Metastatic behavior of upper tract urothelial carcinoma after radical nephroureterectomy: association with primary tumor location.

PURPOSE: To investigate the site-specific pattern of disease recurrence and/or metastasis and the associated patient outcomes after radical nephroureterectomy (RNU) in upper tract urothelial carcinoma (UTUC). METHODS: A total of 733 patients with UTUC from a retrospective multi-institutional cohort were included, with a median follow-up of 34 months. Associated patient outcomes were analyzed by multivariate analysis. To evaluate the influence of primary tumor location, we divided it into four areas: renal pelvis, and upper, middle, and lower ureter. RESULTS: A total of 218 patients experienced disease recurrence, with the majority of relapses occurring within the first 3 years. Cumulative incidence rates of first disease recurrence at 1 and 3 years were 18.9 and 29.8 %, respectively. Of these patients, 38.5 % developed distant recurrence; 17.4 % experienced both local and distant recurrences; and 44.0 % developed isolated local recurrence. The predominant sites of distant metastasis were lung, liver, and bone. Multivariate analysis revealed that the prevalence of local recurrence and lung metastasis was significantly associated, with primary tumor location being independent of other clinicopathological variables. Lower/middle ureter tumors had a higher rate of local recurrence in the pelvic cavity, and renal pelvic tumors had a higher prevalence of distant relapse in the lungs. Similar results were obtained when rerunning the data set by excluding patients who received adjuvant chemotherapy (n = 131). CONCLUSIONS: This multi-institutional study provided a detailed picture of metastatic behavior after RNU, and primary tumor locations were associated with unique patterns of metastatic spread in UTUC patients.