Purpose: To provide future mapping analysis of lymph node positive disease we modified our lymphadenectomy at radical cystectomy for bladder cancer from an en bloc packet to 13 separate nodal packets. We evaluated the clinical and pathological findings resulting from this modification.
Materials and methods: A total of 1,359 patients underwent en bloc radical cystectomy and extended lymphadenectomy for bladder cancer. They were compared to 262 patients who underwent radical cystectomy and extended lymphadenectomy with lymph nodes submitted in 13 distinct nodal packets. Overall 317 patients (23%) of the en bloc group (group 1) and 66 of the 262 (25%) in the separately packaged group (group 2) had node positive disease. Clinical and pathological findings were analyzed to compare these 2 groups of patients.
Results: Although the incidence of lymph node positivity was not different, the median number of total lymph nodes removed in group 2 was significantly higher than that in group 1 (68, range 14 to 132 vs 31, range 1 to 96, p<0.001). A trend toward more lymph nodes involved was observed in group 2 compared to group 1 (3, range 1 to 91 vs 2, range 1 to 63, p=0.062). These findings significantly lowered median lymph node density in group 2 compared to that in group 1 (6% vs 9%, p=0.006).
Conclusions: Although the overall incidence of lymph node positive disease was not different, the submission of 13 separate nodal packets at radical cystectomy significantly increased the total number of lymph nodes removed/analyzed and identified a slightly higher number of positive lymph nodes compared to en bloc submission.