CD274 and metastatic malignant neoplasm in the lymph nodes: No significant association was detected between expression of PD-L1 and patient age (≥ 70 versus < 70 years, P = 1.000), tumor size (≤ 3 cm versus > 3 cm, P = 0.613), clinical stage (I + II versus III+IV, P = 0.067), pleural involvement (P = 0.553), or lymph node metastasis (P = 0.439).