Second malignancies in patients with neuroblastoma: the effects of risk-based therapy

Feasibility of 18F-DOPA and 18F-FDG PET/CT for guiding decision-making for localized incidental neuroblastoma in infants under 18 months of age

BACKGROUND

Neuroblastoma varies widely in risk. Risk indicators in infants with incidental neuroblastoma refine treatment confidence for observation or intervention. The potential of functional imaging, particularly PET/CT, remains to be defined.

PROCEDURE

A retrospective review of infants under 18 months diagnosed with incidental neuroblastoma from 2008 to May 2022 in our institute was conducted. Before October 2015, incidental patients were treated similarly to symptomatic cases, undergoing biopsy or surgical excision upon diagnosis (early cohort). Post October 2015 (late cohort), treatment decisions were guided by PET/CT findings, with 18F-DOPA PET/CT confirming diagnosis and staging. For tumors with low 18F-FDG uptake, an expectant observation approach was considered. Patient characteristics, diagnostic methods, image findings at diagnosis, treatment courses, and responses were compared between cohorts.

RESULTS

Thirty infants less than 18 months were identified with incidental neuroblastoma and completed PET/CT at diagnosis. The early and late cohorts each comprised 15 patients. In the late cohort, nine out of 15 patients (60%) presented with localized FDG non-avid tumors were offered the option of expectant observation. Of these, seven patients opted for observation, thereby avoiding surgery. Treatment outcomes were comparable between early and late cohorts, except for one mortality of a patient who, despite showing 18F-FDG activity, declined treatment.

CONCLUSIONS

This study demonstrates the potential utility of 18F-DOPA and 18F-FDG PET/CT scans in aiding clinical decision-making for infants with localized, incidental neuroblastoma. Given the concerns regarding radiation exposure, such imaging may be valuable for cases with suspected metastasis, initial large tumor size, or growth during follow-up.

Inflammatory myofibroblastic tumor of the liver after adrenal neuroblastoma surgery: a case report

A boy aged 55 months was diagnosed with stage IV Neuroblastoma (NB) of the right adrenal gland 2 years ago. Preoperative chemotherapy was given and he was then treated with retroperitoneal tumor resection and lymph node dissection. After surgery, the children were transferred to the Hemato-Oncology Department for chemotherapy according to the high-risk group NB, with outpatient follow-up every 6 months. In the second postoperative year, abdominal computed tomography (CT) scan revealed a rounded hypodense area in the upper part of the right posterior lobe of the liver, with marked inhomogeneous enhancement in the venous phase after enhancement, which was surgically resected, and postoperative pathology confirmed inflammatory myofibroblastic tumor (IMT) of liver. The patient was not given any special treatment after surgery. In this study, whole transcriptome sequencing was performed on the postoperative specimen of adrenal NB and the specimen of IMT of liver. This unusual case emphasizes the need for close monitoring of second tumor development in NB survivors even in the absence of known predisposing factors.

Opaganib Downregulates N-Myc Expression and Suppresses In Vitro and In Vivo Growth of Neuroblastoma Cells

Neuroblastoma (NB), the most common cancer in infants and the most common solid tumor outside the brain in children, grows aggressively and responds poorly to current therapies. We have identified a new drug (opaganib, also known as ABC294640) that modulates sphingolipid metabolism by inhibiting the synthesis of sphingosine 1-phosphate (S1P) by sphingosine kinase-2 and elevating dihydroceramides by inhibition of dihydroceramide desaturase. The present studies sought to determine the potential therapeutic activity of opaganib in cell culture and xenograft models of NB. Cytotoxicity assays demonstrated that NB cells, including cells with amplified MYCN, are effectively killed by opaganib concentrations well below those that accumulate in tumors in vivo. Opaganib was shown to cause dose-dependent decreases in S1P and hexosylceramide levels in Neuro-2a cells, while concurrently elevating levels of dihydroceramides. As with other tumor cells, opaganib reduced c-Myc and Mcl-1 protein levels in Neuro-2a cells, and also reduced the expression of the N-Myc protein. The in vivo growth of xenografts of human SK-N-(BE)2 cells with amplified MYCN was suppressed by oral administration of opaganib at doses that are well tolerated in mice. Combining opaganib with temozolomide plus irinotecan, considered the backbone for therapy of relapsed or refractory NB, resulted in increased antitumor activity in vivo compared with temozolomide plus irinotecan or opaganib alone. Mice did not lose additional weight when opaganib was combined with temozolomide plus irinotecan, indicating that the combination is well tolerated. Opaganib has additive antitumor activity toward Neuro-2a tumors when combined with the checkpoint inhibitor anti-CTLA-4 antibody; however, the combination of opaganib with anti-PD-1 or anti-PD-L1 antibodies did not provide increased antitumor activity over that seen with opaganib alone. Overall, the data demonstrate that opaganib modulates sphingolipid metabolism and intracellular signaling in NB cells and inhibits NB tumor growth alone and in combination with other anticancer drugs. Amplified MYCN does not confer resistance to opaganib, and, in fact, the drug attenuates the expression of both c-Myc and N-Myc. The safety of opaganib has been established in clinical trials with adults with advanced cancer or severe COVID-19, and so opaganib has excellent potential for treating patients with NB, particularly in combination with temozolomide and irinotecan or anti-CTLA-4 antibody.

Generation of Orthotopic and Subcutaneous Patient-Derived Xenograft Models from Diverse Clinical Tissue Samples of Pediatric Extracranial Solid Tumors

Realistic and renewable laboratory models that accurately reflect the distinct clinical features of childhood cancers have enormous potential to speed research progress. These models help us to understand disease biology, develop new research methods, advance new therapies to clinical trial, and implement personalized medicine. This chapter describes methods to generate patient-derived xenograft models of neuroblastoma and rhabdomyosarcoma, two tumor types for which children with high-risk disease have abysmal survival outcomes and survivors have lifelong-debilitating effects from treatment. Further, this protocol addresses model development from diverse clinical tumor tissue samples, subcutaneous and orthotopic engraftment, and approaches to avoid model loss.

Chimeric single-chain variable fragment-human immunoglobulin G crystallizable fragment antibody against GD2 for neuroblastoma targeted immunotherapy

Aim

The present study aims to generate chimeric mouse single-chain variable fragment (scFv) and immunoglobulin G1 (IgG1) crystallizable fragment (Fc) antibody against disialoganglioside (GD2) for the treatment of neuroblastoma (NB). The generated scFv-IgG Fc antibody, lacking first constant domain of heavy chain (CH1), is of a smaller size than the natural antibody and has anti-tumor activity.

Methods

Vector for scFv-IgG Fc antibody was constructed and scFv-IgG Fc antibody was expressed in human embryonic kidney 293T (HEK293T) cell line. Purification of scFv-IgG Fc antibody from the culture supernatant of transfected HEK293T cells was performed by Protein G affinity chromatography. The structure and binding activity of scFv-IgG Fc antibody were verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), western blotting (WB), and immunofluorescence techniques. Anti-tumor activities by antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) were determined.

Results

Using plasmid fusion-human IgG1-Fc2 tag vector (pFUSE-hIgG1-Fc2), a plasmid vector encoding chimeric mouse scFv and hIgG1 Fc antibody against GD2 was successfully constructed. This vector was transfected into human HEK293T cells to produce scFv-IgG Fc antibody. The transfected HEK293T cells could produce chimeric scFv-IgG Fc antibody against GD2, which lacks the IgG heavy chain CH1 domain but carries CH2 and CH3 domains. The chimeric antibodies could be purified from the culture supernatant of the transfected HEK293T culture in the presence of zeocin drug. The produced GD2 scFv-IgG Fc antibodies, which are smaller in size than the intact antibody, could trigger the killing of GD2 expressed NB cell line SH-SY5Y by ADCC and ADCP mechanisms.

