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

Abstract

Objective: 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).

Methods: 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.

Results: 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.

Conclusions: 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.