Disseminated neuroblastoma in children older than one year at diagnosis: comparable results with three consecutive high-dose protocols adopted by the Italian Co-Operative Group for Neuroblastoma

Iodine-131-metaiodobenzylguanidine as initial induction therapy in stage 4 neuroblastoma patients over 1 year of age

PURPOSE

To determine the response to radionuclide targeted therapy with I-131-metaiodobenzylguanidine ((131)I-MIBG) as induction therapy in high-risk neuroblastoma patients.

PATIENTS AND METHODS

The protocol dictated at least two cycles of (131)I-MIBG with a fixed dose of 7.4 and 3.7 GBq, respectively, followed by surgery, if feasible, or followed by neoadjuvant chemotherapy and surgery. This was followed by consolidation with four courses of chemotherapy myeloablative chemotherapy and autologous stem-cell transplantation (ASCT). Consolidation therapy with 13-cis-retinoic acid was given for 6 months.

RESULTS

Of 44 consecutive patients, 41 were evaluable after two courses of (131)I-MIBG. The objective response rate at this point was 66%. In 24 patients, (131)I-MIBG was continued as pre-operative induction treatment. Seventeen patients required additional chemotherapy before surgery. After pre-operative therapy and surgery, the overall response rate was 73%.

CONCLUSION

First line (131)I-MIBG-targeted therapy is a valuable tool in the treatment of MIBG-positive high-risk neuroblastoma patients.

The novel melphalan prodrug J1 inhibits neuroblastoma growth in vitro and in vivo

Neuroblastoma is the most common extracranial solid tumor of childhood. The activity of J1 (l-melphalanyl-p-l-fluorophenylalanine ethyl ester), an enzymatically activated melphalan prodrug, was evaluated in neuroblastoma models in vitro and in vivo. Seven neuroblastoma cell lines with various levels of drug resistance were screened for cytotoxicity of J1 alone or in combination with standard cytotoxic drugs, using a fluorometric cytotoxicity assay. J1 displayed high cytotoxic activity in vitro against all neuroblastoma cell lines, with IC(50) values in the submicromolar range, significantly more potent than melphalan. The cytotoxicity of J1, but not melphalan, could be significantly inhibited by the aminopeptidase inhibitor bestatin. J1 induced caspase-3 cleavage and apoptotic morphology, had additive effects in combination with doxorubicin, cyclophosphamide, carboplatin, and vincristine, and synergistically killed otherwise drug-resistant cells when combined with etoposide. Athymic rats and mice carrying neuroblastoma xenografts [SH-SY5Y, SK-N-BE(2)] were treated with equimolar doses of melphalan, J1, or no drug, and effects on tumor growth and tissue morphology were analyzed. Tumor growth in vivo was significantly inhibited by J1 compared with untreated controls. Compared with melphalan, J1 more effectively inhibited the growth of mice with SH-SY5Y xenografts, was associated with higher caspase-3 activation, fewer proliferating tumor cells, and significantly decreased mean vascular density. In conclusion, the melphalan prodrug J1 is highly active in models of neuroblastoma in vitro and in vivo, encouraging further clinical development in this patient group.

Incidence of bacteremias and invasive mycoses in children with high risk neuroblastoma

BACKGROUND

Information on the incidence of infectious complications during for treatment for high risk neuroblastoma (HR-NB) is limited. Bacteremias and invasive mycoses may be considered surrogate markers of the infection burden.

PATIENTS AND METHODS

Data on bacteremias and invasive mycoses occurring during 3 consecutive protocols for front line (NB-89; NB-92; NB-97) or salvage therapy (TVD) for HR-NB were reviewed. The cumulative risk of developing a first episode and the rate of infections during the entire length of each protocol were evaluated.

RESULTS

Front line protocols were given to 80 patients for a total of 22,070 days at risk; salvage treatment was given to 24 children for 2,909 days at risk. During front line therapy 41 infectious episodes were diagnosed in 29 (36%) patients, for a 45% cumulative risk and an infection rate (IR) of 0.19/100 patient-days-at risk. Salvage therapy determined five infectious episodes in four (17%) patients, with a 39% cumulative risk, and an IR of 0.17. The IR during the phase of high dose chemotherapy with hematopoietic stem cell rescue (megatherapy) included in the three front line protocols decreased over time (1.54 in NB-89; 0.52 in NB-92 and 0.0 in NB 97; P = 0.001), possibly because of the use of less aggressive conditioning regimens, without radiotherapy.

CONCLUSIONS

The IRs of protocols for HR-NB did not change over time. The megatherapy-related phases are those at highest risk.

Long-term outcomes in children with high-risk neuroblastoma treated with autologous stem cell transplantation

We retrospectively analysed the outcomes of children transplanted for high-risk neuroblastoma (NB) at a single institution predominantly transplanted with total body irradiation and chemotherapy. The aims of this study were to determine the prognostic impact of clinical and biological features and to document long-term health outcomes. Forty patients were transplanted with a single unpurged autograft. Fourteen patients died from disease progression and two from late complications of treatment. Twenty-three patients are alive at a median of 4.6 years from diagnosis. Kaplan-Meier estimates of overall survival at 2, 5 and 10 years are 76+/-7.0, 60.2+/-8.4 and 54.7+/-9.3% following transplant. Response to induction therapy was significantly associated with survival (P<0.01). Long-term complications included growth (100%) and pubertal failure (83%), hearing impairment (73%), orthopaedic complications (63%), renal impairment (47%) and thyroid abnormalities (36%). Intrinsic and acquired resistance to chemotherapy remains the major obstacle to improving outcomes in high-risk NB. Although patients with chemo-sensitive disease are less likely to experience a relapse, substantial therapy-related toxicities result in poor long-term health outcomes for survivors.