Conclusions

The results indicate that chimeric scFv-hIgG Fc antibody, lacking heavy chain CH1 domain, could mediate antibody induced anti-tumor activities. The small size of this type of chimeric antibody may be employed as anti-GD2 antibody for NB therapy.

Persistence of Racial and Ethnic Disparities in Risk and Survival for Patients with Neuroblastoma over Two Decades

BACKGROUND

Racial/ethnic survival disparities in neuroblastoma were first reported more than a decade ago. We sought to investigate if these disparities have persisted with current era therapy.

METHODS

Two patient cohorts were identified in the International Neuroblastoma Risk Group Data Commons (INRGdc) (Cohort 1: diagnosed 2001-2009, n=4359; Cohort 2: diagnosed 2010-2019, n=4891). Chi-squared tests were used to assess the relationship between race/ethnicity and clinical and biologic features. Survival was estimated by the Kaplan-Meier method. Cox proportional hazards regression analyses were performed to investigate the association between racial/ethnic groups and prognostic markers.

RESULTS

Significantly higher 5-year event-free survival (EFS) and overall survival (OS) were observed for Cohort 2 compared to Cohort 1 (P<0.001 and P<0.001, respectively). Compared to White patients, Black patients in both cohorts had a higher proportion of high-risk disease (Cohort 1: P<0.001; Cohort 2: P<0.001) and worse EFS (Cohort 1: P<0.001; Cohort 2 P<0.001) and OS (Cohort 1: P<0.001; Cohort 2: P<0.001). In Cohort 1, Native Americans also had a higher proportion of high-risk disease (P=0.03) and inferior EFS/OS. No significant survival disparities were observed for low- or intermediate-risk patients in either cohort or high-risk patients in Cohort 1. Hispanic patients with high-risk disease in Cohort 2 had significantly inferior OS (P=0.047). Significantly worse OS, but not EFS, (P=0.006 and P=0.02, respectively) was also observed among Black and Hispanic patients assigned to receive post-Consolidation dinutuximab on clinical trials (n=885).

CONCLUSION

Racial/ethnic survival disparities have persisted over time and were observed among high-risk patients assigned to receive post-Consolidation dinutuximab.

Target Genes of c-MYC and MYCN with Prognostic Power in Neuroblastoma Exhibit Different Expressions during Sympathoadrenal Development

Deregulation of the MYC family of transcription factors c-MYC (encoded by MYC), MYCN, and MYCL is prevalent in most human cancers, with an impact on tumor initiation and progression, as well as response to therapy. In neuroblastoma (NB), amplification of the MYCN oncogene and over-expression of MYC characterize approximately 40% and 10% of all high-risk NB cases, respectively. However, the mechanism and stage of neural crest development in which MYCN and c-MYC contribute to the onset and/or progression of NB are not yet fully understood. Here, we hypothesized that subtle differences in the expression of MYCN and/or c-MYC targets could more accurately stratify NB patients in different risk groups rather than using the expression of either MYC gene alone. We employed an integrative approach using the transcriptome of 498 NB patients from the SEQC cohort and previously defined c-MYC and MYCN target genes to model a multigene transcriptional risk score. Our findings demonstrate that defined sets of c-MYC and MYCN targets with significant prognostic value, effectively stratify NB patients into different groups with varying overall survival probabilities. In particular, patients exhibiting a high-risk signature score present unfavorable clinical parameters, including increased clinical risk, higher INSS stage, MYCN amplification, and disease progression. Notably, target genes with prognostic value differ between c-MYC and MYCN, exhibiting distinct expression patterns in the developing sympathoadrenal system. Genes associated with poor outcomes are mainly found in sympathoblasts rather than in chromaffin cells during the sympathoadrenal development.

Systematic review of clinical drug development activities for neuroblastoma from 2011 to 2020

BACKGROUND

Understanding the landscape of clinical trials for patients with neuroblastoma may inform efforts to improve drug development.

PROCEDURE

We evaluated therapeutic trials for patients with neuroblastoma from 2011 to 2020 in our search using clinical trial information from ClinicalTrials.gov, Clinicaltrialregister.eu, PubMed, and American Society of Clinical Oncology (ASCO) annual meeting collection. Trends in trials and treatments over time were evaluated qualitatively.

RESULTS

A total of 192 trials met inclusion criteria. A median of 20.5 trials were started per year, which was stable over time. There were 87 (45%) phase 1, 100 (51%) phase 2, and only five (2.6%) phase 3 trials. The median time to completion was 4.9 years for phase 1 and 2 trials (no phase 3 trials reported as completed during the study period). In all, 34% of trials were international, while 20% of trials were intercontinental. Eighty-nine percent of nonmyeloablative trials included at least one novel agent. 48% of these trials studied combination therapies, and 86% of these combinations included conventional chemotherapy. Among 157 trials that included a targeted agent, 78 targets were identified, with GD2 being the primary target under investigation in 16.7% of these trials. Only eight trials were included in regulatory decisions, which led to European Medicines Agency (EMA) or Food and Drug Administration (FDA) approval for neuroblastoma.

CONCLUSIONS

The large number of trials initiated per year, the range of targets, and the rate of intercontinental collaboration are encouraging. The paucity of late-stage trials, the prolonged trial duration, and relative lack of combination studies are major causes of concern. This work will inform future drug development for neuroblastoma.

Long-Term Morbidity and Mortality Among Survivors of Neuroblastoma Diagnosed During Infancy: A Report From the Childhood Cancer Survivor Study

PURPOSE

To describe the risk of late mortality, subsequent malignant neoplasms (SMNs), and chronic health conditions (CHCs) in survivors of neuroblastoma diagnosed in infancy by treatment era and exposures.

METHODS

Among 5-year survivors of neuroblastoma in the Childhood Cancer Survivor Study diagnosed age < 1 year between 1970 and 1999, we examined the cumulative incidence of late (> 5 years from diagnosis) mortality, SMN, and CHCs (grades 2-5 and 3-5). Multivariable Cox regression models estimated hazard ratios (HRs) and 95% CIs by decade and treatment (surgery-alone v chemotherapy with or without surgery [C ± S] v radiation with or without chemotherapy ± surgery [R ± C ± S]) among survivors and between survivors and 5,051 siblings.

RESULTS

Among 1,397 eligible survivors, the 25-year cumulative incidence of late mortality was 2.1% (95% CI, 1.3 to 3.9) with no difference by treatment era. Among 990 participants who completed a baseline survey, fewer survivors received radiation in more recent eras (51.2% 1970s, 20.4% 1980s, and 10.1% 1990s; P < .001). Risk of SMN was elevated only among individuals treated with radiation-containing regimens compared with surgery alone (HR[C ± S], 3.2 [95% CI, 0.9 to 11.6]; HR[R ± C ± S], 5.7 [95% CI, 1.2 to 28.1]). In adjusted models, there was a 50% reduction in risk of grade 3-5 CHCs in the 1990s versus 1970s (HR, 0.5 [95% CI, 0.3 to 0.9]; P = .01); individuals treated with radiation had a 3.6-fold risk for grade 3-5 CHCs (95% CI, 2.1 to 6.2) versus those treated with surgery alone. When compared with siblings, risk of grade 3-5 CHCs for survivors was lowest in the most recent era (HR[1970s], 4.7 [95% CI, 3.4 to 6.5]; HR[1980s], 4.6 [95% CI, 3.3 to 6.4]; HR[1990s], 2.5 [95% CI, 1.7 to 3.9]).

