Relevance of genetic alterations in squamous and small cell lung cancer.

The precision medicine revolution has led to the development and US FDA approval of multiple targeted therapies in non-squamous non-small cell lung cancers, including tyrosine kinase inhibitors targeting EGFR, ALK, and ROS1. However, the development of targeted therapies for squamous cell lung cancers (SQCLCs) and small cell lung cancers (SCLCs) has lagged behind and the mainstay of systemic therapy for most patients with metastatic disease remains chemotherapy; which has seen little meaningful progress over the past three decades. The ideal of precision medicine in these diseases may appear elusive; however, recent comprehensive genomic analysis of SQCLC and SCLC has led to multiple breakthroughs in our understanding of the biology of these diseases and has led to new therapeutic approaches currently under active clinical investigation. This review will focus on the therapeutic relevance of these alterations in their respective diseases and new insights into promising therapeutics currently under investigation.