title: Association between benign thyroid and endocrine disorders and subsequent risk of thyroid cancer among 4.5 million U.S. male veterans.
abstract: BACKGROUND
  Risk factors for thyroid cancer (TC) in males are poorly understood. OBJECTIVES, SETTING, AND PARTICIPANTS: Our aim was to evaluate the relationship between history of benign thyroid and endocrine disorders and risk of TC among 4.5 million male veterans admitted to U.S. Veterans Affairs hospitals between July 1, 1969, and September 30, 1996.
  
  
  METHODS
  We conducted a retrospective cohort study based on hospital discharge records with 1053 cases of TC.
  
  
  METHODS
  We estimated relative risks (RR) and computed 95% confidence intervals (CI) for TC using time-dependent Poisson regression models. To evaluate potential ascertainment bias and/or delayed diagnosis of TC, we also analyzed RR by time between diagnosis of benign disorder and TC (<5 or ≥ 5 yr).
  
  
  RESULTS
  RR for TC were significantly elevated with many disorders and were often higher less than 5 yr compared with 5 yr or more before TC diagnosis. RR (95% CI) less than 5 yr/at least 5 yr were 67.9 (42.4-108.8)/28.9 (9.2-90.2) for thyroid adenoma, 77.8 (64.5-93.1)/25.9 (17.9-38.0) for nontoxic nodular goiter, 23.9 (13.8-41.3)/12.9 (4.8-34.4) for thyroiditis, 8.8 (6.9-11.3)/6.0 (3.8-9.6) for hypothyroidism, 6.4 (4.4-9.4)/ 2.0 (0.8-4.8) for thyrotoxicosis, and 1.2 (1.0-1.4)/1.1 (0.9-1.5) for diabetes. For some disorders, RR also significantly varied by attained age and race with younger patients and Blacks having higher RR than older patients and Whites.
  
  
  CONCLUSIONS
  We found strong associations for a history of thyroid adenoma, nodular goiter, thyroiditis, or hypothyroidism with TC in males allowing for increased surveillance/delayed diagnosis and evidence that some of these associations are modified by age and race.
authors.affiliation: Cancer Prevention Fellowship Program and Medical Oncology Branch, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20902, USA. balas@nih.gov
authors.forename: Sanjeeve
authors.initials: S
authors.lastname: Balasubramaniam
authors.forename: Elaine
authors.initials: E
authors.lastname: Ron
authors.forename: Gloria
authors.initials: G
authors.lastname: Gridley
authors.forename: Arthur B
authors.initials: AB
authors.lastname: Schneider
authors.forename: Alina V
authors.initials: AV
authors.lastname: Brenner
mesh_terms: D015331:Cohort Studies; D004700:Endocrine System Diseases / Q000150:complications*; D006044:Goiter, Nodular / Q000150:complications; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D008297:Male; D008875:Middle Aged; D016012:Poisson Distribution; D012189:Retrospective Studies; D012306:Risk; D013959:Thyroid Diseases / Q000150:complications* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000209:etiology*; D013966:Thyroiditis / Q000150:complications; D014728:Veterans