Study design
We performed a nationwide, retrospective study including all consecutive
cases of Danish pediatric patients aged 0-14 years diagnosed with a
spinal tumor from January 1st, 1996, to December
31st, 2018. The cohort was identified from a
nationwide (population of 5.8 million) registry-based cohort study,
previously described in detail, using The Danish Childhood Cancer
Registry (DCCR). The DCCR includes all cases classified as neoplasms
according to the International Classification of Diseases, 10th edition
(ICD-10) (diagnoses DC00-DD48). The DCCR is linked to the Danish
National Patient Registry (DNPR), the National Pathology Registry, and
the Danish Cancer Registry using the unique national identification
number assigned to all permanent residents in Denmark at birth or
immigration.