Background
The early diagnosis of prostate cancer (PCa) is mainly based on prostate‐specific antigen (PSA) blood levels and digital rectal examination. However, this approach may result in a high rate of negative biopsies and increased detection of clinically insignificant PCa (CS‐PCa). An important prognostic biomarker, PSA density (PSA‐D) demonstrated improved performance in PCa detection compared to PSA. The relationship between prostate volume and the prognostic accuracy of PSA‐D remains mostly unclear. The aim of our study is to investigate the PSA‐D predictive value of CS‐PCa detection at different prostate volumes.
Methods
Using our local radical prostatectomy registry, patients were divided into three prostate size subgroups based on preoperative sonographic prostate volume assessment: less than 50, 50–75, and more than 75 cc. Patients' and PCa characteristics were recorded, including age, body mass index, PSA at diagnosis, prostate volume, PSA‐D, D'Amico risk classification, Gleason grade group, and pathological staging following surgery.
Results
The study cohort included 364 patients who underwent Robotic Radical prostatectomy for biopsy‐proven clinically localized PCa. 221 (61%) and 143 (39%) patients had PSA‐D less than 0.15 and PSA‐D more than 0.15, respectively. ISUP GG 1–2 PCa (CS‐PCa) was observed in 220 patients (60%), while 144 (40%) had ISUP GG 3–5 PCa at final pathology. PSA‐D correlated with CS‐PCa only in small and medium‐size prostates, but not in large glands (p = .03, p = .01, and p = .36, respectively). The highest sensitivity (72.7%) was observed in small prostates, compared to 3.2% in large prostates. The highest specificity (89.4%) was noted in large prostates. Positive predictive value in small and medium‐size prostates was similar (~50%), compared to 20% in large glands. The negative predictive value was slightly better for small and medium‐size prostates compared with large glands (68.9%, 73.7%, and 53.1%, respectively). An association between PSA‐D and harboring CS‐PCa was detected only in small and medium‐size glands (72.7% and 43%, respectively).
Conclusion
PSA‐D is associated with CS‐PCa detection in radical prostatectomy specimens in small and medium‐size prostates. The level of PSA‐D is directly associated with the ISUP PCa grade group. Therefore, PSA‐D is a beneficial, available, and cost‐effective tool during decision‐making in patients with small and medium‐size prostate when considering treatment for PCa.