Outcomes of treatment for localized prostate cancer in a single institution: comparison of radical prostatectomy and radiation therapy by propensity score matching analysis

Objectives To compare the outcomes of radical prostatectomy (RP), intensity-modulated radiation therapy (IMRT), and low-dose-rate brachytherapy (BT) using propensity score matching analysis in patients with clinically localized prostate cancer. Methods A group of 2273 patients with clinically localized prostate cancer between January 2004 and December 2015 at the Yokohama City University hospital were identified. The records of 1817 of these patients, who were followed up for a minimum of 2 years, were reviewed; 462 were treated with RP, 319 with IMRT, and 1036 with BT. The patients were categorized according to the National Comprehensive Cancer Network risk classification criteria, and biochemical outcomes and overall survival rates were examined. Biochemical failure for RP was defined as prostate-specific antigen (PSA) levels > 0.2 ng/ml, and for IMRT and BT as nadir PSA level + 2 ng/ml. Propensity scores were calculated using multivariable logistic regression based on covariates, including the patient's age, preoperative PSA, Gleason score, number of positive cores, and clinical T stage. Results Median follow-up was 77 months for the RP, 54 months for IMRT, and 66 months for BT patients. After the propensity scores were adjusted, a total of 372 (186 each) and 598 (299 each) patients were categorized into RP vs IMRT and RP vs BT groups, respectively. Kaplan–Meier analysis did not show any statistically significant differences in terms of overall survival rate between these groups (RP vs IMRT: p = 0.220; RP vs BT: p = 0.429). IMRT was associated with improved biochemical failure-free survival compared to RP in all risk groups (high-risk: p