Immunoscore system combining CD8 and PD-1/PD-L1: A novel approach that predicts the clinical outcomes for cervical cancer

Immunoscore was established to evaluate the prognosis of cancer patients. However, the feasibility of Immunoscore for the prognosis of cervical cancer remains unknown. To find other prognostic markers that contribute to immunological importance, immune checkpoint inhibitors targeting programmed cell death protein (PD-1), or its ligand, PD-L1, are of enormous interest. Our purpose is to investigate the expression of CD8 and PD-1/PD-L1 and their potential role in Immunoscore, supplementing the tumor/node/metastasis (TNM) classification of cervical cancer.

Immunoscore was assessed according to the density of PD-1, PD-L1, and CD8 by immunohistochemistry. The association with overall survival and disease-free survival was assessed by the Kaplan–Meier method. To evaluate the effect of Immunoscore, a Cox proportional hazard regression classification was conducted. To compare the prognostic accuracies of Immunoscore and TNM staging, receiver operating characteristic curves were plotted.

Patients with PD-L1^positive and PD-1^high in immune cells had poorer overall survival and disease-free survival; however, PD-L1^positive in tumor cells that infiltrated more CD8⁺ T cells were related to better overall survival and disease-free survival. These immune factors can be independent predictors for prognoses. According to these factors, a new Immunoscore system with priority in predicting prognoses was established. In receiver operating characteristic analysis for predictions of overall survival (the area under curve (AUC) = 0.833 vs. 0.766) and disease-free survival (AUC = 0.861 vs. 0.729), Immunoscore is more accurate than TNM staging.

Thus, this Immunoscore system is an accurate predictive marker, which can be an important supplement to TNM staging for cervical cancer.