title: Characteristics of follicular cell-derived thyroid carcinomas occurring after external radiation exposure: results of a case control study nested in a cohort.
abstract: Radiation exposure is the only well-established risk factor for follicular cell-derived thyroid carcinoma. To compare the clinical characteristics and outcome of thyroid carcinoma in patients with and without a history of radiation exposure, we performed a case control study nested in a cohort of 2,196 patients treated for a papillary or a follicular thyroid cancer at the Institut Gustave Roussy. The study was performed on 91 cases (71% females) and their 273 controls matched for gender, age at thyroid cancer diagnosis (+/-3 years), and period of initial thyroid cancer treatment (+/-6 years). More than 85% of the cases have been first exposed to external radiation before the age of 30 years. Thyroid cancers were more frequently multifocal in cases than in controls (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.3-4.8), and local residual tumor was more frequently observed in cases, but the other clinical features did not differ overall. Female cases with a history of radiation exposure more frequently had a tumor of follicular histology than female controls (OR = 2.7, 95% CI: 1.1-6.5), and conversely the frequency of follicular histology was similar in male cases and in male controls (OR = 0.3, 95% CI: 0.1-1.4). The risks of recurrence and of thyroid cancer related death were similar in cases and in controls.
authors.affiliation: Unit of Cancer Epidemiology, National Institute of Health and Medical Research (U521 INSERM), Villejuif, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Rubino
authors.forename: Anne-Françoise
authors.initials: AF
authors.lastname: Cailleux
authors.forename: Moncef
authors.initials: M
authors.lastname: Abbas
authors.forename: Ibrahima
authors.initials: I
authors.lastname: Diallo
authors.forename: Akthar
authors.initials: A
authors.lastname: Shamsaldin
authors.forename: Bernard
authors.initials: B
authors.lastname: Caillou
authors.forename: Florent
authors.initials: F
authors.lastname: De Vathaire
authors.forename: Martin
authors.initials: M
authors.lastname: Schlumberger
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000473:pathology*; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*