Uncovering PD-L1 and CD8⁺ TILS Expression and Clinical Implication in Cervical Squamous Cell Carcinoma

To investigate the association between programmed death-ligand 1 (PD-L1) coupled with CD8⁺ tumor-infiltrating lymphocytes (TILS) and the clinicopathological features, along with prognosis of cervical squamous cell carcinoma (CSCC).

95 patients of CSCC received tumor resection at the Department of Pathology of the First Affiliated Hospital of University of Science and Technology of China (USTC) from 2015 to 2020. Full-automatic immunohistochemistry was applied to measure PD-L1 expression and CD8⁺ TILS density. Our literature deeply assessed the links between PD-L1 expression, clinicopathological features, and the influences of combination of PD-L1 and CD8⁺ TILS (PD-L1⁺/CD8⁺ TILS) on the prognosis of CSCC.

64.21% of CSCC patients (61/95) expressed PD-L1, and PD-L1 expression was related to the Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, invasion depth, differentiation degree, metastasis of lymph node, and vascular invasion (P < 0.05). Dramatic correlation between PD-L1 expression and CD8⁺ TILS density was illustrated in CSCC patients (r = -0.461, P < 0.001). Obvious differences in differentiation degree, FIGO stage, infiltration depth, and lymph node metastasis were shown between patients with PD-L1 coupled with high-density of CD8⁺ TILS and those with PD-L1 coupled with low-density of CD8⁺ TILS (P < 0.05). Patients with PD-L1 negative expression exhibited better prognosis compared with those with PD-L1 positive expression (P < 0.05). Patients with PD-L1 coupled with high-density of CD8⁺ TILS showed better prognostic status, while those with PD-L1 coupled with low-density of CD8⁺ TILS had worse prognostic condition (P < 0.05). Differentiation, metastasis of lymph node, and FIGO stage were substantive impact elements of a CSCC patient's overall survival (OS) by Cox multivariate analysis.

CD8⁺ TILS density is related to PD-L1 expression in carcinoma. PD-L1/CD8⁺ TILS density can be regarded as evaluation for the prognosis of patients with CSCC, providing a new therapeutic target in clinical application.