Temporal clustering of neuroblastic tumours in children and young adults from Northern England.
BACKGROUND
The aetiology of neuroblastic tumours is unclear with both genetic and environmental factors implicated. The possibility that an infectious agent may be involved has been suggested. 'Temporal clustering' occurs if cases display an irregular temporal distribution and may indicate the involvement of an agent that exhibits epidemicity. We tested for the presence and nature of temporal clustering using population-based data from northern England.


METHODS
We extracted all cases of neuroblastic tumours diagnosed in children and young adults aged 0-24 years during 1968-2011 from the Northern Region Young Persons' Malignant Disease Registry. This is a population-based registry, covering a population of approximately 900,000 young persons, and includes all cases resident in northern England at the time of diagnosis. Tests for temporal clustering were applied using a modified version of the Potthoff-Whittinghill method. Estimates of extra-Poisson variation (β) and standard errors (SEs) were obtained.


RESULTS
227 cases of neuroblastic tumours were diagnosed during the study period. All the analyses between fortnights and between months found significant extra-Poisson variation, with β = 0.846 (SE = 0.310, P = 0.004) for the analysis between fortnights within months. Restricting the analyses to the 76 cases diagnosed at ages less than 18 months showed significant extra-Poisson variation between fortnights within months (β = 1.532, SE = 0.866, P = 0.038), but not between months. In contrast, analyses of cases aged 18 months to 24 years showed significant extra-Poisson variation between quarters within years, as well as over shorter timescales.


CONCLUSIONS
Transient environmental agents may be involved in the aetiology of neuroblastic tumours. The initiating factor might be a geographically-widespread agent that occurs in 'mini-epidemics'.
Institute of Health & Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK. Colin.Muirhead@Newcastle.ac.uk.
Colin R
CR
Muirhead
Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK. Deborah.Tweddle@Newcastle.ac.uk.
Deborah A
DA
Tweddle
Institute of Health & Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK. Nermine.Basta@Newcastle.ac.uk.
Nermine O
NO
Basta
Institute of Health & Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK. Richard.McNally@Newcastle.ac.uk.
Richard J Q
RJ
McNally
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004739:England / Q000453:epidemiology; D005260:Female; D018305:Ganglioneuroblastoma / Q000453:epidemiology / Q000209:etiology; D005729:Ganglioneuroma / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009447:Neuroblastoma / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors; D055815:Young Adult