Neuroblastoma, the most common extra- cranial solid tumor in children, is derived from neural crest cells. Nearly half of patients present with metastatic disease, and have 5-year EFS of less than 50%. New approaches with targeted therapy may improve efficacy without increased toxicity. The current review will evaluate three promising targeted therapies, including 131I-metaiodobenzylguanidine (MIBG), a radiopharmaceutical taken up by the human norepinephrine transporter expressed in 90% of neuroblastomas, immunotherapy with monoclonal antibodies targeting the GD2 ganglioside, expressed on 98% of neuroblastoma cells, and inhibitors of ALK, a tyrosine kinase which is mutated or amplified in approximately 10% of neuroblastoma and expressed on the surface of most neuroblastoma cells. Early phase trials have confirmed the activity of 131I-MIBG in relapsed neuroblastoma, with response rates of about 30%, but the technical aspects of administration of large amounts of radioactivity in young children and the limited access have hindered incorporation into treatment of newly diagnosed patients. Anti-GD2 antibodies have also demonstrated activity in relapsed disease, and a recent phase III randomized trial showed a significant improvement in event-free survival for patients receiving chimeric anti-GD2 (ch14.18) combined with cytokines and isotretinoin after myeloablative consolidation therapy. A recently approved small molecule inhibitor of ALK has promising pre-clinical activity for neuroblastoma, and is currently in phase I and II trials. This is the first agent directed to a specific mutation in neuroblastoma, and marks a new step toward personalized therapy for neuroblastoma. Further clinical development of targeted treatments offers new hope for children with neuroblastoma.
Adolescent and adult patients with neuroblastoma appear to have a more indolent disease course but a lower survival than their younger counterparts. The majority of neuroblastoma tumors specifically accumulate the radiolabeled norepinephrine analogue 131I-metaiodobenzylguanidine (MIBG). 131I-MIBG has therefore become increasingly used as targeted radiotherapy for relapsed or refractory neuroblastoma. The aim of this study was to characterize the toxicity and activity of this therapy in older patients.
We performed a retrospective analysis of 39 consecutive patients ages 10 years and older with relapsed or refractory neuroblastoma who were treated with 131I-MIBG monotherapy at UCSF under Phase I, Phase II, and compassionate access protocols.
Sixteen patients were ≥18 years old at MIBG treatment initiation, whereas twenty-three were 10–17 years old. The median cumulative administered dose of 131I-MIBG was 17.8 mCi/kg. The majority of treatments led to grade 3 or 4 hematologic toxicities which were similar in frequency among age strata. Three patients subsequently developed hematologic malignancy or myelodysplasia. The overall rate of complete plus partial response was 46%. Patients ≥18 years old at time of first MIBG treatment had a significantly higher response rate compared to patients 10–17 years old (56% vs 39%, p=0.023). Median overall survival was 23 months with a trend toward longer overall survival for the ≥18 year old subgroup (p = 0.12).
Our findings suggest that 131I-MIBG is a highly effective salvage agent for adolescents and adults with neuroblastoma.
neuroblastoma; adult; adolescent; MIBG; radiopharmaceutical
Ewing sarcoma (ES) is a malignant tumor of bone and soft tissue of children and young adults. Patients with ES are treated with intensive chemotherapy regimens. We describe predictors of acute chemotherapy-associated toxicity in this population.
In this retrospective cohort study, records of ES patients treated at two academic medical centers between 1980 and 2010 were reviewed. Grade 3 and 4 non-hematologic chemotherapy-associated toxicities during frontline therapy were recorded for each patient, along with potential clinical and demographic predictors of toxicity. Bivariate analyses were performed using the Fisher exact test. Multivariate analysis was performed using logistic regression.
The cohort included 142 patients with ES and toxicity data. In bivariate analyses, age <12 years at diagnosis, Latino ethnicity, low family income, and treatment on a clinical trial were associated with higher incidence of toxicity (p <0.01). Tumor size, site, stage, mode of local control, body mass index, overall chemotherapy exposure and dose-intensity were not associated with toxicity. In multivariate analysis, low income (odds ratio (OR) 4.97, 95% CI 1.9–13.1), clinical trial enrollment (OR 3.67, 95% CI 1.2–10.9), pelvic tumor site (OR 3.88, 95% CI 1.17–12.88), and age <12 years (OR 2.8, 95% CI 1.0–7.5) were independent predictors of toxicity.
