Utility of Gleason pattern 4 morphologies detected on transrectal ultrasound (TRUS)-guided biopsies for prediction of upgrading or upstaging in Gleason score 3 + 4 = 7 prostate cancer

Selected patients with Gleason score (GS) 3 + 4 = 7 prostate cancer (PCa) detected on transrectal ultrasound (TRUS)-guided biopsies may be considered for active surveillance (AS); however, a proportion of these will harbor more aggressive disease. The purpose of this study was to determine if morphologies of Gleason pattern 4 PCa may predict upgrading and/or upstaging after radical prostatectomy (RP). A database search for men with GS 3 + 4 = 7 PCa diagnosed on TRUS-guided biopsy that underwent RP between January 2010 and October 2015 identified 152 patients. Two blinded genitourinary pathologists independently reviewed the biopsies and assessed ill-defined glands (IDG), fused glands, small or large cribriform patterns, and glomerulations. Patient age, serum prostate-specific antigen (PSA), percentage (%) of biopsy sites involved by 3 + 4 = 7 PCa, and overall extent of pattern 4 were also recorded. GS and stage (presence or absence of extraprostatic extension [EPE]) were retrieved from RP reports. Data were compared using independent t tests and chi-square. Inter-observer agreement was calculated using Cohen’s Kappa statistic. Percent of biopsy sites and extent of pattern 4 were compared to statistically significant morphologies using the Spearman correlation. 28.3 % (43/152) of patients were upgraded to GS >3 + 4 = 7 at RP (GS 4 + 3 = 7 [N = 17], GS 4 + 3 = 7 with tertiary pattern 5 [N = 25], and GS 4 + 5 = 9 [N = 1]) and 44.1 % (67/152) showed EPE after RP. PSA was associated with both upgrading (8.5 ± 5.4 vs. 6.9 ± 3.2 ng/mL, [p = 0.04]) and EPE (8.2 ± 4.6 vs. 6.7 ± 3.2 ng/mL, [p = 0.03]). IDG, fused glands, and glomerulations were not associated with upgrading or EPE (p > 0.05) with moderate to strong inter-observer agreement (K = 0.76–0.88). There was strong inter-observer agreement for small and large cribriform formations (K = 0.93 and 0.94, respectively) and both patterns were strongly associated with upgrading (p < 0.001) and EPE (p = 0.02) on RP. Strong associations were observed between increasing number of morphologies and both upgrading (p = 0.0.25) and EPE (p < 0.001). Overall extent of pattern 4 was associated with upgrading (p = 0.009) and EPE (p = 0.019) while percent of sites involved by GS 3 + 4 = 7 was only associated with EPE (p = 0.023). Cribriform morphology correlated to percentage of sites with 3 + 4 and overall extent of pattern 4 (rho = 0.25, p = 0.002, rho = 0.20, p = 0.015, respectively). Presence of cribriform morphology on TRUS-guided biopsy is strongly associated with upgrading and upstaging at RP and shows near-perfect inter-observer agreement whereas IDG, fused glands, and glomerulations were not useful. Cribriform morphology may be of importance when considering treatment plans for patients with intermediate risk PCa.