(HealthDay News) — The magnitude of change in serum prostate specific antigen (PSA) after 5α-reductase inhibitor therapy may help diagnose prostate cancer in men with persistently increased serum PSA and previously negative biopsies, according to a study published in the September issue of The Journal of Urology.
Steven A. Kaplan, M.D., from Cornell University in New York City, and colleagues examined the effect of 5α-reductase inhibitor therapy on prostate cancer detection in 276 men with PSA greater than 4 ng/mL (208) or a PSA velocity change of 0.75 ng/mL (68) and a normal digital rectal examination who had previously undergone biopsy at least twice. Patients were given finasteride (154) or dutasteride (122) daily. In phase 1, PSA was measured at six and 12 months in 97. In phase 2, biopsy was performed on patients with a nadir PSA of more than 0.4 ng/mL.
In phase 1 at one year, the researchers found that PSA had decreased by 46.7 percent and prostate volume had decreased by 17.9 percent. In 27.8 percent of the 97 patients, prostate cancer was detected with a mean minimum PSA velocity of 0.6 ng/mL from a nadir of 0.4 ng/mL. At a mean of 14.6 months, 26.8 percent of the 179 participants in phase 2 underwent repeat biopsy. Of these, 54.1 percent had prostate cancer, and Gleason score 7 or greater disease was detected in 76.9 percent of them.
“The data in this study support the concept that the magnitude of change in serum PSA after one year of 5α-reductase inhibitor therapy may be useful in diagnosing prostate cancer in men with persistently increased serum PSA and previously negative prostate biopsies,” the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.