Effect of Finasteride and/or Terazosin on Serum PSA: Results of VA Cooperative Study #359

The study investigated the effect of finasteride and/or terazosin on serum prostate-specific antigen (PSA) levels in men with benign prostatic hyperplasia (BPH). The study included patients enrolled in the VA Cooperative Study #359 trial and evaluated four treatment groups: placebo, finasteride, terazosin, and a combination of finasteride plus terazosin. The results showed that there was no significant difference in baseline PSA levels between the four groups. However, at 52 weeks, there was a statistically significant reduction in PSA levels in the finasteride and combination therapy groups, while significant increases were observed in the terazosin and placebo groups. The study concluded that terazosin had no clinically significant effect on PSA levels, and the heterogeneity of PSA response to finasteride may make monitoring patients for the development of prostate cancer problematic.