Abstract
Lung cancer is the most common cancer worldwide and the most common cause of cancer-related death. Non-small-cell lung cancer comprises ~87% of newly diagnosed cases of lung cancer, and nearly one-third of these patients have stage III disease. Despite improvements in the treatment of stage IV lung cancer, particularly with the introduction and dissemination of checkpoint inhibitors, very little progress has been made in the treatment of stage III lung cancer. In this article, we discuss the general staging criteria and treatment options for stage III lung cancer. We review how concurrent radiation and chemotherapy can have immunomodulatory effects, supporting the rationale for incorporating immunotherapy into existing treatment paradigms. Finally, we discuss the results of the PACIFIC trial and implications for the treatment of stage III lung cancer. In the PACIFIC trial, adding durvalumab as a maintenance therapy following the completion of chemoradiotherapy improved progression-free survival in patients with locally advanced unresectable stage III lung cancer. On the strength of these results, durvalumab has been approved by the US Food and Drug Administration for use in this setting, representing the first advance in the treatment of stage III lung cancer in nearly a decade.