ES patients who are younger, of Latino ethnicity, have pelvic tumors or low income have higher rates of toxicity that may require increased supportive care. Treatment on a clinical trial was also associated with higher rates of toxicity, though this finding may reflect better reporting in these patients.
Ewing sarcoma; toxicity; income; ethnicity; age
Children diagnosed at age ≥ 18 months with metastatic MYCN-nonamplified neuroblastoma (NBL-NA) are at high risk for disease relapse, whereas those diagnosed at age < 18 months are nearly always cured. In this study, we investigated the hypothesis that expression of genes related to tumor-associated inflammatory cells correlates with the observed differences in survival by age at diagnosis and contributes to a prognostic signature.
Tumor-associated macrophages (TAMs) in localized and metastatic neuroblastomas (n = 71) were assessed by immunohistochemistry. Expression of 44 genes representing tumor and inflammatory cells was quantified in 133 metastatic NBL-NAs to assess age-dependent expression and to develop a logistic regression model to provide low- and high-risk scores for predicting progression-free survival (PFS). Tumors from high-risk patients enrolled onto two additional studies (n = 91) served as independent validation cohorts.
Metastatic neuroblastomas had higher infiltration of TAMs than locoregional tumors, and metastatic tumors diagnosed in patients at age ≥ 18 months had higher expression of inflammation-related genes than those in patients diagnosed at age < 18 months. Expression of genes representing TAMs (CD33/CD16/IL6R/IL10/FCGR3) contributed to 25% of the accuracy of a novel 14-gene tumor classification score. PFS at 5 years for children diagnosed at age ≥ 18 months with NBL-NA with a low- versus high-risk score was 47% versus 12%, 57% versus 8%, and 50% versus 20% in three independent clinical trials, respectively.
These data suggest that interactions between tumor and inflammatory cells may contribute to the clinical metastatic neuroblastoma phenotype, improve prognostication, and reveal novel therapeutic targets.
Ewing sarcoma is a malignant bone tumor characterized by a high frequency of somatic EWSR1 translocations. Ewing sarcoma is less common in people of African or African-American ancestry, suggesting a genetic etiology.
Germline DNA from white patients with Ewing sarcoma (n = 135), white controls with Wilms tumor (n = 200), and African-American controls (n = 285) was genotyped at 21 SNPs in the EWSR1 gene. Intron 7 of EWSR1, the most common site of translocation, was also sequenced in all subjects. Genetic variation between groups was evaluated statistically using exact logistic regression and Fisher exact tests.
One SNP in EWSR1 (rs2857461) showed a low level of statistical association with the diagnosis of Ewing sarcoma compared to Wilms tumor. The odds ratio for having Ewing sarcoma in people with at least one copy of the minor allele of rs2857461 was 3.57 (95% confidence interval 0.79 – 21.7; p = 0.07). No other SNPs or variations in intron 7 of EWSR1 were associated with Ewing sarcoma. The median relative difference in minor allele frequencies between white subjects with Ewing sarcoma and African-American controls at the evaluated EWSR1 SNPs was 45%.
Variations in EWSR1 at known SNPs or across intron 7 are not associated with the diagnosis of Ewing sarcoma. EWSR1 does not appear to be a Ewing sarcoma susceptibility gene. The genetic basis for this disease remains unknown.
Ewing sarcoma; EWSR1; single nucleotide polymorphism; genetic epidemiology
To assess poly (ADP-ribose) polymerase (PARP) inhibitor MK-4827 together with radiation for the treatment of neuroblastoma.
Material and Methods
Clonogenic survival assays were used to assess MK-4827, radiation and combination thereof in four neuroblastoma cell lines. In vivo efficacy was tested in a murine xenograft model of metastatic neuroblastoma. In vivo targeted inhibition and biological effects included measurement of cleaved caspase-3, gamma-H2AX, and Ki 67 by immunohistochemistry (IHC) and poly-ADP-ribose by Enzyme-Linked Immunosorbent Assay.
