Lymph node ratio has greater prognostic value than positive lymph node count in papillary renal cell carcinoma

Abstract

Abstract Purpose Approximately 10–15% of renal cell carcinoma (RCC) cases are papillary renal cell carcinoma (pRCC). pRCC is associated with a higher risk of lymph node metastases than clear cell RCC. The objective of this study was to compare the predictive significance of positive lymph node count (PLNC) versus lymph node ratio (LNR) in pRCC. Methods The Surveillance, Epidemiology, and End Results (SEER) database was searched, and a total of 372 patients with pRCC were selected. The optimum cut-off values for PLNC and LNR were determined. We performed χ2 or Fisher’s exact probability test to determine whether certain clinicopathological traits were associated with LNR or PLNC. Independent predictors of 5-year overall survival (OS) and 5-year cancer-specific survival (CSS) were determined using univariate and multivariate Cox proportional hazards regression analyses. The association between LNR and PLNC was determined using Spearman correlation analysis. Results Patients with high levels of LNR or PLNC were associated with advanced 6th/7th American Joint Committee on Cancer (AJCC) stage, T stage, N stage, M stage, and higher pathological grade. According to the univariate Cox proportional hazards regression analysis, the 6th/7th AJCC stage, T stage, N stage, M stage, tumor size, pathological grade, radiotherapy, chemotherapy, PLNC, and LNR were significantly linked to prognosis. Unlike PLNC, LNR was an independent predictive factor for OS and CSS based on the multivariate Cox proportional hazards regression analysis. A subgroup analysis of patients with positive nodes corroborated these findings. Conclusion LNR may have greater prognostic value than PLNC in pRCC.