Use of 5α-reductase inhibitors does not affect Gleason grading

A recent study has found no significant impact of 5α-reductase inhibitors on Gleason grading, with no difference in mortality seen among users and nonusers in each Gleason group.

The authors accessed the Prostate Cancer data Base Sweden (PCBase Sweden), which consists of linkages between the National Prostate Cancer Register, the Prescribed Drug Registry, and the Cause of Death Registry. A total of 89,227 men diagnosed with prostate cancer between July 2007 and December 2016 were identified. Follow-up ended in December 2018.

Hazard ratios {HRs} for prostate cancer death were estimated using a Cox proportional hazard model, with adjustments for age, education, comorbidity, and curative treatment. Men with high-risk cancer were also stratified according to Gleason Grade Group.

Of the men, 5,816 had been on 5α-reductase inhibitors for >180 days before the date of diagnosis. The risk of prostate cancer death in men with high-risk cancer was comparable between 5α-reductase inhibitor users and nonusers.

The HRs for 5α-reductase inhibitor users vs nonusers based on Gleason grading were 1.02 (95 percent CI, 0.53–1.95) for Gleason Grade group 1, 1.04 (95 percent CI, 0.65–1.69) for Gleason Grade group 2, 1.27 (95 percent CI, 0.89–1.80) for Gleason Grade group 3, 0.95 (95 percent CI, 0.76–1.18) for Gleason Grade group 4, and 0.99 (95 percent CI, 0.83–1.19) for Gleason Grade group 5.

“5α-Reductase inhibitors reduced the risk of prostate cancer in 25 percent in two randomized trials but increased the risk of Gleason 8–10 at biopsy,” the authors noted. “One explanation is that 5α-reductase inhibitors induce morphological changes in prostate cancer cells similar to higher Gleason grades but without its adverse biology.”