96 Background: There is an unmet need for non-invasive methods that can accurately identify patients at increased risk for clinically significant prostate cancer (PCa). SelectMDx is a urine-based molecular test that has been clinically validated for the detection of high-grade PCa. We evaluated SelectMDx clinical performance in a cohort of German men undergoing initial prostate biopsy. Methods: The study population consisted of 443 men sequentially enrolled men who underwent initial prostate biopsy between July 2009 and December 2014 due to suspected PCa. Post-DRE urine was collected from all subjects prior to biopsy, and samples stored at -70C. Urinary HOXC6 and DLX-1 mRNAs were quantified by PCR in May 2018, and RNA results combined with clinical risk factors to determine the likelihood that biopsy would identify ISUP grade group (GG) ≥ 2 (Gleason Score ≥ 7) PCa. We assessed SelectMDx performance for detection of GG ≥ 2 PCa, compared to the PCPT Risk Calculator Version 2.0 (PCPTRC, http://myprostatecancerrisk.com , accessed Oct 7, 2018). Results: For the 443 subjects enrolled, average age was 66 years (median 66, interquartile range 61 to 71), and average serum PSA level 8.8 ng/mL (6.4, 4.8 to 9.7). Cancer was detected in 243/443 (55%) men biopsied (43% GG1, 36% GG2, 9% GG3 and 12% GG4-5). The prevalence of GG2-5 PCa in this population was 31.4% (139/443). For detection of GG2 or higher PCa versus GG1 or no PCa at biopsy, SelectMDx AUC was 0.82 (95% C.I. 0.78-0.86) and the PCPTRC yielded AUC 0.75 (0.70-0.80), P < 0.001. SelectMDx sensitivity was 94% (89-98%), specificity 46% (40-52%), positive predictive value 45% (42-47%) and negative predictive value (NPV) 95% (90-97%). If the initial biopsy had been performed based on SelectMDx results alone, 46% of potentially unnecessary biopsies and 34% of all biopsies would have been avoided, while 5.8% of men with biopsy-detectable high-grade PCa (seven GG2, one GG3) may have had their diagnosis delayed. Conclusions: In this first validation study of SelectMDx in German men, the test’s clinical performance was comparable to the published EU validation study, showing a high NPV for detection of GG2 or higher PCa. These results provide further evidence for the clinical validity of SelectMDx.
Can Urinary PCA3 Supplement PSA in the Early Detection of Prostate Cancer?
