The lymph node ratio (LNR) is gaining recognition as a prognostic biomarker for various malignant neoplasms. However, its prognostic role in postoperative chemotherapy for high-risk muscle-invasive bladder cancer (MIBC) remains unclear. This study included 2,320 patients with lymph node-positive T2-4N1-3M0 MIBC receiving postoperative chemotherapy from the Surveillance, Epidemiology, and End Results (SEER) database, and a validation cohort of 273 patients from Sun Yat-sen University Cancer Center (SYSUCC). Optimal LNR thresholds were identified by using X-tile software. The relationship between LNR and overall survival (OS) was evaluated via Kaplan-Meier analysis, Cox regression, subgroup analyses, and restricted cubic splines. Nomograms and 101 machine learning (ML) algorithms were developed, incorporating LNR and clinical covariates for enhanced prognosis. The Kaplan–Meier and restricted cubic splines analyses revealed that LNR was an independent risk factor of OS in post-radical cystectomy and chemotherapy patients with lymph node-positive MIBC. Furthermore, the logistic regression model demonstrated that a lower LNR was significantly associated with a reduced incidence of second primary malignancies. After adjustment for potential confounders—including age, sex, histology, radiotherapy, and TNM staging—patients with elevated LNR values exhibited markedly inferior OS compared with those with lower LNR values, a finding consistent across both the SEER database and SYSUCC cohort. Additionally, the nomogram and machine learning algorithms, integrating LNR with clinical parameters, exhibited robust discriminative performance, with calibration curves confirming excellent concordance between predicted and observed outcomes. LNR is an independent prognostic factor for OS in post-radical cystectomy and chemotherapy patients with lymph node-positive MIBC.
Wang et al. (2026) studied this question.