Treatment of neuroblastoma cell lines reduced clonogenicity and resulted in additive effects with radiation. In vivo treatment with MK-4827 and radiation prolonged survival (p<0.01) compared to single modalities. In vivo superiority of MK-4827 plus radiation was further documented by significant elevations of cleaved caspase-3 and γ-H2AX in tumors from the combination group compared to single modality cohorts.
Combination of MK-4827 and radiation might provide effective therapy for children with high-risk neuroblastoma.
The primary objective of Children's Oncology Group study P9641 was to demonstrate that surgery alone would achieve 3-year overall survival (OS) ≥ 95% for patients with asymptomatic International Neuroblastoma Staging System stages 2a and 2b neuroblastoma (NBL). Secondary objectives focused on other low-risk patients with NBL and on those who required chemotherapy according to protocol-defined criteria.
Patients and Methods
Patients underwent maximally safe resection of tumor. Chemotherapy was reserved for patients with, or at risk for, symptomatic disease, with less than 50% tumor resection at diagnosis, or with unresectable progressive disease after surgery alone.
For all 915 eligible patients, 5-year event-free survival (EFS) and OS were 89% ± 1% and 97% ± 1%, respectively. For patients with asymptomatic stage 2a or 2b disease, 5-year EFS and OS were 87% ± 2% and 96% ± 1%, respectively. Among patients with stage 2b disease, EFS and OS were significantly lower for those with unfavorable histology or diploid tumors, and OS was significantly lower for those ≥ 18 months old. For patients with stage 1 and 4s NBL, 5-year OS rates were 99% ± 1% and 91% ± 1%, respectively. Patients who required chemotherapy at diagnosis achieved 5-year OS of 98% ± 1%. Of all patients observed after surgery, 11.1% experienced recurrence or progression of disease.
Excellent survival rates can be achieved in asymptomatic low-risk patients with stages 2a and 2b NBL after surgery alone. Immediate use of chemotherapy may be restricted to a minority of patients with low-risk NBL. Patients with stage 2b disease who are older or have diploid or unfavorable histology tumors fare less well. Future studies will seek to refine risk classification.
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.
The available English language literature was reviewed for original research investigating in vitro, in vivo, and clinical applications of radiolabeled MIBG for neuroblastoma.
MIBG is actively transported into neuroblastoma cells by the norepinephrine transporter. Preclinical studies demonstrate substantial activity of radiolabeled MIBG in neuroblastoma models, with 131I-MIBG showing enhanced activity in larger tumors compared to 125I-MIBG. Clinical studies of 131I-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 131I-MIBG in this population. More recent studies have focused on the use of 131I-MIBG in combination with chemotherapy or myeloablative regimens.
131I-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.
Metaiodobenzylguanidine; neuroblastoma; pediatric; radionuclide
Symptom cluster research is an emerging field in symptom management. The ability to identify symptom clusters that are specific to pediatric oncology patients may lead to improved understanding of symptoms’ underlying mechanisms among patients of all ages.
The purpose of this study, in a sample of children and adolescents with cancer who underwent a cycle of myelosuppressive chemotherapy, was to compare the number and types of symptom clusters identified using patients’ ratings of symptom occurrence and symptom severity.
Children and adolescents with cancer (10 to 18 years of age; N=131) completed the Memorial Symptom Assessment Scale 10–18 on the day they started a cycle of myelosuppressive chemotherapy, using a one week recall of experiences. Symptom data based on occurrence and severity ratings were examined using Exploratory Factor Analysis (EFA). The defined measurement model suggested by the best EFA model was then examined with a latent variable analysis.
Three clusters were identified when symptom occurrence ratings were evaluated which were classified as a chemotherapy sequelae cluster, mood disturbance cluster, and a neuropsychological discomforts cluster. Analysis of symptom severity ratings yielded similar cluster configurations.
Cluster configurations remained relatively stable between symptom occurrence and severity ratings. The evaluation of patients at a common point in the chemotherapy cycle may have contributed to these findings.
Implications for Practice
Additional uniformity in symptom clusters investigations is needed to allow appropriate comparisons among studies. The dissemination of symptom clusters research methodology through publication and presentation may promote uniformity in this field.
