The mutational spectrum of ATRX aberrations in neuroblastoma and the associated patient and tumor characteristics

Neuroblastoma is the most common extracranial solid tumor in children. The chromatin remodeler ATRX is frequently mutated in high‐risk patients with a poor prognosis. Although many studies have reported ATRX aberrations and the associated clinical characteristics in neuroblastoma, a comprehensive overview is currently lacking. In this study, we extensively characterize the mutational spectrum of ATRX aberrations in neuroblastoma tumors reported in previous studies and present an overview of patient and tumor characteristics. We collected the data of a total of 127 neuroblastoma patients and three cell lines with ATRX aberrations originating from 20 papers. We subdivide the ATRX aberrations into nonsense, missense, and multiexon deletions (MEDs) and show that 68% of them are MEDs. Of these MEDs, 75% are predicted to be in‐frame. Furthermore, we identify a missense mutational hotspot region in the helicase domain. We also confirm that all three ATRX mutation types are more often identified in patients diagnosed at an older age, but still approximately 40% of the patients are aged 5 years or younger at diagnosis. Surprisingly, we found that 11q deletions are enriched in neuroblastomas with ATRX deletions compared to a reference cohort, but not in neuroblastomas with ATRX point mutations. Taken together, our data emphasizes a distinct ATRX mutation spectrum in neuroblastoma, which should be considered when studying molecular phenotypes and therapeutic strategies.

Neuroblastoma: The basis for cure in limited-resource settings

BACKGROUND

Neuroblastoma (NB) contributes the most to the mortality of childhood malignancies worldwide. The disease spectrum is heterogenous and the management complex and costly, especially in advanced disease or disease with adverse biology. In low- and middle-income countries (LMICs) the majority of NB presents in advanced stages. Therefore, with limited resources and poor prognosis the treatment of NB is often not a priority. The aim of the study was to evaluate the research activities and perceptions of the management of NB that determine the research and treatment approaches in LMICs.

METHODS

Data were sourced from https://www.clinicaltrials.gov/ identifying NB trials open to LMIC. Abstracts on NB research presented at the International Society for Paediatric Oncology (SIOP) Congresses between 2014 and 2020 were evaluated according to income status. An online survey evaluating medical views on NB in LMICs and the effect on the management was conducted. Descriptive analysis was done. Where appropriate categorical association between covariates was assessed using the Pearson chi-square (χ² ) test or Fishers exact test.

RESULTS

There were 15/562 (2.7%) trials open to LMIC. Only six of 138 (4.3%) LMIC participated in NB trials. Of the 688 abstracts presented between 2014 and 2020 at the SIOP International Congress on NB as primary subject, 297 (42.7%) were from LMICs. Only two were from low-income countries (LICs). Sixty-one countries responded to the NB survey. Positive views towards NB management were present when treatment was based on a national protocol, the availability of trimodal or advanced treatment options were present, and when a balance of metastatic or local disease were treated.

CONCLUSION

Management of NB in LMICs should include increased advocacy and research as well as implementation of national management strategies.

Survival in patients with high-risk neuroblastoma treated without autologous stem cell transplant or dinutuximab beta

The majority of patients with high-risk neuroblastoma (HR-NB) in low- and middle-income countries (LMIC) do not have access to autologous stem cell transplant (ASCT) and dinutuximab. Consolidation with nonmyeloablative chemotherapy is not well-defined, and the outcomes are variable. We report a single-center outcome of patients with HR-NB, treated with nonmyeloablative consolidation. A tabulated compilation of similar reports is included. A retrospective chart review of patients with HR-NB was performed from January 2009 till June 2016. Patients were treated on the backbone of HR-NBL1/SIOPEN protocol. Treatment included induction with rapid-COJEC, surgery, followed by consolidation. Consolidation involved 4 cycles of topotecan, vincristine, and doxorubicin (TVD) instead of ASCT. Infusion of vincristine and doxorubicin were modified for ease and to enable administration in the clinic. Subsequent treatment included radiotherapy to the primary tumor and differentiation therapy with isotretinoin. Over 7½ years, 28 patients with HR-NB were treated. Two (7%) patients had therapy-related mortality. A relapse or disease progression occurred in 11 (39%) patients at a median duration of 17 months (IQR: 5, 18). Treatment abandonment was observed in 4 (14%) patients. The median follow-up of disease-free patients was 49 months (IQR: 45, 79). Patients with relapse were not treated further. A 4-year EFS of 29.3% was observed when 4-cycles of TVD were administered instead of ASCT in patients with HR-NB. The study and the review will aid decision-making for care of patients in LMIC while considering the options of treatment for HR-NB if access to ACST and dinutuximab is lacking.

Management of neuroblastoma in limited-resource settings

BACKGROUND

Neuroblastoma (NB) is a heterogeneous disease with variable outcomes among countries. Little is known about NB in low- and middle-income countries (LMICs).

AIM

The aim of this review was to evaluate regional management protocols and challenges in treating NB in paediatric oncology units in LMICs compared to high-income countries (HICs).

METHODS

PubMed, Global Health, Embase, SciELO, African Index Medicus and Google Scholar were searched for publications with keywords pertaining to NB, LMICs and outcomes. Only English language manuscripts and abstracts were included. A descriptive review was done, and tables illustrating the findings were constructed.

RESULTS

Limited information beyond single-institution experiences regarding NB outcomes in LMICs was available. The disease characteristics varied among countries for the following variables: sex, age at presentation, MYCN amplification, stage and outcome. LMICs were found to be burdened with a higher percentage of stage 4 and high-risk NB compared to HICs. Implementation of evidence-based treatment protocols was still a barrier to care. Many socioeconomic variables also influenced the diagnosis, management and follow-up of patients with NB.

CONCLUSION

Patients presented at a later age with more advanced disease in LMICs. Management was limited by the lack of resources and genetic studies for improved NB classification. Further research is needed to develop modified diagnostic and treatment protocols for LMICs in the face of limited resources.

Neuroblastoma in Sudan: experience of a single institute

Neuroblastoma (NBL) is the most common malignant solid extracranial tumour in children. It accounts for about 8%-10% of overall childhood malignancies in developed countries and only 1%-3% in developing countries. We aim to study the clinical presentation and outcome of NBL in children treated at the National Cancer Institute (NCI), University of Gezira, Wad Madani, Sudan. This is a retrospective, descriptive, hospital-based study, where patients' records were reviewed from the years 2004-2015. During this period, 38 paediatric patients were treated in the Paediatric Oncology Unit at the NCI, accounting for about 4% of the overall childhood malignancies. Of them, 24 (63%) were males and 14 (37%) were females with a ratio of 1.7: 1. The age at presentation ranged between 2 months and 7 years with a mean age at the presentation of 3 years. Twenty-nine (76%) of them were classified as high-risk disease, no one received high-dose chemotherapy, 33(87%) died and only 5 (13%) achieved complete remission. This study reflects the poor outcome of NBL among Sudanese children which can be explained by the late presentation of the patients, lack of the diagnostic modalities and lack of the sophisticated treatment modalities for high-risk NBL.