Combined Therapeutic Effects of Vinblastine and Rapamycin on Human Neuroblastoma Growth, Apoptosis, and Angiogenesis

Purpose: Vinblastine and rapamycin displayed synergistic inhibition of human neuroblastoma-related angiogenesis. Here, we studied the antitumor activity of vinblastine and rapamycin against human neuroblastoma.

Experimental Design: Cell proliferation, cell cycle progression, and apoptosis were evaluated by measuring 3H-thymidine incorporation, bromodeoxyuridine uptake, and phosphatidylserine exposure, respectively. The in vivo sensitivity of neuroblastoma cells to vinblastine and rapamycin was determined in orthotopic neuroblastoma-engrafted mice. Angiogenesis was assessed by the chick embryo chorioallantoic membrane assay.

Results: Each compound alone was able to induce a dose-dependent significant inhibition of cell proliferation, with a dramatically enhanced antiproliferative effect for the drugs used in combination. A marked G2-M cell cycle arrest with a nearly complete depletion of S phase was associated. The combined treatment triggered an increased apoptosis compared with either drug tested alone. A significant inhibition of tumor growth and microvessel area was obtained in neuroblastoma-bearing mice when treated with vinblastine or rapamycin alone, and a more dramatic effect with the combined treatment, compared with control mice. The therapeutic effectiveness, expressed as increased life span, was statistically improved by the combined therapy, compared with mice treated with either drug tested separately. Histologic evaluation of primary tumors showed that the combined treatment inhibited proliferation and angiogenesis and induced apoptosis. Combined treatment of neuroblastoma cells and neuroblastoma-bearing mice with vinblastine and rapamycin induced the down-modulation of both vascular endothelial growth factor production and vascular endothelial growth factor receptor 2 expression. In the chorioallantoic membrane assay, angiogenesis induced by human neuroblastoma biopsy specimens was significantly inhibited by vinblastine and rapamycin.

Conclusions: These results may be relevant to design new therapeutic strategies against neuroblastoma.

Neuroblastoma

The clinical hallmark of neuroblastoma is heterogeneity, with the likelihood of cure varying widely according to age at diagnosis, extent of disease, and tumour biology. A subset of tumours will undergo spontaneous regression while others show relentless progression. Around half of all cases are currently classified as high-risk for disease relapse, with overall survival rates less than 40% despite intensive multimodal therapy. This Seminar focuses on recent advances in our understanding of the biology of this complex paediatric solid tumour. We outline plans for the development of a uniform International Neuroblastoma Risk Group (INRG) classification system, and summarise strategies for risk-based therapies. We also update readers on new discoveries related to the underlying molecular pathogenesis of this tumour, with special emphasis on advances that are translatable to the clinic. Finally, we discuss new approaches to treatment, including recently discovered molecular targets that might provide more effective treatment strategies with the potential for less toxicity.

Phase II study of temozolomide in relapsed or refractory high-risk neuroblastoma: a joint Société Française des Cancers de l'Enfant and United Kingdom Children Cancer Study Group-New Agents Group Study

PURPOSE

To determine the response rate (RR) of neuroblastoma (NB) in children to temozolomide (TMZ), and evaluate the duration of response and tolerance of the drug in this patient population.

PATIENTS AND METHODS

A multicenter, phase II evaluation of an oral, daily schedule of TMZ (200 mg/m2/d x 5 days every 28 days) was undertaken in children with refractory or relapsed high-risk NB (metastatic or localized with Myc-N amplification). Response assessment was based on imaging with two-dimentional measurement of disease and meta-iodobenzylguanidine (MIBG) score. Activity was defined by a reduction in lesion size or isotope uptake at anytime. Methodology included a two-step design using Fleming's method with a first step of 15 patients and a second of 10 additional patients if two to four responses had been observed in the first cohort. All data was centrally reviewed by a panel.

RESULTS

Twenty-five assessable patients were recruited over a 14-month period in 14 centers and received 94 cycles of chemotherapy. Twenty-three patients had metastatic NB either refractory (n = 9) or in relapse (n = 14). Grade 3 or 4 thrombocytopenia was the most frequent toxicity (16% of cycles). Myelosuppression resulted in treatment delays and dose reductions (24% and 21% of cycles, respectively). Response (complete response, very good partial response, or partial response) was observed in five patients (RR = 20% +/- 8%) with a median duration of 6 months and an objective or mixed response in five additional patients.

CONCLUSION

Temozolomide shows activity in heavily pretreated patients with NB, and deserves further evaluation in combination with another drug.

Down-Regulation of Insulin-Like Growth Factor I Receptor Activity by NVP-AEW541 Has an Antitumor Effect on Neuroblastoma Cells In vitro and In vivo

PURPOSE

Signaling through insulin-like growth factor I receptor (IGF-IR) is important for growth and survival of many tumor types. Neuroblastoma is sensitive to IGF.

EXPERIMENTAL DESIGN

We assessed the ability of NVP-AEW541, a recently developed small molecule that selectively inhibits IGF-IR activity, for neuroblastoma growth effects in vitro and in vivo. Our data showed that, in a panel of 10 neuroblastoma cell lines positive for IGF-IR expression, NVP-AEW541 inhibited in vitro proliferation in a submicromolar/micromolar (0.4-6.8) range of concentrations.

RESULTS

As expected, NVP-AEW541 inhibited IGF-II-mediated stimulation of IGF-IR and Akt. In addition to growth inhibition, the drug also induced apoptosis in vitro. Oral administration of NVP-AEW541 (50 mg/kg twice daily) inhibited tumor growth of neuroblastoma xenografts in nude mice. Analysis of tumors from the drug-treated animals revealed a marked apoptotic pattern and a decrease in microvascularization compared with controls. Interestingly, quantitative real-time PCR detected both in vitro and in vivo a significant down-regulation of mRNA for vascular endothelial growth factor (VEGF) caused by NVP-AEW541. In addition, in Matrigel-coated chambers and in severe combined immunodeficient mice tail vein injected with neuroblastoma cells, tumor invasiveness was significantly reduced by this agent. Analysis of IGF-IR expression in a series of 43 neuroblastoma primary tumors revealed IGF-IR positivity in 86% of cases.

