Treatment with finasteride preserves usefulness of prostate-specific antigen in the detection of prostate cancer: results of a randomized, double-blind, placebo-controlled clinical trial

• Published in: Urology (Ridgewood, N.J.) Vol. 52; no. 2; pp. 195 - 202
• Main Authors: Andriole, G.L., Guess, H.A., Epstein, J.I., Wise, H., Kadmon, D., Crawford, E.D., Hudson, P., Jackson, C.L., Romas, N.A., Patterson, L., Cook, T.J., Waldstreicher, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-08-1998
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/S0090-4295(98)00184-8

Objectives. To evaluate prostate cancer detection and prostate-specific antigen (PSA) among men with benign prostatic hyperplasia treated with finasteride.
Methods. Three thousand forty men 45 to 78 years of age with PSA less than 10 ng/mL and no history of prostate cancer were randomized in a double-blind, placebo-controlled trial to finasteride (n = 1524) or placebo (n = 1516) for up to 4 years. A prerandomization biopsy negative for prostate cancer was obtained in 98% of patients with a screening PSA of 4.0 ng/mL or more, and an end-of-study biopsy was requested of all such patients without a recent second negative biopsy or a prostate cancer diagnosis.
Results. Overall, 644 patients (21%) underwent biopsy and 201 (6.6%) underwent transurethral resection of the prostate. Prostate cancer was diagnosed in 4.7% of men on finasteride and 5.1% on placebo (
P = 0.7). Elevated PSA prompted diagnosis in 35% of cases on finasteride and 34% on placebo. The area under the receiver operating characteristic curve for last PSA was 0.84 on finasteride and 0.79 on placebo (
P = 0.07). Use of an upper limit of normal for last PSA of 2.0 ng/mL for finasteride and 4.0 ng/mL for placebo yielded similar sensitivity (66% versus 70%,
P = 0.6), higher specificity (82% versus 74%,
P < 0.0001), and a higher likelihood ratio (3.6 versus 2.7,
P < 0.05) for finasteride than for placebo.
Conclusions. In men treated with finasteride, multiplying PSA by 2 and using normal ranges for untreated men preserves the usefulness of PSA for prostate cancer detection.