Evaluating 4Kscore's role in predicting progression on active surveillance for prostate cancer independently of clinical information and PIRADS score.

BACKGROUND

4Kscore is used to aid the decision for prostate biopsy, however its role in active surveillance (AS) has not been investigated in a magnetic resonance imaging (MRI)-based protocol. Our objective was to assess the association between 4Kscore and progression in men undergoing AS on a prospective MRI-based protocol.

METHODS

This was a single-institution, single-arm, non-therapeutic, interventional trial of 166 men with biopsy-confirmed prostate cancer enrolled between 2014-2020. Patients were placed on a trial-mandated AS protocol including yearly multiparametric (mp)MRI, prostate biopsy, and 4Kscore followed for 48 months after diagnosis. We analyzed protocol-defined and grade progression at confirmatory and subsequent surveillance biopsies.

RESULTS

Out of 166 patients, 83 (50%) men progressed per protocol and of them 41 (24.7% of whole cohort) progressed by grade. At confirmatory biopsy, men with a baseline 4Kscore ≥ 20% had a higher risk of grade progression compared to those with 4Kscore < 20% (OR = 4.04, 95% CI: 1.05-15.59, p = 0.043) after adjusting for National Comprehensive Cancer Network (NCCN) risk and baseline PIRADS score. At surveillance biopsies, most recent 4Kscore ≥ 20% significantly predicted per protocol (OR = 2.61, 95% CI: 1.03-6.63, p = 0.044) and grade progression (OR = 5.13, 95% CI: 1.63-16.11, p = 0.005).

CONCLUSIONS

For patients on AS, baseline 4Kscore predicted grade progression at confirmatory biopsy, and most recent 4Kscore predicted per-protocol and grade progression at surveillance biopsy.