Cytoreductive cryosurgery in patients with bone metastatic prostate cancer: A retrospective analysis

The current study is a retrospective analysis of 49 patients with bone metastatic prostate cancer: 26 receiving androgen deprivation therapy (ADT) alone versus 23 receiving cytoreductive cryosurgery of the primary tumor plus ADT treatment. Progression‐free survival (PFS) was the primary outcome variable, and Cox proportional hazards regression analysis was used to identify predictors for PFS. The baseline characteristics were generally comparable between the 2 groups. Median follow‐up time was 41 months (range 24–56) and 37 months (range 19–53) in ADT alone group and cryosurgery groups, respectively. Patients receiving cryosurgery had significantly longer PFS (35 vs 25 months, P = 0.0027) and time to castration resistance (36 vs 25 months, P = 0.0011). Cox multivariate analysis associated longer PFS with the following factors: cryosurgery (HR0.207, 95% CI 0.094–0.456), lower prostate specific antigen at diagnosis (≤100 ng/ml, HR0.235, 95% CI 0.072–0.763) and lower Gleason score (≤7, HR0.195, 95% CI 0.077–0.496). Cryosurgery reduced the risk of progression by 79.3%. In conclusion, cytoreductive cryosurgery of the primary tumor in patients with bone metastatic prostate cancer could reduce the risk of progression and delay time to castration‐resistant prostate cancer.