Purpose: To evaluate the impact of lymph node dissection (LND) on clinical outcome during radical nephroureterectomy (RNU) for patients with upper urinary tract urothelial cancer (UTUC).
Methods: We, the Urologic Oncology Study Group of the Japan Clinical Oncology Group (JCOG), retrospectively collected data from patients with non-metastatic UTUC who underwent RNU in 30 centers in 1995-2009. Ineligible patients and patients with previous and/or synchronous bladder cancer were excluded, and the remaining 2037 patients were analyzed. We compared overall and cancer-specific mortality between patients who underwent LND (LND group) and those without LND (no-LND group).
Results: Among 2037 patients, LND was performed in 1046 (51.4%) patients, and 223 (10.9%) patients had pathological node-positive (pN+) disease. All-cause mortality was observed in 503 patients (24.7%) during follow-up (median 45.8 months), including 363 patients (17.8%) who died of UTUC. Patients with pN+ disease showed significantly shorter overall survival (OS) compared with pN0 patients, and the estimated 5-year OS for pN+ patients was 30%. Older age, ≥cT3, and clinical node-positive disease were found as preoperative predictors for pN+ disease by multivariate analysis. In the comparison of OS and cancer-specific mortality between LND and no-LND groups, there was no significant improvement by LND in multivariate analysis. The median number of lymph nodes removed was six (IQR 3-11). There was no significant association between the number of lymph nodes removed and OS.
Conclusions: The present study indicates that there is no therapeutic benefit of LND during RNU for UTUC, although pathologically positive LN status can predict poor prognosis.
Keywords: Japanese; Lymph node dissection; Prognosis; Radical nephroureterectomy; Survival; Upper urinary tract urothelial cancer.