title: Second to fourth digit ratio and prostate cancer severity.
abstract: BACKGROUND
  The ratio of the second to the fourth digit (2D:4D ratio) is a sexually dimorphic trait established in utero that differs between ethnic groups. It is associated with prenatal androgen exposure, and studies have evaluated the ratio as a marker for certain traits and disease states known to be associated with higher levels of in utero androgens, such as prostate cancer. There are currently no screening tools that stratify men with prostate cancer according to the severity of their disease. This study aims to investigate the 2D:4D ratio as a potential marker for prostate cancer severity. Our hypothesis was that lower digit ratios, representing higher in utero androgen exposure, would be associated with more severe disease.
  
  
  METHODS
  Measurements were taken of the second and fourth digits of the right hand of male patients diagnosed with prostate cancer. Gleason score, presence of metastasis, family history, age at diagnosis and race were recorded. The distribution of demographic and other patient characteristics were compared with digit ratios to determine relationships.
  
  
  RESULTS
  African-American men with prostate cancer are 3.70 times more likely to have a low 2D:4D digit ratio than Caucasian men with prostate cancer (95% confidence interval: 1.98, 6.92; P < 0.0001). There were no statistically significant differences in the presence of metastasis, Gleason score, family history or age at diagnosis by digit ratio.
  
  
  CONCLUSIONS
  2D:4D ratio shows strong differences between African-Americans and Caucasians; however, it does not correlate with disease severity in men already diagnosed with prostate cancer. Although this is a small population sample with possible confounding factors, it does not provide evidence to support the hypothesis that prenatal androgens affect prostate cancer grade or progression.
authors.affiliation: Tulane University School of Medicine, New Orleans, LA 70112, USA.
authors.forename: M
authors.initials: M
authors.lastname: Waters
authors.forename: C M
authors.initials: CM
authors.lastname: Rebholz
authors.forename: B
authors.initials: B
authors.lastname: Wood
authors.forename: A
authors.initials: A
authors.lastname: Kuske
authors.forename: M
authors.initials: M
authors.lastname: McIntyre
authors.forename: O
authors.initials: O
authors.lastname: Sartor
mesh_terms: D000886:Anthropometry; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology*; D012727:Sex Characteristics