Lymph Node Density Is Superior to TNM Nodal Status in Predicting Disease-Specific Survival After Radical Cystectomy for Bladder Cancer: Analysis of Pooled Data From MDACC and MSKCC

Abstract

Purpose To compare the utility of lymph node density (LND) with TNM nodal status in predicting disease-specific survival (DSS) after radical cystectomy. Patients and Methods We identified 248 patients with nodal metastasis after radical cystectomy (without neoadjuvant chemotherapy): 162 patients from Memorial Sloan-Kettering Cancer Center (MSKCC) and 86 patients from M.D. Anderson Cancer Center (MDACC). We assessed the effect of several variables on DSS. Results After a median follow-up duration of 24 months, 134 patients died of their disease. The median DSS was 36 months, and the 1-year, 2-year, and 5-year DSS rates were 83.7%, 57.4%, and 36.6%, respectively. The median LND was 20%. The 5-year DSS rate was 54.6% for patients with LND ≤ 20% v 15.3% for patients with LND higher than 20% (P < .01). Pathologic nodal (pN) status in patients was 78 for pN1 (32%), 127 for pN2 (51%), and 43 for pN3 (17%). On univariate analysis, pN status and LND were significant predictors of DSS (P < .01). However, when pN status and LND were considered jointly in a multivariate model, only LND higher than 20% predicted decreased DSS (hazard ratio [HR], 2.75; P < .01). In addition, while nonorgan-confined (ie, > pT2) primary tumor (HR, 2.40; P < .01) and adjuvant chemotherapy (HR, 0.47; P < .01) were predictors of DSS, LND remained a predictor of DSS even after accounting for adjuvant chemotherapy. Conclusion LND is superior to TNM nodal status in predicting DSS for patients with lymph node–positive disease after radical cystectomy, even in the context of adjuvant chemotherapy.