Locoregional Recurrence Risk Score Effectively Stratifies Patients With nmUC

Patients with urothelial carcinoma who have undergone radical cystectomy (RC) can be at risk of locoregional recurrence (LR), in which recurrence occurs in the soft tissue of the cystectomy bed or pelvic lymph nodes.

LR can result in poor prognosis, and reported cases vary widely in medical literature. As no risk stratification tools exist for the prediction of LR after RC, a recent study presented at the 25th Annual Meeting of the Society of Urologic Oncology sought to develop and validate a tool to determine factors associated with LR post-RC.

Researchers utilized an RC registry to collect data from patients with non-metastatic urothelial carcinoma with available LR data who were diagnosed between 1988 and 2022. Univariable and Cox regression models were used to determine factors linked with LR after cystectomy. An LR risk score was developed and externally validated using a different set of data.

Data were gathered from 1256 patients, with 227 patients (18%) experiencing LR at a median time of 0.89 years; this translated to a 2- and 5-year LR risk of 17% and 22%, respectively.

Multivariable analysis showed that increasing pT stage (HR 1.72) and pN+ (HR 1.90) were linked to increased LR, and more lymph nodes removed were inversely associated with LR (HR 0.98, all P<.01). A positive ureteral/urethral margin (P=.06) and positive radial margin (P=.07) were both associated with increased LR.

A risk score was developed based on regression coefficients was used to stratify patients with an increasing risk of 5-year LR from 2% to 52% with Harrell’s c-index of 0.73. The risk score was externally validated in a separate cohort (n=614), where 48 patients (7.8%) had LR.

The risk score stratified patients with a similar performance to the development cohort, with a c-index of 0.75 at 3 years.

About 10%-20% of patients who undergo RC will experience LR within 5 years, with the majority of these cases occurring within 2 years. This newly developed LR risk score can be used to develop eligibility criteria for clinical trials on adjuvant radiation therapy after RC.