CONCLUSION

Neuroblastoma survivors treated during infancy have a relatively low absolute burden of late mortality and SMN. Encouragingly, risk of CHCs has declined in more recent eras with reduced exposure to radiation therapy.

Advancing therapy for neuroblastoma

Neuroblastomas are tumours of sympathetic origin, with a heterogeneous clinical course ranging from localized or spontaneously regressing to widely metastatic disease. Neuroblastomas recapitulate many of the features of sympathoadrenal development, which have been directly targeted to improve the survival outcomes in patients with high-risk disease. Over the past few decades, improvements in the 5-year survival of patients with metastatic neuroblastomas, from <20% to >50%, have resulted from clinical trials incorporating high-dose chemotherapy with autologous stem cell transplantation, differentiating agents and immunotherapy with anti-GD2 monoclonal antibodies. The next generation of trials are designed to improve the initial response rates in patients with high-risk neuroblastomas via the addition of immunotherapies, targeted therapies (such as ALK inhibitors) and radiopharmaceuticals to standard induction regimens. Other trials are focused on testing precision medicine strategies for patients with relapsed and/or refractory disease, enhancing the antitumour immune response and improving the effectiveness of maintenance regimens, in order to prolong disease remission. In this Review, we describe advances in delineating the pathogenesis of neuroblastoma and in identifying the drivers of high-risk disease. We then discuss how this knowledge has informed improvements in risk stratification, risk-adapted therapy and the development of novel therapies.

First phase 1 clinical study of olaparib in pediatric patients with refractory solid tumors

BACKGROUND

The survival of patients with high-risk, refractory, relapsed, or metastatic solid tumors remains dismal. A poly(ADP-ribose) polymerase (PARP) inhibitor could be effective for the treatment of pediatric solid tumors with defective homologous recombination.

METHODS

This open-label, multicenter phase 1 clinical trial evaluated the safety, tolerability, and efficacy of olaparib, a PARP inhibitor, in pediatric patients with refractory solid tumors to recommend a dose for Phase 2 trials. Olaparib (62.5, 125, and 187.5 mg/m² twice daily) was administered orally every day (1 cycle = 28 days) using a standard 3 + 3 dose-escalation design. Patients aged 3-18 years with recurrent pediatric solid tumors were eligible. Pharmacokinetic and pharmacodynamic analyses were performed.

RESULTS

Fifteen patients were enrolled and received olaparib monotherapy, which was well tolerated. The recommended phase 2 dose for daily administration was 187.5 mg/m² twice daily. Pharmacokinetics were dose proportional. The area under the concentration-time curve from 0 to 12 h and the peak plasma concentration for 187.5 mg/m² twice daily in children were comparable to previous data obtained in a 200-mg, twice-daily cohort and lower than those in the 300-mg twice-daily cohort in adults. Pharmacodynamic studies demonstrated substantial inhibition of PARP activity. Two partial responses were observed in patients with Wilms tumor and neuroblastoma.

CONCLUSIONS

This report is the first clinical trial to describe the use of a PARP inhibitor as monotherapy in children. Olaparib was well tolerated, with preliminary antitumor responses observed in DNA damage response-defective pediatric tumors.

LAY SUMMARY

This Phase 1 trial evaluated the efficacy and safety of olaparib in patients with refractory childhood solid tumors. Olaparib was well tolerated, achieving objective response in 2/15 patients. The DNA damage response was attenuated in nearly one-half of advanced neuroblastoma patients, demonstrating the utility of the PARP inhibitor. The results support further investigation of olaparib as a new treatment for DNA damage-response or repair-defective pediatric cancers.

High-Risk and Relapsed Neuroblastoma: Toward More Cures and Better Outcomes

Approximately half of the patients diagnosed with neuroblastoma are classified as having high-risk disease. This group continues to have inadequate cure rates despite multiagent chemotherapy, surgery, high-dose chemotherapy with autologous stem cell rescue, and immunotherapy directed against GD2. We review current efforts to try to improve outcomes in patients with newly diagnosed disease by integrating novel targeted therapies earlier in the course of the disease. We further examine a growing list of options available for patients with relapsed or refractory high-risk disease, with an eye toward graduating successful strategies from a relapsed/refractory setting to the frontline setting. Last, we review efforts to study and potentially mitigate the array of late effects faced by survivors of high-risk neuroblastoma.

Late effects in survivors of high-risk neuroblastoma following stem cell transplant with and without total body irradiation

BACKGROUND

Neuroblastoma is the most common extracranial solid tumor in children. Those with high-risk disease are treated with multimodal therapy, including high-dose chemotherapy, stem cell transplant, radiation, and immunotherapy that have led to multiple long-term complications in survivors. In the late 1990s, consolidation therapy involved myeloablative conditioning including total body irradiation (TBI) with autologous stem cell rescue. Recognizing the significant long-term toxicities of exposure to TBI, more contemporary treatment protocols have removed this from conditioning regimens. This study examines an expanded cohort of 48 high-risk neuroblastoma patients to identify differences in the late effect profiles for those treated with TBI and those treated without TBI.

PROCEDURE

Data on the study cohort were collected from clinic charts, provider documentation in the electronic medical record of visits to survivorship clinic, including all subspecialists, and ancillary reports of laboratory and diagnostic tests done as part of risk-based screening at each visit.

RESULTS

All 48 survivors of BMT for high-risk neuroblastoma had numerous late effects of therapy, with 73% having between five and 10 late effects. TBI impacted some late effects significantly, including growth hormone deficiency (GHD), bone outcomes, and cataracts.

CONCLUSION

Although high-risk neuroblastoma survivors treated with TBI have significant late effects, those treated without TBI also continue to have significant morbidity related to high-dose chemotherapy and local radiation. A multidisciplinary care team assists in providing comprehensive care to those survivors who are at highest risk for significant late effects.

PCLAF promotes neuroblastoma G1/S cell cycle progression via the E2F1/PTTG1 axis

PCLAF (PCNA clamp-associated factor), also known as PAF15/ KIAA0101, is overexpressed in most human cancers and is a predominant regulator of tumor progression. However, its biological function in neuroblastoma remains unclear. PCLAF is extremely overexpressed in neuroblastoma and is associated with poor prognosis. Through the analysis of various data sets, we found that the high expression of PCLAF is positively correlated with increased stage and high risk of neuroblastoma. Most importantly, knocking down PCLAF could restrict the proliferation of neuroblastoma cells in vitro and in vitro. By analyzing RNA-seq data, we found that the enrichment of cell cycle-related pathway genes was most significant among the differentially expressed downregulated genes after reducing the expression of PCLAF. In addition, PCLAF accelerated the G1/S transition of the neuroblastoma cell cycle by activating the E2F1/PTTG1 signaling pathway. In this study, we reveal the mechanism by which PCLAF facilitates cell cycle progression and recommend that the PCLAF/E2F1/PTTG1 axis is a therapeutic target in neuroblastoma.

