Risk Factors for Patients With Pelvic Lymph Node Metastases Following Radical Cystectomy With En Bloc Pelvic Lymphadenectomy: The Concept of Lymph Node Density

Abstract

Patients with lymph node tumor involvement following radical cystectomy may be stratified into high risk groups based on the primary bladder tumor, pathological subgroup, number of lymph nodes removed and total number of lymph nodes involved. Lymph node density, which is a novel prognostic indicator, may better stratify lymph node positive cases because this concept collectively accounts for the total number of positive lymph nodes (tumor burden) and the total number of lymph nodes removed (extent of lymphadenectomy). Future staging systems and the application of adjuvant therapies in clinical trials should consider applying lymph node density to help standardize this high risk group of patients following radical cystectomy.

Staging and reporting of urothelial carcinoma of the urinary bladder

“…Recent studies have emphasized the importance of lymph node density for nodal staging. [100][101][102][103] Lymph node density is defined by the ratio of positive lymph nodes to the total number of lymph nodes sampled. In an analysis of 248 patients with positive nodal metastasis, Kassouf et al 101 found that lymph node density was an independent predictor of cancer survival.…”

Lymph node density: surrogate marker for quality of resection in bladder cancer?

“…LND has been demonstrated to be directly correlated with recurrence-free survival [3][4][5][6]. In a recent review, LND was found to be a better surrogate end point than total number of positive nodes in four out of five studies in the literature evaluated by Herr [14].…”

“…Thus, LND takes two known prognostic factors for recurrence and combines them into one composite variable (a percentage) [4][5][6]. The numerator (number of positive nodes) is one component of the American Joint Committee on Cancer (AJCC) staging criteria and incorporating this variable makes intuitive sense as the greater the extent of disease the worse the prognosis will be.…”

“…In an attempt to answer these types of question, Stein [4] and Herr [5] in 2003, put forward the idea of 'lymph node density' (LND). Herein, we examine whether LND may be a surrogate end point for the quality of node dissection at cystectomy.…”

“…First, the arbitrary LND cut offs of 20-25% were assigned retrospectively, and represent statistical cut points [4,5] that would benefit from prospective validation. The effect of chemotherapy on LND also needs further evaluation although, in our series, it appears to hold true [KAMAT ET AL., UNPUBLISHED OBSERVATION].…”