Programmed Death Ligand-1 (PD-L1) Expression in Cervical Squamous Cell Carcinoma: Does it Correlate With Outcomes?

Abstract

Cervical cancer is one of the most common gynecological malignancies. Upregulation of programmed death ligand-1 (PD-L1), an immunoregulatory protein, is associated with an adverse outcomes in several malignancies. Most studies evaluating PD-L1 expression in cervical squamous cell carcinoma (CSCC) lack data on outcomes. In this study, we correlate PD-L1 expression with clinicopathologic factors and clinical outcomes in invasive CSCC. Seventy-three cases of CSCC from 2010 to 2018 were immunostained for PD-L1. A combined positive score (CPS) of ≥1 and ≥10 was correlated with age, stage, and survival outcomes. Kaplan-Meier curves for progression-free survival and overall survival were plotted and compared using the log-rank test. Cox regression analysis was performed to identify significant prognostic factors (2-tailed P<0.05 was considered statistically significant). With CPS ≥1 or ≥10 as the cut-off, PD-L1 was positive in 52/73 (71.2%) and 23/73 (31.5%) of cases, respectively. PD-L1 positive patients present at a higher stage of disease, especially those with CPS ≥10. With CPS of ≥10 as the cut-off, the 5-yr progression-free survival and 5-yr overall survival were significantly lower (P = 0.034 and 0.012, respectively). Only stage was statistically significant for worse overall survival on multivariate analysis. PD-L1 positive patients present at a higher stage of disease, and stage is an independent prognostic indicator for adverse outcomes in CSCC. This study highlights the potential of PD-L1 targeted therapy in patients with CSCC.