TY - JOUR AU - Davis Bondarenko, Helen AU - Zanaty, Marc AU - Harmouch, Sabrina S. AU - Negrean, Cristina AU - Pompe, Raisa S. AU - Liberman, Daniel AU - Bhojani, Naeem AU - Karakiewicz, Pierre I. AU - Zorn, Kevin C. AU - El-Hakim, Assaad PY - 2018/06/19 Y2 - 2024/03/29 TI - External validation of the novel International Society of Urological Pathology (ISUP) Gleason grading groups in a large contemporary Canadian cohort JF - Canadian Urological Association Journal JA - CUAJ VL - 12 IS - 12 SE - Original Research DO - 10.5489/cuaj.5284 UR - https://cuaj.ca/index.php/journal/article/view/5284 SP - AB - <p><strong>Introduction:</strong> We sought to test the discriminatory ability of the 2014 International Society of Urological Pathology (ISUP) Gleason grading groups (GGG) for predicting biochemical recurrence (BCR) after robot-assisted radical prostatectomy (RARP) in a large, contemporary, Canadian cohort.</p><p><strong>Methods:</strong> A total of 621 patients who underwent RARP in two major Canadian centres were identified in a prospectively maintained Canadian database between 2006 and 2016. Followup endpoint was BCR. Log-rank test, univariable, and multivariable Cox regression analyses were used.</p><p><strong>Results:</strong> Mean followup was 27.9 months. All five ISUP GGG independently predicted BCR. Statistically significant differences in BCR rates were found between GGG 2 and GGG 3 strata (p&lt;&lt;0.001). No statistically significant differences in BCR rates were found between GGG 4 and GGG 5 strata (p=0.3). Relative to GGG 1, the GGG 2, GGG 3, GGG 4, and GGG 5 yielded a 1.10-, 3.44-, 4.18-, and 4.74-fold hazard ratio (HR) increment in BCR, respectively.</p><p><strong>Conclusions:</strong> This population-based Canadian cohort study confirms the added discriminatory property of the novel ISUP grading, specifically for GGG 2 and GGG 3 strata. No difference, however, was observed between GGG 4 and GGG 5, likely due to the lower number of patients in these groups. As such, after external validation, the 2014 ISUP GGG appears to retain clinical prognostic significance in a Canadian population.</p> ER -