Programmed Death Ligand-1 Expression Is Associated With Poorer Survival in Anal Squamous Cell Carcinoma

Abstract

Context.-Upregulation of programmed death ligand-1 (PD-L1), an immunoregulatory protein, is associated with an adverse outcome in several malignancies. Very few studies have evaluated PD-L1 expression in invasive anal squamous cell carcinoma (ASCC). Objective.-To assess PD-L1 expression in patients with ASCC and correlate it with clinicopathologic factors and clinical outcomes. Design.-Fifty-one cases of ASCC were immunostained for PD-L1. PD-L1 expression by combined positive score and tumor proportion score was correlated with age, sex, HIV status, HIV viral load, CD4 count, stage, and outcomes. Kaplan-Meier curves for overall survival were plotted and compared using the log-rank test. Cox regression analysis was performed to identify significant prognostic factors (2-tailed P