To assess the feasibility of adding dose-intensive topotecan and cyclophosphamide to induction therapy for newly diagnosed high-risk neuroblastoma (HRNB).
Patients and Methods
Enrolled patients received two cycles of topotecan (approximately 1.2 mg/m2/d) and cyclophosphamide (400 mg/m2/d) for 5 days followed by four cycles of multiagent chemotherapy (Memorial Sloan-Kettering Cancer Center [MSKCC] regimen). Pharmacokinetically guided topotecan dosing (target systemic exposure with area under the curve of 50 to 70 ng/mL/hr) was performed. Peripheral-blood stem cell (PBSC) harvest and surgical resection of residual primary tumor occurred after cycles 2 and 5, respectively. Patients achieving at least a partial response received myeloablative chemotherapy with PBSC rescue and radiation to the presurgical primary tumor volume. Oral 13-cis-retinoic acid maintenance therapy was administered twice daily for 14 days in six 28-day cycles.
Thirty-one patients were enrolled onto the study. No deaths related to toxicity or dose-limiting toxicities occurred during induction. Mucositis rarely occurred after topotecan cycles (9.7%) in contrast to 30% after MSKCC cycles. Thirty patients underwent PBSC collection with median 31.1 × 106 CD34+ cells/kg (range, 1.8 to 541.8 × 106 CD34+ cells/kg), all negative for tumor contamination by immunocytochemical analysis. Targeted topotecan systemic exposure was achieved in 26 (84%) of 31 patients. At the end of induction, 26 patients (84%) had tumor response and one patient had progressive disease. In the overall cohort, 3-year event-free and overall survival were 37.8% ± 9.4% and 57.1% ± 9.4%, respectively.
This pilot induction regimen was well tolerated with expected and reversible toxicities. These data support investigation of efficacy in a phase III clinical trial for newly diagnosed HRNB.
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.
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.
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.
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.
Survival after neuroblastoma relapse is poor. Understanding the relationship between clinical and biologic features and outcome after relapse may help in selection of optimal therapy. Our aim was to determine which factors were significantly predictive of postrelapse overall survival (OS) in patients with recurrent neuroblastoma—particularly whether time from diagnosis to first relapse (TTFR) was a significant predictor of OS.
Patients and Methods
Patients with first relapse/progression were identified in the International Neuroblastoma Risk Group (INRG) database. Time from study enrollment until first event and OS time starting from first event were calculated. Cox regression models were used to calculate the hazard ratio of increased death risk and perform survival tree regression. TTFR was tested in a multivariable Cox model with other factors.
In the INRG database (N = 8,800), 2,266 patients experienced first progression/relapse. Median time to relapse was 13.2 months (range, 1 day to 11.4 years). Five-year OS from time of first event was 20% (SE, ± 1%). TTFR was statistically significantly associated with OS time in a nonlinear relationship; patients with TTFR of 36 months or longer had the lowest risk of death, followed by patients who relapsed in the period of 0 to less than 6 months or 18 to 36 months. Patients who relapsed between 6 and 18 months after diagnosis had the highest risk of death. TTFR, age, International Neuroblastoma Staging System stage, and MYCN copy number status were independently predictive of postrelapse OS in multivariable analysis.
Age, stage, MYCN status, and TTFR are significant prognostic factors for postrelapse survival and may help in the design of clinical trials evaluating novel agents.
Neuroblastoma, a tumor of peripheral neural crest origin, numbers among the most common childhood cancers. Both amplification of the proto-oncogene MYCN and increased neoangiogenesis mark high-risk disease. Because angiogenesis is regulated by phosphatidylinositol 3-kinase (PI3K), we tested a clinical PI3K inhibitor, NVP-BEZ235, in MYCN-dependent neuroblastoma. NVP-BEZ235 decreased angiogenesis and improved survival in both primary human (highly pretreated recurrent MYCN-amplified orthotopic xenograft) and transgenic mouse models for MYCN-driven neuroblastoma. Using both gain- and loss-of-function approaches, we demonstrated that the anti-angiogenic efficacy of NVP-BEZ235 depended critically on MYCN in vitro and in vivo. Thus, clinical PI3K/mammalian target of rapamycin inhibitors drove degradation of MYCN in tumor cells, with secondary paracrine blockade of angiogenesis. Our data demonstrated significantly improved survival in treated animals and suggest that NVP-BEZ235 should be tested in children with high-risk, MYCN-amplified neuroblastoma.
