ObjectiveTo detect expressions of cell programmed death ligand 1 (PD-L1) and adenosine 2a receptor (A2aR) proteins in colorectal cancer tissues and investigate its relationship with clinicopathologic features of patients with colorectal cancer.MethodsThe colorectal cancer tissues and corresponding paracancerous tissues of 106 patients with colorectal cancer were collected, the patients underwent surgery in the Affiliated Hospital of Xuzhou Medical University from August 2013 to August 2015. The immunohistochemical staining was used to detect the expressions of A2aR and PD-L1 proteins.ResultsThe positive rates of A2aR and PD-L1 protein expression in the colorectal cancer tissues were significantly higher than those in the corresponding paracancerous tissues, respectively [A2aR: 74 (69.8%) versus 35 (33.0%), χ2=28.721, P<0.001; PD-L1: 57 (53.8%) versus 28 (26.4%), χ2=16.516, P<0.001], which in the colorectal cancer tissues were correlated with the Broders grading (A2aR: χ2=9.198, P=0.010; PD-L1: χ2=8.354, P=0.015), T staging (A2aR: χ2=6.737, P=0.009; PD-L1: χ2=6.437, P=0.011), and TNM staging (A2aR: χ2=4.884, P=0.027; PD-L1: χ2=8.246, P=0.004) and were not correlated with the gender, age, tumor portion, lymph node metastasis and CA19-9 (P>0.05), but the positive rates of A2aR protein expression were correlated with the tumor diameter (χ2=4.386, P=0.036) and CEA positive (χ2=6.315, P=0.012), and the positive rates of PD-L1 protein expression were not correlated with them (P>0.05). The expression of PD-L1 protein was positively correlated with the expression of A2aR in the colorectal cancer tissues (rs=0.237, P=0.027).ConclusionPD-L1 and A2aR protein expressions are higher in colorectal cancer tissues, it is provided that both of them might play an important role in promoting occurrence and development of colorectal cancer.