Comparative effectiveness of robot-assisted versus open radical prostatectomy cancer control

Background Robot-assisted radical prostatectomy (RARP) remains controversial, and no improvement in cancer control outcomes has been demonstrated over open radical prostatectomy (ORP). Objective To examine population-based, comparative effectiveness of RARP versus ORP pertaining surgical margin status and use of additional cancer therapy. Design, setting, and participants This was a retrospective observational study of 5556 RARP and 7878 ORP cases from 2004 to 2009 from Surveillance Epidemiology and End Results-Medicare linked data. Intervention RARP versus ORP. Outcome measurements and statistical analysis Propensity-based analyses were performed to minimize treatment selection biases. Generalized linear regression models were computed for comparison of RP surgical margin status and use of additional cancer therapy (radiation therapy [RT] or androgen deprivation therapy [ADT]) by surgical approach. Results and limitations In the propensity-adjusted analysis, RARP was associated with fewer positive surgical margins (13.6% vs 18.3%; odds ratio [OR]: 0.70; 95% confidence interval [CI], 0.66-0.75), largely because of fewer RARP positive margins for intermediate-risk (15.0% vs 21.0%; OR: 0.66; 95% CI, 0.59-0.75) and high-risk (15.1% vs 20.6%; OR: 0.70; 95% CI, 0.63-0.77) disease. In addition, RARP was associated with less use of additional cancer therapy within 6 mo (4.5% vs 6.2%; OR: 0.75; 95% CI, 0.69-0.81), 12 mo (OR: 0.73; 95% CI, 0.62-0.86), and 24 mo (OR: 0.67; 95% CI, 0.57-0.78) of surgery. Limitations include the retrospective nature of the study and the absence of prostate-specific antigen levels to determine biochemical recurrence. Conclusions RARP is associated with improved surgical margin status relative to ORP for intermediate- and high-risk disease and less use of postprostatectomy ADT and RT. This has important implications for quality of life, health care delivery, and costs. Patient summary Robot-assisted radical prostatectomy (RP) versus open RP is associated with fewer positive margins and better early cancer control because of less use of additional androgen deprivation and radiation therapy within 2 yr of surgery.