EFFECT OF FINASTERIDE ON FREE AND TOTAL SERUM PROSTATE-SPECIFIC ANTIGEN IN MEN WITH BENIGN PROSTATIC HYPERPLASIA

Objective To examine changes in the free-to-total (f/t) serum prostate -specific antigen (PSA) ratio among men treated with finasteride for b enign prostatic hypertrophy. Patients and methods Blood samples were t aken from 20 men (mean age 71 years, range 61-87) before and after a m inimum of 9 months of treatment with finasteride and the f/tPSA ratio determined using the Immulite assay system. Results Although mean tota l and free PSA levels decreased significantly, the mean f/tPSA ratio i ncreased only slightly and not significantly; the ratios remained unch anged in men with an initially low or high (< > 10%) ratio. Conclusion s Concern has been expressed over the loss of the discriminatory power of serum PSA in a patient receiving treatment with finasteride. The f /tPSA ratio, currently used to help differentiate benign from malignan t processes in the prostate, remains valid during treatment with finas teride; it does not affect the f/tPSA ratio.