Impact of gender on the natural history of neuroblastoma

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.

Temporal clustering of neuroblastic tumours in children and young adults from Ontario, Canada

BACKGROUND

The aetiology of neuroblastic tumours is likely to involve both genetic and environmental factors. A number of possible environmental risk factors have been suggested, including infection. If an irregular temporal pattern in incidence is found, this might suggest that a transient agent, such as an infection, is implicated. Previous work has found evidence for temporal clustering in children and young adults living in northern England.

METHODS

We examined data from a second population-based registry from Ontario, Canada to determine whether there was evidence of temporal clustering of neuroblastic tumours. Cases diagnosed in children and young adults aged 0-19 years between 1985 and 2016 were extracted from the population-based Pediatric Oncology Group of Ontario Networked Information System (POGONIS). A modified version of the Potthoff-Whittinghill method was used to test for temporal clustering. Estimates of extra-Poisson variation (EPV) and standard errors (SE) were obtained.

RESULTS

Eight hundred seventy-six cases of neuroblastic tumours were diagnosed during the study period. Overall, no evidence of temporal clustering was found between fortnights, between months or between quarters within years. However, significant EPV was found between years within the full study period (EPV = 1.05, SE = 0.25; P = 0.005).

CONCLUSIONS

The findings are consistent with the possibility that a transient agent, such as an infection that is characterised by 'peaks and troughs' in its occurrence, might be implicated in the aetiology of neuroblastic tumours. However, this pattern may also reflect a long-term increase in the numbers of cases, rather than peaks and troughs.

Incidence and Prognostic Role of the Ocular Manifestations of Neuroblastoma in Children

PURPOSE

To describe the ocular manifestations of neuroblastoma in a large cohort of children.

DESIGN

Retrospective cohort study.

METHODS

The medical records of patients diagnosed with neuroblastoma between 1989 and 2017 at a tertiary care pediatric hospital were analyzed. The main outcome measurements were the incidence and prognostic role of ocular findings.

RESULTS

There were 523 patients with neuroblastoma in the study cohort. Median age at diagnosis was 1.9 years, median follow-up was 4.0 years, and 57.2% were male. At last follow-up, 55.3% were in disease remission, 5.0% had stable disease, 28.1% were deceased, and 11.7% were on active or palliative treatment. A total of 86 patients (16.4%) had ocular manifestations of neuroblastoma, 58 at presentation and 29 during the disease course. The most common findings were orbital involvement in 37 (43.0%), opsoclonus in 20 (23.3%), and Horner syndrome in 24 (27.9%). In 16 patients (3.1%), there were only ocular findings at presentation, including 8 (1.5%) with orbital involvement, 7 (1.3%) with Horner syndrome, and 1 (0.2%) with orbital involvement and a cranial nerve palsy. On survival analysis, a favorable prognosis was associated with opsoclonus, female sex, and diagnosis before 12 months of age, whereas a worse prognosis was associated with orbital involvement.

CONCLUSIONS

In this cohort, approximately 1 in 6 patients with neuroblastoma had ocular manifestations, but only 3% presented with only ocular findings. Orbital involvement was common and associated with a poor prognosis, whereas opsoclonus, female sex, and younger age at diagnosis were associated with a favorable prognosis.

Neuroblastoma presenting as hip pain and skull prominence in a child

Neuroblastoma is a common cancer in children especially those under 5-years old, however they can have varied presentations that may make diagnosis difficult. Neuroblastoma is not usually high on a clinician's differential for a child's gait dysfunction. We describe a case of a 6-year-old female who presented to the Emergency Department for new onset right hip pain. She had associated gait disturbance and pain with ambulation as well as a new lump on her right parietal skull. An MRI of the brain, lumbar spine, and pelvis revealed the diagnosis of a left adrenal neuroblastoma that had metastasized to the femur, the lumbar spine, and the skull. This case shows the importance of early suspicion of malignancy in a patient with seemingly disparate symptoms to ensure early intervention.

Expression quantitative trait loci and receptor pharmacology implicate Arg1 and the GABA-A receptor as therapeutic targets in neuroblastoma

The development of targeted therapeutics for neuroblastoma, the third most common tumor in children, has been limited by a poor understanding of growth signaling mechanisms unique to the peripheral nerve precursors from which tumors arise. In this study, we combined genetics with gene-expression analysis in the peripheral sympathetic nervous system to implicate arginase 1 and GABA signaling in tumor formation in vivo. In human neuroblastoma cells, either blockade of ARG1 or benzodiazepine-mediated activation of GABA-A receptors induced apoptosis and inhibited mitogenic signaling through AKT and MAPK. These results suggest that ARG1 and GABA influence both neural development and neuroblastoma and that benzodiazepines in clinical use may have potential applications for neuroblastoma therapy.