title: Relationship between body size and prostate cancer in a sibling based case-control study.
abstract: OBJECTIVE
  Body size has been hypothesized to affect the risk of prostate cancer (PCa). However, previous studies have provided conflicting results, in that some show positive associations, whereas others indicate inverse associations or null findings. To further understand this we examined the effects of weight, height, body mass index and lean body mass (LBM) on PCa risk and aggressiveness in a sibling based case-control study.
  
  
  METHODS
  A total of 439 cases were recruited at major medical institutions in Cleveland, Ohio and Detroit, Michigan, and 479 unaffected brothers were recruited as controls. Conditional logistic regression with robust variance estimation was used to evaluate the association between body size and PCa.
  
  
  RESULTS
  Higher LBM was inversely associated with PCa, especially in men with more aggressive disease or a later age at onset. Comparing those above and below the 25th percentile showed an OR of 0.49 (95% CI 0.28 to 0.84) and 0.28 (95% CI 0.14, 0.56), respectively. Similar inverse patterns were observed for weight. No noteworthy associations were observed between PCa and height or body mass index.
  
  
  CONCLUSIONS
  These observations suggest that PCa may be affected by LBM.
authors.affiliation: Department of Epidemiology and Biostatistics, University of California-San Francisco, 500 Parnassus Avenue, San Francisco, CA 94143-0560, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Rybicki
authors.forename: Graham
authors.initials: G
authors.lastname: Casey
authors.forename: John S
authors.initials: JS
authors.lastname: Witte
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D015992:Body Mass Index; D049628:Body Size; D016022:Case-Control Studies; D005192:Family Health; D006801:Humans; D016015:Logistic Models; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology*; D012307:Risk Factors; D035781:Siblings
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen