Prostatic-specific antigen density behavior according to multiparametric magnetic resonance imaging result

Abstract

Objective: To analyze prostatic-specific antigen density (PSAD) according to the Prostate Imaging Reporting and Data System (PIRADSv.2) score, in order to determine how it should be used.

Methods: This correlative series considered 952 men with prostatic-specific antigen >3 ng/ml and/or abnormal digital rectal examination who were subjected to prostatic biopsy (PB) between 2016 and 2017. Of these men, 768 had no previous 5-α-reductase inhibitor use or history of prostate cancer (CaP) and had previously undergone 3-T multiparametric magnetic resonance imaging (mpMRI). In this sample, 549 men were biopsy-naïve and 219 had at least 1 previous negative PB. A 12-core transrectal ultrasound-guided PB was performed in all participants, as well as at least 2-core targeted biopsies of every detected lesion with a PIRADSv.2 score ≥3. Significant CaP (sCaP) was defined as an International Society of Uropathologist grade >1 or tumor length >4 mm.

Results: The overall CaP detection was 41.7%, with sCaP detected in 37.4%. sCaP was detected in 4.3% of PIRADSv.2 <3, 21.5% of PIRADSv.2 =3, 56.6% of PIRADSv.2 =4, and 78.5% of PIRADSv.2 =5, (P < 0.001). Insignificant CaP detection ranged from 6.5% to 1.5% respectively (P = 0.099). PSAD was an independent predictor of sCaP (odds ratios 1.971, 95% confidence interval [1.633, 2.378], P <0.001) and mpMRI (OR 3.179, 95%CI [2.593, 4.950], P < 0.001). Age (P = 0.013), family history of CaP (P = 0.021), and the type of PB (initial vs. repeated, P < 0.001) were also independent predictors of sCaP. PSAD was determined by PIRADSv.2 (P = 0.013) and the presence of sCaP (P < 0.001). PSAD increased with PIRADSv.2 score, even in men with CaP (P < 0.001) and slightly in men without CaP (P = 0.019). The area under the curve for mpMRI increased from 0.830 to 0.869 when PSAD was associated, (P < 0.001). The area under the curve of PSAD decreased from 0.727 in men with a PIRADSv.2 score <3 to 0.706 in those with a score of 5.

Conclusions: The efficacy of PSAD to detect sCaP decreases with PIRADSv.2. Predictors other than mpMRI and PSAD exist. Considering these conditions, independent predictors should be integrated in a nomogram and risk-calculator to personalize PB recommendation.

Keywords: Multiparametric magnetic resonance imaging; Prostate cancer; Prostatic-specific antigen density.