CONCLUSIONS

Taken together, these data indicate that NVP-AEW541 can be considered as a novel promising candidate for treatment of neuroblastoma patients.

Neuroblastoma incidence and survival in European children (1978-1997): report from the Automated Childhood Cancer Information System project

The Automated Childhood Cancer Information System (ACCIS) collects and presents data on childhood cancer in Europe. This report describes trends (1978-1997) and geographical differences (1988-1997) in incidence and survival for 6202 children with neuroblastoma from 59 registries in 19 countries, grouped into five regions (British Isles, West, East, North, and South). The age-standardised incidence rate (ASR) of neuroblastoma in Europe in 1988-1997 was 10.9 cases per million children, being highest in infants (52.6). The ASR of neuroblastoma increased in Europe from 8.4 in 1978-1982 to 11.6 in 1993-1997, mostly due to an increase in infants (from 35.4 to 57.8). Overall 5-year survival was 59%, ranging from 47% (East) to 67% (West). It improved markedly from 37% in 1978-1982 to 66% in 1993-1997, especially in infants. A certain amount of overdiagnosis in children under 2 years of age may explain the increased incidence rates and partially the increase in survival. Survival of older children (aged 2-14 years), which is likely to be largely affected by therapy, has also improved from 21% to 45%.

Effect of bortezomib on human neuroblastoma cell growth, apoptosis, and angiogenesis

BACKGROUND

Bortezomib is a selective and reversible inhibitor of the 26S proteasome that shows potent antitumor activity in vitro and in vivo against several human cancers of adulthood. No data are available on bortezomib activity against human pediatric neuroblastoma.

METHODS

Ten neuroblastoma cell lines and suspensions of primary neuroblastoma cells from three patients were tested for sensitivity to bortezomib. Colony formation, cell proliferation, cell cycle progression, and apoptosis were evaluated by a clonogenic assay and by measuring 3H-thymidine incorporation, bromodeoxyuridine uptake, DNA fragmentation, and phosphatidylserine exposure and propidium iodide staining, respectively. Angiogenesis was assessed by the chick embryo chorioallantoic membrane (CAM) assay. Two mouse xenograft models that mimic the growth and spread of neuroblastoma in humans were used to examine in vivo sensitivity of neuroblastoma to bortezomib. All statistical tests were two-sided.

RESULTS

Bortezomib inhibited proliferation and colony formation of neuroblastoma cell lines in a time- and dose-dependent manner. The mean bortezomib concentration that caused 50% inhibition of growth was 6.1 nM (95% confidence interval [CI] = 0.9 to 11.3 nM) at 72 hours. Bortezomib-treated neuroblastoma cells were arrested at G2/M and underwent apoptosis (mean percentage of apoptotic cells in four neuroblastoma cell lines treated with 20 nM bortezomib for 24 hours ranged from 20% to 35%, and caspases were activated by two- to fivefold with respect to untreated cells). Similar results were obtained for primary neuroblastoma cells exposed to bortezomib. Bortezomib inhibited angiogenesis in CAMs stimulated by conditioned medium from neuroblastoma cell lines, by neuroblastoma xenografts, and by primary neuroblastoma biopsy specimens (microvessel area: 2.9 x 10(-2) mm2, 95% CI = 1.8 x 10(-2) to 3.8 x 10(-2) mm2 in CAMs treated with biopsy specimens alone and 1.3 x 10(-2) mm2, 95% CI = 1 x 10(-2) to 1.5 x 10(-2) mm2 in CAMs treated with biopsy specimens plus bortezomib, P = .024). In both mouse models, mice treated with bortezomib lived statistically significantly longer than control mice (mean survival time in the pseudometastatic model: 74.2 versus 50.3 days, P<.001; mean survival time in the orthotopic model: 72.3 versus 50.6 days, P<.001).

CONCLUSIONS

Bortezomib is an effective inhibitor of neuroblastoma cell growth and angiogenesis. These findings provide the rationale for further clinical investigation of bortezomib in pediatric neuroblastoma.

Morphological and molecular assessment of apoptotic mechanisms in peripheral neuroblastic tumours

Multiple defects in apoptotic pathways have been described in peripheral neuroblastic tumours (NTs). Mitosis–karyorrhexis index (MKI) is a reliable morphological marker identifying favourable and unfavourable NTs. The extent to which apoptotic processes contribute to determine the clinical significance of MKI is still undefined. Apoptosis was investigated in a series of 110 peripheral NTs by comparing MKI to immunohistochemical and molecular apoptotic features. High MKI was found in 55 out of 110 NTs (50%) and was associated with advanced stage (P=0.007), neuroblastoma (NB) histological category (P=0.024), MYCN amplification (P<0.001), and poor outcome (P=0.011). Overall survival probability was 45% in patients with high MKI compared to 73% in patients with low MKI. In the same 110 NTs, the expression of Bcl-2, Bcl-X_L, Bax and Mcl-1 was studied by immunohistochemistry, but no significant associations were found with clinicohistological features. Microarray analysis of apoptotic genes was performed in 40 out of 110 representative tumours. No significant association was found between the expression of apoptotic genes and MKI or clinicohistological features. Proliferative activity was assessed in 60 out of 110 representative tumours using Ki67 immunostaining, but no significant correlations with MKI or clinicobiological features were found. In NTs, the combination of apoptosis and proliferation as expressed by MKI is a significant prognostic parameter, although neither of them is per se indicative of the clinicobiological behaviour and outcome.

Neuroblastoma in adolescents

BACKGROUND

Neuroblastoma (NB) occurs rarely during adolescence, and information is scarce on its characteristics and clinical course in this age group.

