PURPOSE

Non-muscle-invasive bladder cancers (NMIBC) constitute 3-quarters of all primary diagnosed bladder tumors. For risk-adapted management of patients with NMIBC, different risk group systems and predictive models have been developed. This study aimed to externally validate EORTC2016, CUETO and novel EAU2021 risk scoring models in a multi-institutional retrospective cohort of patients with high-grade NMIBC who were treated with an adequate BCG immunotherapy.

METHODS

The Kaplan-Meier estimates for recurrence-free survival and progression-free survival were performed, predictive abilities were assessed using the concordance index (C-index) and area under the curve (AUC).

RESULTS

A total of 1690 patients were included and the median follow-up was 51 months. For the overall cohort, the estimates recurrence-free survival and progression-free survival rates at 5-years were 57.1% and 82.3%, respectively. The CUETO scoring model had poor discrimination for disease recurrence (C-index/AUC for G2 and G3 grade tumors: 0.570/0.493 and 0.559/0.492) and both CUETO (C-index/AUC for G2 and G3 grade tumors: 0.634/0.521 and 0.622/0.525) EAU2021 (c-index/AUC: 0.644/0.522) had poor discrimination for disease progression.

CONCLUSION

Both the CUETO and EAU2021 scoring systems were able to successfully stratify risks in our population, but presented poor discriminative value in predicting clinical events. Due to the lack of data, model validation was not possible for EORTC2016. The CUETO and EAU2021 systems overestimated the risk, especially in highest-risk patients. The risk of progression according to EORTC2016 was slightly lower when compared with our population analysis.