Exploration Of Alternative Digit Ratios As A Predictor Of Prostate Cancer Aggressiveness.

231 Background: During gestation, development of the prostate is dependent on a functional androgen receptor and the presence of dihydrotestosterone. Prenatal androgen exposure has been correlated with a range of diseases including prostate cancer (PCa). Historically, the ratio of the second to the fourth digit (2D:4D) has been linked to prenatal androgen levels; however, the use of alternate finger ratios have been shown to be a greater indicator of prenatal androgen exposure compared to the traditional 2D:4D ratio. Studies have shown that the distal fingertip extent of the second digit (2T:2D) was also associated with prenatal androgens. This study aims to use alternative digit ratio measurements to determine aggressiveness of PCa. Our hypothesis is that alternative digit ratios are more sensitive to prenatal androgen levels, and a better predictor of disease than the traditional 2D:4D ratio. Methods: Digital measurements were made from hand scans of PCa patients. All fingers on the right hand were measured from the basal crease to the fingertip as well as the distal fingertip extent of the second digit. Race, family history (FH) (first degree relatives with PCa), and age at diagnosis were recorded. These clinical covariates were then compared to the finger length ratios which were dichotomized based on the median values and analyzed for possible correlations. Results: Hand measurements were taken on 350 Caucasian (CA) and 100 African American (AA) PCa patients. AA men were more likely to have a smaller 2D:3D (P < 0.0001) and 2D:4D digit ratio (P < 0.0001), and larger 3D:5D (P = 0.0002) and 4D:5D (P = 0.0125) when compared to CA men. AA men with a smaller 2T:2D ratio were younger at the time of diagnosis (P = 0.0446). Additionally, AA men with a larger 2D:5D ratio were more likely to have a FH of PCa (P= 0.0238). Conclusions: Alternative finger length ratios show strong differences between AA and CA men. In AA men, alternative digit ratios are associated with age of PCa diagnosis and FH of PCa. These hypothesis generating results require validation in a larger cohort, but may provide insight to the underlying racial disparity observed in PCa. Finger length may represent a unique, non-invasive predictor of PCa, specifically age of onset and FH in AA men.