title: Childhood CT scans and cancer risk: impact of predisposing factors for cancer on the risk estimates.
abstract: To investigate the role of cancer predisposing factors (PFs) on the associations between paediatric computed tomography (CT) scan exposures and subsequent risk of central nervous system (CNS) tumours and leukaemia. A cohort of children who underwent a CT scan in 2000-2010 in 23 French radiology departments was linked with the national childhood cancers registry and national vital status registry; information on PFs was retrieved through hospital discharge databases. In children without PF, hazard ratios of 1.07 (95% CI 0.99-1.10) for CNS tumours (15 cases) and 1.16 (95% CI 0.77-1.27) for leukaemia (12 cases) were estimated for each 10 mGy increment in CT x-rays organ doses. These estimates were similar to those obtained in the whole cohort. In children with PFs, no positive dose-risk association was observed, possibly related to earlier non-cancer mortality in this group. Our results suggest a modifying effect of PFs on CT-related cancer risks, but need to be confirmed by longer follow-up and other studies.
authors.affiliation: Laboratory of Epidemiology, Institute for Radiological Protection and Nuclear Safety, BP 17, 92262 Fontenay-aux-Roses, France.
authors.forename: N
authors.initials: N
authors.lastname: Journy
authors.forename: T
authors.initials: T
authors.lastname: Roué
authors.forename: E
authors.initials: E
authors.lastname: Cardis
authors.forename: H Ducou
authors.initials: HD
authors.lastname: Le Pointe
authors.forename: H
authors.initials: H
authors.lastname: Brisse
authors.forename: J-F
authors.initials: JF
authors.lastname: Chateil
authors.forename: D
authors.initials: D
authors.lastname: Laurier
authors.forename: M-O
authors.initials: MO
authors.lastname: Bernier
mesh_terms: D016543:Central Nervous System Neoplasms / Q000209:etiology* / Q000401:mortality; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007953:Leukemia, Radiation-Induced / Q000209:etiology* / Q000401:mortality; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000401:mortality; D012306:Risk; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*