CD274 and adenocarcinoma: The majority of patients were younger than 60 years (67.9%) and had an Eastern Cooperative Oncology Group (ECOG) performance status of 0–1 (88.7%), no smoking history (86.8%), a histological diagnosis of adenocarcinoma (90.7%), negative/unknown PD-L1 expression (81.1%), and three or more metastatic organs (53.2%).