Association of PD-1 and PD-L1 protein expression with selected clinical and morphological parameters in colorectal...

Colorectal cancer is the third most common cancer worldwide and the second cause of death from malignant tumors. Colorectal cancers are treated with surgery, chemotherapy, gene therapy and immunotherapy. PD-1 and PD-L1 proteins have recently been considered as potential targets of anticancer therapy in colorectal cancer. The aim of this study was to evaluate the association of immunohistochemical expression of PD-1 and PD-L1 proteins in colorectal cancer patients with selected clinical and morphological parameters and their survival. Ninety-eight cases of colorectal cancer were studied. Immunohistochemistry was used to evaluate the expression of PD-1 and PD-L1 proteins. Correlations were found between the expression of PD-L1 protein in lymphocytes and lack of lymph node metastases and a lower clinical stage. There was also a correlation between PD-L1 protein expression in cancer cells and a higher grade of histological malignancy.