Evolving use of liquid biopsy in non-small-cell-lung cancer patients.

Liquid biopsy is routinely used to detect epidermal growth factor receptor mutations in advanced or metastatic lung cancer, due to some limitations of tissue genotyping, especially at relapse. However, the existence of a non-marginal proportion of oncogene-addicted lung cancers that can benefit from target therapy is rapidly expanding clinical relevance of plasma genotyping. Apart from static assessment of mutations in circulating free DNA, the fact that liquid biopsy is minimally invasive and can be repeated several times makes it a suitable assay for the dynamic monitoring of cancer response to treatment. It is likely that quantitative mutation assessment by liquid biopsy will be increasingly included in the design of innovative clinical trials for patient stratification purposes.