PSA Density to Select MRI Targeted versus Combined Biopsy for Prostate Cancer Diagnosis: A Secondary Analysis of the Trio Study

The addition of systematic prostate biopsy enhances the detection of clinically significant prostate cancer compared to MRI-targeted biopsy alone. However, there is growing interest in using only MRI-targeted biopsy. We sought to evaluate PSA density as an adjunctive predictor of clinically significant prostate cancer detection in men undergoing combined biopsy and as a potential metric to stratify which patients may reasonably avoid systematic biopsies in favor of MRI-targeted biopsy only. Men with elevated PSA and/or abnormal digital rectal exam found to have an MRI-visible prostate lesion underwent MRI-targeted and systematic prostate biopsy. Primary outcomes were clinically significant cancer detection rates by MRI-targeted, systematic biopsy, and combined biopsy across four discrete PSA density intervals (<0.1, >0.1 and <0.15, >0.15 and <0.2, and >0.2 ng/ml/cm3). Secondary outcomes were the added value of systematic biopsy relative to MRI-targeted biopsy alone. Among men with PI-RADS >2 lesions, as PSA density surpassed each interval, the rate of grade group >3 cancer detection approximately doubled (<0.1:9.3%, >0.1 and <0.15:18.2%, >0.15 and <0.2:36%, and >0.2:61.2%). For PSA density >0.2, added detection of clinically significant cancer with systematic biopsy was low(2%, 95%CI:0.4%-5.9%). Given an approximate doubling in grade group >3 cancer detection on combined biopsy with rising PSA density intervals, clinicians may consider PSA density in risk stratifying men at high risk of clinically significant prostate cancer. Clinicians may consider omitting systematic biopsy for targeted biopsy of MRI-visible lesions in patients with PSA density >0.2ng/ml/cm3, as systematic biopsy results in low rates of additional clinically significant cancer detection.