Prognostic value of initial prostate-specific antigen levels after salvage cryoablation for prostate cancer.

Objective: To assess the prognostic value of initial prostate-specific antigen (PSA) levels after salvage cryoablation (SCA) for the long-term biochemical progression-free survival (bPFS) in patients with prostate cancer.

Methods: In all, 455 hormone-naïve patients from the Cryo On Line Data Registry, and treated with whole-gland SCA were assessed for PSA-based bPFS using the Phoenix criteria. The initial PSA level measured after SCA was considered the nadir. Kaplan-Meier plots of bPFS for initial PSA level of <0.6, ≥0.6-≤5.0 and >5.0 ng/mL were constructed and plotted to 60 months.

Results: In all, 280 patients had an initial PSA level of <0.6 ng/mL after SCA. At 12, 24 and 36 months 80%, 73.6%, and 67% of patients, respectively, were progression-free. For 118 patients with an initial PSA level after SCA of ≥0.6-≤5 ng/mL, 28% and 50% of these patients at 6 and 12 months, respectively, had PSA progression. Of 57 patients with an initial PSA level of ≥5 ng/mL, 64% progressed at 6 months. The PSA level before SCA and Gleason score correlated with bPFS by Spearman correlation (P < 0.001 and 0.002), respectively.

Conclusions: Curative therapy in prostate cancer not responding to radiotherapy is extremely challenging. There is no definition of success for cryosurgical treatment. The available data indicate that an initial PSA level of <0.6 ng/mL after SCA portends a favourable (67% at 36 months) bPFS. Individuals with initial PSA levels of ≥0.6 ng/mL after SCA are at risk of short-term biochemical progression (50% at 12 months).