Robotic Radical Prostatectomy: Margins Positivity and Implications on Cancer Control

Abstract

Robot-assisted radical prostatectomy (RARP) is the standard surgical treatment for localized prostate cancer in the United States. After more than a decade of experience with the robotic approach, its oncological safety has been confirmed with margins positivity comparable to the open approach. Large scale RARP series yielded positive surgical margin (PSM) rates between 9 and 19%. PSM rates are strongly associated with preoperative disease characteristics (i.e., PSA, Gleason score, and clinical stage). As more patients with intermediate and high risk disease undergo RARP, the overall rates of PSM may potentially increase. While PSMs have been repeatedly shown to predict biochemical recurrence (BCR), their impact on more meaningful outcomes, such as the development of metastatic disease and cancer-specific mortality is not completely clear. Gleason score at PSM and PSM margins length are important features of PSM that seems to have influence on the long term impact of PSM. Various surgical techniques and tailoring nerve preservation based on disease severity appear to improve cancer control during RARP. Post radical prostatectomy radiation therapy (RT) also improves oncological outcomes. Level I evidence from open radical prostatectomy literature, demonstrated improved biochemical recurrence-free, metastasis-free, and overall survival when adjuvant radiation therapy was given to patients with adverse pathological features, including PSMs. Yet, the optimal timing of when to deliver additional RT is still unknown and awaits the results of several randomized clinical trials.