Cryoablation versus radiation therapy for low and intermediate risk localized prostate cancer: a propensity score-adjusted cohort analysis of oncologic outcomes

Abstract Background: We are aiming to compare the oncologic outcomes between cryoablation and radiation therapy for low or intermediate risk localized prostate cancer. Methods : Among patients diagnosed between 2004 and 2016 in SEER databases, we identified cases confirmed low or intermediate risk prostate adenocarcinoma treated with radiation treatment (n = 93041) or cryoablation (n = 2350). Propensity score matching (PSM) was performed. Kaplan-Meier method, Cox proportional hazards model were used to calculate cancer specific mortality (CSM) and overall survival (OS) in the unmatched and matched cohort, and in subgroups based on clinical characteristics. Results: A total of 95391 patients who were diagnosed with first prostate adenocarcinoma and treated with radiation treatment (97.54%) or cryoablation (2.46%) were identified. In the matched cohort, cryoablation group has similar CSM (HR 1.13, 95%CI 0.72-1.77, P=0.6) and worse OS (HR 1.20, 95%CI 1.04-1.39, P=0.01) than radiation treatment group in the non-adjusted model as well as those in the adjusted model (HR 1.06, 95%CI 0.68-1.65, P=0.8; HR 1.18, 95%CI 1.02-1.36, P=0.02, respectively). For low risk disease, CSM and OS outcomes were similar between cryoablation and radiation treatment group. Last but not least, for intermediate risk patients, compared with radiation treatment group, cryoablation group has similar CSM (HR 1.26, 95%CI 0.90-1.77, P=0.2) and inferior OS (HR 1.17, 95%CI 1.04-1.32, P=0.01). Conclusion: In summary, for low risk disease, CSM and OS outcomes were similar between cryoablation and radiation treatment group. For intermediate risk disease, we found that radiation treatment group showed superior OS than cryoablation group.