Impact of lymph node dissection on clinical outcomes during nephroureterectomy in patients with clinically node-negative upper urinary tract urothelial cancer: subanalysis of a multi-institutional nationwide case series of the Japanese Urological Association.

Abstract

To evaluate the impact of lymph node dissection (LND) on the clinical outcomes during radical nephroureterectomy (RNU) in patients with clinically node-negative upper urinary tract urothelial cancer (UTUC). Within the nationwide case series of the Japanese Urological Association, which comprises 1509 patients with UTUC diagnosed in 2005, we identified 823 patients with clinically node-negative UTUC who underwent RNU. The extent of limited LND was defined as the renal hilar region only for renal pelvic cancer and as either the pelvic region or para-aortic/paracaval region only for ureteral cancer, while the extent of wider LND was defined as at least one perilesional LND region in addition to limited LND. Multivariate analysis with a Cox regression hazard model was used to evaluate the survival benefit. Among the 823 patients, LND was performed in 197 (23.9%) patients, and 26 (13.2%) of them had pathologically node-positive disease. Of 197 patients who underwent LND, limited and wider LND was performed in 119 (60.4%) and 78 (39.6%) patients, respectively. Patients with node-positive disease showed significantly shorter overall survival than those with node-negative disease. No LND-associated survival improvement was observed in a direct comparison between patients with and without LND. In addition, limited or wider LND was not associated with overall survival or cancer-specific survival. The therapeutic benefit obtained by LND remains unclear regardless of the extent of LND, although LND has diagnostic value with respect to the prediction of a poor prognosis especially in patients with clinically muscle-invasive disease.