Statistical difference was not present in age, sex, ECOG PS, presence of lymph node metastasis, presence of visceral metastasis, visceral metastatic sites, prior definitive surgery, line of pembrolizumab, time since most recent chemotherapy, first‐line chemotherapy regimen, hemoglobin, serum CRP, and rates of any grade and grade 3‐4 irAE of pembrolizumab between the Radiotherapy and Non‐radiotherapy groups. This evidence concerns the gene CRP and metastatic malignant neoplasm in the lymph nodes.