Beyond circulating tumor cell enumeration: Cell-based liquid biopsy to assess protein biomarkers and cancer genomics

The promise of liquid biopsy is that it will be able to do what tissue biopsy has done: generate essential information for the diagnosis, phenotyping and molecular analysis of cancer. The challenge for liquid biopsy is to combine appropriate technologies with robust assay methods that can extract that information from blood components. ctDNA sequencing has rapidly gained adoption as a mutational testing method. We have described here how the phenotypic and molecular analysis of CTCs can supplement ctDNA sequencing to advance the capacity of liquid biopsy to meet the requirements of twenty-first century medicine.