OBJECTIVES: To investigate the prognoses of patients with upper urinary tract carcinoma who had recurrence after radical nephroureterectomy according to the presence or absence of systemic therapy after recurrences. Moreover, to evaluate the reasons for not being treated and to predict these untreated patients using pre-surgical clinical factors. METHODS: We retrospectively evaluated patients who underwent radical nephroureterectomy between 2012 and 2022. The reasons for not being treated were retrospectively analyzed. Recurrence was defined as extra-urinary tract recurrence. RESULTS: Among 599 patients, 159 (26.5%) experienced recurrence during the follow-up period. Sixty-six (41.5%) patients who did not receive any systemic therapy at recurrence had a poorer overall survival compared to those who received systemic therapy (Log-rank test, p <
0.002). Among the 159 patients who had recurrence, female gender, low serum albumin level, and age of 75 years or older at the time of radical nephroureterectomy were risk factors for being untreated at the time of recurrence. Additionally, the top 3 reasons for being untreated were older age (57.6%), poor performance status (42.4%), and deteriorated renal function (34.8%). CONCLUSIONS: Patients who did not receive systemic therapy at the time of recurrence after radical surgery demonstrated poorer survival outcomes compared to those who underwent systemic therapy. Our data provide essential support for discussions with patients and their families about treatment options, including adjuvant therapy, especially in consideration of the possibility that treatment may not be feasible at the time of recurrence.