Too late to fall: Time to PSA nadir and early oncologic failure after cryotherapy and high-intensity focused ultrasound for localized prostate cancer.

INTRODUCTION

The ability of time to PSA nadir (TTN) to predict early treatment failure after focal therapy for prostate cancer remains unclear. We assessed whether TTN and PSA nadir-related parameters are associated with early oncologic failure after primary cryotherapy or high-intensity focused ultrasound (HIFU).

MATERIALS AND

METHODS

We relied on a prospective registry of 319 men treated with primary cryotherapy (n = 221) or HIFU (n = 98). TTN was categorised as ≤6, 6-12, or >12 months. PSA nadir and nadir PSA density (nPSAD) were analysed. Treatment failure (TF) included biochemical/local recurrence, metastatic progression, or salvage therapy. Primary endpoint was early TF (≤24 months). Independent predictors were evaluated with Firth logistic regression; failure-free survival (FFS) was estimated with Kaplan-Meier analysis.

RESULTS

Men selected for HIFU had slightly more favourable baseline features. Median TTN was 6 months overall but longer after cryotherapy than after HIFU (6 vs 3 months; p < 0.001). Cryotherapy achieved lower PSA nadir and nPSAD than HIFU (each p < 0.001). At a median follow-up of 26 months, overall FFS was 84.8% (82.1% after cryotherapy and 90.8% after HIFU; p = 0.046). TTN strata were associated with differences in FFS (log-rank p < 0.001). In multivariable models, TTN >12 months independently predicted early TF after cryotherapy (OR 17.5; p < 0.001). After HIFU, ablation extent was independently associated with early treatment failure.

CONCLUSIONS

Delayed TTN was independently associated with early failure after cryotherapy, whereas no independent association emerged after HIFU. These findings support modality-specific interpretation of TTN when planning post-ablation follow-up.