Navigating Nomograms To Identify Prostate Cancer Patients for Lymph Node Dissection

In this issue of European Urology Oncology, two excellent contributions address the topic of identifying prostate cancer patients who require pelvic lymph node dissection (PLND). In those contributions, Vis et al. [ [1] Vis AN, Meijer D, Roberts MJ, et al. Development and external validation of a novel nomogram to predict the probability of pelvic lymph-node metastases in prostate cancer patients using magnetic resonance imaging and molecular imaging with prostate-specific membrane antigen positron emission tomography. Eur Urol Oncol. In press. https://doi.org/10.1016/j.euo.2023.03.010. Google Scholar ] as well as Gandaglia et al. [ [2] Gandaglia G, Barletta F, Robesti D, et al. Identification of the optimal candidates for nodal staging with extended pelvic lymph node dissection among prostate cancer patients who underwent preoperative prostate-specific membrane antigen positron emission tomography. External validation of the Memorial Sloan Kettering Cancer Center and Briganti nomograms and development of a novel tool. Eur Urol Oncol. In press. https://doi.org/10.1016/j.euo.2023.05.003. Google Scholar ] developed new tools for predicting lymph node invasion (LNI). Both tools integrate prostate-specific membrane antigen (PSMA) positron emission tomography (PET) among the predictors used and outperform previous tools, where PSMA PET was not used. Analyses provide detailed head-to-head comparisons of each novel nomogram and existing tools. Both reports rely on excellent statistics and include all required statistical validation metrics. The following observations may help in identifying differences between these two seemingly similar contributions from two different groups of investigators.