Preoperative hydronephrosis as a predictor of postnephroureterectomy survival in patients with upper tract urothelial carcinoma: a two-center study in Japan.

Objective: To evaluate the predictive value of preoperative hydronephrosis for pathological outcome and prognosis in patients with upper tract urothelial carcinoma treated with nephroureterectomy.

Methods: 167 patients with UTUC treated with nephroureterectomy at our two institutions in Japan between 2002 and 2017 were retrospectively analyzed. Preoperative computed tomography scans were evaluated for the presence of ipsilateral hydronephrosis. Preoperative hydronephrosis's associations with pathological outcome and postnephroureterectomy survival were assessed.

Results: Ipsilateral hydronephrosis was present in 102 patients (61.1%). Preoperative hydronephrosis was not associated with higher pathological T stage (T3 or greater). Patients with preoperative hydronephrosis compared with patients without preoperative hydronephrosis had significantly worse recurrence-free survival (RFS) (5-year survival, 61.9% and 77.6%, respectively; p = 0.033), disease-specific survival (DSS) (5-year survival, 66.9% and 88.1%, respectively; p = 0.026), and overall survival (OS) (5-year survival, 54.5% and 80.6%, respectively; p = 0.030). A multivariate Cox regression model identified preoperative hydronephrosis and higher clinical T stage (T3 or greater) as an independent predictor of shorter RFS (p = 0.015 and 0.0009, respectively). We segregated the patients into three risk groups based on the number of these two prognostic factors: 0, favorable risk; 1, intermediate risk; 2, poor risk. The favorable-risk group had significantly better RFS (p = 0.0003), DFS (p = 0.0001), and OS (p = 0.0007) than the poor and intermediate-risk groups (RFS (p = 0.0011), DFS (p = 0.0017), and OS (p = 0.0043)).

Conclusion: The presence of preoperative hydronephrosis was a significant risk factor affecting survival. Our risk classification based on preoperative hydronephrosis and clinical T stage may be helpful for patient counselling and decision-making before nephroureterectomy.