title: Hormonal predictors of prostate cancer: a meta-analysis.
abstract: OBJECTIVE
  Although there is strong circumstantial evidence that androgens are implicated in the etiology of prostate cancer, epidemiologic investigations have failed to demonstrate consistently that one or more steroid hormones are implicated. In contrast, recent epidemiologic studies unequivocally link serum insulin-like growth factor 1 (IGF-1) levels with risk for prostate cancer.
  
  
  METHODS
  We have performed the first meta-analysis of all previously published studies on hormonal predictors of risk for prostate cancer.
  
  
  RESULTS
  A meta-analysis restricted to studies that performed mutual adjustment for all measured serum hormones, age, and body mass index indicated that men whose total testosterone is in the highest quartile are 2.34 times more likely to develop prostate cancer (95% confidence interval, 1.30 to 4.20). In contrast, levels of dihydrotestosterone and estradiol do not seem to play a role of equal importance. The only study that provides multivariably adjusted sex hormone-binding globulin data indicates that this binding protein is inversely related to prostate cancer risk (odds ratio, 0.46; 95% confidence interval, 0.24 to 0.89). Finally, all three studies that examined the role of serum IGF-1 have consistently demonstrated a positive and significant association with prostate cancer risk that is similar in magnitude to that of testosterone.
  
  
  CONCLUSIONS
  Men with either serum testosterone or IGF-1 levels in upper quartile of the population distribution have an approximately two-fold higher risk for developing prostate cancer.
authors.affiliation: Divisions of Endocrinology and Oncology, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, and Harvard School of Public Health, Boston, MA 02215, USA.
authors.forename: T
authors.initials: T
authors.lastname: Shaneyfelt
authors.forename: R
authors.initials: R
authors.lastname: Husein
authors.forename: G
authors.initials: G
authors.lastname: Bubley
authors.forename: C S
authors.initials: CS
authors.lastname: Mantzoros
mesh_terms: D000367:Age Factors; D000728:Androgens / Q000097:blood; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D013196:Dihydrotestosterone / Q000097:blood; D004958:Estradiol / Q000097:blood; D005544:Forecasting; D012739:Gonadal Steroid Hormones / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000209:etiology*; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013256:Steroids / Q000097:blood; D013739:Testosterone / Q000097:blood
chemical_list: D000728:Androgens; D012739:Gonadal Steroid Hormones; D006728:Hormones; D012738:Sex Hormone-Binding Globulin; D013256:Steroids; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I