Cancer Prognostics and Health Outcomes Unit Department of Urology, University of Montreal Health Centre, Montreal, QC, Canada.Department of Urology, Vita Salute San Raffaele University, Milan, Italy; Martini-Clinic, Prostate Cancer Center Hamburg-Eppendorf, Hamburg, Germany; Department of Urology, Weill Medical College of Cornell University, New York, NY, USA.
Study Type - Therapy (cohort) Level of Evidence 2b.
What's known on the subject? and What does the study add? The National Comprehensive Cancer Network guidelines recommend pelvic lymph node dissection in patients with a nomogram-predicted lymph node invasion risk of 2% or more. We set out to examine the validity of this recommendation.
To examine the ability of the threshold recommended by the National Comprehensive Cancer Network (NCCN) in correctly predicting histologically-confirmed lymph node invasion (LNI). The 2010 NCCN practice guidelines for prostate cancer recommend a pelvic lymph node dissection (PLND) at radical prostatectomy in all individuals with a nomogram predicted LNI risk of ≥2%.
We assessed 20 877 patients who were treated with radical prostatectomy and PLND between 2004 and 2006, within the Surveillance, Epidemiology and End Results database. The 2% nomogram threshold, as well as other threshold values (range 1-10%) were tested. Finally, we externally validated the NCCN guideline nomogram.
Overall, 2.5% of patients had LNI. The use of the 2% threshold would allow the avoidance of 23% of PLNDs, at the cost of missing 1.7% of patients with LNI. Conversely, the use of a 3% threshold would allow the avoidance of 58% of PLNDs, at the cost of missing 15% of patients with LNI vs 72% and 26%, respectively, for the 4% threshold. Overall, the accuracy of the NCCN guideline nomogram quantified according to the receiver-operator characteristics-derived area under the curve was 82%.
In a population-based sample, the NCCN guideline nomogram is highly accurate. However, the 2% threshold will permit the avoidance of only 23% of PLNDs, instead of the 48% intended by the NCCN guidelines. The use of a 3% threshold may allow a lower rate of PLND overtreatment, although it will miss more patients with LNI.
Abdollah F, Schmitges J, Sun M, Shariat SF, Briganti A, Abdo A, Tian Z, Perrotte P, Montorsi F, Karakiewicz PI. Are you the author?
Reference: BJU Int. 2011 Aug 22. Epub ahead of print.