Use of Radioactive Iodine for Thyroid Cancer and Risk of Second Primary Malignancy: A Nationwide Population-Based Study
Journal
Journal of the National Cancer Institute
Journal Volume
108
Journal Issue
2
Date Issued
2016
Author(s)
HUEY-LING CHIANG
Abstract
Background: Radioactive iodine (RAI) is widely used for the treatment of thyroid cancers. However, information on associations between RAI dose and second primary malignancy (SPM) is lacking. Methods: Patients without antecedent cancer age 20 years or older and newly diagnosed with thyroid cancer were recruited from the Taiwan National Health Insurance database between 1997 and 2010. Standardized incidence ratios (SIRs) for the cancers were calculated to compare the incidence of thyroid cancer with the general population. The association between RAI dosage and cancer development was estimated using time-dependent Cox regression analysis. All statistical tests were two-sided. Results: A total of 692 cases of SPM were identified among 20 235 patients with thyroid cancer. Regarding the latter, 79.7% of the patients were women, the median age was 46 years, and the follow-up period included 134 178 person-years. The SIR for any SPM was 1.41 (95% confidence interval [CI] = 1.31 to 1.52). A statistically significantly higher SIR was observed in leukemia (2.74), non-Hodgkin's lymphoma (2.38), prostate (2.30), lung and mediastinum (1.93), pancreas (1.83), kidney (1.81), breast (1.48), and colon-rectum (1.31) cancers. Cumulative RAI dose (per 30 mCi increase) conferred a strong risk for SPM (adjusted hazard ratio [aHR] = 1.01, 95% CI = 1.01 to 1.02, P <. 001) and leukemia (aHR = 1.03, 95% CI = 1.02 to 1.04, P <. 001) occurrences. A cumulative RAI dose greater than 150 mCi possessed a statistically significant risk for all cancer combined (aHR = 1.30) and leukemia (aHR = 6.03). Conclusions: An increased risk of SPM was observed for thyroid cancer patients, especially with cumulative RAI doses over 150 mCi. ? 2015 The Author 2015.
SDGs
Other Subjects
radioactive iodine; radioactive iodine; adult; aged; Article; breast cancer; cancer diagnosis; cancer incidence; cancer radiotherapy; cancer risk; colon cancer; comorbidity; drug use; female; human; kidney cancer; leukemia; lung cancer; major clinical study; male; mediastinum cancer; nonhodgkin lymphoma; pancreas cancer; population research; priority journal; prostate cancer; radiation dose; radiation hazard; rectum cancer; second cancer; Taiwan; thyroid cancer; Breast Neoplasms; Colorectal Neoplasms; comparative study; follow up; incidence; Kidney Neoplasms; leukemia; Lung Neoplasms; Lymphoma, Non-Hodgkin; Mediastinal Neoplasms; middle aged; Neoplasms, Second Primary; odds ratio; Pancreatic Neoplasms; proportional hazards model; Prostatic Neoplasms; risk; Thyroid Neoplasms; time; very elderly; Adult; Aged; Aged, 80 and over; Breast Neoplasms; Colorectal Neoplasms; Female; Follow-Up Studies; Humans; Incidence; Iodine Radioisotopes; Kidney Neoplasms; Leukemia; Lung Neoplasms; Lymphoma, Non-Hodgkin; Male; Mediastinal Neoplasms; Middle Aged; Neoplasms, Second Primary; Odds Ratio; Pancreatic Neoplasms; Proportional Hazards Models; Prostatic Neoplasms; Radiation Dosage; Radiotherapy Dosage; Risk; Taiwan; Thyroid Neoplasms; Time Factors
Type
journal article