Malte Rieken1, Luis A Kluth2, Christian Seitz3, Mohammad Abufaraj4, Beat Foerster5, Romain Mathieu6, Pierre I Karakiewicz7, Alexander Bachmann8, Alberto Briganti9, Morgan Rouprê10, Mithat Gönen11, Shahrokh F Shariat12, Veronika Seebacher13. 1. Department of Urology, Medical University of Vienna, Vienna, Austria; Department of Urology, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY. 2. Department of Urology, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY; Department of Urology, University Medical-Center Hamburg-Eppendorf, Hamburg, Germany. 3. Department of Urology, Medical University of Vienna, Vienna, Austria; Karl Landsteiner Institute of Urology and Andrology, Vienna, Austria. 4. Department of Urology, Medical University of Vienna, Vienna, Austria; Division of Urology, Department of Special Surgery, Jordan University Hospital, The University of Jordan, Amman, Jordan. 5. Department of Urology, Medical University of Vienna, Vienna, Austria; Department of Urology, Kantonsspital Winterthur, Winterthur, Switzerland. 6. Department of Urology, University of Rennes, Rennes, France. 7. Department of Urology, University of Montreal, Montreal, ON, Canada. 8. Department of Urology, University Hospital Basel, University of Basel, Basel, Switzerland. 9. Department of Urology, Urological Research Institute, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy. 10. Department of Urology, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY; Department of Urology, Pitié-Salpétrière, Assistance-Publique Hôpitaux de Paris, Faculté de Médecine Pierre et Marie Curie, University Paris VI, Paris, France. 11. Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. 12. Department of Urology, Medical University of Vienna, Vienna, Austria; Department of Urology, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY; Karl Landsteiner Institute of Urology and Andrology, Vienna, Austria; Department of Urology, The University of Texas M.D. Anderson Cancer Center, Houston, TX. Electronic address: sfshariat@gmail.com. 13. Department for Gynaecology and Gynaecologic Oncology, Medical University of Vienna, Vienna, Austria.
Abstract
BACKGROUND: We sought to externally validate our pathologic nodal staging score (pNSS) model, which allows for quantification of the likelihood that a pathologically node-negative patient will not have lymph node (LN) metastasis after radical prostatectomy for prostate cancer (PCa) in a population-based cohort. PATIENTS AND METHODS: We analyzed data from 50,598 patients treated with radical prostatectomy and pelvic LN dissection using the Surveillance, Epidemiology, and End Results database. We estimated the sensitivity of pathologic nodal staging using a β-binomial model and developed a novel pNSS model, which represents the probability that a patient's PCa has been correctly staged as node negative as a function of the number of examined LNs. These findings were compared against those from the original cohort of 7135 patients. RESULTS: The mean and median number of LNs removed was 6.5 and 5, respectively (range, 1-89; interquartile range, 2-8), and 96.9% of the patients (n = 49,020) had stage pN0. Similar to the original cohort, the probability of missing a positive LN decreased with the increasing number of LNs examined. In both the validation and the original cohort, the number of LNs needed to correctly stage a patient's disease as node negative increased with more advanced tumor stage, higher Gleason sum, positive surgical margins, and higher preoperative prostate-specific antigen levels. CONCLUSION: We have confirmed that the number of examined LNs needed for adequate nodal staging in PCa depends on the pathologic tumor stage, Gleason sum, surgical margins status, and preoperative prostate-specific antigen. We externally validated our pNSS in a population-based cohort, which could help to refine decision-making regarding the administration of adjuvant therapy.
BACKGROUND: We sought to externally validate our pathologic nodal staging score (pNSS) model, which allows for quantification of the likelihood that a pathologically node-negative patient will not have lymph node (LN) metastasis after radical prostatectomy for prostate cancer (PCa) in a population-based cohort. PATIENTS AND METHODS: We analyzed data from 50,598 patients treated with radical prostatectomy and pelvic LN dissection using the Surveillance, Epidemiology, and End Results database. We estimated the sensitivity of pathologic nodal staging using a β-binomial model and developed a novel pNSS model, which represents the probability that a patient's PCa has been correctly staged as node negative as a function of the number of examined LNs. These findings were compared against those from the original cohort of 7135 patients. RESULTS: The mean and median number of LNs removed was 6.5 and 5, respectively (range, 1-89; interquartile range, 2-8), and 96.9% of the patients (n = 49,020) had stage pN0. Similar to the original cohort, the probability of missing a positive LN decreased with the increasing number of LNs examined. In both the validation and the original cohort, the number of LNs needed to correctly stage a patient's disease as node negative increased with more advanced tumor stage, higher Gleason sum, positive surgical margins, and higher preoperative prostate-specific antigen levels. CONCLUSION: We have confirmed that the number of examined LNs needed for adequate nodal staging in PCa depends on the pathologic tumor stage, Gleason sum, surgical margins status, and preoperative prostate-specific antigen. We externally validated our pNSS in a population-based cohort, which could help to refine decision-making regarding the administration of adjuvant therapy.