Association of Prostate Imaging Reporting and Data System (PI-RADS) Score and Prostate-Specific Antigen Density (PSAD) With Prostate Biopsy Histology Outcomes: A Retrospective Study.

OBJECTIVE: This study aimed to investigate the association of Prostate Imaging Reporting and Data System (PI-RADS) and prostate-specific antigen density (PSAD) with prostate biopsy histology outcomes in a retrospective cohort. METHODS: We audited 594 consecutive men who underwent local anaesthetic transperineal prostate biopsy between January 2022 and June 2025. Data collected included age, prostate-specific antigen (PSA), prostate volume, PI-RADS score, and Gleason grade. PI-RADS scores were categorised as low (1-2), intermediate (3), and high (4-5). PSAD was categorised as <0.15 ng/mL2 and ≥0.15 ng/mL2. Multinomial logistic regression was performed to assess the association between PSAD and PI-RADS with benign histology, Gleason 6 cancers, and Gleason ≥7 cancers. Significance was set at p<0.05. RESULTS: The median patient age was 68.7 years, median PSA 8.20 ng/mL, and median PSAD 0.17 ng/mL2. About 30.1% of biopsies were benign, with malignancies in 69.9% (34.7% Gleason 6; 65.3% Gleason ≥7). High PSAD (≥0.15 ng/mL2) and high PI-RADS (4-5) independently are strongly associated with Gleason ≥7 cancers (OR 5.63 and 95% CI 3.54-8.96; OR 9.14 and 95% CI 4.36-19.19; both p<0.001). PI-RADS 3 demonstrated non-significant trends. Age was an independent predictor of clinically significant cancer but not Gleason 1 disease (OR 1.04; 95% CI 1.01-1.07; p=0.01) Conclusions: Elevated PSAD and high PI-RADS scores are strongly associated with Gleason ≥7 cancers. PSAD also adds discriminatory value in PI-RADS 3 lesions.