Long?term outcomes of radical prostatectomy versus low?dose?rate brachytherapy in patients with intermediate?risk prostate cancer: Propensity score matched comparison

AbstractPurpose

To compare long-term outcomes of radical prostatectomy (RP) and low-dose-rate brachytherapy (LDR-BT) using propensity score-matched analysis in patients with clinically localized, intermediate-risk prostate cancer (PCa).

Methods

Between October 2003 and March 2014, our institution treated 1241 patients with intermediate-risk PCa (RP: n?=?531; LDR-BT: n?=?710). Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) levels of 0.2?ng/ml or greater for RP, and as PSA nadir plus 2?ng/ml or higher (Phoenix definition) for LDR-BT. We calculated propensity scores by multivariate logistic regression based on covariates that included age, pretreatment PSA, biopsy Gleason grade, the percentage of positive biopsy cores (PPBC), and clinical T stage.

Results

Median follow-up was 108 months for RP and 99 months for LDR-BT. After propensity score adjustment, a total of 642 (321 each) patients remained for further analysis. Kaplan–Meier curves showed no statistically significant difference in overall survival (OS) (p?=?0.99). LDR-BT was associated with improved BCR-free survival and salvage therapy-free survival  compared to RP (p?<?0.001), and RP was associated with improved metastasis-free survival (MFS, p?<?0.001).

Conclusion

BCR cannot be a surrogate for survival comparison, primarily due to differences between treatment modalities in how this term was defined post-therapy. Long-term follow-up showed that RP was associated with lower MFS in intermediate-risk PCa. However, this has not yet translated into superior OS.