Oncology - Prostate
Introduction & Objective :
Multiparametric magnetic resonance imaging (mpMRI) has emerged as a valuable tool to improve the risk stratification of patients with clinically localized prostate cancer (PCa). We hoped to better identify the risk of adverse pathologic features following radical prostatectomy (RP) in patients with Grade Group (GG) 1 and 2 on biopsy who had high PI-RADS scores.
Between 2014 and 2017, we retrospectively analyzed 203 patients who had an mpMRI prior to radical prostatectomy (RP) with Grade Group (GG) 1 (Gleason 3+3=6) and GG 2 (Gleason 3+4=7) prostate cancer on systematic +/- mpMRI-TRUS fusion targeted prostate biopsy. PI-RADS version 2 (PI-RADSv2) scores were grouped into high (4 and 5) and low (≤ 3) and compared to adverse RP pathology results including any upgrading, upgrading to ≥ GG 3 (Gleason 4+3=7), extraprostatic extension (EPE), seminal vesical invasion (SVI), and positive pelvic lymph nodes.
On biopsy, 102 and 101 patients had GG1 and GG2 pathology, respectively prior to RP. 43.6% (44/102) of patients with GG1 and 61.8% (63/102) with GG2 had PI-RADSv2 4 and 5 lesions. For GG1, PI-RADSv2 4 and 5 lesions were significantly associated with any upgrading (68% vs 47%, p=0.02), upgrading to ≥ GG3 (16% vs 2%, p=0.02), EPE (18% vs 3.5%, p=0.01), and any adverse pathology (≥ GG3, SVI, EPE or positive pelvic lymph nodes; 27% vs 5%, p=0.002). Men with PIRADSv2 < 4 had a NPV of 95% for adverse pathology. For GG2, compared to low PI-RADSv2 scores, PI-RADSv2 4 and 5 scores were significantly associated with EPE (40% vs 21%, p=0.03), adverse pathology (49% vs. 23%, p =0.006), and had higher rates of upgrading to ≥ GG3 (21% vs. 13%, p=0.21) although the latter did not reach significance at conventional thresholds. Pre-RP PSA was higher in those with any adverse pathology in GG1 group (median [IQR]; 7.4 [5.6 - 21] vs. 5.4[3.8 -8.3], p=0.005), as well as GG2 group (median [IQR]; 6.6[5.5 -14.4] vs. 6.1[4.3 -7.6], p=0.02).
For patients with GG1 and GG2 PCa on biopsy, high PI-RADSv2 lesions are associated adverse pathologic features on RP. For those with GG1 PCa, PI-RADSv2 4 and 5 lesions are associated with a 7-fold risk of adverse pathology on RP, raising the suspicion for radiologic-pathologic discordance. Additional studies are required to determine whether high PI-RADSv2 scores should influence eligibility for active surveillance or need for repeat targeted biopsy.