Is suspicious upstaging on multiparametric magnetic resonance imaging useful in improving the reliability of Prostate Cancer Research International Active Surveillance (PRIAS) criteria? Use of the K-CaP registry

Background and objective To evaluate the clinical effects of suspicious upstaging on multiparametric magnetic resonance imaging (mpMRI) for improving the quality of Prostate Cancer Research International Active Surveillance (PRIAS) criteria. Material and methods A total of 363 patients with low-risk prostate cancer (PCa) were selected from the K-CaP registry (the multicenter Korean PCa Database). Patients were divided into 2 groups according to the results of mpMRI (with or without suspicious upstaging). The variables for predicting significant PCa, defined as locally advanced PCa, Gleason score≥7, or tumor volume>0.5 cc or all of these, and adverse PCa, defined as locally advanced PCa, Gleason score≥7 (4+3), or tumor volume>2.5 cc or all of these, were assessed. Results The mpMRI led to “suspicious” upstaging in 56 patients (15.4%). Significant PCa (98.2% vs. 74.6%, P<0.001) and adverse PCa (85.7% vs. 32.6%, P<0.001) were more common in patients with suspicious upstaging. The sensitivity/specificity of mpMRI for significant PCa and adverse PCa were 25.4%/98.2% and 32.4%/96.3%, respectively. On multivariate analyses, suspicious upstaging on mpMRI (odds ratio: 15.82, P = 0.007) was a predictor for significant PCa in addition to PRIAS criteria and age at diagnosis. In addition, suspicious upstaging on mpMRI (odds ratio: 11.11, P<0.001) was a significant predictor for adverse PCa in addition to PRIAS criteria, age at diagnosis, and body mass index. Conclusion Along with the PRIAS criteria, suspicious upstaging on mpMRI is a potent diagnostic tool for distinguishing patients suitable for active surveillance among patients with low-risk PCa.