INTRODUCTION AND OBJECTIVE:
Grade Group (GG) and invasive cribriform and/or intraductal carcinoma (CR/IDC) are important parameters for clinical decision-making in prostate cancer. One of the inclusion criteria for active surveillance is GG1 or GG2 without CR/IDC. However, up- and downgrading following radical prostatectomy is frequently observed. The aim of this study was to determine pre-operative parameters for upgrading to GG2 with CR/IDC or higher GG.
Biopsies prior to radical prostatectomy performed in one high-volume center between 2018-2020, were reviewed. The cumulative tumor length, CR/IDC, GG and proportion of grade 4 were assessed. Men with GG1 to 3 on biopsy were included. Biopsy findings were correlated with radical prostatectomy outcome. Men were divided in two groups: one with GG1 or GG2 without CR/IDC on radical prostatectomy (GG≤2-) and the other group with GG2 with CR/IDC or GG>2 (GG≥2+). Logistic regression analysis of men with biopsy GG2 was used to predict GG≥2+ on radical prostatectomy.
Of 526 men, 17.3% had biopsy GG1, 49.6% GG2 and 33.1% GG3 on biopsy; at radical prostatectomy 32.3% had GG≤2- and 67.7% GG≥2+. Biopsy and prostatectomy GG were concordant in 333/526 men (63.3%), with upgrading in 26.4% and downgrading in 10.3%. Men with biopsy GG3 were downgraded to GG≤2- on radical prostatectomy in 8.0%; 4.5% GG3 biopsies with CR/IDC were downgraded compared to 19.5% of GG3 without CR/IDC (P=0.006). Men with biopsy GG1 or GG2 without CR/IDC were upgraded to GG≥2+ in 46.1%. Logistic regression analysis of predicting GG≥2+ on radical prostatectomy in patients with biopsy GG2 showed that age (OR: 1.06, 95% CI: 1.01-1.11), proportion grade 4 (OR: 1.56, 95% CI: 1.18-2.09), biopsy CR/IDC (OR: 2.95, 95% CI: 1.35-6.94) were independent parameters in multivariable analysis. PSA, MRI PIRADS, number of biopsies, percentage of positive biopsies, cumulative tumor length and presence of targeted biopsies were not significant.
Of men with biopsy GG1 or GG2 without CR/IDC 46% were upgraded to GG2 with CR/IDC or GG>2 at prostatectomy. Older age, higher proportion Gleason pattern 4 and CR/IDC were significantly associated with upgrading of GG2 biopsies. These findings indicate that subgroups of men with biopsy GG2 are eligible to active surveillance, if detailed pathological characteristics at biopsy are taken into consideration.
Source of Funding: