Effect of lymph node dissection on stage-specific survival in patients with upper urinary tract urothelial carcinoma treated with nephroureterectomy

BACKGROUND: We aimed to estimate the stage-specific impact of lymph node dissection (LND) on survival for upper urinary tract urothelial carcinoma (UTUC) patients treated with nephroureterectomy (NU). METHODS: Overall, 7278 UTUC patients undergoing NU within the SEER database from 2004 to 2015 were identified. Kaplan-Meier plots illustrated overall survival (OS) and cancer-specific survival (CSS) rates according to LND status. Multivariable Cox regression analyses assessed the effect of LND on OS and CSS rates stratified by pathological tumor stage. RESULTS: LND was performed in 26.9% of patients, and in 18.6, 23.3, 31.2 and 45.9% for pT1, pT2, pT3 and pT4 patients, respectively (P < 0.001). In multivariable Cox regression analyses, LND was associated with a higher OS or CSS in UTUC patients with pT3 and pT4 disease (all P < 0.05), but failed to achieve independent predictor status in patients with pT1 and pT2 disease (all P > 0.05). LND with 1 to 3 regional lymph nodes removed was prone to a higher OS or CSS only in pT4 compared to no LND (both P < 0.01). LND with 4 or more regional lymph nodes removed predisposed to a higher OS or CSS in pT3 or pT4 (all P < 0.05). CONCLUSIONS: The beneficial effect of LND especially LND with 4 or more regional lymph nodes removed on survival was evident in pT3/4 patients. LND can be considered for pT3 and pT4, for pT1/2 remains to be seen, both of which will be verified by further prospective studies.