Higher second fourth digit ratio predicts higher incidence of prostate cancer in prostate biopsy.

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.