Novel Classification for Upper Tract Urothelial Carcinoma to Better Risk-stratify Patients Eligible for...

The European Association of Urology risk stratification dichotomizes patients with upper tract urothelial carcinoma (UTUC) into two risk categories.

To evaluate the predictive value of a new classification to better risk stratify patients eligible for kidney-sparing surgery (KSS).

This was a retrospective study including 1214 patients from 21 centers who underwent ureterorenoscopy (URS) with biopsy followed by radical nephroureterectomy (RNU) for nonmetastatic UTUC between 2000 and 2017.

A multivariate logistic regression analysis identified predictors of muscle invasion (≥pT2) at RNU. The Youden index was used to identify cutoff points.

A total of 811 patients (67%) were male and the median age was 71 yr (interquartile range 63-77). The presence of non-organ-confined disease on preoperative imaging (p < 0.0001), sessile tumor (p < 0.0001), hydronephrosis (p = 0.0003), high-grade cytology (p = 0.0043), or biopsy (p = 0.0174) and higher age at diagnosis (p = 0.029) were independently associated with ≥pT2 at RNU. Tumor size was significantly associated with ≥pT2 disease only in univariate analysis with a cutoff of 2 cm. Tumor size and all significant categorical variables defined the high-risk category. Tumor multifocality and a history of radical cystectomy help to dichotomize between low-risk and intermediate-risk categories. The odds ratio for muscle invasion were 5.5 (95% confidence interval [CI] 1.3-24.0; p = 0.023) for intermediate risk versus low risk, and 12.7 (95% CI 3.0-54.5; p = 0.0006) for high risk versus low risk. Limitations include the retrospective design and selection bias (all patients underwent RNU).

Patients with low-risk UTUC represent ideal candidates for KSS, while some patients with intermediate-risk UTUC may also be considered. This classification needs further prospective validation and may help stratification in clinical trial design.

We investigated factors predicting stage 2 or greater cancer of the upper urinary tract at the time of surgery for ureter and kidney removal and designed a new risk stratification. Patients with low or intermediate risk may be eligible for kidney-sparing surgery with close follow-up. Our classification scheme needs further validation based on cancer outcomes.