Ewing sarcoma can arise in either bone or soft tissue locations. We sought to investigate if patient characteristics, treatment strategies, and outcomes differ between skeletal Ewing sarcoma and extraskeletal Ewing sarcoma (EES).
Patients < 40 years of age with Ewing sarcoma or peripheral primitive neuroectodermal tumor (PNET) reported to the US SEER database from 1973 to 2007 were evaluated based on skeletal (n=1519) vs. extraskeletal (n=683) site of origin. Patient characteristics were compared using Fisher exact tests. Overall survival was estimated by Kaplan-Meier methods and compared using log-rank tests and Cox models.
Patients with EES had a higher mean age (19.5 vs. 16.3 years; p < 0.001) and were less likely to be male (53.4% vs. 63.3%; p < 0.001) or white (84.8% vs. 92.5%; p < 0.001) compared to patients with skeletal tumors. Extraskeletal tumors were more likely to arise in axial locations (72.9% vs. 54.2%; p = 0.001), though less likely to arise specifically in the pelvis (19.8% vs. 26.6%; p < 0.001). Metastatic status or tumor size did not differ by group. Five-year overall survival was superior for localized EES compared to localized skeletal tumors (69.7% vs. 62.6%; p = 0.02). The hazard ratio for death in patients with localized skeletal tumors compared to localized EES was 2.36 (95% CI 1.61-3.44) beyond 24 months from initial diagnosis.
Patient characteristics and outcomes differ among patients with EES compared to patients with skeletal Ewing sarcoma. These findings may have important implications for patient care.
Ewing sarcoma; extraskeletal; extraosseous; PNET; SEER
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 131I-metaiodobenzylguanidine (MIBG) would lead to preferential accumulation of the latter in neuroblastoma (NB) tumors via increased expression of the human norepinephrine transporter (NET).
In vitro and in vivo experiments examined the effect of vorinostat on the expression of NET, an uptake transporter for 131I-MIBG. Human NB cell lines (Kelly and SH-SY-5Y) and NB1691luc mouse xenografts were employed. The upregulated NET protein was characterized for its effect on 123I-MIBG biodistribution.
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-fold and 2.5 fold increases were observed in Kelly and SH-SY-5Y cells, respectively, pre-treated 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 123I-MIBG biodistribution was observed in tumors that exhibited enhanced uptake in vorinostat treated (0.062 ± 0.011 μCi/(mg tissue-dose injected)) versus untreated mice (0.022 ± 0.003 μCi/(mg tissue-dose injected); p < 0.05).
The results of our study provide preclinical evidence that vorinostat treatment can enhance NB therapy with 131I-MIBG.
norepinephrine transporter; MIBG; Vorinostat; histone deacetylase inhibitor; neuroblastoma xenograft; biodistribution
The incidence of Ewing sarcoma varies by race, with very low rates among persons of African and East Asian ancestry. The incidence by race of other mesenchymal tumors that also harbor EWSR1 translocations has not been studied.
The SEER database was queried to find cases of mesenchymal tumors associated with EWSR1 translocations: Ewing sarcoma; clear cell sarcoma; extraskeletal myxoid chondrosarcoma; myxoid liposarcoma; desmoplastic small round cell tumor and myoepithelial tumor. Age-adjusted incidence rates were calculated for white, African-American, and Asian/Native American populations and compared statistically.
Ewing sarcoma was significantly less common in the African-American and Asian/Native American populations compared to the white population, with incidence rate ratios of 0.12 (95% confidence interval 0.08 – 0.20; p < 0.001) and 0.54 (95% confidence interval 0.41 – 0.69; p < 0.001), respectively. Desmoplastic small round cell tumor was significantly more common in the African-American population compared to the white population (incidence rate ratio 3.0; 95% confidence interval 1.62 – 5.49; p < 0.001). Myxoid liposarcoma was significantly less common in the Asian/Native American population compared to the white population (incidence rate ratio 0.72; 95% confidence interval 0.56 – 0.92; p-value 0.006). The incidence rates for extraskeletal myxoid chondrosarcoma, myoepithelial tumors, and clear cell sarcoma did not differ significantly by race.
