Table 1.

Comparison of liquid biopsy approaches in renal cell carcinoma.

Techniques	Advantages	Limitations
Tumor-agnostic ctDNA assays	Mature technologies in clinical use Fairly cost-effective	Paucity of actionable mutations Limited sensitivity at low tumor fraction
Bespoke ctDNA assays	Higher sensitivity enabled by knowledge of patient-specific mutations.	Requires tumor tissue to identify patient-specific mutations Paucity of actionable mutations
Epigenetic approaches	May provide actionable information beyond mutations, including histologic subtypes and gene expression DNA methylation profiling may improve sensitivity	Maturing technology, additional benchmarking of sensitivity required Higher cost Does not identify actionable mutations
Circulating tumor cells	Direct sampling of tumor cells	Challenging detection especially in early stage High cost Requires specialized technology