Validation of the European association of urology biochemical recurrence risk groups after radical prostatectomy in an Asian cohort and suggestions for refinement

Abstract

Background: To validate the prognostic utility of the novel European Urology Association (EAU) biochemical recurrence (BCR) risk groups in an Asian cohort and to determine whether refinement is necessary.

Methods: Two cohorts of men who experienced BCR after radical prostatectomy between 1998 and 2014 were employed. The Cox model was used to validate and model the probability of metastasis and death after BCR. Data from 817 men from the first cohort were used to develop a modified model and external validation was performed on 344 men from the second cohort.

Results: Distant metastasis-free survival and cancer-specific survival from the time of BCR were significantly higher in patients with a low EAU BCR risk (prostate-specific antigen doubling time [PSADT] >1 year and pathologic Gleason score [pGS] ≤7) than in high EAU BCR risk patients (PSADT ≤1 year or pGS 8-10). In the high EAU BCR risk group, survival outcomes and efficacy of early salvage radiotherapy in patients with PSADT 6-12 months and pGS ≤7 were similar to those in the low EAU BCR risk group. The C-index, which predicts metastatic progression and cancer-specific death, improved after PSADT cutoff point was modified to 6 months, and was validated externally.

Conclusion: EAU BCR risk stratification reliably identified patients at increased risk of metastasis and cancer-specific mortality in the present cohort. Modification of the PSADT cutoff point may help to optimize the predictive performance and utility of the EAU BCR risk groups in clinical practice.

Keywords: Prostate cancer; Prostatectomy; Recurrence.