North American Population-Based Validation of the National Comprehensive Cancer Network Practice Guideline Recommendation of Pelvic Lymphadenectomy in Contemporary Prostate Cancer

BACKGROUND. National Comprehensive Cancer Network (NCCN) guidelines recommend a pelvic lymph node dissection (PLND) in prostate cancer (PCa) patients treated with radical prostatectomy (RP) if a nomogram predicted risk of lymph node invasion (LNI) is ≥2%. We examined this and other thresholds, including nomogram validation. METHODS. We examined records of 26,713 patients treated with RP and PLND between 2010 and 2013, within the Surveillance, Epidemiology, and End Results database. Nomogram thresholds of 2–5% were tested and external validation was performed. RESULTS. LNI was recorded in 4.7% of patients. Nomogram accuracy was 80.4% and maintained minimum accuracy of 75.6% in subgroup analyses, according to age, race, and nodal yield >10. With the NCCN recommended 2% nomogram threshold, PLND could be avoided in 22.3% of patients at the expense of missing 3.0% of individuals with LNI. Alternative thresholds of 3%, 4%, and 5% yielded respective PLND avoidance rates of 60.4%, 71.0%, and 79.8% at the expense of missing 17.8%, 27.2%, and 36.6% of patients with LNI. NCCN cut-off recommendation was best satisfied with a threshold of