Impact of preoperative chemotherapy on pathologic nodal status in muscle-invasive bladder cancer: optimal lymphadenectomy in the preoperative chemotherapy era.

PURPOSE: To investigate the impact of preoperative chemotherapy (pCTX) on pathologic nodal (pN) status and evaluate the optimal lymphadenectomy method according to clinical nodal (cN) status in patients with muscle-invasive bladder cancer who received pCTX.
MATERIALS AND METHODS: We retrospectively reviewed 449 patients with muscle-invasive bladder cancer who underwent radical cystectomy. Among them, 139 (31.0%) received pCTX. We analyzed overall survival among three groups (cN-pCTX-, cN-pCTX+, and cN+pCTX+); the impact of lymphadenectomy extent according to the history of pCTX in cN- patients (n = 393); and the pN status which includes number of positive lymph nodes, and lymph node density in cN- patients who underwent extended lymphadenectomy (n = 222).
RESULTS: Overall survival was significantly dependent on cN status, and pCTX had no survival advantage although it decreased the percentage of pN+ patients and the number of positive lymph nodes in cN- patients. Lymph node density showed a significant prognostic effect on overall survival in Cox regression analysis both in cN- and cN+ patients. In cN- patients, there was no significant survival difference according to lymphadenectomy extent regardless of receiving pCTX.
CONCLUSIONS: pCTX can control micrometastases but not overt metastases, despite decreasing the number of positive lymph nodes in patients with muscle-invasive bladder cancer. Although extended lymphadenectomy is a reasonable diagnostic strategy in the pCTX era, standard dissection is as therapeutic as extended dissection in patients with cN- disease.