Liu AQ, Remmers S, Lau SY, et al. - The results of this study demonstrate that initial phi or phi density predicted a six-year risk of prostate cancer (PCa) in men with initial negative prostate biopsy. Closer follow-up and repeated investigation were needed in men with higher phi (≥35) or phi density (≥1.2), while men with lower phi (<25) or phi density (<0.4) could have a less frequent follow-up.

• Researchers recruited a total of 569 men with prostate-specific antigen 4–10 ng/mL between 2008 and 2015 for prostate biopsy with prior phi.

• They included 461 men with complete follow-up data.

• In this study, 77 months was the median follow-up.

• They diagnosed PCa and HGPCa in 8.2% (38/461) and 4.8% (22/461) of cohorts respectively.

• It has been reported that a higher baseline phi value was correlated with PCa (p = 0.003) and HGPCa (p < 0.001).

• The results showed that HGPCa was diagnosed in 0.6% (1/163) of phi < 25, 4.6% (9/195) of phi 25–34.9, and 11.7% (12/103) of phi ≥ 35 (p < 0.001).

• They diagnosed HGPCa in 0% (0/109) and 21.0% (13/62) with phi density of <0.4 and ≥1.2, respectively, (p < 0.001).

• Furthermore, Kaplan–Meier curves demonstrated phi and phi density predicted PCa and HGPCa diagnoses (log-rank test, all p ≤ 0.002).