CD274 and metastatic malignant neoplasm: In conclusion, the results of our meta-analysis show that anti-PD-1/PD-L1 inhibitors are more advantageous for the treatment of advanced and metastatic cancer than conventional therapies, especially among male patients, those younger than 65 years of age, current or former smokers, those with no CNS or liver metastasis, those negative for EGFR mutations, and those with high PD-L1 expression.