Tumors associated with EWSR1 translocation are not uniformly more common in people of European ancestry.
The relationship between race and EWSR1 somatic translocation is complex. Future studies investigating the genetic epidemiology of EWSR1 translocated tumors are required.
Mesenchymal tumors; sarcoma translocations; EWSR1; race; SEER
Histone deacetylase (HDAC) inhibitors can radiosensitize cancer cells. Radiation is critical in high-risk neuroblastoma treatment, and combinations of HDAC inhibitor vorinostat and radiation are proposed for neuroblastoma trials. Therefore, we investigated radiosensitizing effects of vorinostat in neuroblastoma. Treatment of neuroblastoma cell lines decreased cell viability and resulted in additive effects with radiation. In a murine metastatic neuroblastoma in vivo model vorinostat and radiation combinations decreased tumor volumes compared to single modality. DNA repair enzyme Ku-86 was reduced in several neuroblastoma cells treated with vorinostat. Thus, vorinostat potentiates anti-neoplastic effects of radiation in neuroblastoma possibly due to down-regulation of DNA repair enzyme Ku-86.
Metastatic neuroblastoma; Radiation; Vorinostat; DNA repair
Single-agent topotecan (TOPO) and combination topotecan and cyclophosphamide (TOPO/CTX) were compared in a phase II randomized trial in relapsed/refractory neuroblastoma. Because responders often underwent further therapies, novel statistical methods were required to compare the long-term outcome of the two treatments.
Patients and Methods
Children with refractory/recurrent neuroblastoma (only one prior aggressive chemotherapy regimen) were randomly assigned to daily 5-day topotecan (2 mg/m2) or combination topotecan (0.75 mg/m2) and cyclophosphamide (250 mg/m2). A randomized two-stage group sequential design enrolled 119 eligible patients. Toxicity and response were estimated. Long-term outcome of protocol therapy was assessed using novel methods—causal inference—which allowed adjustment for the confounding effect of off-study therapies.
Seven more responses were observed for TOPO/CTX (complete response [CR] plus partial response [PR], 18 [32%] of 57) than TOPO (CR+PR, 11 [19%] of 59;P = .081); toxicity was similar. At 3 years, progression-free survival (PFS) and overall survival (OS) were 4% ± 2% and 15% ± 4%, respectively. PFS was significantly better for TOPO/CTX (P = .029); there was no difference in OS. Older age at diagnosis and lack of MYCN amplification predicted increased OS (P < .05). Adjusting for randomized treatment effect and subsequent autologous stem-cell transplantation, there was no difference between TOPO and TOPO/CTX in terms of the proportion alive at 2 years.
TOPO/CTX was superior to TOPO in terms of PFS, but there was no OS difference. After adjustment for subsequent therapies, no difference was detected in the proportion alive at 2 years. Causal inference methods for assessing long-term outcomes of phase II therapies after subsequent treatment can elucidate effects of initial therapies.
Since osteosarcoma is extremely rare in children ≤ 5 years of age, we sought to investigate if tumor characteristics, treatment strategies, and outcomes differ compared to older patients.
Patients < 20 years of age with high-grade osteosarcoma reported to national SEER database from 1973–2006 were separated into two groups based on age at diagnosis: ≤ 5 years (n=49) and 6–19 years (n = 1687). Patient, tumor, and treatment characteristics were compared using Fisher exact tests. Overall survival was estimated by Kaplan-Meier methods and compared using log-rank tests and Cox models.
Patients ≤ 5 years had higher proportions of osteosarcoma arising from the upper limb compared to older patients (24.5% vs. 11.2%; p = 0.006). These very young patients had a significantly higher proportion of telangiectatic histology (10.2% vs. 2.9%; p = 0.017). Sex, metastatic status, race, or ethnicity did not differ by age. A higher proportion of very young patients was treated with amputation (55.2% vs. 27.3%; p = 0.002). Five-year overall survival was inferior for patients with localized osteosarcoma 5 years of age or younger compared to older children (51.9% vs. 67.3%; p = 0.03). After controlling for metastatic status, year of diagnosis, and tumor site, the hazard ratio for death in very young patients was 1.6 (95% confidence interval 1.02 – 2.36; p = 0.04) compared to older patients.
Tumor characteristics, treatment, and outcomes differ among children ≤ 5 years of age compared to older pediatric patients. These differences may reflect differences in tumor biology.
osteosarcoma; young children; treatment; outcome; SEER
Preclinical and preliminary clinical data indicate that ch14.18, a monoclonal antibody against the tumor-associated disialoganglioside GD2, has activity against neuroblastoma and that such activity is enhanced when ch14.18 is combined with granulocyte–macrophage colony-stimulating factor (GM-CSF) or interleukin-2. We conducted a study to determine whether adding ch14.18, GM-CSF, and interleukin-2 to standard isotretinoin therapy after intensive multimodal therapy would improve outcomes in high-risk neuroblastoma.
Patients with high-risk neuroblastoma who had a response to induction therapy and stem-cell transplantation were randomly assigned, in a 1:1 ratio, to receive standard therapy (six cycles of isotretinoin) or immunotherapy (six cycles of isotretinoin and five concomitant cycles of ch14.18 in combination with alternating GM-CSF and interleukin-2). Event-free survival and overall survival were compared between the immunotherapy group and the standard-therapy group, on an intention-to-treat basis.
A total of 226 eligible patients were randomly assigned to a treatment group. In the immunotherapy group, a total of 52% of patients had pain of grade 3, 4, or 5, and 23% and 25% of patients had capillary leak syndrome and hypersensitivity reactions, respectively. With 61% of the number of expected events observed, the study met the criteria for early stopping owing to efficacy. The median duration of follow-up was 2.1 years. Immunotherapy was superior to standard therapy with regard to rates of event-free survival (66±5% vs. 46±5% at 2 years, P = 0.01) and overall survival (86±4% vs. 75±5% at 2 years, P = 0.02 without adjustment for interim analyses).
Immunotherapy with ch14.18, GM-CSF, and interleukin-2 was associated with a significantly improved outcome as compared with standard therapy in patients with high-risk neuroblastoma.
Poor outcome in Stage 4 neuroblastoma may be improved with increased dose intensity of therapy. We investigated the feasibility of sequential collection and infusion of peripheral blood stem cells (PBSC) as hematopoietic support for non-myeloablative dose intensive induction chemotherapy given every 21-28 days.
Twenty-two children with Stage 4 neuroblastoma (≥ 1yr of age) received 2 cycles of high dose cyclophosphamide (4 gm/m2), doxorubicin (75mg/m2) and vincristine (2mg/m2) followed by 3 cycles of interpatient dose escalating carboplatin (dose level 0 = 800 mg/m2; dose level 1 = 1000 mg/m2), high dose cyclophosphamide (4 gm/m2) and etoposide (600 mg/m2). PBSC were harvested following cycle 2, 3, and 4 in Cohort 1 and infused after each subsequent cycle. In Cohort 2, PBSC were harvested after cycle 2 and split into 3 aliquots for infusion. Dose limiting toxicity (DLT) and ability to administer cycles within 28 days was assessed.
Sufficient PBSC (≥ 2 × 106 CD34 cells/kg per infusion) were collected from 17/21 eligible patients with minimal toxicity and no detectable neuroblastoma cells by immunocytology. Carboplatin at 1000 mg/m2 resulted in DLT of delayed platelet recovery > 28 days in 4/8 patients. Despite de-escalation to 800 mg/m2, platelet DLT occurred in 4/7 Cohort 1 and 3/7 Cohort 2 patients.
As defined in this protocol, doses of carboplatin were not tolerable with the PBSC dose administered. However, it was feasible to collect sufficient PBSC from small neuroblastoma patients to use as hematopoietic support with minimal risk of tumor contamination and toxicity.
neuroblastoma; peripheral blood stem cell support; dose intensity; carboplatin
Ewing sarcoma (ES) is a malignant tumor of bone or soft tissue. One of the few risk factors for developing ES is race, with a higher incidence in populations of European rather than African or Asian ancestry. The goal of this study was to evaluate racial and ethnic differences in presentation and overall survival (OS) among patients diagnosed with ES before age 40.
