Introduction

Aim of our study was to evaluate differences between the old and the new classification systems in upgrading and downgrading rates in a cohort of patients undergoing radical prostatectomy (RP) for PCa.

Methods

Between 2012 and 2016, 636 patients with clinically localized PCa were treated with RP at two tertiary referral centers. Blood samples were collected and tested for total PSA. All the patients included in the study presented a biopsy performed in the same center where the RP was performed. Biopsy specimens as well as RP specimens were graded according to both 2005 Gleason and 2015 Epstein Gleason grading systems. Upgrading and downgrading rates on RP were recorded for both classifications and then compared. Clinically significant upgrading was defined as: Epstein score raising from ≤2 to ≥3 or from 3 to 5 and Gleason (2005) raising from ≤6 to ≥7 or from 7 to ≥9. As well clinically significant downgrading was defined as: Epstein score decreasing from ≥3 to ≤2 or from 5 to ≤3 and Gleason (2005) decreasing from ≥7 to ≤6 or from ≥9 to ≤7. The accuracy of the biopsy for each Gleason score classification was determined using the kappa coefficient of agreement: <0.4 poor agreement, 0.4-0.75 good agreement and > 0.75 excellent agreement.

Results

Median age and preoperative PSA levels were 66 years (IQR: 61-69) and 7.1 ng/ml (IQR: 5.2-10.0), respectively. Overall 247/636 (39 %) had advanced disease (pT≥3a). Pathological grading of biopsies and RP specimens according to both classifications are described in table 1. The Epstein Gleason score presented a lower upgrading rate (93/636:15% vs 150/636:24%; p=0.000) and a similar downgrading rate (36/636:6 % vs 28/636:4% p=0.194) when compared to the 2005 one. The kappa-statistics measures of agreement between needle biopsy and RP specimens was better for the Epstein score when compared to the 2005 Gleason score (k= 0.569±0.034 vs k= 0.481±0.033).

Conclusions

The new Epstein Gleason score classification significantly reduces upgrading events in patients with PCa treated with RP. The implementation of this new classification could better define prostate cancer aggressiveness with important clinical implications particularly in PCa management. Further studies with a pathological review and reclassification of the specimens are needed to confirm our data.

Funding

none