Despite recent therapeutic advances, lung cancer continues to be one of the leading causes of cancer-related mortality. Of the various histologic subtypes, non–small-cell lung cancer (NSCLC) is the most common—accounting for approximately 85% of all lung cancers—and will be the focus of this article. In general, the treatment of lung cancer may include surgery, radiation therapy, systemic therapy (eg, chemotherapy with or without targeted therapy), or a combination of the above. Surgery continues to offer the best chance of long-term cure. The initial treatment of stage I and II NSCLC usually entails surgical resection, whereas stage IV disease is primarily treated with systemic agents, in light of the lack of curative potential with surgery and/or radiation therapy alone. It is locally advanced NSCLC, including stage IIIA and IIIB disease, that continues to pose a therapeutic dilemma, given its heterogeneous nature.