METHODS

Patients with NB who were included in the Italian Neuroblastoma Registry were considered for the current study. The clinical characteristics and survival of adolescents (age at diagnosis between 10 yrs and 18 yrs) were compared with those of children (ages 1-9 yrs). Infants (age < 1 yr) were excluded because of their well known favorable clinical course.

RESULTS

Between 1116 children and 53 adolescents who were evaluated, no differences were documented with regard to the primary tumor site and the prevalence of advanced stage at diagnosis. If only patients with Stage IV NB were considered, then adolescents were less likely to be diagnosed with bone/bone marrow metastases (77%) compared with children (94%; P = 0.038), but adolescents were more likely to have metastases at unusual sites, such as the lung parenchyma or the central nervous system (23% vs. 7%, respectively; P = 0.005). With regard to biologic characteristics, adolescents did not differ significantly from children, although they always had a lower prevalence of unfavorable markers. In particular, MYCN amplification was documented in 21% of children and in 11% of adolescents (P = 0.173). At age 10 years, adolescents had a 20% overall survival rate and a 22% event-free survival rate. Adolescents who had resectable disease had a 73% overall survival rate, which was worse compared with the rate among children with the same disease stage (89%), although the difference did not reach statistical significance (P = 0.159). No differences in survival were observed among patients with Stage IV NB, and adolescents had a probability of survival almost identical to that among children (6% vs. 16%, respectively; P = 0.481). However, when the analysis was restricted to events that occurred after patients developed a recurrence, even if the final outcome was poor for both groups, the difference was statistically significant (P = 0.022) mostly because of the more indolent disease course observed among the adolescents. This effect was even more evident for patients with Stage IV NB. When the 6-year cut-off point was used to separate children from adolescents, a significantly worse overall survival rate (P = 0.036) was documented for adolescents who had resectable disease (81% vs. 93% in children).

CONCLUSIONS

NB in adolescents had clinical and biologic characteristics similar to those observed among children. The clinical course of NB probably is correlated significantly with age at diagnosis, but information is scarce on the role of the biologic risk factors in this age group. The authors were able to identify a group of patients with a cut-off age between 6 years and 10 years that had a more indolent course but a worse prognosis.

Neuroblastoma in southern Brazil: an 11-year study

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

Long-term outcomes in patients with stage IV neuroblastoma

AIM OF STUDY

Long-term outcome studies in survivors with stage IV neuroblastoma (NB) are sparse. This review evaluates late complications and long-term outcomes in stage IV NB survivors.

METHODS

A retrospective review of stage IV NB survivors was performed to analyze outcomes, including long-term morbidity, recurrence, and survival.

MAIN RESULTS

Of 153 patients with stage IV NB, 52 (34%) survived (male-female, 26:26). Age at diagnosis was 29.1 +/- 31.7 months in survivors. Eighteen were 1 year or younger and 34 were older than 1 year compared with 10 nonsurvivors 1 year or younger and 91 older than 1 year (P = .0003, Fisher's Exact test). Primary tumor sites were adrenal (35), retroperitoneal (11), mediastinal (3), pelvic (2), and no primary with tumor metastases identified (1). Ten survivors had favorable and 16 had unfavorable histology compared with 1 favorable and 18 unfavorable in nonsurvivors (P = .01). Four survivors had MYCN amplification (> or = 10 copies) and 2 deletions of 1p and 11q. Sites of metastasis in survivors and nonsurvivors were similar. Treatment in survivors included surgery in 51 (75% [39/51] complete tumor resection [CTR]); chemotherapy, 50; radiation, 17; stem cell transplantation, 20; and bone marrow transplant, 1. In nonsurvivors, 13 (25%) of 53 (P < < .0001) had CTR, 18 stem cell transplantation, and 12 bone marrow transplant. Six patients had tumor recurrence but survived (mean, 9.3 +/- 8.3 years; range, 6 months-24 years). Recurrence was local (1), distant (2), and both (3) and was treated by resection, chemotherapy, and radiation. The mean age of survivors was 12.4 +/- 8.3 years (range, 2-34 years). In all stage IV cases, event-free survival was 30% and overall survival was 34%. Long-term complications occurred in 23 (44%) survivors, including endocrine disturbances (7), orthopedic (5), cataracts (2), adhesive bowel obstruction (2), hypertension (1), bronchiolitis (1), blindness (1), peripheral neuropathy (1), nonfunctioning kidney (1), cholelithiasis (1), and thyroid nodule (1).

CONCLUSION

Only 34% of patients with stage IV NB survived despite aggressive multimodal therapy. Age of younger than 1 year, favorable pathology, CTR, and no recurrence were the only statistically significant factors that favored survival. Forty-four percent of survivors experienced late morbidity, and tumor recurred in 6 (11.5%) of 52. Patients should be monitored for tumor recurrence and long-term sequelae. New methods of treatment are required to achieve better outcomes.

Neuroblastoma cell death in response to docosahexaenoic acid: Sensitization to chemotherapy and arsenic-induced oxidative stress

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid vital for the developing nervous system and significantly decreased in neuroblastoma cells compared to nontransformed nervous tissue. We investigated whether supplementation of DHA affects the susceptibility of neuroblastoma cells to oxidative stress generated endogenously and in response to cytotoxic therapy. DHA, but not the monounsaturated oleic acid (OA), induced dose- and time-dependent neuroblastoma cell death. DHA supplementation was associated with depolarization of the mitochondrial membrane potential, production of reactive oxygen species (ROS) and accumulation of DNA in sub-G1 phase of the cell cycle. The antioxidant, vitamin E, inhibited mitochondrial depolarization and subsequent cell death induced by DHA, whereas, the mitochondrial pore inhibitor, cyclosporin A, partly inhibited DHA-induced neuroblastoma cell death. Depletion of glutathione by L-buthionine-sulfoximine significantly enhanced the cytotoxic effects of DHA. Nontransformed fibroblasts were not substantially affected by DHA. DHA, but not OA, significantly enhanced the cytotoxicity of cisplatin, doxorubicin and irinotecan both in chemosensitive and in multidrug-resistant neuroblastoma cells. DHA potently sensitized neuroblastoma cells to a clinically relevant concentration (1 microM) of arsenic trioxide (As2O3) and enhanced the effect of the nonsteroidal antiinflammatory drug (NSAID), diclofenac. These findings provide experimental evidence that the omega-3 fatty acid, DHA, is cytotoxic to drug-resistant neuroblastoma. The potent action of DHA with arsenic trioxide, NSAID and chemotherapeutic agents suggests clinical testing of this therapeutic concept in children with neuroblastoma.

