CD274 and small cell lung carcinoma: The addition of a PD-1 inhibitor or PD-L1 inhibitor to the chemotherapy regimen can improve OS and prolong PFS in patients with ES-SCLC.<h4>Conclusions</h4>PD-1/PD-L1 inhibitors combination chemotherapy significantly improves PFS and OS in ES-SCLC patients without increasing the overall incidence of TRAEs.