OBJECTIVES: To analyze the validity of the ratio between the second and fourth 
finger (digit ratio; 2D/4D) of the left hand as a predictor for prostate cancer 
(PCa) in a group of men undergoing prostate biopsy.
METHODS: We prospectively recruited 204 consecutive patients referred for 
transrectal prostate biopsy due to PSA elevation or abnormal digital rectal 
examination between January 2008 and June 2009. The same physician performed all 
clinical examinations, digit ratio measurements and transrectal biopsy in all 
cases. Digit ratio determination was done with a Vernier caliper in the left 
hand. Patients underwent determination of hormone profile (testosterone and 
sexual hormone binding globulin (SHBG)) between 7:00AM and 11:00AM. Age, digital 
rectal examination, PSA, free PSA, PSA density, testosterone and SHBG, 
pathological report and D2 and D4 measurements were recorded prospectively.
RESULTS: Variables age and SHBG were directly related to PCa. Prostate volume 
was inversely related to neoplasia. 2D/4D ratio >0,95 (OR (CI 95%) 4,4 
(1,491-13,107) was related to neoplasia. No differences in PCa were seen 
regarding PSA, free PSA, PSA density, digital rectal examination and 
testosterone.
CONCLUSION: High digit ratio predicts PCa in men undergoing prostate biopsy. 
Digit ratio >0,95 has 4-fold risk of PCa compared to men with digit ratio ≤0.95.