In univariate analysis, small cell lung cancer (SCLC) histology (HR = 1.83, 95% CI: 1.26–2.66, P = 0.002), higher ECOG performance status (HR = 1.59, 95% CI: 1.24–2.05, P < 0.001), and brain metastases (HR = 1.61, 95% CI: 1.14–2.27, P = 0.007) were significantly associated with shorter PFS, whereas BBs use (HR = 0.72, 95% CI: 0.53–0.98, P = 0.039) and PD-L1 positivity (HR = 0.41, 95% CI: 0.29–0.56, P < 0.001) were linked to longer PFS. Here, CD274 is linked to small cell lung carcinoma.