Since the new 2014 grading system was recommended by international society of urological pathology (ISUP), it has been validated in patients with localized prostate cancer(PCa) with excellent prognostic value. However, its predictive power in high-risk PCa has not been verified.
A total of 420 patients with high-risk PCa underwent radical prostatectomy(RP) were included. The predictive accuracy of the 2005 and 2014 grading systems were validated and compared. Biochemical-recurrence free survival (BRFS) was set as the endpoint.
Compared to the 2005 system, the 2014 system could fairly well distinguish BRFS of patients into five groups with higher predictive accuracy(C-index: 0.599 vs 0.646). In multivariate analyses, together with baseline prostate specific antigen, extraprostatic extension and perineural invasion status, the new system was independent predictor for BRFS in these population. The relatively higher proportion of tertiary Gleason pattern 5 (TGP5) among patients with Gleason grade group 3(GGG3) could be considered as an important interfering factor leading to the overlap of survival between GGG4 and GGG3.
This is the first study to validate the new 2014 ISUP grading system in patients with high-risk PCa underwent RP. The new system could better separate patients into five groups with higher predictive accuracy over the old one. It should be paid attention that, the existence of TGP5 need to be routinely reported in clinical practice, which could help retaining the predictive ability of the new grading system. Due to miscellaneous factors among these patients, the prognostic prediction need to be comprehensively evaluated.
Clinical trial identification
Legal entity responsible for the study
Department of Urology, Institute of Urology, West China Hospital, SiChuan University.
National Natural Science Foundation of China (NSFC 81402110, 81672547, 81572380, and 81272820); Science and Technology Support Program of Sichuan Province (2015SZ0142); 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University.
All authors have declared no conflicts of interest.