Therapeutically targeting oncogenic CRCs facilitates induced differentiation of NB by RA and the BET bromodomain inhibitor

Retinoic acids (RAs) are the most successful therapeutics for cancer differentiation therapy used in high-risk neuroblastoma (NB) maintenance therapy but are limited in effectiveness. This study identifies a strategy for improving efficacy through disruption of cancer cell identity via BET inhibitors. Mutations that block development are theorized to cause NB through retention of immature cell identities contributing to oncogenesis. NB has two interchangeable cell identities, maintained by two different core transcriptional regulatory circuitries (CRCs): a therapy-resistant mesenchymal/stem cell state and a proliferative adrenergic cell state. MYCN amplification is a common mutation of high-risk NB and recently found to block differentiation by driving high expression of the adrenergic CRC transcription factor ASCL1. We investigated whether disruption of immature CRCs can promote RA-induced differentiation since only a subset of NB patients responds to RA. We found that silencing ASCL1, a critical member of the adrenergic CRC, or global disruption of CRCs with the BET inhibitor JQ1, suppresses gene expression of multiple CRC factors, improving RA-mediated differentiation. Further, JQ1 and RA synergistically decrease proliferation and induce differentiation in NB cell lines. Our findings support preclinical studies of RA and BET inhibitors as a combination therapy in treating NB.

Risk of developing second malignant neoplasms in patients with neuroblastoma: a population study of the US SEER database

BACKGROUND

Neuroblastoma is a common extracranial malignant tumor in children. Its main treatment modality is a combination of chemotherapy, radiotherapy, and surgery. Given the advances in chemotherapy regimens and the widespread use of bone marrow transplantation over the decades, there has been improvement in treatment efficacy, which has led to prolonged patient survival. Accordingly, long-term complications have become a growing concern among physicians and patients. This study aimed to analyze the survival rate of patients with neuroblastoma and the risk factors for developing second malignant neoplasms (SMNs).

METHODS

The SEER 18 Regs (1973-2015) and SEER 9 Regs (1973-2015) data of the surveillance, epidemiology, and end results (SEER) database of the US National Cancer Institute were adopted for survival and SMN analysis.

RESULTS

The 5-, 10-, and 20-year overall survival rates of patients with neuroblastoma were 67%, 65%, and 62%, respectively. Among 38 patients with neuroblastoma who presented with SMNs, those with abdomen as the primary site accounted for the majority (63.2%), followed by those with thorax (26.3%) and other sites (10.5%). SMNs occurred more commonly in non-specific neuroblastoma (incidence: 0.87%) than ganglioneuroblastoma (incidence: 0.3%). Compared with the general population, the risk of SMN is significantly higher (SIR = 4.36). The risk of developing SMNs was significantly higher in the digestive system (SIR = 7.29), bones and joints (SIR = 12.91), urinary system (SIR = 23.48), brain and other nervous systems (SIR = 5.70), and endocrine system (SIR = 5.84). Multivariate analysis revealed that the year of diagnosis (OR = 2.138, 95% CI = 1.634-2.797, p < 0.001) was the only independent risk factor for developing SMNs.

CONCLUSION

This study identifies the risk factor for developing SMNs in patients with neuroblastoma, which could facilitate individualized screening for high-risk patients, to allow early diagnosis and treatment of SMNs.

123Iodine-metaiodobenzylguanidine scintigraphy versus whole-body magnetic resonance imaging with diffusion-weighted imaging in children with high-risk neuroblastoma - pilot study

BACKGROUND

The prognostic value of the International Society of Paediatric Oncology European Neuroblastoma Research Network (SIOPEN) skeletal score using ¹²³iodine-metaiodobenzylguanidine (MIBG) has been confirmed for people with high-risk neuroblastoma. Whole-body MRI with diffusion-weighted imaging is used increasingly.

OBJECTIVE

To compare the original SIOPEN score and its adaption by diffusion-weighted imaging in high-risk stage 4 neuroblastoma and to evaluate any consequences of score differences on overall survival.

MATERIALS AND METHODS

This retrospective observational study included pediatric patients who underwent MIBG scintigraphy and whole-body MRI, including diffusion-weighted imaging, between 2010 and 2015. Semi-quantitative skeletal scores for each exam were calculated independently. A difference of two or more points was defined as clinically relevant and counted as M+ (more in diffusion-weighted imaging) or S+ (more in MIBG). In cases of a negative result in one of the studies, residual disease of 1 point was also rated as relevant. We tested correlation and differences on an exam basis and also grouped by different therapeutic conditions. Overall survival was used to evaluate prognostic relevance.

RESULTS

Seventeen children with 25 paired examinations were evaluated. Median MIBG scintigraphy score was 0 (interquartile range [IQR] 0-4, range 0-25) vs. a median whole-body MRI score of 1 (IQR 0-5.5, range 0-35) (P=0.018). A relevant difference between whole-body MRI and MIBG scintigraphy was noted in 14 of the 25 paired examinations (M+: n=9; S+: n=5). After treatment, the median survival of cases with M+ was 14 months (IQR 4-59, range 1-74 months), while S+ cases showed a median survival of 49 months (IQR 36-52, range 36-52 months) (P=0.413).

CONCLUSION

The SIOPEN scoring system is feasible for whole-body MRI but might result in slightly higher scores, probably because of MRI's superior spatial resolution. Further studies are necessary to validate any impact on prognosis.

Increased burden of familial-associated early-onset cancer risk among minority Americans compared to non-Latino Whites

Background

The role of race/ethnicity in genetic predisposition of early-onset cancers can be estimated by comparing family-based cancer concordance rates among ethnic groups.

Methods

We used linked California health registries to evaluate the relative cancer risks for first-degree relatives of patients diagnosed between ages 0 and 26, and the relative risks of developing distinct second primary malignancies (SPMs). From 1989 to 2015, we identified 29,631 cancer patients and 62,863 healthy family members. We calculated the standardized incident ratios (SIRs) of early-onset primary cancers diagnosed in proband siblings and mothers, as well as SPMs detected among early-onset patients. Analyses were stratified by self-identified race/ethnicity.

Results

Given probands with cancer, there were increased relative risks of any cancer for siblings and mothers (SIR = 3.32; 95% confidence interval [CI]: 2.85-3.85) and of SPMs (SIR = 7.27; 95% CI: 6.56-8.03). Given a proband with solid cancer, both Latinos (SIR = 4.98; 95% CI: 3.82-6.39) and non-Latino Blacks (SIR = 7.35; 95% CI: 3.36-13.95) exhibited significantly higher relative risk of any cancer in siblings and mothers when compared to non-Latino White subjects (SIR = 3.02; 95% CI: 2.12-4.16). For hematologic cancers, higher familial risk was evident for Asian/Pacific Islanders (SIR = 7.56; 95% CI: 3.26-14.90) compared to non-Latino whites (SIR = 2.69; 95% CI: 1.62-4.20).

Conclusions

The data support a need for increased attention to the genetics of early-onset cancer predisposition and environmental factors in race/ethnic minority families in the United States.

Funding

This work was supported by the V Foundation for funding this work (Grant FP067172).

Treatment and outcomes of 1041 pediatric patients with neuroblastoma who received multidisciplinary care in China

Importance

Neuroblastoma is the most common extracranial malignant solid tumor in children. Multidisciplinary care is critical to improving the survival of pediatric patients with neuroblastoma.

Objective

To systematically summarize the clinical characteristics of children with neuroblastoma and evaluate their prognosis with multidisciplinary care provided in a single center.

