A liquid biopsy in primary lung cancer.

A tissue biopsy is the "golden standard" for molecular profiling that is essential in decision-making regarding treatment for malignant tumors, including primary lung cancer. However, tumor biopsies are associated with several limitations, including invasiveness and difficulty in achieving access. Liquid biopsies have several potential advantages over tissue biopsies, and recent advances in molecular technologies have enabled liquid biopsies to be introduced into daily clinical practice. Cell-free blood-based liquid biopsies to detect mutations in the epidermal growth factor receptor (EGFR) gene in the plasma have been approved and may be useful in selecting patients for treatment with tyrosine kinase inhibitors of EGFR. We herein describe blood-based liquid biopsies and review the current status and future perspectives of plasma genotyping in primary lung cancer.