Personalized medicine in lung cancer: what we need to know.

Lung cancer is a complex and often fatal disease. The recent discovery of activating mutations in EGFR and fusion genes involving ALK has set the stage for personalized medicine for lung cancer. Patients selected using biomarkers have benefited from the development of EGFR tyrosine kinase inhibitors and ALK inhibitors with considerable improvement in tumor control and survival. Four key areas of knowledge that are essential to the development of targeted therapy are discussed in this Review: knowing the target, knowing the biomarker, knowing the end point and knowing the mechanisms of resistance.