Methods

This retrospective study analyzed the clinical data of 1041 patients with neuroblastoma who were diagnosed, treated, and followed‐up in the Hematology‐Oncology Center of Beijing Children’s Hospital from 2007 to 2019.

Results

The median age at diagnosis was 34 months; 80.8% of the patients were younger than 5 years of age. Notably, 243 patients (23.3%) were classified as low‐risk, 249 patients (23.9%) were classified as intermediate‐risk, and 549 (52.7%) were classified as high‐risk. Furthermore, 956 patients underwent surgical resections; 986 (94.7%) patients received chemotherapy; and 176 patients with high‐risk neuroblastoma received hematopoietic stem cell transplantation. The 5‐year event‐free survival (EFS) rate was 91.3% and 5‐year overall survival (OS) rate was 97.5% in low‐risk group; in the intermediate‐risk group, these rates were 85.1% and 96.7%, respectively, while they were 37.7% and 48.9% in the high‐risk group (P < 0.001 for both). The 5‐year EFS and OS rates were significantly higher in patients diagnosed between 2015 and 2019 than in patients diagnosed between 2007 and 2014 (P < 0.001). In total, 278 patients (26.7%) exhibited tumor relapse or progression; the median interval until relapse or progression was 14 months. Of the 233 patients who died, 83% died of relapse or progression of neuroblastoma and 4.3% died of therapy‐related complications.

Interpretation

The 5‐year OS rate was low in high‐risk patients, compared with low‐and intermediate‐risk patients. Multidisciplinary care is critical for improvement of survival in pediatric patients with neuroblastoma. Additional treatment strategies should be sought to improve the prognosis of patients with high‐risk neuroblastoma.

Identification of Novel Small-Molecule Kinase Modulators for the Treatment of Neuroblastoma

Neuroblastoma represents 8-10% of all childhood cancer cases and is responsible for 15% of all cancer-related deaths in infants. Even though patients with low- and intermediate-risk disease have a good prognosis, the 5-year survival rate of the vast majority of patients with high-risk neuroblastoma is 50%. Despite extensive research efforts to find a cure for neuroblastoma, current treatment options are still limited. The aim of our study was to identify novel therapeutic compounds using high-throughput drug screening of a small molecule kinase inhibitor library containing 960 compounds. This screening resulted in the identification of two compounds, ST013381 and ST022328, that showed pronounced cytotoxic effects in six human neuroblastoma cell lines in vitro while having reduced effects in the BJ-5ta control cell line. These effects were observed in both MYCN-amplified and -non-amplified cells, indicating that these compounds can affect a wide range of neuroblastomas. Our experiments also revealed that several signaling pathways underlie the selective elimination of neuroblastoma cells by the ST013381 and ST022328 compounds. In summary, we have identified two novel compounds with a strong cytotoxic effect in vitro as promising agents for the treatment of neuroblastoma.

Accelerating development of high-risk neuroblastoma patient-derived xenograft models for preclinical testing and personalised therapy

Background

Predictive preclinical models play an important role in the assessment of new treatment strategies and as avatar models for personalised medicine; however, reliable and timely model generation is challenging. We investigated the feasibility of establishing patient-derived xenograft (PDX) models of high-risk neuroblastoma from a range of tumour-bearing patient materials and assessed approaches to improve engraftment efficiency.

Methods

PDX model development was attempted in NSG mice by using tumour materials from 12 patients, including primary and metastatic solid tumour samples, bone marrow, pleural fluid and residual cells from cytogenetic analysis. Subcutaneous, intramuscular and orthotopic engraftment were directly compared for three patients.

Results

PDX models were established for 44% (4/9) of patients at diagnosis and 100% (5/5) at relapse. In one case, attempted engraftment from pleural fluid resulted in an EBV-associated atypical lymphoid proliferation. Xenogeneic graft versus host disease was observed with attempted engraftment from lymph node and bone marrow tumour samples but could be prevented by T-cell depletion. Orthotopic engraftment was more efficient than subcutaneous or intramuscular engraftment.

Conclusions

High-risk neuroblastoma PDX models can be reliably established from diverse sample types. Orthotopic implantation allows more rapid model development, increasing the likelihood of developing an avatar model within a clinically useful timeframe.

Patient-derived xenograft models-the future of personalised cancer treatment

For many tumours there is a lack of randomised data from which we can guide systemic treatments. Although gene expression profiling along with proteomics has led to advances in diagnosis, classification and prognosis, our ability to target many cancers has been further limited due to a lack of therapeutic options. The use of patient-derived xenograft (PDX) models in the setting of a rare malignancy is discussed here by Kamili et al, with the successful establishment of new model systems.

Upfront Therapies and Downstream Effects: Navigating Late Effects in Childhood Cancer Survivors in the Current Era

PURPOSE OF REVIEW

As survival rates of those diagnosed with childhood cancer improve over time, the number of long-term survivors continues to grow. Advances have not only been made in the upfront treatment of childhood cancer, but also in the identification and treatment of late complications that may arise as a result of the chemotherapy, radiotherapy, or surgical interventions required to provide a cure.

RECENT FINDINGS

As new therapies emerge that are often more targeted to cancerous cells while sparing healthy tissues, the hope is that cure can be achieved without the same long-term side effects for survivors. However, much is unknown regarding how these novel interventions will impact patients in the years to come. It is critical that we continue to follow patients treated with new modalities in order to identify and treat the long-term complications that may arise in future childhood cancer survivors.

Second Reported Case of Pediatric Bladder Alveolar Soft Part Sarcoma as Secondary Malignancy After Prior Cytotoxic Chemotherapy

Alveolar soft part sarcoma (ASPS) is a rare malignancy with high rates of metastasis at presentation, defined by an unclear cellular origin and a unique unbalanced ASPSCR1-TFE3 translocation (der(17)t(X:17)(p11:q25)).¹ ASPS is insensitive to chemotherapy and has been reported to involve the bladder only twice in the pediatric literature; once as a primary malignancy,² and once as a secondary malignancy after cytotoxic chemotherapy.³ Herein, we report the third case of pediatric bladder ASPS in a female patient who received cytotoxic chemotherapy for low-risk neuroblastoma. This would represent the second case of pediatric bladder ASPS as a secondary malignancy after prior chemotherapy.

Advances in neuroblastoma therapy

PURPOSE OF REVIEW

Our understanding of the biologic basis of neuroblastoma, the genetic heterogeneity of this malignancy and the role of host factors has expanded significantly in recent years. In this review, we highlight current and future risk-based treatment approaches and discuss the opportunities and challenges of selecting optimal therapies for specific patient subsets.

RECENT FINDINGS

Significant progress has been made in understanding neuroblastoma predisposition and new approaches have been taken to treatment of this disease. Although survival remains poor for patients with high-risk neuroblastoma, current-era therapy has improved outcomes. Integration of new prognostic markers into neuroblastoma classification systems will allow more precise risk classification and refined treatment assignment. Promising treatments that include targeted therapies as well as immunotherapeutics are being evaluated in clinical trials, and new predictive biomarkers are being developed.

SUMMARY

As our understanding of neuroblastoma biology deepens, our approaches to therapy for this disease continue to evolve. Improved risk stratification and the use of predictive biomarkers will aid in treatment selection for patients with neuroblastoma, and it is expected that future treatments will be associated with greater efficacy and less toxicity.

