Tumor Immunology and Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer

Lung cancer is one of the most commonly diagnosed cancers and the leading cause of cancer-related deaths worldwide. Although progress in the treatment of advanced non-small cell lung cancer (NSCLC) has been made over the past decade, the 5-year survival rate in patients with lung cancer remains only 10%-20%. Obviously, new therapeutic options are required for patients with advanced NSCLC and unmet medical needs. Cancer immunotherapy is an evolving treatment modality that uses a patient's own immune systems to fight cancer. Theoretically, cancer immunotherapy can result in long-term cancer remission and may not cause the same side effects as chemotherapy and radiation. Immunooncology has become an important focus of basic research as well as clinical trials for the treatment of NSCLC. Immune checkpoint inhibitors are the most promising approach for cancer immunotherapy and they have become the standard of care for patients with advanced NSCLC. This review summarizes basic tumor immunology and the relevant clinical data on immunotherapeutic approaches, especially immune checkpoint inhibitors in NSCLC.