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

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.