(UroToday.com) Temporal and spatial heterogeneity have been consistently identified as contributing to perceived discordance between circulating tumor DNA and tissue-based assays. At the 2020 European Society of Medical Oncology Annual Congress, Zengin et al. previously demonstrated the feasibility of circulating tumor DNA assessment in metastatic renal cell carcinoma (mRCC) and preliminarily showed agreement between circulating tumor DNA and tissue-based genomic findings. This data suggested that the degree of agreement is dependent upon the temporal separation of blood and tissue samples. At the 2021 American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium, Dr. Zeynep Zengin and colleagues presented results of their study further exploring this temporal impact in a separate validation cohort.