MP53-10: The role of SelectMDx in men undergoing primary prostate biopsy: a prospective multi-institutional study

Martina Maggi*, Francesco Del Giudice, Rome, Italy, Ugo G Falagario, Foggia, Italy, Andrea Cocci, Florence, Italy, Giorgio I. Russo, Marina Di Mauro, Catania, Italy, Giuseppe Salvatore Sepe, Mondragone, Italy, Fabio Galasso, Eboli , Italy, Rosario Leonardi, Gravina di Catania, Italy, Gabriele Iacona, Acireale, Italy, Peter R. Carroll, Matthew R. Cooperberg, San Francisco, CA, Angelo Porreca, Padua, Italy, Matteo Ferro, Milan, Italy, Giuseppe Lucarelli, Bari, Italy, Daniela Terracciano, Naples, Italy, Luigi Cormio, Giuseppe Carrieri, Foggia, Italy, Ettore De Berardinis, Alessandro Sciarra, Rome, Italy, Gian Maria Busetto, Foggia, Italy

Introduction: Prostate-specific antigen (PSA) testing as the sole indication for prostate biopsy lacks specificity, resulting in over-diagnosis of indolent prostate cancer (PCa), and, missing clinically significant PCa (csPCa). SelectMDx is a biomarker-based risk score assessing urinary HOXC6 and DLX1 mRNA expression combined with traditional clinical risk factors. Aim of this prospective multi-institutional study was to evaluate the diagnostic accuracy of SelectMDx and its association with multiparametric magnetic resonance (mpMRI) in predicting PCa on prostate biopsies.

Methods: In this multi-institutional prospective study, men from 5 different sites have been consecutively enrolled. All patients were scheduled for first prostate biopsy, based on a clinical suspicion of PCa (i.e., elevated total PSA level >3 ng/ml and/or abnormal DRE). All patients underwent mpMRI and SelectMDx prior to prostate biopsy.

Results: Overall, 310 consecutive subjects have been included. SelectMDx and mpMRI showed sensitivity and specificity of 86.5% vs 51.9%, and 73.8% vs 88.3%, respectively, in predicting PCa at biopsy, and 87.1% vs 61.3%, and 63.7% vs 83.9%, respectively, in predicting csPCa at biopsy. With analysis of strategies assessed to define the best diagnostic strategy to avoid unnecessary biopsy, SelectMDx after an initial negative mpMRI appeared to be a reliable pathway.

Conclusions: SelectMDx revealed to be a good predictor of PCa, while, with regards to csPCa detection, it demonstrated to be less effective, showing results similar to mpMRI. Biopsy could be proposed to all cases of mpMRI PI-RADS 4-5 score and to those with Prostate Imaging-Reporting and Data System (PI-RADS) 1-3 score followed by a positive SelectMDx.

Source of Funding: none