Extracapsular extension but not the tumour burden of lymph node metastases is an independent adverse risk factor in lymph node-positive bladder cancer

Aims: To evaluate risk factors in lymph node-positive bladder cancer. Methods and results: Lymph node-positive bladder cancer patients (n = 162), preoperatively staged N0M0, underwent cystectomy and standardized extended lymphadenectomy. Five-year overall survival of the cohort was 33%. In univariate analysis, tumour stage (P < 0.006), extracapsular extension of lymph node metastases (P < 0.001), total diameter of metastases (P < 0.04) and lymph node stage (P < 0.03) were significantly correlated with overall survival (OS), disease-specific survival (DSS) and recurrence-free survival (RFS). On multivariate analysis, only extracapsular extension (OS, P < 0.002; DSS, P < 0.02; RFS, P = 0.058) and primary tumour stage (OS, P = 0.058; DSS, P < 0.02; RFS, P < 0.02) added independent prognostic information. Extracapsular extension of lymph node metastases did not correlate with a specific recurrence pattern; patients with organ-confined tumours (pT1/2) never had pelvic relapse. Conclusions: Extracapsular extension of lymph node metastases but not lymph node tumour burden adds independent prognostic information in lymph node-positive bladder cancer. These biological differences in lymph node-positive bladder cancer are not reflected in the sixth, and challenge future, TNM classification.