title: Use of Radioactive Iodine for Thyroid Cancer and Risk of Second Primary Malignancy: A Nationwide Population-Based Study.
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.
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: Chung-Jen
authors.initials: CJ
authors.lastname: Teng
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Hu
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: San-Chi
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: Chiu-Mei
authors.initials: CM
authors.lastname: Yeh
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: Huey-Ling
authors.initials: HL
authors.lastname: Chiang
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC).
authors.forename: Tzeng-Ji
authors.initials: TJ
authors.lastname: Chen
authors.affiliation: Division of Hematology and Oncology, Department of Medicine (CJT) and Department of Psychiatry (HLC), Far Eastern Memorial Hospital, New Taipei City, Taiwan; Division of Hematology and Oncology, Department of Medicine (CJT, SCC, CJL), Cancer Center (YWH), and Department of Family Medicine (CMY, TJC), Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan (CJT, YWH, SCC, TJC, CJL); Institute of Public Health, National Yang-Ming University, Taipei, Taiwan (CJT, YWH, CJL); Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan (HLC). chiajenliu@gmail.com.
authors.forename: Chia-Jen
authors.initials: CJ
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007457:Iodine Radioisotopes / Q000008:administration & dosage* / Q000009:adverse effects*; D007680:Kidney Neoplasms / Q000453:epidemiology; D007938:Leukemia / Q000453:epidemiology; D008175:Lung Neoplasms / Q000453:epidemiology; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology; D008297:Male; D008479:Mediastinal Neoplasms / Q000453:epidemiology; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000209:etiology; D016017:Odds Ratio; D010190:Pancreatic Neoplasms / Q000453:epidemiology; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000453:epidemiology; D011829:Radiation Dosage; D011879:Radiotherapy Dosage; D012306:Risk; D013624:Taiwan / Q000453:epidemiology; D013964:Thyroid Neoplasms / Q000532:radiotherapy*; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes