Levels of 5α-Reductase Type 1 and Type 2 are Increased in Localized High Grade Compared to Low Grade Prostate Cancer

Conclusions Levels of 5α-reductase type 1 and 2 are increased in localized high vs low grade prostate cancer. Levels of 5α-reductase type 1 are higher in benign tissue adjacent to cancer than in benign prostatic hyperplasia. These results raise the possibility that increased 5α-reductase type 1 in localized high grade cancers may contribute to the decreased effectiveness of the 5α-reductase type 2 selective inhibitor finasteride against high grade prostate cancer in the Prostate Cancer Prevention Trial.