title: Gender, Race, and Age at Diagnosis as Risk Factors for Metastasis or Recurrence among 1,657 Thyroid Cancer Patients Treated with Radioiodine across 40 Years in Singapore.
abstract: BACKGROUND
  To obtain descriptive data on Singaporean thyroid cancer patients treated with radioiodine and to assess gender, race, and age at diagnosis as risk factors for metastasis or recurrence.
  
  
  METHODS
  This is a retrospective study of all thyroid cancer patients treated with radioiodine of any prescribed activity at our institution. Data collected included: age at diagnosis, gender, race, histopathological type, duration of follow-up, and metastasis at diagnosis (locoregional or distant) or recurrence at any time. Gender, race, and age at diagnosis were analyzed for possible associations with metastasis or recurrence.
  
  
  RESULTS
  A total of 1,657 thyroid cancer patients were treated with radioiodine across a 40-year period; mean follow-up 6.4 ± 6.9 years (median 4.2 years). 656 (39.6%) patients had metastasis or recurrence over the duration of their follow-up. Male gender (odds ratio (OR) 1.38; p = 0.006), Malay race (OR 1.71; p < 0.0001), and age at diagnosis of > 46 years (OR 1.31; p = 0.007) were significantly associated with metastasis or recurrence.
  
  
  CONCLUSIONS
  Male gender, Malay race, and age at diagnosis of > 46 years were significant risk factors for metastasis or recurrence in Singaporean thyroid cancer patients treated with radioiodine.
authors.affiliation: Department of Nuclear Medicine and PET, Singapore General Hospital, Singapore.
authors.forename: Yung Hsiang
authors.initials: YH
authors.lastname: Kao
authors.forename: Hui Kong
authors.initials: HK
authors.lastname: Gan
authors.forename: Sumbul
authors.initials: S
authors.lastname: Zaheer
authors.forename: Winnie W C
authors.initials: WW
authors.lastname: Lam
authors.forename: Kelvin S H
authors.initials: KS
authors.lastname: Loke
authors.forename: Wai Yin
authors.initials: WY
authors.lastname: Wong
authors.forename: David C E
authors.initials: DC
authors.lastname: Ng
authors.forename: Anthony S W
authors.initials: AS
authors.lastname: Goh
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality* / Q000517:prevention & control / Q000556:secondary*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000517:prevention & control*; D015995:Prevalence; D044469:Racial Groups / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D012846:Singapore / Q000208:ethnology; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D016896:Treatment Outcome; D055815:Young Adult