Maternal Embryonic Leucine Zipper Kinase (MELK), a Potential Therapeutic Target for Neuroblastoma

Maternal embryonic leucine zipper kinase (MELK) activates pathways that mediate aggressive tumor growth and therapy resistance in many types of adult cancers. Pharmacologic and genomic inhibition of MELK impairs tumor growth and increases sensitivity to radiation and chemotherapy. On the basis of these promising preclinical studies, early-phase adult clinical trials testing the MELK inhibitor OTS167 are ongoing. To investigate whether MELK is also a therapeutic target in neuroblastoma, we analyzed MELK expression in primary tumors and cell lines, and examined the effects of OTS167 on neuroblastoma growth. In primary tumors, high levels of MELK were associated with advanced stage disease and inferior survival. Higher levels of MELK were also detected in tumorigenic versus nontumorigenic neuroblastoma cell lines, and cells with higher levels of MELK expression were more sensitive to OTS167 than low-MELK expressing cells. OTS167 suppressed the growth of neuroblastoma xenografts, and in a preclinical model of minimal residual disease, survival was prolonged with MELK inhibition. OTS167 treatment downregulated MELK and its target enhancer of zeste homolog 2 (EZH2), a component of the polycomb repressive complex 2 (PRC2) that is known to modulate the DNA damage response. We also show that OTS167 reduced the formation of collapsed replication forks induced by camptothecin or radiation. Taken together, our results indicate that MELK indirectly mediates efficient processing of replication-associated DNA lesions in neuroblastoma, and that OTS167 sensitizes cells to DNA-damaging agents by abrogating this process. Further studies evaluating the activity of combination treatment regimens with OTS167 in neuroblastoma are warranted.

Insulin and glucose homeostasis in childhood cancer survivors treated with abdominal radiation: A pilot study

BACKGROUND

Childhood cancer survivors exposed to abdominal radiation (abdRT) are at increased risk for both insulin-dependent and non-insulin-dependent diabetes. We sought to clarify the pathophysiology of diabetes after abdRT by performing dynamic studies of insulin and glucose and testing for type 1 diabetes-associated autoantibodies.

PROCEDURE

Cross-sectional analysis of 2-year childhood cancer survivors treated with abdRT at age ≤21 years who underwent oral glucose tolerance testing and assessment of diabetes-related autoantibodies from December 2014 to September 2016. Prevalence of insulin/glucose derangements, indices of insulin sensitivity/secretion (homeostatic model assessment of insulin resistance [HOMA-IR], whole-body insulin sensitivity, insulinogenic index), autoantibody positivity, and treatment/demographic factors associated with adverse metabolic outcomes were assessed.

RESULTS

Among 40 participants previously exposed to abdRT (57.5% male; median age at cancer diagnosis, 3.3 years [range, 0.5-20.1]; median age at study 14.3 years [range, 8.3-49.8]; none with obesity), 9 (22.5%) had glucose derangements (n = 4 with impaired fasting glucose [≥100 mg/dL]; n = 4 with impaired glucose tolerance [2-hour glucose 140-199 mg/dL]; n = 1 with previously unrecognized diabetes [2-hour glucose ≥200 mg/dL]). Three of the four individuals with impaired fasting glucose also had insulin resistance, as measured by HOMA-IR; an additional four subjects with normal glucose tolerance were insulin resistant. The subject with diabetes had normal HOMA-IR. No participant had absolute insulinopenia or >1 positive diabetes-related autoantibody.

CONCLUSIONS

This study suggests that radiation-induced damage to the insulin-producing β-cells is an unlikely explanation for the early derangements in glucose metabolism observed after abdRT. Research into alternative pathways leading to diabetes after abdRT is needed.

Genetic Predisposition to Neuroblastoma

Neuroblastoma is the most common solid tumor in children under the age of one. It displays remarkable phenotypic heterogeneity, resulting in differences in outcomes that correlate with clinical and biologic features at diagnosis. While neuroblastoma accounts for approximately 5% of all cancer diagnoses in pediatrics, it disproportionately results in about 9% of all childhood deaths. Research advances over the decades have led to an improved understanding of neuroblastoma biology. However, the initiating events that lead to the development of neuroblastoma remain to be fully elucidated. It has only been recently that advances in genetics and genomics have allowed researchers to unravel the predisposing factors enabling the development of neuroblastoma and fully appreciate the interplay between the genetics of tumor and host. In this review, we outline the current understanding of familial neuroblastoma and highlight germline variations that predispose children to sporadic disease. We also discuss promising future directions in neuroblastoma genomic research and potential clinical applications for these advances.

Late Effects and Survivorship Issues in Patients with Neuroblastoma

Over the past two decades, marked progress has been made in understanding the biology of neuroblastoma; this has led to refined risk stratification and treatment modifications with resultant increasing 5-year survival rates for children with neuroblastoma. Survivors, however, remain at risk for a wide variety of potential treatment-related complications, or "late effects", which may lead to excess morbidity and premature mortality in this cohort. This review summarizes the existing survivorship literature on long-term health outcomes for survivors of neuroblastoma, focusing specifically on potential injury to the endocrine, sensory, cardiovascular, pulmonary, and renal systems, as well as survivors' treatment-related risk for subsequent neoplasms and impaired quality of life. Additional work is needed to assess the potential late effects of newer multimodality therapies with the aim of optimizing long-term medical and psychosocial outcomes for all survivors of neuroblastoma.

Late Effects in Pediatric High-risk Neuroblastoma Survivors After Intensive Induction Chemotherapy Followed by Myeloablative Consolidation Chemotherapy and Triple Autologous Stem Cell Transplants

Multimodal treatment in high-risk neuroblastoma has modestly improved survival; limited data exist on the late effects from these regimens. We report the sequelae of treatment incorporating 3 consecutive cycles of high-dose therapy and autologous stem cell transplants (ASCTs) without the use of total body irradiation (TBI). We reviewed the medical records of 61 patients treated on or following the Chicago Pilot 2 protocol between 1991 and 2008. Of the 25 patients who are alive (41%), 19 had near complete data to report. Specific treatment modalities and therapy-related side effects were collected. Fourteen of these 19 patients (74%) received 3 cycles of high-dose therapy with ASCT; follow-up occurred over a median of 13.9 years (range, 5.8 to 18.8 y). The majority of late effects were endocrine-related, including growth failure, hypothyroidism, and hypogonadism. Patients also developed secondary neoplasms and skeletal deformities. The most frequent sequela was hearing loss, seen in 17/19 patients. We found a high prevalence of various late effects in survivors of high-risk neuroblastoma using a non-TBI-based regimen including 3 cycles of high-dose therapy with ASCTs. As current treatment regimens recommend tandem ASCT without TBI, it is imperative that we understand and monitor for the sequelae from these modalities.

Second malignant neoplasms after childhood non-central nervous system embryonal tumours in North America: A population-based study

BACKGROUND

Few studies in North America have quantified the risks of second malignant neoplasms (SMNs) among survivors of childhood non-central nervous system (non-CNS) embryonal tumours due to their rarity. We aimed to investigate these risks by combining population-based data from the United States of America and Canada.

METHODS

We evaluated patients with childhood non-CNS embryonal tumours reported to the Surveillance Epidemiology and End Results program and eight Canadian cancer registries from 1969 to 2010. Standardised incidence ratio (SIR) and cumulative incidence of SMNs were calculated. Subgroup analyses were conducted by the type of first primary cancer, age at first primary diagnosis and follow-up duration.

