Understanding molecular diagnostic technology in oncology through the lens of lung cancer.

Historically, advanced lung cancer conferred a poor prognosis, and chemotherapy only improved outcomes in patients with good performance status. The identification of certain molecular subtypes of non-small cell lung cancer changed the treatment paradigm by incorporating tumor genomic information into clinical decision-making. To meet the demands of this emerging approach, genomic technology rapidly expanded in an effort to detect specific driver mutations. While polymerase-chain reaction testing, immunohistochemistry, and fluorescent in situ hybridization have been standard-of-care, next-generation sequencing is increasingly replacing older technologies. Plasma-based testing is also gaining use given its convenience. Advances in molecular technology in this new era of precision medicine have led to the parallel development of companion diagnostics and novel tyrosine kinase inhibitors.