Induction treatment in patients with stage III non-small cell lung cancer.

Stage III non-small cell lung cancer (NSCLC) comprises a highly heterogeneous group of patients defined according to the extent and localization of disease. Patients with discrete N2 involvement identified preoperatively with resectable disease are candidates for multimodal therapy either with definitive chemoradiation therapy, induction chemotherapy, or chemoradiotherapy (CTRT) followed by surgery. Neoadjuvant chemotherapy has yielded comparable survival benefit to adjuvant chemotherapy in patients with stage II-III disease and may allow for downstaging the tumor or the lymph nodes, an earlier delivery of systemic treatment, and better compliance to systemic therapy. The use of immune checkpoint inhibitors (ICIs) as induction therapy shows encouraging activity and a favorable safety profile in patients with resectable early stage or locally advanced NSCLC. An unprecedented rate of pathological response and downstaging has been reported in single-arm clinical trials, especially when immunotherapy is combined with neoadjuvant chemotherapy. Ongoing randomized phase II/III clinical trials assessing the efficacy and safety of induction with immunotherapy plus chemotherapy have the potential to establish this therapeutic approach as a novel standard of care. These trials aim to validate pathological response as a surrogate marker of survival benefit and to demonstrate that this therapeutic strategy can improve the cure rate in patients with stage II-III NSCLC.