This study suggests a significant discordance between clinically available NGS panels in advanced urothelial cancer, even when collected around the same time. There is a need for better understanding of these two possibly complementary NGS platforms for better integration into clinical practice.

Patients with mUC who progressed on atezolizumab were unlikely to receive subsequent systemic treatments and the benefit of those treatments appeared limited in our cohort. The findings may impact timing and designs of clinical trials in mUC.