title: Subfertility increases risk of testicular cancer: evidence from population-based semen samples.
abstract: OBJECTIVE
  To further understand the association between semen quality and cancer risk by means of well defined semen parameters.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  A total of 20,433 men who underwent semen analysis (SA) and a sample of 20,433 fertile control subjects matched by age and birth year.
  
  
  METHODS
  None.
  
  
  METHODS
  Risk of all cancers as well as site-specific results for prostate cancer, testicular cancer, and melanoma.
  
  
  RESULTS
  Compared with fertile men, men with SA had an increased risk of testicular cancer (hazard rate [HR] 3.3). When the characterization of infertility was refined using individual semen parameters, we found that oligozoospermic men had an increased risk of cancer compared with fertile control subjects. This association was particularly strong for testicular cancer, with increased risk in men with oligozoospermia based on concentration (HR 11.9) and on sperm count (HR 10.3). Men in the in the lowest quartile of motility (HR 4.1), viability (HR 6.6), morphology (HR 4.2), or total motile count (HR 6.9) had higher risk of testicular cancer compared with fertile men. Men with sperm concentration and count in the 90th percentiles of the distribution (≥178 and ≥579 × 10(6)/mL, respectively), as well as total motile count, had an increased risk of melanoma (HRs 2.1, 2.7, and 2.0, respectively). We found no differences in cancer risk between azoospermic and fertile men.
  
  
  CONCLUSIONS
  Men with SA had an increased risk of testicular cancer which varied by semen quality. Unlike earlier work, we did not find an association between azoospermia and increased cancer risk.
authors.affiliation: Department of Family and Preventive Medicine, University of Utah, Salt Lake City, Utah; Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah. Electronic address: heidi.hanson@hci.utah.edu.
authors.forename: Heidi A
authors.initials: HA
authors.lastname: Hanson
authors.affiliation: Division of Urology, Department of Surgery, University of Utah, Salt Lake City, Utah.
authors.forename: Ross E
authors.initials: RE
authors.lastname: Anderson
authors.affiliation: Division of Urology, Department of Surgery, University of Utah, Salt Lake City, Utah; Center for Men's Health and Reconstructive Surgery, University of Utah, Salt Lake City, Utah; Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Kenneth I
authors.initials: KI
authors.lastname: Aston
authors.affiliation: Division of Urology, Department of Surgery, University of Utah, Salt Lake City, Utah; Center for Men's Health and Reconstructive Surgery, University of Utah, Salt Lake City, Utah; Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell
authors.affiliation: Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah; Department of Family and Consumer Studies and Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.
authors.forename: Ken R
authors.initials: KR
authors.lastname: Smith
authors.affiliation: Center for Men's Health and Reconstructive Surgery, University of Utah, Salt Lake City, Utah.
authors.forename: James M
authors.initials: JM
authors.lastname: Hotaling
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005298:Fertility; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055101:Semen Analysis; D013076:Sperm Count; D013081:Sperm Motility; D013736:Testicular Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D014589:Utah / Q000453:epidemiology; D055815:Young Adult
keywords: Semen quality; cancer; infertility; testicular cancer