title: Increased risk of cancer among azoospermic men.
abstract: OBJECTIVE
  To determine whether men with azoospermia are at an elevated risk of developing cancer in the years following an infertility evaluation.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  United States andrology clinic.
  
  
  METHODS
  A total of 2,238 men with complete records were evaluated for infertility at a single andrology clinic in Texas from 1989 to 2009.
  
  
  METHODS
  None.
  
  
  METHODS
  Cancer incidence was determined by linkage to the Texas Cancer Registry.
  
  
  RESULTS
  In all, 451 men had azoospermia, and 1,787 were not azoospermic, with a mean age at infertility evaluation of 35.7 years. Compared with the general population, infertile men had a higher risk of cancer, with 29 cases observed compared with 16.7 expected (standardized incidence rate [SIR] 1.7, 95% confidence interval [CI] 1.2-2.5). When stratifying by azoospermia status, azoospermic men had an elevated risk of cancer (SIR 2.9, 95% CI 1.4-5.4). Infertile men without azoospermia had a trend toward a higher rate of cancer (SIR 1.4, 95% CI 0.9-2.2). The Cox regression model revealed that azoospermic men had 2.2-fold higher cancer risk compared with nonazoospermic men (hazard ratio 2.2, 95% CI 1.0-4.8).
  
  
  CONCLUSIONS
  Men with azoospermia have an increased risk of subsequently developing cancer, suggesting a possible common etiology between azoospermia and cancer development. Additional follow-up of azoospermic men after reproductive efforts end may be warranted.
authors.affiliation: Departments of Urology and Obstetrics/Gynecology, Stanford University School of Medicine, Stanford, California 94305-5118, USA. eisenberg@stanford.edu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Eisenberg
authors.forename: Paul
authors.initials: P
authors.lastname: Betts
authors.forename: Danielle
authors.initials: D
authors.lastname: Herder
authors.forename: Dolores J
authors.initials: DJ
authors.lastname: Lamb
authors.forename: Larry I
authors.initials: LI
authors.lastname: Lipshultz
mesh_terms: D000328:Adult; D000368:Aged; D053713:Azoospermia / Q000453:epidemiology*; D015331:Cohort Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D055815:Young Adult
keywords: Azoospermia; male infertility; neoplasms