Biomarkers in the selection of maintenance therapy in non-small cell lung cancer

Long gone are the days where identification of lung cancer as either non-small cell lung or small cell is sufficient to initiate therapy. Today, the optimal treatment of lung cancer hinges not only on accurate histopathologic diagnosis but further tumor description through molecular characterization (1). The importance of molecular testing prior to initiation of therapy is best highlighted by epidermal growth factor receptor (EGFR) mutational analyses. There have been a number of trials that have identified patients who gleaned a greater benefit from EGFR tyrosine kinase inhibitor (TKI) therapy on the basis of EGFR mutation positivity in first, second and third line treatment regimens.