Global Gleason grade groups in prostate cancer: concordance of biopsy and radical prostatectomy grades and predictors of upgrade and downgrade.

AIMS

To evaluate concordance, upgrades and downgrades from biopsy to prostatectomy, and associated clincopathological parameters, using the recently proposed Gleason grade groups/International Society of Urologic Pathology (ISUP) grades.

METHODS AND RESULTS

We evaluated 2529 patients who underwent biopsy and prostatectomy in our institution from 2005 to 2014. A global grade group (GR)/Gleason score (GS) was used. Factors associated with GR1/GS ≤6 upgrades and GR2/GS3 + 4 downgrades were analysed by multivariable logistic regression. The final GR/GS was identical with the biopsy GR/GS in 59.3% of cases, with the highest concordance for GR2 and GR5 and lowest for GR4. In GR1-5, identical grades were found in GR: (i) 47.6%, (ii) 73.6%, (iii) 52.8%, (iv) 21.4% and (v) 68.3%, respectively. Final GR was upgraded in 32.3% cases; in GR1-4: (i) 52.4%, (ii) 19.0%, (iii) 16.4% and (iv) 32.9%. Most frequent upgrades occurred from biopsy GR1 to prostatectomy GR2. A final GR downgrade was found in 8.3% cases. For individual GR2-5 the downgrades were found in GR: (i) 7.4%, (ii) 30.8%, (iii) 45.7% and (iv) 31.7%. Upgrades of biopsy GR1 were associated with: age ≥60 years, PSA density ≥0.2, ≥2 positive cores, ≥5% core tissue involvement and perineural invasion [area under receiver operating characteristic (ROC) curve 0.699]. Downgrades of biopsy GR2 correlated inversely with: age ≥60 years, PSA >10 ng/ml and ≥2 positive core (area under ROC curve 0.623).

CONCLUSIONS

We found highest concordance for GR2 and GR5 and lowest for GR4. The baseline clinical variables associated with GR1 upgrades and GR2 downgrades may play a role in clinical decision-making.