Immunotherapy era in the treatment of small cell lung cancer

Small cell lung cancer (SCLC) is differentiated from non-small cell lung cancers with its histological and morphological features, rapid response to chemotherapy, and recurrence in a short time after treatment is discontinued. Platinum plus etoposide chemotherapy combination has been used as a standard treatment, and no new drug has been found for more than 30 years in this disease. In research, the targeted pathways that may affect survival have not been identified yet. During the second half of the second decade of the 2000s, with immunotherapies that inhibit immune checkpoints, improvements in survival were achieved for the first time in treating SCLC after many years. Then a rapid increase was observed in chemotherapy plus immunotherapy combination studies in this field. Updated analyses of these studies were represented at international oncology meetings in 2020. Here, we reviewed immunotherapy studies conducted in patients with SCLC and the reflections on the daily practice.