FINDINGS

Of the 13,107 survivors, 190 SMNs were reported over 134,548 person-years of follow-up. The SIR for all SMNs combined was 6.4 (95% confidence interval [CI]: 5.5-7.4). Most site-specific SIRs were significantly increased, ranging from 36 (95% CI: 26-49) for bone and joint cancer to 3.1 (95% CI: 1.5-5.2) for brain tumour. The risk for second malignancies declined as the time elapsed from the first primary diagnosis and was less prominent for patients first diagnosed at age 1-4 years. Notably, rhabdomyosarcoma survivors had a higher risk for SMNs than those with other first primaries. The overall cumulative incidence of SMNs was 1.0% at 10 years, increasing to 2.2% at 20 years and 4.1% at 30 years.

INTERPRETATION

Survivors with childhood non-CNS embryonal tumours faced an increased risk for SMNs compared to the general population. The risk variations observed in different patient categories may help target prevention strategies in high-risk subgroups.

Individualized risk assessment in neuroblastoma: does the tumoral metabolic activity on 123I-MIBG SPECT predict the outcome?

PURPOSE

Risk-adapted treatment in children with neuroblastoma (NB) is based on clinical and genetic factors. This study evaluated the metabolic tumour volume (MTV) and its asphericity (ASP) in pretherapeutic ¹²³I-MIBG SPECT for individualized image-based prediction of outcome.

METHODS

This retrospective study included 23 children (11 girls, 12 boys; median age 1.8 years, range 0.3-6.8 years) with newly diagnosed NB consecutively examined with pretherapeutic ¹²³I-MIBG SPECT. Primary tumour MTV and ASP were defined using semiautomatic thresholds. Cox regression analysis, receiver operating characteristic analysis (cut-off determination) and Kaplan-Meier analysis with the log-rank test for event-free survival (EFS) were performed for ASP, MTV, laboratory parameters (including urinary homovanillic acid-to-creatinine ratio, HVA/C), and clinical (age, stage) and genetic factors. Predictive accuracy of the optimal multifactorial model was determined in terms of Harrell's C and likelihood ratio χ ².

RESULTS

Median follow-up was 36 months (range 7-107 months; eight patients showed disease progression/relapse, four patients died). The only significant predictors of EFS in the univariate Cox regression analysis were ASP (p = 0.029; hazard ratio, HR, 1.032 for a one unit increase), MTV (p = 0.038; HR 1.012) and MYCN amplification status (p = 0.047; HR 4.67). The mean EFS in patients with high ASP (>32.0%) and low ASP were 21 and 88 months, respectively (p = 0.013), and in those with high MTV (>46.7 ml) and low MTV were 22 and 87 months, respectively (p = 0.023). A combined risk model of either high ASP and high HVA/C or high MTV and high HVA/C best predicted EFS.

CONCLUSIONS

In this exploratory study, pretherapeutic image-derived and laboratory markers of tumoral metabolic activity in NB (ASP, MTV, urinary HVA/C) allowed the identification of children with a high and low risk of progression/relapse under current therapy.

Identification of Cancer-Targeted Tropomyosin Inhibitors and Their Synergy with Microtubule Drugs

Actin filaments, with their associated tropomyosin polymers, and microtubules are dynamic cytoskeletal systems regulating numerous cell functions. While antimicrotubule drugs are well-established, antiactin drugs have been more elusive. We previously targeted actin in cancer cells by inhibiting the function of a tropomyosin isoform enriched in cancer cells, Tpm3.1, using a first-in-class compound, TR100. Here, we screened over 200 other antitropomyosin analogues for anticancer and on-target activity using a series of in vitro cell-based and biochemical assays. ATM-3507 was selected as the new lead based on its ability to disable Tpm3.1-containing filaments, its cytotoxicity potency, and more favorable drug-like characteristics. We tested ATM-3507 and TR100 alone and in combination with antimicrotubule agents against neuroblastoma models in vitro and in vivo Both ATM-3507 and TR100 showed a high degree of synergy in vitro with vinca alkaloid and taxane antimicrotubule agents. In vivo, combination-treated animals bearing human neuroblastoma xenografts treated with antitropomyosin combined with vincristine showed minimal weight loss, a significant and profound regression of tumor growth and improved survival compared with control and either drug alone. Antitropomyosin combined with vincristine resulted in G₂-M phase arrest, disruption of mitotic spindle formation, and cellular apoptosis. Our data suggest that small molecules targeting the actin cytoskeleton via tropomyosin sensitize cancer cells to antimicrotubule agents and are tolerated together in vivo This combination warrants further study. Mol Cancer Ther; 16(8); 1555-65. ©2017 AACR.

Overview and recent advances in the treatment of neuroblastoma

INTRODUCTION

Children with neuroblastoma have widely divergent outcomes, ranging from cure in >90% of patients with low risk disease to <50% for those with high risk disease. Recent research has shed light on the biology of neuroblastoma, allowing for more accurate risk stratification and treatment reduction in many cases, although newer treatment strategies for children with high-risk and relapsed neuroblastoma are needed to improve outcomes. Areas covered: Neuroblastoma epidemiology, diagnosis, risk stratification, and recent advances in treatment of both newly diagnosed and relapsed neuroblastoma. Expert commentary: The identification of newer tumor targets and of novel cell-mediated immunotherapy agents may lead to novel therapeutic approaches, and clinical trials for regimens designed to target individual genetic aberrations in tumors are underway. A combination of therapeutic modalities will likely be required to improve survival and cure rates for patients with high-risk neuroblastoma.

Advances in emerging drugs for the treatment of neuroblastoma

INTRODUCTION

Neuroblastoma is the most common solid extracranial tumor of childhood. Outcome for children with high-risk neuroblastoma remains suboptimal. More than half of children diagnosed with high-risk neuroblastoma either do not respond to conventional therapies or relapse after treatment with dismal prognosis. Areas covered: This paper presents a short review of the state of the art in the current treatment of high-risk neuroblastoma. An updated review of new targeted therapies in this group of patients is also presented. Expert opinion: In order to improve prognosis for high-risk patients there is an urgent need to better understand spatial and temporal heterogeneity and obtain new predictive preclinical models in neuroblastoma. Combination strategies with conventional chemotherapy and/or other targeted therapies may overcome current ALK inhibitors resistance. Improvement of international and transatlantic cooperation to speed clinical trials accrual is needed.

Neuroblastoma: A Tough Nut to Crack

Neuroblastoma, an embryonal tumor arising from neural crest-derived progenitor cells, is the most common solid tumor in childhood, with more than 700 cases diagnosed per year in the United States. In the past several decades, significant advances have been made in the treatment of neuroblastoma. Treatment advances reflect improved understanding of the biology of neuroblastoma. Although amplification of MYCN was discovered in the early 1980s, our understanding of neuroblastoma oncogenesis has advanced in the last decade as a result of high-throughput genomic analysis, exome and whole-genome sequencing, genome-wide association studies, and synthetic lethal drug screens. Our refined understanding of neuroblastoma biology and genetics is reflected in improved prognostic stratification and appropriate tailoring of therapy in recent clinical trials. Moreover, for high-risk neuroblastoma, a disease that was uniformly fatal 3 decades ago, recent clinical trials incorporating autologous hematopoietic transplant and immunotherapy utilizing anti-GD2 antibody plus cytokines have shown improved event-free and overall survival. These advances have resulted in a growing population of long-term survivors of neuroblastoma. Examination of the late effects and second malignant neoplasms (SMNs) in both older generations of survivors and more recently treated survivors will inform both design of future trials and surveillance guidelines for long-term follow-up. As a consequence of advances in understanding of the biology of neuroblastoma, successful clinical trials, and refined understanding of the late effects and SMNs of survivors, the promise of precision medicine is becoming a reality for patients with neuroblastoma.

