Abstract
Childhood cancer five-year survival now exceeds 70-80%. Childhood exposure to radiation is a known thyroid carcinogen; however, data are limited for the evaluation of radiation dose-response at high doses, modifiers of the dose-response relationship and joint effects of radiotherapy and chemotherapy. To address these issues, we pooled two cohort and two nested case-control studies of childhood cancer survivors including 16,757 patients, with 187 developing primary thyroid cancer. Relative risks (RR) with 95% confidence intervals (CI) for thyroid cancer by treatment with alkylating agents, anthracyclines or bleomycin were 3.25 (0.9-14.9), 4.5 (1.4-17.8) and 3.2 (0.8-10.4), respectively, in patients without radiotherapy, and declined with greater radiation dose (RR trends, P = 0.02, 0.12 and 0.01, respectively). Radiation dose-related RRs increased approximately linearly for 50 Gy. The fitted RR at 10 Gy was 13.7 (95% CI: 8.0-24.0). Dose-related excess RRs increased with decreasing age at exposure (P
Original language | English |
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Pages (from-to) | 365-76 |
Journal | Radiation Research |
Volume | 178 |
Issue number | 4 |
Publication status | Published - Oct 2012 |
Keywords
- Adolescent
- Adult
- Case-Control Studies
- Child
- Child, Preschool
- Dose-Response Relationship, Radiation
- Female
- Humans
- Incidence
- Infant
- Male
- Neoplasms
- Neoplasms, Radiation-Induced
- Neoplasms, Second Primary
- Radiotherapy
- Thyroid Neoplasms