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

Preoperative assessment of the probability of pelvic lymph-node metastatic disease (pN1) is required to identify patients with prostate cancer (PCa) who are candidates for extended pelvic lymph-node dissection (ePLND).

To develop a novel intuitive prognostic nomogram for predicting pathological lymph-node (pN) status in contemporary patients with primary diagnosed localized PCa, using preoperative clinical and histopathological parameters, magnetic resonance imaging (MRI), and prostate-specific membrane antigen (PSMA) positron emission tomography (PET).

In total, 700 eligible patients who underwent robot-assisted radical prostatectomy and ePLND were included in the model-building cohort. The external validation cohort consisted of 305 surgically treated patients. Logistic regression with backward elimination was used to select variables for the Amsterdam-Brisbane-Sydney nomogram.

Performance of the final model was evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision-curve analyses. Models were subsequently validated in an external population.

The Amsterdam-Brisbane-Sydney nomogram included initial prostate-specific antigen value, MRI T stage, highest biopsy grade group (GG), biopsy technique, percentage of systematic cores with clinically significant PCa (GG ≥2), and lymph-node status on PSMA-PET. The AUC for predicting pN status was 0.81 (95% confidence interval [CI] 0.78-0.85) for the final model. On external validation, the Amsterdam-Brisbane-Sydney nomogram showed superior discriminative ability to the Briganti-2017 and Memorial Sloan Kettering Cancer Center (MSKCC) nomograms (AUC 0.75 [95% CI 0.69-0.81] vs 0.67 [95% CI 0.61-0.74] and 0.65 [95% CI 0.58-0.72], respectively; p < 0.05), and similar discriminative ability to the Briganti-2019 nomogram (AUC 0.78 [95% CI 0.71-0.86] vs 0.80 [95% CI 0.73-0.86]; p = 0.76). The Amsterdam-Brisbane-Sydney nomogram showed excellent calibration on external validation, with an increased net benefit at a threshold probability of ≥4%.

The validated Amsterdam-Brisbane-Sydney nomogram performs superior to the Briganti-2017 and MSKCC nomograms, and similar to the Briganti-2019 nomogram. Furthermore, it is applicable in all patients with newly diagnosed unfavorable intermediate- and high-risk PCa.

We developed and validated the Amsterdam-Brisbane-Sydney nomogram for the prediction of prostate cancer spread to lymph nodes before surgery. This nomogram performs similar or superior to all presently available nomograms.

European urology oncology. 2023 Apr 10 [Epub ahead of print]

André N Vis, Dennie Meijer, Matthew J Roberts, Amila R Siriwardana, Andrew Morton, John W Yaxley, Hemamali Samaratunga, Louise Emmett, Peter M van de Ven, Martijn W Heymans, Jakko A Nieuwenhuijzen, Henk G van der Poel, Maarten L Donswijk, Thierry N Boellaard, Ivo G Schoots, Phillip Stricker, Anne-Maree Haynes, Daniela E Oprea-Lager, Geoffrey D Coughlin, Pim J van Leeuwen

Department of Urology, Prostate Cancer Network Netherlands, Amsterdam University Medical Center, VU University, Amsterdam, The Netherlands; Department of Urology, Prostate Cancer Network Netherlands, The Netherlands Cancer Institute, Amsterdam, The Netherlands., Department of Urology, Prostate Cancer Network Netherlands, Amsterdam University Medical Center, VU University, Amsterdam, The Netherlands; Department of Urology, Prostate Cancer Network Netherlands, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Radiology & Nuclear Medicine, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, The Netherlands. Electronic address: ., Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia; University of Queensland Centre for Clinical Research, Herston, Australia; Department of Urology, Redcliffe Hospital, Brisbane, Australia., Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia., Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia; Faculty of Medicine, University of Queensland, Brisbane, Australia., Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia; Faculty of Medicine, University of Queensland, Brisbane, Australia; Department of Urology, Wesley Hospital, Brisbane, Australia., Faculty of Medicine, University of Queensland, Brisbane, Australia; Department of Pathology, Aquesta Uropathology, Brisbane, Australia., St. Vincent's Clinical School, University of New South Wales, Kensington, Australia; Department of Theranostics and Nuclear Medicine, St. Vincent's Hospital Sydney, Darlinghurst, Australia., Department of Epidemiology and Data Science, Amsterdam University Medical Center, VU University, Amsterdam, The Netherlands., Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands., Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands., Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands., St Vincent's Clinic, St. Vincent's Prostate Cancer Centre, Sydney, Australia; Australian Prostate Cancer Research Centre - New South Wales, The Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Sydney, Australia., Australian Prostate Cancer Research Centre - New South Wales, The Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Sydney, Australia., Department of Radiology & Nuclear Medicine, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, The Netherlands., Faculty of Medicine, University of Queensland, Brisbane, Australia; Department of Urology, Wesley Hospital, Brisbane, Australia., Department of Urology, Prostate Cancer Network Netherlands, The Netherlands Cancer Institute, Amsterdam, The Netherlands.