Open AccessExternal validation of the novel International Society of Urological Pathology (ISUP) Gleason grading groups in a large contemporary Canadian cohort
Author(s) -
Helen Davis Bondarenko,
Marc Zanaty,
Sabrina S. Harmouch,
Cristiegrean,
Raisa S. Pompe,
Daniel Liberman,
Naeem Bhojani,
Pierre I. Karakiewicz,
Kevin C. Zorn,
Assaad El-Hakim
Publication year - 2018
Publication title -
canadian urological association journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.477
H-Index - 38
eISSN - 1920-1214
pISSN - 1911-6470
DOI - 10.5489/cuaj.5284
Subject(s) - medicine , prostatectomy , population , grading (engineering) , proportional hazards model , cohort , hazard ratio , nuclear medicine , urology , surgery , pathology , prostate cancer , confidence interval , cancer , civil engineering , environmental health , engineering
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.
Methods: 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.
Results: 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<<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.
Conclusions: 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.