Neuroblastoma survivors are at increased risk for second malignancies: A report from the International Neuroblastoma Risk Group Project

BACKGROUND

The incidence of second malignant neoplasm (SMN) within the first ten years of diagnosis in high-risk neuroblastoma patients treated with modern, intensive therapy is unknown. Further, the underlying germline genetics that contribute to SMN in these survivors are not known.

METHODS

The International Neuroblastoma Risk Group (INRG) database of patients diagnosed from 1990 to 2010 was analysed. SMN risk was accessed by cumulative incidence, standardised incidence ratios (SIRs) and absolute excess risk. A candidate gene-based association study evaluated genetic susceptibility to SMN in neuroblastoma survivors.

RESULTS

Of the 5987 patients in the INRG database with SMN data enrolled in a clinical trial, 43 (0.72%) developed a SMN. The 10-year cumulative incidence of SMN for high-risk patients was 1.8% (95% confidence interval [CI] 1.0-2.6%) compared with 0.38% (95% CI: 0.22-0.94%) for low-risk patients (P = 0.01). High-risk patients had an almost 18-fold higher incidence of SMN compared to age- and sex-matched controls (SIR = 17.5 (95% CI: 11.4-25.3), absolute excess risk = 27.6). For patients treated on high- and intermediate-risk clinical trials, the SIR of acute myelogenous leukaemia was 106.8 (95% CI: 28.7-273.4) and 127.7 (95%CI: 25.7-373.3), respectively. Variants implicating DNA repair genes XRCC3 (rs861539: P = 0.006; odds ratio: 2.04, 95%CI: 1.19-3.46) and MSH2 (rs17036651: P = 0.009; odds ratio: 0.26, 95% CI: 0.08-0.81) were associated with SMN.

CONCLUSION

The intensive multi-modality treatment strategy currently used to treat high-risk neuroblastoma is associated with a significantly increased risk of secondary acute myelogenous leukaemia. Defining the interactions of treatment exposures and genetic factors that promote the development of SMN is critical for optimising survivorship care.

Neuroblastoma

Neuroblastoma is the most common extracranial solid tumour occurring in childhood and has a diverse clinical presentation and course depending on the tumour biology. Unique features of these neuroendocrine tumours are the early age of onset, the high frequency of metastatic disease at diagnosis and the tendency for spontaneous regression of tumours in infancy. The most malignant tumours have amplification of the MYCN oncogene (encoding a transcription factor), which is usually associated with poor survival, even in localized disease. Although transgenic mouse models have shown that MYCN overexpression can be a tumour-initiating factor, many other cooperating genes and tumour suppressor genes are still under investigation and might also have a role in tumour development. Segmental chromosome alterations are frequent in neuroblastoma and are associated with worse outcome. The rare familial neuroblastomas are usually associated with germline mutations in ALK, which is mutated in 10-15% of primary tumours, and provides a potential therapeutic target. Risk-stratified therapy has facilitated the reduction of therapy for children with low-risk and intermediate-risk disease. Advances in therapy for patients with high-risk disease include intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy; these have improved 5-year overall survival to 50%. Currently, new approaches targeting the noradrenaline transporter, genetic pathways and the tumour microenvironment hold promise for further improvements in survival and long-term quality of life.

Incidence and risk factors for secondary malignancy in patients with neuroblastoma after treatment with (131)I-metaiodobenzylguanidine

Several reports of second malignant neoplasm (SMN) in patients with relapsed neuroblastoma after treatment with (131)I-MIBG suggest the possibility of increased risk. Incidence of and risk factors for SMN after (131)I-MIBG have not been defined. This is a multi-institutional retrospective review of patients with neuroblastoma treated with (131)I-MIBG therapy. A competing risk approach was used to calculate the cumulative incidence of SMN from time of first exposure to (131)I-MIBG. A competing risk regression was used to identify potential risk factors for SMN. The analytical cohort included 644 patients treated with (131)I-MIBG. The cumulative incidence of SMN was 7.6% (95% confidence interval [CI], 4.4-13.0%) and 14.3% (95% CI, 8.3-23.9%) at 5 and 10 years from first (131)I-MIBG, respectively. No increase in SMN risk was found with increased number of (131)I-MIBG treatments or higher cumulative activity per kilogram of (131)I-MIBG received (p = 0.72 and p = 0.84, respectively). Thirteen of the 19 reported SMN were haematologic. In a multivariate analysis controlling for variables with p < 0.1 (stage, age at first (131)I-MIBG, bone disease, disease status at time of first (131)I-MIBG), patients with relapsed/progressive disease had significantly lower risk of SMN (subdistribution hazard ratio 0.3, 95% CI, 0.1-0.8, p = 0.023) compared to patients with persistent/refractory neuroblastoma. The cumulative risk of SMN after (131)I-MIBG therapy for patients with relapsed or refractory neuroblastoma is similar to the greatest published incidence for high-risk neuroblastoma after myeloablative therapy, with no dose-dependent increase. As the number of patients treated and length of follow-up time increase, it will be important to reassess this risk.

Genetic discoveries and treatment advances in neuroblastoma

PURPOSE OF REVIEW

Major advances in our understanding of the genetic basis of neuroblastoma, and the role somatic alterations play in driving tumor growth, have led to improvements in risk-stratified therapy and have provided the rationale for targeted therapies. In this review, we highlight current risk-based treatment approaches and discuss the opportunities and challenges of translating recent genomic discoveries into the clinic.

RECENT FINDINGS

Significant progress in the treatment of neuroblastoma has been realized using risk-based treatment strategies. Outcome has improved for all patients, including those classified as high-risk, although survival remains poor for this cohort. Integration of whole-genome DNA copy number and comprehensive molecular profiles into neuroblastoma classification systems will allow more precise prognostication and refined treatment assignment. Promising treatments that include targeted systemic radiotherapy, pathway-targeted small molecules, and therapy targeted at cell surface molecules are being evaluated in clinical trials, and recent genomic discoveries in relapsed tumor samples have led to the identification of new actionable mutations.

SUMMARY

The integration of refined treatment stratification based on whole-genome profiles with therapeutics that target the molecular drivers of malignant behavior in neuroblastoma has the potential to dramatically improve survival, with decreased toxicity.

Pediatric cancer gone viral. Part II: potential clinical application of oncolytic herpes simplex virus-1 in children

Oncolytic engineered herpes simplex viruses (HSVs) possess many biologic and functional attributes that support their use in clinical trials in children with solid tumors. Tumor cells, in an effort to escape regulatory mechanisms that would impair their growth and progression, have removed many mechanisms that would have protected them from virus infection and eventual virus-mediated destruction. Viruses engineered to exploit this weakness, like mutant HSV, can be safely employed as tumor cell killers, since normal cells retain these antiviral strategies. Many preclinical studies and early phase trials in adults demonstrated that oncolytic HSV can be safely used and are highly effective in killing tumor cells that comprise pediatric malignancies, without generating the toxic side effects of nondiscriminatory chemotherapy or radiation therapy. A variety of engineered viruses have been developed and tested in numerous preclinical models of pediatric cancers and initial trials in patients are underway. In Part II of this review series, we examine the preclinical evidence to support the further advancement of oncolytic HSV in the pediatric population. We discuss clinical advances made to date in this emerging era of oncolytic virotherapy.