Five-year Oncologic Outcomes Following Primary Partial Gland Cryo-ablation Prospective Cohort Study of Men With Intermediate-risk Prostate Cancer

Abstract

To assess 5-year oncologic outcomes following primary partial gland cryo-ablation (PPGCA) in intermediate risk prostate cancer. Of 476 men undergoing PPGCA enrolled in our prospective oncologic and functional outcomes study, 313 had MRI concordant intermediate risk prostate cancer with no out-of-field Gleason Grade Group (GGG) ≥2, gross extracapsular extension or extreme apical disease on pre-treatment mpMRI. PSA was monitored every 6 months, and mpMRI at 6-12, 24, 42 and 60 months. Protocol biopsy at 6-12 months and 24 months were discontinued after interim analysis showing low rates of clinically-significant prostate cancer (csPCa) defined as any GGG≥2 disease. Freedom-from-failure (FFF) was defined as no prostate cancer specific mortality, metastatic disease, or whole-gland salvage treatment (WGST) RESULTS: csPCa was detected in 33 (10.5%) subjects. 91 had ≥4.5 years of follow-up data with a mean of 8.9, 3.4, and 2.0 surveillance PSA tests, MRIs, and prostate biopsies; none were lost to follow-up. At 5-years, rates of freedom-from-recurrence of in-field, out-of-field and overall csPCa were 86% (95% CI: 78-96), 85% (95% CI: 63-94), and 70% (95% CI: 57-84). The proportion with freedom-from-failure (FFF) at 5 years was 89% (95% CI: 83-95). None died from prostate cancer, 1 (1%) developed metastasis, 15 (16.5%) underwent WGST, and 15 (16.5%) underwent salvage focal therapy (FT). Only 3 of 91 (3.3%) eligible men were noncompliant with 5-year surveillance protocol. Very encouraging intermediate-term oncological outcomes following PPGCA were observed with very high compliance to a rigorous prospective protocol for identifying recurrent csPCa.