CD274 and small cell lung carcinoma: The findings for both atezolizumab and durvalumab in extensive SCLC and their disappointing cost-effectiveness are in contrast to those for pembrolizumab in the first-line treatment of NSCLC, where the PD1 inhibitor pembrolizumab with or without chemotherapy has been suggested to be a cost-effective option as a first-line treatment for metastatic NSCLC expressing high levels of PD-L1.33