Risk Model for Lymph Node-Positive Prostate Cancer After Radical Prostatectomy

Post-radical prostatectomy (RP) lymph node positivity (pN1) is associated with disease progression. However, the optimal treatment strategy for pN1 patients has remained unclear. This study aimed to establish a risk model for predicting survival outcomes in these patients.

We retrospectively studied 528 eligible patients with pN1 undergoing RP with pelvic lymph node dissection between 2006 and 2019 at 33 participant institutions in the Japanese Urologic Oncology Study Group. Metastasis-free survival (MFS) was used to evaluate for survival outcome. A least absolute shrinkage and selection operator (LASSO)-penalized, multivariate Cox regression model for MFS was used to evaluate patients for their risk factors and establish a risk model with an associated nomogram.

Grade group (GGs 4-5 vs. GGs 1-3: HR, 7.35; 95% confidence intervals (CI), 1.76-30.7; p = 0.006), pathological T-stage (pT3b or more vs. pT2 to pT3a: HR, 2.01; 95% CI, 0.93-4.34; p = 0.075), number of positive lymph nodes (HR, 2.03; 95% CI, 0.83-4.96; p = 0.044), and positive lymph node diameter (> 2 mm vs. ≤ 2 mm: HR, 2.03; 95% CI, 1.09-9.00; p = 0.034) were identified as independent prognostic factors for predicting 60-month MFS.

This study explored prognostic factors for pN1 prostate cancer patients for predicting their MFS and identified a risk model involving a nomogram. Randomized controlled trials are necessary in patients with pN1 prostate cancer to elucidate optimal postoperative treatment indications and selection.