Is cryosurgery a feasible local therapy for bone metastatic prostate cancer?

INTRODUCTION This study aims to assess whether cryosurgery is a feasible local therapy for bone metastatic prostate cancer (bmPCa). METHODS A total of 23 patients with bmPCa who received cryosurgery and adjuvant androgen deprivation therapy (ADT) were included in the cryosurgery group (Group 1). Another 23 matched patients who received only ADT served as the control (Group 2). Prostate-specific antigen (PSA) nadir level, time to PSA nadir, time to castration-resistant prostate cancer (CRPC), progression-free survival and therapy response of bone metastases were compared between the groups. RESULTS The median follow-up time in Group 1 and Group 2 patients was 37 (range 19-53) months and 42 (range 24-56) months, respectively. Patients in Group 1 had fewer local complications, lower PSA nadir level (0.23 ng/mL vs. 4.01 ng/mL; p = 0.024), shorter median time to PSA nadir (3 months vs. 7 months; p < 0.001), longer median time to CRPC (36 months vs. 27 months; p = 0.002) and longer progression-free survival (35 months vs. 26 months; p = 0.003) compared to those in Group 2. Therapy responses of bone metastases were similar in the two treatment groups (p = 0.689). CONCLUSION Cryosurgery is a feasible local therapy for bmPCa patients with prostate volume less than 50 mL and without bulk tumours outside the prostate capsula. Cryosurgery may decrease PSA nadir level, local complications and time to PSA nadir, delay time to CRPC and improve progression-free survival.