Salvage Cryoablation for Radiorecurrent Prostate Cancer: Initial Experience at a Regional Health Care System

CONTEXT: Local recurrence after radiotherapy for prostate cancer remains challenging to treat effectively. Although oncologic control is highest with salvage prostatectomy, the procedure is associated with substantial morbidity. OBJECTIVE: To identify factors associated with successful salvage cryoablation for radiorecurrent prostate cancer. DESIGN: We retrospectively reviewed the medical records of patients who underwent salvage cryoablation at our institution between 2005 and 2015. All patients had biopsy-proven local recurrence after radiotherapy. Patients with seminal vesicle invasion or metastases were excluded. Complete follow-up was obtained for all patients. MAIN OUTCOME MEASURES: Primary study endpoint was biochemical progression-free survival based on the Phoenix criteria. RESULTS: Seventy-five patients underwent salvage cryotherapy. Mean patient age was 69.3 years. The overall biochemical salvage rate was 50.7% at a median follow-up of 3.9 years. The following factors were independently associated with successful cryotherapy: Precryotherapy Gleason score of 3 + 3 or 3 + 4, low precryotherapy prostate-specific antigen (PSA), low precryotherapy PSA density, longer time to PSA nadir after radiotherapy, and low postcryotherapy PSA nadir. A postcryotherapy PSA nadir of 0.5 ng/mL or less was associated with a biochemical progression-free survival of 79.7% at 3 years and 64.7% at 5 years, whereas a postcryotherapy PSA nadir above 0.5 was associated with a biochemical progression-free survival of 5.6% at 3 years and 0% at 5 years (p < 0.0001). CONCLUSION: Approximately 50% of the patients achieved biochemical salvage with cryoablation at 5 years. Nadir PSA after salvage was the strongest predictor of biochemical progression-free survival in our cohort.