Evaluation of the relevance of lymph node density in a contemporary series of patients undergoing radical cystectomy

Purpose: Lymph node density, that is the ratio of positive nodes to the total number of nodes excised, has been suggested to better stratify patients with bladder cancer who have nodal metastasis. We evaluated its relevance in a contemporary series of patients treated with radical cystectomy and in the context of adjuvant chemotherapy. Materials and Methods: From 1993 to 2003, 150 patients had pN+MO disease at cystectomy, of whom 108 who did not receive neoadjuvant chemotherapy form the basis of this report. Statistical analyses were performed using standard methodology. Results: Five-year overall, disease specific and recurrence-free survival rates were 30.9%, 45.5% and 29.7%, respectively. The median number of lymph nodes removed was 12 and the median number of positive nodes was 2. Of the patients 70% received adjuvant chemotherapy. Patients with a lymph node density of 25% or less had 5-year overall and recurrence-free survival rates of 37.3% and 38.1% compared with 18.7% and 10.6%, respectively in those with a lymph node density of greater than 25% (p = 0.02). In the context of adjuvant chemotherapy, which was associated with prolonged overall, disease specific and recurrence-free survival (p <= 0.01), lymph node density still remained prognostic for recurrence-free survival (HR 1.69, p = 0.047). The total number of nodes removed and the number of positive nodes were not prognostic. Conclusions: Our results support the relevance of lymph node density in a contemporary series of patients with bladder cancer treated with radical cystectomy. Lymph node density remains a significant prognostic factor for recurrence-free survival even when adjuvant chemotherapy is used.