Non–small cell lung carcinoma is the most prevalent kind of lung cancer, and it is also the disease that causes the most fatalities globally each year. The liquid biopsy is the most recent step forward in personalized medicine in cancer therapy, allowing treatment depending on driver mutations found within a patient. 

Cell-free DNA (cfDNA) is lost by cells throughout the body, including tumor cells. This circulating tumor DNA may be collected and examined for therapeutic and diagnostically useful genes and gene alterations. Because circulating tumor DNA is extremely rare, the existing diagnostics are intended to have very high sensitivity at the expense of lower specificity. 

The supporting data for the major commercially available liquid biopsies are examined and summarized. The liquid biopsy is most commonly used to screen for actionable mutations, but it may also be used to monitor disease progression and test for resistance mutations in patients undergoing therapy.

Reference:journals.lww.com/clinpulm/Abstract/2018/03000/The_Liquid_Biopsy,_What_is_it,_How_is_it_Provided,.1.aspx