Immunotherapy in Lung Cancer.

Lung cancer has not traditionally been viewed as an immune-responsive tumor. However, it is becoming evident that tumor-induced immune suppression is vital to malignant progression. Immunotherapies act by enhancing the patient's innate immune response and hold promise for inducing long-term responses in select patients with non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Immune checkpoint inhibitors, in particular, inhibitors to cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) and programmed death receptor ligand 1 (PD-L1) have shown promise in early studies and are currently in clinical trials in both small cell lung cancer and non-small cell lung cancer patients. Two large randomized phase III trials recently demonstrated superior overall survival (OS) in patients treated with anti-PD-1 therapy compared to chemotherapy in the second-line setting.