A comparison of the survival outcomes of robotic-assisted radical prostatectomy and radiation therapy in patients over 75 years old with non-metastatic prostate cancer: A Korean multicenter study.

PURPOSE To compare overall survivals (OSs) and cancer-specific survivals (CSSs) after robotic-assisted radical prostatectomy (RARP) and radiation therapy (RT), the latter of which has long been recommended primarily for elderly patients (≥75 years) with non-metastatic prostate cancer (PCa), given the Korean male life span of 79.7 years (2018). MATERIALS AND METHODS Retrospective data for aged ≥75 years who underwent RARP or RT at seven tertiary hospitals were analyzed. To account for indication-related bias, inverse probability of treatment-weighting (IPTW) was applied before and after Cox regression. RESULTS Of the 1,110 study subjects, 883 underwent RARP and 227 RT from 2007 to 2016. The differences between groups including the age (≥80 y; 25.4% vs. 32.8%; p=0.034), concomitant diabetes (14.9% vs. 22.9%; p=0.007), coronary heart disease (3.5% vs. 7.5%; p=0.015), and PCa risk stratification (high-risk; 18.2% vs. 59.7%; p<0.001) were balanced after IPTW. During a mean follow-up of 74.5 months, OSs (91.9% vs. 91.0%) and CSSs (97.8% vs. 98.0%) were similar. After IPTW, overall mortality was associated with diabetes (hazard ratio [HR], 2.273; p<0.0001) and inversely with low-risk PCa (HR, 0.314; p<0.0001), the last of which was solely associated with cancer-specific mortality (HR, 0.245; p=0.0005). The implementation of local treatment between RARP and RT demonstrated no impact on survival, for whole and high-risk populations. CONCLUSIONS Even aged over 75 years, patients who underwent RARP for non-metastatic PCa had similar survival with RT regardless of risk stratification. However, the survival needs to be weighed with the morbidity of local treatment in a future study.