Gleason Regrading After Prostatectomy-Results From the Irish Prostate Cancer Outcome Research (IPCOR) Situated in the International Context.

BACKGROUND

Accurate Gleason grading is crucial for prostate cancer (PCa) treatment decisions; incorrect assessment can lead to under- or overtreatment; discordance between biopsy and radical prostatectomy (RP) grades is a marker of this inaccuracy. Using the Irish Prostate Cancer Outcomes Research (IPCOR) cohort, we sought to quantify Gleason grade concordance, upgrading, and downgrading trends in PCa RP patients, assess the impact of pre-biopsy MRI on diagnostic accuracy, and compare Irish trends with international findings.

METHODS

A contextual literature review summarized international regrading rates. IPCOR enrolled 6816 men diagnosed with PCa. We included 1194 men who underwent both biopsy and RP within 180 days. Biopsy and RP Gleason Grade Groups (GG) were compared to estimate concordance, upgrading, and downgrading. Sub-analyses examined regrading by biopsy modality and pre-biopsy MRI.

RESULTS

Overall concordance was 57.0%, similar international median of 52.9%. Concordance was lowest for GG1 (32.7%) and highest for GG2 (74.8%), while higher GGs showed frequent downgrading (GG4 46.8%; GG5 33.3%). Among men with TRUS biopsy, pre-biopsy MRI was associated with higher concordance (59.8% vs. 55.8%) and lower upgrading (19.3% vs. 29.4%), though differences were not statistically significant.

CONCLUSIONS

Gleason regrading patterns in Ireland mirror global experience, with upgrading in lower and downgrading in higher GGs. Pre-biopsy MRI shows a favorable trend toward improved diagnostic accuracy, supporting its integration into clinical pathways.