Antitumor activity of imatinib mesylate in neuroblastoma xenografts

Imatinib mesylate has antitumor activity in vitro and in vivo against neuroblastoma cell lines and xenografts characterized by a different expression of receptor tyrosine kinases. In this article, we report that imatinib tumor concentration can be independent of the administered dose and does not correlate with the antitumor effect. In xenografts, high-dose administration does not improve imatinib efficacy. In conclusion, there is no clear-cut correlation between the levels of expression for imatinib-responsive targets and the in vitro and in vivo sensitivity. This further suggests that in neuroblastoma the antitumor activity of imatinib may involve the inhibition of other tyrosine kinases and/or pathways.

Neuroblastoma targeting by c-myb-selective antisense oligonucleotides entrapped in anti-GD2 immunoliposome: immune cell-mediated anti-tumor activities

Liposome encapsulation of anticancer agents results in reduced side effects of the entrapped drug and improved therapeutic efficacy. The external surface of the lipidic envelope can be coupled with antibodies directed against tumor-associated antigens. The resulting immunoliposomes allow to increase the therapeutic index of cytotoxic drugs while minimizing their systemic toxicity. In this regard, the disialoganglioside GD2 is a very promising tumor-associated antigen since it is expressed at high intensity on human neuroblastoma cells, but is detected only in normal cerebellum and peripheral nerves. Immunoliposomes can be used as vectors to deliver antisense oligonucleotides to cancer cells with the aim to modulate oncogene expression. Furthermore, antisense oligonucleotides have attracted much interest because of their ability to stimulate immune responses. Here, we will describe a novel experimental therapeutic approach for neuroblastoma based on anti-GD2 liposomal c-myb-selective antisense oligonucleotides.

Surgical Risk Factors in Primary Surgery for Localized Neuroblastoma: The LNESG1 Study of the European International Society of Pediatric Oncology Neuroblastoma Group

Purpose

Although tumor resection is the mainstay of treatment for localized neuroblastoma, there are no established guidelines indicating which patients should be operated on immediately and which should undergo surgery after tumor reduction with chemotherapy. In an effort to develop such guidelines, the LNESG1 study defined surgical risk factors (SRFs) based on the imaging characteristics.

Patients and Methods

A total of 905 patients with suspected localized neuroblastoma were registered by 10 European countries between January 1995 and October 1999; 811 of 905 patients were eligible for this analysis.

Results

Information on SRFs was obtained for 719 of 811 patients; 367 without and 352 with SRFs. Of these 719 patients, 201 patients (four without and 197 with SRFs) underwent biopsy only. An attempt at tumor excision was made in 518 patients: 363 of 367 patients without and 155 of 352 patients with SRFs (98.9% v 44.0%). Complete excision was achieved in 271 of 363 patients without and in 72 of 155 patients with SRF (74.6% v 46.4%), near-complete excision was achieved in 81 and 61 patients (22.3% v 39.3%), and incomplete excision was achieved in 11 and 22 patients (3.0% v 14.2%), respectively. There were two surgery-related deaths. Nonfatal surgery-related complications occurred in 45 of 518 patients (8.7%) and were less frequent in patients without SRFs (5.0% v 17.4%). Associated surgical procedures were also less frequent in patients without SRFs (1.6% v 9.7%).

Conclusion

The adoption of SRFs as predictors of adverse surgical outcome was validated because their presence was associated with lower complete resection rate and greater risk of surgery-related complications. Additional studies aiming to better define the surgical approach to localized neuroblastoma are warranted.

Ligands for the peroxisome proliferator-activated receptor-gamma have inhibitory effects on growth of human neuroblastoma cells in vitro

The thiazolidinedione (TZD) or glitazone class of peroxisome proliferator-activated-gamma (PPAR-gamma) ligands not only induce adipocyte differentiation and increase insulin sensitivity, but also exert growth inhibitory effects on several carcinoma cell lines in vitro as well as in vivo. In the current study the in vitro effect of four PPAR-gamma agonists (ciglitazone, pioglitazone, troglitazone, rosiglitazone) on the cell growth of seven human neuroblastoma cell lines (Kelly, LAN-1, LAN-5, LS, IMR-32, SK-N-SH, SH-SY5Y) was investigated. Growth rates were assessed by a colorimetric XTT-based assay kit. Expression of PPAR-gamma protein was examined by immunohistochemistry and Western blot analysis. All glitazones inhibited in vitro growth and viability of the human neuroblastoma cell lines in a dose-dependent manner showing considerable effects only at high concentrations (10 microM and 100 microM). Effectiveness of the glitazones on neuroblastoma cell growth differed depending on the cell line and the agent. The presence of PPAR-gamma protein was demonstrated in all cell lines. Our findings indicate that ligands for PPAR-gamma may be useful therapeutic agents for the treatment of neuroblastoma. Thus the effect of glitazones on the growth of neuroblastoma should now be investigated in an in vivo animal model.

Histologic survey of neuroblastomas after intensive induction chemotherapy

BACKGROUND

Histology after intensive induction chemotherapy is expected to become a beacon indicating when and how extensively radical surgery and lymph node dissection should be performed in advanced neuroblastoma. A thorough histologic review of surgical specimens was undertaken.

