CD274 and small cell lung carcinoma: The treatments ranked from best to worst in terms of OS prolongation in patients with ES‐SCLC without LM were anti‐angiogenesis + anti‐PD‐L1 + CT, anti‐PD‐L1 + CT, anti‐PD‐1 + CT, anti‐CTLA‐4 + anti‐PD‐L1 + CT, and CT.