Oncology Head-to-head Comparison of Three Commonly Used Preoperative Tools for Prediction of Lymph Node Invasion at Radical Prostatectomy Firas Abdollah, Jan Schmitges, Maxine Sun, Rodolphe Thuret, Orchidee Djahangirian, Zhe Tian, Shahrokh F. Shariat, Alberto Briganti, Paul Perrotte, Francesco Montorsi, and Pierre I. Karakiewicz OBJECTIVE A formal validation and head-to-head comparison of the National Comprehensive Cancer Network (NCCN) practice guideline lymph node invasion (LNI) nomogram, Partin tables, and D’Amico risk-classification was conducted for prediction of LNI at radical prostatectomy (RP). METHODS We focused on 20,877 patients treated with RP and pelvic lymph node dissection (PLND) between 2004 and 2006 within the Surveillance, Epidemiology and End Results database. The discrimination of the 3 tools in predicting histologically confirmed LNI was quantified using the area under the curve (AUC). Calibration plots were used to graphically depict the performance characteristics of the examined tools. In addition, we relied on decision curve analyses to compare the 3 models directly in a head-to-head fashion. RESULTS Overall, 2.5% of patients had LNI. The NCCN LNI nomogram (AUC 82%) outperformed the Partin tables (73%) and the D’Amico risk-classification (75%) for prediction of LNI. Calibration plots revealed that all 3 tools overestimated the risk of LNI. Partin tables showed the highest net-benefit for probability threshold range between 1% and 4%. Conversely, the NCCN LNI nomogram showed the highest net-benefit for the remaining threshold probabilities. CONCLUSION The NCCN LNI nomogram had the highest discrimination accuracy. However, using the decision curve analysis, the Partin tables demonstrated the highest net benefit when a threshold probability of LNI is 4%. In contrast, the NCCN LNI nomogram had the highest net benefit when the threshold probability used to perform PLND is greater than 4%. UROLOGY 78: 1363–1368, 2011. Crown Copyright © 2011 Published by Elsevier Inc. P elvic lymph node dissection (PLND) represents the most accurate procedure for lymph node stag- ing at radical prostatectomy (RP) in patients diag- nosed with prostate cancer (PCa). 1,2 Moreover, PLND has been associated with improved cancer control out- comes. 3,4 Despite these advantages, PLND also has sev- eral disadvantages. It may contribute to an increased morbidity, longer operating time, and higher cost. Ac- cordingly, PLND is not recommended in all patients. 5,6 In contemporary patients, the majority harbor clini- cally impalpable localized tumors with low-grade and low-serum prostate-specific antigen (PSA) level. 7-9 In these patients, the risk of lymph node invasion (LNI) is low. 9-11 Accordingly, these patients may have no benefit of PLND. By contrast, omitting PLND in patients with LNI may deteriorate their cancer control outcomes. In consequence, it is primordial to distinguish between pa- tients with vs without LNI in the preoperative setting. To date, several preoperative LNI prediction tools have been developed and internally validated. 2,11-13 De- spite their widespread use, these tools were not subjected to formal validation that included accuracy and calibra- tion. Based on the lack of such data, we performed an external validation and a head-to-head comparison of the National Comprehensive Control Network (NCCN) practice guidelines LNI nomogram, 5,11 the Partin ta- Firas Abdollah and Jan Schmitges contributed equally to this work. Funding Support: Pierre I. Karakiewicz is partially supported by the University of Montréal Health Center Fonds de la Recherche en Santé du Quebec, the University of Montréal Department of Surgery and the University of Montréal Health Center (CHUM) Foundation. From the Cancer Prognostics and Health Outcomes Unit, University of Montréal Health Centre, Montreal, Canada; Department of Urology, Vita Salute San Raffaele University, Milan, Italy; Martini-Clinic, Prostate Cancer Center Hamburg-Eppendorf, Hamburg, Germany; Department of Urology, University of Montpellier Health Centre, Montpellier, France; Department of Urology, Weill Medical College of Cornell Uni- versity, New York, NY; and Department of Urology, University of Montréal Health Centre, Montreal, Canada Reprint requests: Dr. Maxine Sun, University of Montréal Health Center, 1058, Rue Street-Denis, Montreal, Quebec, H2X 3J4, Canada. E-mail: mcw.sun@ umontreal.ca Submitted: June 8, 2011, accepted (with revisions): July 14, 2011 Crown Copyright © 2011 Published by Elsevier Inc. 0090-4295/11/$36.00 1363 All Rights Reserved doi:10.1016/j.urology.2011.07.1423