Estimating the Effect of Finasteride on Kallikrein Marker Levels in Blood and the Use of Converted Markers in the Four-Kallikrein Model
March 2026
in “
European Urology Focus
”
TLDR Finasteride improves prostate cancer prediction by adjusting kallikrein marker levels.
The study investigated the impact of finasteride, a 5-α-reductase inhibitor, on kallikrein markers in blood and its implications for prostate cancer screening using the four-kallikrein (4K) model. Analyzing 500 participants from the Prostate Cancer Prevention Trial, the study found that finasteride use halved total PSA and human kallikrein 2 levels, while free PSA and intact PSA were slightly more than halved. Adjusted marker levels improved the 4K model's ability to predict high-grade prostate cancer on biopsy, with an AUC of 0.734 compared to 0.595 for adjusted total PSA alone. The 4K model demonstrated the highest net benefit for risk thresholds of ≥7%, suggesting its utility in informing prostate biopsy decisions for men on 5-ARIs.