractory neuroblastoma have identified myelosuppression as the main dose-limiting toxicity, necessitating stem cell reinfusion at higher doses. Most studies report a response rate of 30-40% with (131)I-MIBG in this population. More recent studies have focused on the use of (131)I-MIBG in combination with chemotherapy or myeloablative regimens.

CONCLUSIONS

(131)I-MIBG is an active agent for the treatment of patients with neuroblastoma. Future studies will need to define the optimal role of this targeted radiopharmaceutical in the therapy of this disease.