Low-risk prostate cancer (PCa) is currently managed also with active surveillance (AS). However, up to 40% of patients in AS may require radical treatment at a long-term follow-up. The aim of our study is to further investigate the role of prostate-specific antigen (PSA) density in AS.

A prospective observational study on PCa naïve patients with PSA<20 ng/ml submitted to prostate biopsy was conducted. Data on family history of PCa, PSA at biopsy, and digitorectal examination were collected. Prostate volume was calculated during TRUS. Bioptic cores number, Gleason Score, and International Society of Urological Pathology (ISUP) Grade Group were recorded. Patients who subsequently underwent radical prostatectomy (RP) were selected and stratified in low, intermediate, and high Risk based on the D'Amico risk classification at biopsy and after RP.

A total of 746 patients were enrolled. PCa was found in 320 patients (42.9%), of whom 252 underwent RP (78.8% of positive biopsies). At biopsy, patients were stratified based on the D'Amico risk classification in low, intermediate, and high risk and were 20.6%, 66.7%, and 12.7%, respectively. Definitive pathology after RP showed PCa change in the risk group in 52.4% of patients (n = 132) and PCa upgrading in 46.8% of patients (n = 118). At Student  test and logistic regression, PSA density was significantly correlated with change in the risk group and upgrading in low-risk PCa (p = 0.024) with an age adjusted odds ratio of 10.01 and 7.53, respectively.

PSA density is a strong instrument in AS to decide whether to treat. However, further larger studies are needed to strongly assess this correlation.