Abstract
Small cell lung cancer (SCLC) is complex heterogeneous due to unclear biological characteristics in terms of cell origin, pathogenesis and driver genes etc. Diagnosis and treatment of SCLC has been slowly improved and few breakthroughs have been discovered up to now. Therefore new strategies are urgently needed to improve the efficacy of SCLC treatment. Tumor immunotherapy has potential to restore and trigger the immune system to recognize and eliminate tumor cells, notably it has only minimal adverse impact on normal tissue. Cancer vaccine, adoptive immunotherapy, cytokines and checkpoint inhibitors have now been launched for clinical treatment of SCLC. Ipilimumab is the most promising medicine of immunotherapy. Immunotherapy is expected to bring new vision to the treatment of SCLC. And further researches are needed on such problems affecting efficacy of immunotherapy as the heterogeneity of SCLC, the uncertainty of target for immunotherapy, the immune tolerance, etc.