The degree of preoperative hydronephrosis to predict pathologic features and oncologic outcomes in high-grade upper tract urothelial carcinoma.
525 Background: There have been multiple reports implicating the role of hydronephrosis (HN) as a predictor of outcome in patients diagnosed with upper tract urothelial carcinoma (UTUC). However, this was done in mixed populations (low-/high-grade) and degree of HN (DOH) was not taken into account. We evaluated the impact of severity of hydronephrosis on systemic and bladder relapse in patients with UTUC. Methods: We retrospectively reviewed the records of 141 patients with localized UTUC that underwent extirpative surgery. Preoperative imaging was used to evaluate ipsilateral DOH. We analyzed the association between DOH (none/mild vs. moderate/severe), pathological findings and oncological outcomes in high-grade vs. low-grade patients. Bladder recurrence was assessed separately from local or systemic (L/S) recurrence. Results: High-grade UTUC was present in 80% of patients, 35% had muscle-invasive disease (≥pT2), and 29% had non-organ-confined disease. At a median follow-up of 34 months (range, 1-149), 35% of patients experienced intravesical recurrence, 20% developed L/S recurrence, and 17% died of UTUC. No difference in outcomes was seen between patients without HN and mild HN. DOH was none/mild in 55% and moderate/severe in 45% of cases. In patients with high-grade UTUC, moderate/severe HN was associated with advanced pathologic stage (p<0.001) and positive lymph node status (p=0.01). On Kaplan-Meier analysis, DOH was a predictor of L/S recurrence-free survival (RFS) (HR 5.5, p=0.019) and cancer-specific survival (CSS) (HR 5.2, p=0.022) but not intravesical recurrence. On multivariable analysis with preoperatively known factors controlling for grade and tumor location, DOH was independently associated with L/S RFS (HR 2.8, p=0.016) and CSS (HR 2.5, p=0.044). Conclusions: Moderate/severe HN was associated with features of advanced disease and predicted worse oncological outcomes in patients with high-grade UTUC. Since preoperative imaging is a routinely available diagnostic tool, this can serve as a surrogate parameter for advanced disease and can help to counsel patients towards preoperative chemotherapy and radical surgery.