Data from the SEER database identified1715 patients with ES <40 years of age from 1973–2005. Racial and ethnic group differences were compared using chi square tests. OS was estimated by Kaplan-Meier analysis and compared using log-rank tests and Cox models.
Black patients had significantly more soft-tissue tumors compared to white non-Hispanic patients (p < 0.0001). Asian and white Hispanic patients had an intermediate frequency of soft tissue tumors that also differed from white non-Hispanic patients (p < 0.0001). White Hispanic patients presented with a higher proportion of larger tumors compared to white non-Hispanic patients (p = 0.042). Black patients were older than white non-Hispanic patients (p = 0.012). Sex, frequency of pelvic tumors, and metastatic status did not differ by ethnicity or race. OS was different according to race and ethnicity. Even after controlling for known confounders, OS was significantly worse for black, Asian, and white Hispanic patients compared to white non-Hispanic patients (p=0.0031, p= 0.0182 and p=0.0051, respectively).
Ethnic and racial differences in characteristics and outcomes for patients with ES exist. Understanding the etiology of these differences requires further study.
Ewing sarcoma family of tumors; prognosis; soft-tissue; race; ethnicity; SEER
A new method for detecting circulating Ewing sarcoma cells using flow cytometry is described. This strategy exploits the nearly universal expression of CD99 and the lack of expression of CD45 by Ewing sarcoma cells.
Ewing sarcoma cell line A673, peripheral blood mononuclear cells (PBMCs), and bone marrow mononuclear cells (BMMCs) were stained for CD99 and CD45 in order to detect CD99+CD45- cells by flow cytometry. Known quantities of A673 Ewing sarcoma cells were spiked into control PBMCs to test the accuracy of this method. Control PBMCs were evaluated to assess the level of background staining.
Flow cytometry was accurate at frequencies as low as one A673 cell per 500,000 PBMCs. The background rate of CD99+CD45- cell detection was low in PBMCs from 9 healthy volunteers (median 0.0001% of total cells; range 0-0.00046%) and was further reduced by incorporating stains to exclude dead cells, progenitor cells, and monocytes. In one subject with newly diagnosed localized Ewing sarcoma, CD99+CD45- cells were detected in both blood (0.0021%) and bone marrow (0.048%).
Multicolor flow cytometry for CD99+CD45- cells provides a new strategy for detecting circulating Ewing sarcoma cells. Clinical evaluation and validation of this method is ongoing.
Ewing sarcoma; flow cytometry; CD99
Neuroblastoma is a common pediatric malignancy that metastasizes to the liver, bone, and other organs. Children with metastatic disease have a less than 50% chance of survival with current treatments. Insulin-like growth factors (IGFs) stimulate neuroblastoma growth, survival, and motility, and are expressed by neuroblastoma cells and the tissues they invade. Thus, therapies that disrupt the effects of IGFs on neuroblastoma tumorigenesis may slow disease progression. We show that NVP-AEW541, a specific inhibitor of the IGF-I receptor (IGF-IR), potently inhibits neuroblastoma growth in vitro. Nordihydroguaiaretic acid (NDGA), a phenolic compound isolated from the creosote bush (Larrea divaricata), has anti-tumor properties against a number of malignancies, has been shown to inhibit the phosphorylation and activation of the IGF-IR in breast cancer cells, and is currently in Phase I trials for prostate cancer. In the present study in neuroblastoma, NDGA inhibits IGF-I-mediated activation of the IGF-IR and disrupts activation of ERK and Akt signaling pathways induced by IGF-I. NDGA inhibits growth of neuroblastoma cells and induces apoptosis at higher doses, causing IGF-I-resistant activation of caspase-3 and a large increase in the fraction of sub-G0 cells. In addition, NDGA inhibits the growth of xenografted human neuroblastoma tumors in nude mice. These results indicate that NDGA may be useful in the treatment of neuroblastoma and may function in part via disruption of IGF-IR signaling.
insulin-like growth factor I receptor; neuroblastoma; small molecule inhibitor; nordihydroguaiaretic acid; apoptosis
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 [18F]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 (131I) MIBG (NANT-2000-01) were eligible for inclusion if they had concomitant FDG-PET and MIBG scans. 131I-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.
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.
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.