Incidence of Low-risk Upper Tract Urothelial Carcinoma in Candidates for Kidney-sparing Surgery

This study aimed to determine the incidence of low-risk upper tract urothelial carcinoma in candidates for kidney-sparing surgery based on the European Association of Urology risk stratification system by analyzing specimens obtained after radical nephroureterectomy.

We retrospectively analyzed 118 patients who underwent radical nephroureterectomy without distant metastases or prior treatment between 2010-2022. Patients meeting all six factors of risk stratification were classified as having low-risk upper tract urothelial carcinoma. The incidence of low-risk patients was calculated. Additionally, the extravesical recurrence-free survival rate was assessed in these patients. Pathological data from radical nephroureterectomy specimens were used for conducting a detailed analysis of the aforementioned factors.

The pathological T stage was pT1 or lower in 58 patients (49%). Seven patients (6%) met all six factors for low-risk upper tract urothelial carcinoma, and low-risk patients had a pathological T stage of pT1 or lower. The 5-year extravesical recurrence-free survival rate for the overall cohort was 74.9%. Low-risk patients demonstrated a more favorable extravesical recurrence-free survival rate compared to non-low-risk patients (100% vs. 73.3% at 5 years, respectively). Among the six risk factors, "tumor size <20 mm" was the only significant predictor of extravesical recurrence in both univariate and multivariable analyses.

Six percent of patients undergoing radical nephroureterectomy may be eligible for kidney-sparing surgery. Despite the limited number of identified patients, patients with low-risk upper tract urothelial carcinoma exhibited excellent outcomes. Kidney-sparing surgery may be a viable option in carefully selected patients.