Questions and Answers
5α-reductase inhibitors, such as finasteride and dutasteride, decrease the size of the prostate and the serum PSA level. Do these agents also impact on the PCA3 Score?
Finasteride and dutasteride act by inhibiting 5α-reductase, the enzyme that converts testosterone to dihydrotestosterone. This leads to a reduction in prostate size, and also in the serum prostate specific antigen (PSA) level since the PSA level is dependent of prostate size. The PCA3 Score, contrary to PSA, is not affected by prostate size. It is therefore unlikely that the PCA3 Score will be affected by the use of finasteride or dutasteride in the absence of prostate cancer. However, this should be evaluated in dedicated studies. In addition, given that PCA3 is specifically over-expressed in the presence of prostate cancer, any impact 5α-reductase inhibitors might have on prostate cancer cells may potentially impact the PCA3 Score. A recent study suggests that the use of dutasteride does not impact on the utility of the PCA3 Score to aid in the diagnosis of prostate cancer [1]. This is also not expected for finasteride.
- Aubin SM, Reid J, Sarno MJ, Blase A, Aussie J, Rittenhouse H,
Rittmaster RS, Andriole GL, Groskopf J. Prostate cancer gene 3 score
predicts prostate biopsy outcome in men receiving dutasteride for
prevention of prostate cancer: results from the REDUCE trial. Urology
2011;78:380-5