Importance of Molecular Features of Non–Small Cell Lung Cancer for Choice of Treatment

Lung cancer is the leading cause of cancer-related deaths in the United States. Approximately 85% of lung cancer is categorized as non–small cell lung cancer, and traditionally, non–small cell lung cancer has been treated with surgery, radiation, and chemotherapy. Targeted agents that inhibit the epidermal growth factor receptor pathway have been developed and integrated into the treatment regimens in non–small cell lung cancer. Currently, approved epidermal growth factor receptor inhibitors include the tyrosine kinase inhibitors erlotinib and gefitinib. Molecular determinants, such as epidermal growth factor receptor–activating mutations, have been associated with response to epidermal growth factor receptor tyrosine kinase inhibitors and may be used to guide treatment choices in patients with non–small cell lung cancer. Thus, treatment choice for patients with non–small cell lung cancer depends on molecular features of tumors; however, improved techniques are required to increase the specificity and efficiency of molecular profiling so that these methods can be incorporated into routine clinical practice. This review provides an overview of how genetic analysis is currently used to direct treatment choices in non–small cell lung cancer.