Impact of Low Dose Finasteride for the Treatment of Androgenic Alopecia on Serum Prostate Specific Antigen Levels in Men Participated in Population-Based Screening for Prostate Cancer

In a study conducted between April 2006 and March 2008 involving 37,645 men who participated in population-based screening for prostate cancer in Gunma Prefecture, Japan, the impact of low dose finasteride (1 mg per day) on serum prostate specific antigen (PSA) levels was investigated. Out of the screened men, 88 (0.23%) were taking finasteride, with the highest proportion (0.43%) in the age range of 50 to 59 years. Among the 66 men who had been taking finasteride and had PSA screening one year prior, PSA levels decreased more than 20% in 16 men, decreased less than 20% in 17 men, and increased in 29 men. The mean (median) percent changes of serum PSA levels were small, with variations depending on the PSA level range. The study concluded that, contrary to previous studies suggesting that low dose finasteride affects serum PSA concentration similarly to higher doses used for benign prostatic hyperplasia (BPH), the changes in PSA levels for men older than 50 years and with BPH were unexpectedly small. This suggests that aging and existing BPH may result in minor changes in serum PSA levels while taking low dose finasteride.