External validation of the novel International Society of Urological Pathology (ISUP) Gleason grading groups in a large contemporary Canadian cohort

  • Helen Davis Bondarenko University of montreal
  • Marc Zanaty Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Sabrina S. Harmouch Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Cristina Negrean Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Raisa S. Pompe Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany
  • Daniel Liberman Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Naeem Bhojani Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Pierre I. Karakiewicz Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Kevin C. Zorn Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada
  • Assaad El-Hakim Division of Urology, Department of Surgery, Centre hospitalier de l’université de Montréal (CHUM), Montreal, Quebec, Canada Division of Robotic Urology, Department of Surgery, Hôpital du Sacré Coeur de Montréal, Montreal, Quebec, Canada

Abstract

Introduction: 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.

Author Biography

Helen Davis Bondarenko, University of montreal
Resident 3 in urology
Published
2018-06-19
How to Cite
Davis Bondarenko, H., Zanaty, M., Harmouch, S. S., Negrean, C., Pompe, R. S., Liberman, D., Bhojani, N., Karakiewicz, P. I., Zorn, K. C., & El-Hakim, A. (2018). External validation of the novel International Society of Urological Pathology (ISUP) Gleason grading groups in a large contemporary Canadian cohort. Canadian Urological Association Journal, 12(12). https://doi.org/10.5489/cuaj.5284
Section
Original Research