Age and gleason score upgrading between prostate biopsy and radical prostatectomy: Is this still true in the multiparametric resonance imaging era?

Abstract

Introduction: Several studies have invariably shown that the risk of Grade Group (GG) upgrading between biopsy and radical prostatectomy (RP) is higher in elderly men. Whether this is due to a real biological effect or to a diagnostic bias is still unknown. We hypothesized that the introduction of multiparametric magnetic resonance imaging (MRI) has improved the diagnostic accuracy of PCa detection in older men thus reducing the risk of GG upgrading at RP reported in the pre-MRI era.

Materials and methods: We selected 424 men who received a systematic plus targeted biopsy for a positive MRI and subsequent RP at two referral centers between 2013 and 2019. Upgrading was defined as an increase in GG at final pathology as compared to biopsy. Multivariable logistic regressions tested the risk of upgrading over increasing age according to any upgrading definition and after stratifying definitions according to GG group and biopsy type. Non-parametric functions explored the relationship between age and upgrading rate.

Results: Median rate of upgrading was 17%. In multivariable models, while age was not associated with increased risk of GG upgrading (p=0.4). At non-parametric analyses, probability of upgrading slightly decreased with age, without reaching statistical significance. In subgroup analyses according to different upgrading definition and to biopsy type, age did not predict higher risk of upgrading regardless of outcome definitions (GG 1 to 2 P = 0.1; GG 2 to 3 P = 0.2; GG 3 to 4-5 P = 0.2) and in GG detected at TBx (OR 0.998, P = 0.8).

Conclusions: We showed that use of MRI has obliterated the association between older age and increased risk of upgrading mainly due to improved diagnostic approaches in this group of men. Therefore, it is likely that the effect of age and GG upgrading reported in previous studies in elderly men was due to misdiagnosis and lead-time bias in the pre-MRI era.

Keywords: PI-RADS version 2; elderly patients; multiparametric magnetic resonance imaging; prostate cancer; targeted biopsy; upgrading.