PROCEDURE

All specimens from 34 patients who were pretreated intensively (> or =3 cycles) with recent chemotherapy were reviewed. Thirty patients were >12 months of age with stage 3/4 disease, and 4 were <12 months of age but with MYCN-amplified stage 4 diseases. After 3 to 7 cycles (mean, 4.3 cycles) of induction chemotherapy, patients underwent radical surgery of the primary tumor and lymph nodes in all retroperitoneal sections. A single pathologist reviewed all of the specimens, and histologic chemotherapeutic effects were graded as: (+++), <1% viable tumor; (++), 1%-10% viable tumor; (+), 11%-50% viable tumor; (+/-), 51%-90% viable tumor; and (-), >91% viable tumor.

RESULTS

Grade (+++) effects were observed in 56% of patients treated with the new regimens, whereas grade (+++) was seen in only 20% treated with regimens before 1991. Operation time and blood loss were 7 hr and 6 min (P = 0.087) and 646 ml (P = 0.064), respectively, in patients with >5 cycles (mean, 5.3 cycles) of chemotherapy, while they were 7 hr and 50 min and 1,168 ml, respectively, in those with approximately 3 cycles (mean, 3.2 cycles). Histologically, metastases were found in the contralateral nodes beyond the aorta in 92% of those whose tumor originated on the left, and in 80% of those with tumors occurring on the right.

CONCLUSIONS

Five cycles of induction chemotherapy did not improve histologic chemotherapeutic effects, but helped to facilitate a shorter operation time and less blood loss than 3 cycles of chemotherapy. Surgery after 5 cycles of (98)A(3) also appears to be easier to perform than that after 3 cycles of A(1)/new A(1). Only 14% of the children treated before 1985 with the St. Jude protocols experienced grade (+++) chemotherapeutic effects, and 22% of the patients treated before 1991 with regimen A(1), or new A(1) of the Study Group of Japan showed grade (+++) effects, whereas 56% of the patients treated after 1991 with either regimen A(3) or (98)A(3) exhibited grade (+++) chemotherapeutic effects. Histologic chemotherapeutic effects were roughly parallel with a good prognosis.

Induction of apoptosis by flavopiridol in human neuroblastoma cells is enhanced under hypoxia and associated with N-myc proto-oncogene down-regulation

PURPOSE

Neuroblastoma is the most common extracranial solid tumor of children that arises from the sympathetic nervous system. Survival rates for neuroblastoma patients is low despite intensive therapeutic intervention, and the identification of new effective drugs remains a primary goal. The cyclin-dependent kinase inhibitor, flavopiridol, has demonstrated growth-inhibitory and cytotoxic activity against various tumor types. Our aim was to investigate flavopiridol effects on advanced-stage, N-myc proto-oncogene (MYCN)-amplified human neuroblastomas and the modulation of its activity by hypoxia, a critical determinant of tumor progression and a major challenge of therapy.

EXPERIMENTAL DESIGN

Cell viability was monitored by 3-(4,5 dimethyl-2 thiazolyl)-2,5 diphenyl-2H tetrazolium bromide (MTT) and trypan blue dye exclusion assays; DNA synthesis was assessed with the bromodeoxyuridine pulse-labeling technique; apoptosis was studied by Giemsa staining, DNA fragmentation, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling reaction, flow cytometric determination of hypodiploid DNA content, and evaluation of caspase activity and cytochrome c (CytC) release; MYCN expression was determined by Northern and Western blotting.

RESULTS

Flavopiridol caused dose- and time-dependent decreases in neuroblastoma viability by inducing apoptosis, as confirmed by morphologic and biochemical criteria. Cell death was preceded by DNA synthesis inhibition and G1-G2 arrest, reversed by the pancaspase inhibitor, zVAD-fmk, and associated with caspase-3 and -2 activation and CytC increase. Moreover, flavopiridol strongly down-regulated MYCN mRNA and protein expression. Exposure to hypoxia enhanced both the extent of apoptosis and flavopiridol effects on CytC, caspase 3, and MYCN.

CONCLUSIONS

These results indicate that flavopiridol has growth-inhibitory and apoptotic activity against advanced-stage neuroblastomas in vitro and is worthy of further investigation for the treatment of this disease.

The secretion of ibuprofen metabolites interferes with the capillary chromatography of urinary homovanillic acid and 4-hydroxy-3-methoxymandelic acid in neuroblastoma diagnosis

Neuroblastoma is the most common extracranial solid tumor in children. Abnormal secretion of catecholamines in tissues and body fluids allows for the differential diagnosis of neuroblastoma from other neoplasms and its distinction from non-neoplastic inflammatory diseases. This is achieved by assaying homovanillic acid and 4-hydroxy-3-methoxymandelic acid, the catabolites of catecholamine metabolism. In the course of an evaluation of children with suspected neuroblastoma, homovanillic acid and 4-hydroxy-3-methoxymandelic acid were analyzed in urine samples by capillary gas chromatography with flame ionization detection after extraction and derivatization of these compounds as trimethylsilyl derivatives. In three urine samples a significant increase in biogenic amines was observed, but these results were not confirmed by thin-layer chromatography. Patient history revealed that these children had been treated with ibuprofen, an analgesic and anti-inflammatory drug. To verify how ibuprofen or its metabolites may have interfered with capillary gas chromatography with flame ionization detection, we analyzed the same samples by capillary gas chromatography-mass spectrometry. In urine samples from patients on the drug, the presence of a peak identified as the trimethylsilyl ester of hydroxyibuprofen, which had the same retention time as 4-hydroxy-3-methoxymandelic acid, was found to interfere with the capillary gas chromatography with flame ionization detection analysis of the metabolite. This interference must be taken into account during the laboratory diagnosis of neuroblastoma.

Stage 4 neuroblastoma: sequential hemi-body irradiation or high-dose chemotherapy plus autologous haemopoietic stem cell transplantation to consolidate primary treatment

The aim of the present study was to evaluate the effectiveness of two consecutive nonrandomised treatment programs applied between 1989 and 1999 at the Istituto Nazionale Tumori of Milan in an unselected cohort of 59 children over the age of one with stage 4 neuroblastoma. Both treatment programs consisted of two phases, the induction of the remission phase and the consolidation phase. The induction of the remission phase consisted of intensive chemotherapy, and remained the same throughout the study period. The consolidation phase consisted of sequential hemi-body irradiation (HBI) (10 Gy per session, 6 weeks apart) in the first period (1988–June 1994) and sequential high-dose cyclophosphamide, etoposide, mitoxantrone+L-PAM and autologous haemopoietic stem cell transplantation in the second (July 1994–1999). Intention-to-treat analysis revealed a significantly better outcome for patients treated with the second program, the 5-year event-free survival probability being 0.12 for program 1 and 0.31 for program 2 (P=0.03). This finding led us to conclude that sequential HBI is useless as consolidation treatment. The high-dose chemotherapy adopted in the second program enabled a proportion of patients to obtain long-term survival but, since the clinical results remain unsatisfactory, new treatment strategies are warranted.

A comparison of current neuroblastoma chemotherapeutics

Neuroblastoma is the most common solid tumour in childhood. Modern management includes a biopsy to perform genetic studies. Based on clinical data and Myc-N amplification (MNA), patients are divided in three prognostic groups: the low-risk (Stage 1, 2, 4S without MNA) has an event-free survival (EFS) of > 90% with surgery alone; the intermediate-risk (Stage 3, > 1 year of age, without MNA and Stage 3 and 4 infants without MNA) has an EFS of approximately 80% with mild chemotherapy and surgery; the high-risk group includes Stage 4, > 1 year of age and any stage and age with MNA. These patients are treated with chemotherapy, surgery, megatherapy, irradiation and 13-cis-retinoic acid. With this complex therapy, a 5-year EFS of 30-50% can be obtained.

Sequential Immunogene Therapy with Interleukin-12– and Interleukin-15–Engineered Neuroblastoma Cells Cures Metastatic Disease in Syngeneic Mice

Purpose: To investigate the potential synergistic effects of Neuro2a neuroblastoma cells engineered with IL-12 and/or IL-15 genes in improving survival of syngeneic mice bearing neuroblastoma metastatic disease.

Experimental Design: Neuro2a cells engineered with interleukin (IL)-12 (Neuro2a/IL-12), IL-15 (Neuro2a/IL-15), or both cytokines (Neuro2a/IL-12/IL-15) were injected s.c. in syngeneic A/J mice challenged i.v. with Neuro2a parental cells (Neuro2apc) using different schedules of administration in either preventive or therapeutic settings.

Results: A single injection of Neuro2a/IL-12 or Neuro2a/IL-15 cells induced resistance to a subsequent i.v. Neuro2apc challenge in 45% and 28% of mice, respectively. Neuro2a/IL-12/IL-15 cells protected 28% of mice, showing no synergistic effect. However, sequential vaccination with Neuro2a/IL-12 (day −30) followed by Neuro2a/IL-15 (day −15) protected 71% of mice from subsequent challenge with Neuro2apc. A single dose of Neuro2a/IL-12 prolonged the mean survival time of mice bearing established metastatic neuroblastoma from 21 ± 3 to 46 ± 27 days but failed to cure mice, whereas Neuro2a/IL-15 or Neuro2a/IL-12/IL-15 were ineffective. However, sequential vaccination with Neuro2a/IL-12 (day +3) followed by Neuro2a/IL-15 (day +13) cured 43% of mice as assessed by histologic analysis of different organs from long-term surviving mice. CTL activity against Neuro2apc cells was observed in splenocytes from treated mice, and CD8+ T-cell depletion abrogated the therapeutic effect of vaccination.

Conclusions: Sequential vaccination with IL-12- and IL-15-engineered neuroblastoma cells induced optimal preventive and therapeutic effects, which may be related to the Th1 priming effect of IL-12 followed by the enhancement of CD8+ T-cell responses and their maintenance mediated by IL-15.

Reduction From Seven to Five Cycles of Intensive Induction Chemotherapy in Children With High-Risk Neuroblastoma

Purpose

We previously reported a high response rate with a dose-intensive chemotherapy regimen in 24 children with high-risk neuroblastoma (NB). We now describe similar results with changes that reduce toxicity (fewer cycles, less vincristine, use of granulocyte colony-stimulating factor).

Patients and Methods

Eighty-seven consecutive newly diagnosed children with high-risk NB underwent induction that initially had seven cycles (57 patients) but was later limited to five (30 patients). Cycles 1, 2, 4, and 6 used cyclophosphamide (140 mg/kg)/doxorubicin (75 mg/m2)/vincristine (0.15 mg/kg in the first 27 patients, 0.067 mg/kg subsequently). Cycles 3, 5, and 7 used cisplatin (200 mg/m2)/etoposide (600 mg/m2). Tumor resection followed a minimum of three cycles. The induction was eventually modified to include anti-GD2 immunotherapy after each of the last three cycles (38 patients).

Results

Bone marrow disease resolved in 70 (91%) of 77 patients and was not detected pre- and postinduction in 10 patients. After cycle 3 or 4, 86% of primary tumors were more than 50% smaller. Postinduction metaiodobenzylguanidine scans showed normal radiotracer distribution in metastatic sites in 74 (87%) of 85 patients. Overall results were: 68 (79%) complete/very good partial responses (CR/VGPR); 14 (16%) partial responses (PR); three (3%) less than PR; one (1%) death from infection; and one patient not assessable for response. Five cycles yielded a CR/VGPR rate of 83%, compared with a 77% rate from seven cycles. Side effects were myelosuppression, mucositis, and hearing deficits; neurotoxicity was insignificant with the lower vincristine dosage. Four patients (each received seven cycles) developed myelodysplasia/leukemia.

