Prognostic implications of 2005 Gleason grade modification. Population-based study of biochemical recurrence following radical prostatectomy

To assess the impact of the 2005 modification of the Gleason classification on risk of biochemical recurrence (BCR) after radical prostatectomy (RP).

In the Prostate Cancer data Base Sweden (PCBaSe), 2,574 men assessed with the original Gleason classification and 1,890 men assessed with the modified Gleason classification, diagnosed between 2003 and 2007, underwent primary RP.

Histopathology was reported according to the Gleason Grading Groups (GGG): GGG1 = Gleason score (GS) 6, GGG2 = GS 7(3 + 4), GGG3 = GS 7(4 + 3), GGG4 = GS 8 and GGG5 = GS 9-10. Cumulative incidence and multivariable Cox proportional hazards regression models were used to assess difference in BCR.

The cumulative incidence of BCR was lower using the modified compared to the original classification: GGG2 (16% vs. 23%), GGG3 (21% vs. 35%) and GGG4 (18% vs. 34%), respectively. Risk of BCR was lower for modified versus original classification, GGG2 Hazard ratio (HR) 0.66, (95%CI 0.49-0.88), GGG3 HR 0.57 (95%CI 0.38-0.88) and GGG4 HR 0.53 (95%CI 0.29-0.94).

Due to grade migration following the 2005 Gleason modification, outcome after RP are more favourable. Consequently, outcomes from historical studies cannot directly be applied to a contemporary setting. J. Surg. Oncol. © 2016 Wiley Periodicals, Inc.

Journal of surgical oncology. 2016 Aug 11 [Epub ahead of print]

Frederik B Thomsen, Yasin Folkvaljon, Klaus Brasso, Stacy Loeb, David Robinson, Lars Egevad, Pär Stattin

Copenhagen Prostate Cancer Center and Department of Urology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark., Regional Cancer Centre, Uppsala/Örebro, Uppsala University Hospital, Uppsala, Sweden., Copenhagen Prostate Cancer Center and Department of Urology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark., Department of Urology, Population Health and the Laura and Isaac Perlmutter Cancer Institute, New York University and Manhattan Veterans Affairs Medical Center, New York, New York., Department of Surgical Sciences, Uppsala University, Uppsala, Sweden., Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden., Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.