Presentation Authors: Shiva Nair*, London, Canada, Max Peters, Utrecht, Netherlands, Haider Abed, London, Canada, Jochem van der Voort van Zyp, Marieke van Son, Utrecht, Netherlands, Joseph Chin, London, Canada
Introduction: Local prostate cancer recurrences after primary radiotherapy can occur, even with dose-escalation schedules. Salvage therapies can defer the use of subsequent systemic therapies, which tend to be non-curative with significant side-effects. The results of a large cohort of salvage cryotherapy (sCryo) patients is presented here with median 12 years follow-up.
Methods: Patients treated with salvage cryotherapy from 1995 to 2004 were included. Patients had histological confirmation of local recurrence with a transrectal ultrasound guided biopsy (except 2 patients). Metastatic screen with CT and radionucleotide bone scan were negative. Pre-salvage data was collected to predict oncological outcomes. Kaplan-Meier analysis was performed to assess overall survival (OS), prostate cancer specific survival (PCSS), metastases free survival (MFS), development of castrate resistant prostate cancer (CRPC) and biochemical disease free survival (BDFS) according to the Phoenix definition. Cox-regression was used to assess predictive factors for OS, PCSS, CRPC and MFS.
Results: 187 patients with completed data on were treated with sCryo. Median follow-up was 149 months. Median age before salvage was 71 years (interquartile range [IQR] 66-74), median PSA pre-salvage 11 ng/ml (IQR 7.8-18.7). Twelve-year OS was 56% (CI 49-64). Pre-salvage age and PSA nadir post-salvage predicted overall mortality. Twelve-year PCSS was 81% (CI 75-88). Pre-radiation Gleason score 8-10 and stage (T3a-T4), pre-salvage PSA and PSA-nadir post-salvage cryotherapy predicted PCSS in multivariable analysis. Twelve-year freedom from CRPC was 80%, (CI 73-87). Multivariate analysis showed primary stage and PSA-nadir post-salvage treatment to be significant predictors of CRPC. Twelve-year MFS was 78% (CI 71-85). T3a-T4 and PSA-nadir post-salvage cryotherapy predicted metastases in multivariable analysis. Median time to biochemical recurrence was 58 months (CI 44-79); with median time to ADT 101 months (CI 65-NA). 91 patients (48.7%) were ADT free at end of follow up.
Conclusions: Salvage cryotherapy for localized radiorecurrent prostate cancer can provide durable response, with PCSS and MFS of approximately 80% at 12 years. OS, PCSS, CRPC and MFS are affected by a combination of primary T-stage, pre-radiation Gleason score, pre-salvage PSA and PSA-nadir post-salvage. Salvage treatment can achieve ADT free status in selected patients and delay in those who subsequently developed systemic disease.