Conclusion

Five cycles of this induction regimen, plus surgery, suffice to achieve CR/VGPR in ≈80% of children with high-risk NB.

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

PURPOSE

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

EXPERIMENTAL DESIGN

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

RESULTS

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

CONCLUSIONS

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

Scintigraphic response by 123I-metaiodobenzylguanidine scan correlates with event-free survival in high-risk neuroblastoma

PURPOSE

To investigate whether response to induction therapy, evaluated by metaiodobenzylguanadine (MIBG) and bone scintigraphy, correlates with event-free survival (EFS) in children with high-risk neuroblastoma (NB).

PATIENTS AND METHODS

Twenty-nine high-risk NB patients were treated prospectively with an intensive induction regimen and consolidated with three cycles of high-dose therapy with peripheral blood stem-cell rescue. The scintigraphic response was evaluated by MIBG and bone scans using a semi-quantitative scoring system. The prognostic significance of the imaging scores at diagnosis and following induction therapy was evaluated.

RESULTS

A trend associating worse 4-year EFS rates for patients with versus without osteomedullary uptake on MIBG scintigraphs at diagnosis was seen (35% +/- 11% v 80% +/- 18%, respectively; P =.13). Similarly, patients with positive bone scans at diagnosis had worse EFS than those with negative scans, although the difference did not receive statistical significance (34% +/- 10% v 83% +/- 15%, respectively; P =.06). However, significantly worse EFS was observed in patients with a postinduction MIBG score of >/= 3 compared to those with scores of less than 3 (0% v 58% +/- 11%; P =.002). There was no correlation between bone scan scores and outcome following induction therapy.

CONCLUSION

MIBG scores >/= 3 following induction therapy identifies a subset of NB patients who are likely to relapse following three cycles of high-dose therapy with peripheral blood stem-cell rescue, local radiotherapy, and 13-cis-retinoic acid. Alternative therapeutic strategies should be considered for patients with a poor response to induction therapy.

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

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

Immune cell-mediated antitumor activities of GD2-targeted liposomal c-myb antisense oligonucleotides containing CpG motifs

BACKGROUND

Expression of the c-myb proto-oncogene in neuroblastoma, the most common extracranial solid tumor of infancy, is linked with cell proliferation and differentiation. Neuroblastoma can be selectively targeted via monoclonal antibodies against the disialoganglioside (GD2) tumor-associated antigen. Liposomes coated with anti-GD2 antibodies (targeted liposomes) and entrapping a c-myb antisense oligonucleotide have antitumor activity. Because antisense oligonucleotides containing CpG motifs can stimulate immune responses, we evaluated the effect of CpG-containing c-myb antisense oligonucleotides encapsulated within targeted liposomes.

METHODS

Antisense (myb-as) and scrambled (myb-scr) control oligonucleotides with CpG motifs were encapsulated within GD2-targeted and non-targeted liposomes. Two murine (nude and SCID-bg) xenograft models of neuroblastoma were established. Mice (groups of 10) were injected intravenously with various oligonucleotide and liposome formulations, and life span, long-term survival, immune cell activation, and cytokine release were measured over time.

RESULTS

Tumor-bearing mice injected with targeted liposome-CpG-myb-as or targeted liposome-CpG-myb-scr lived longer than mice in any other group, although long-term survival (i.e., more than 120 days) was obtained only in mice injected with targeted liposome-CpG-myb-as. Splenocytes isolated from mice injected with targeted liposome-CpG-myb-as contained activated macrophages, B cells, and natural killer (NK) cells, but only activated NK cells were associated with antitumor cytotoxic activity. In vivo immune cell activation was accompanied by the time-dependent increases in plasma levels of the cytokines interleukin 12 (IL-12; maximum level reached by 2 hours) and interferon gamma (IFN-gamma; maximum level reached by 18 hours) and was dependent on the oligonucleotide CpG motif. Ablation of macrophages or NK cells resulted in a loss of in vivo antitumor activity.

CONCLUSION

Immune cell activation, involving the time-dependent activation of macrophages and NK cells, contributes to the antitumor activity of targeted liposome-CpG-myb-as against neuroblastoma and could improve the effectiveness of antitumor targeted liposomes.

A phase II study of topotecan with vincristine and doxorubicin in children with recurrent/refractory neuroblastoma

BACKGROUND

A Phase II trial in children with advanced neuroblastoma was carried out in five Italian institutions to evaluate the antitumor activity and tolerability of topotecan followed by vincristine and doxorubicin.

METHODS

Children older than age 1 year with Stage III or Stage IV neuroblastoma, all of whom had been treated previously with chemotherapy and were diagnosed with either refractory or recurrent disease, were treated with topotecan at an intravenous dose of 1.5 mg/m(2) (the dose was 0.75 mg/m(2) for patients who were treated within 1 year of previous megatherapy) per day for 5 days followed by 48-hour intravenous infusions of 2 mg/m(2) vincristine and 45 mg/m(2) doxorubicin. Cycles of therapy were repeated every 3 weeks.

RESULTS

Twenty-five patients (2 with Stage III disease and 23 with Stage IV disease; 19 with refractory disease and 6 with recurrent disease) were treated with a total of 115 cycles. Four patients had complete responses, 12 patients had partial responses, 4 patients had minor responses or stable disease, and 5 patients had tumor progression. The overall response rate (including complete and partial responses) was 64% (95% confidence interval, 43-82%). Fifteen patients were alive at the time of the current report and were progression free at 4-16 months (median, 9 months) after the first course of this treatment. Toxicity generally was limited to the hematopoietic system. Dose-limiting toxicity was observed in only 1 patient (Grade 4 liver toxicity). There were no deaths due to infectious or toxic causes.

CONCLUSIONS

The topotecan-vincristine-doxorubicin combination was active and well tolerated in previously treated patients with advanced neuroblastoma.