Purpose: To evaluate the performance of the Zumsteg classification to estimate the risk of lymph-node invasion (LNI) compared with the Briganti nomogram (BN) in prostatectomy patients with intermediate-risk prostate cancer (IRPC).
Methods: We included consecutive patients who had extended pelvic lymph-node dissection associated with radical prostatectomy for IRPC. To be classified favorable intermediate risk (FIR), patients could only have one intermediate-risk factor, fewer than 50% positive biopsies and no primary Gleason score of 4.
Results: On the 387 patients included, 149 (38.5%) and 238 (54.3%) were classified FIR and unfavorable intermediate risk (UIR), respectively, and 212 (54.8%) had a BN inferior to 5%. Thirty-eight patients (9.8%) had LNI: 6 FIR patients (4.0%) versus 32 UIR patients (13.4%) and 14 patients (6.6%) with a BN inferior to 5% versus 24 patients (13.7%) with a BN superior to 5%. Eight patients with a BN inferior to 5%, but classified UIR, had LNI. Sensitivity to detect LNI was higher with the Zumsteg classification than with the BN: 84.2% (CI 95% [68-93]) versus 63.2% (CI 95% [46-78]). Both screening tests were concordant to predict LNI (kappa coefficient of 0.076, p < 0.05 for Zumsteg and Briganti) CONCLUSIONS: Zumsteg classification appeared to be more sensitive and as effective (despite the impossibility to make decision curve analysis) than the BN to estimate the risk of LNI. Regarding the modest number of pN+ patients, further studies are needed to see the interest of proposing ePLND for UIR patients only.
Keywords: Briganti nomogram; Intermediate risk; Lymph-node invasion; Prostate cancer; Radical prostatectomy; Zumsteg classification.