Correlation Between Tumor Infiltration CD8+ T-cells And PD-L1 Expression In Laryngeal Cancer And Their Prognostic Significance: Prospective Non-interventional Trial.

Abstract

Introduction: Tumor microenvironment plays crucial role in cancer evolution. There is a dynamic and continuous relation between immune cells and cancer cells' resistance. Tumor infiltration CD8-lymphocytes and programmed death ligand-1 have proved important prognostic role in different malignancies. We aimed at evaluating this role in laryngeal cancer.

Patients and methods: We prospectively analyzed laryngeal cancer patients' specimens, to identify the CD8-lymphocytes and the PD-L1 expression. A total score formed of the sum of percentage and intensity of PD-L1. A final rate was considered as negative or low when combined percentage and intensity scores 0 to 4, and high when scores 5-7. CD8-lymphocyte infiltration was divided into strong (= 10/100 of epithelial cells or =20/100 stromal cell infiltration) or weak (<10/100 epithelial cells or <20/100 stromal cell infiltration).

Results: Forty patients were included; twelve had stage 1 or 2 and 28 with advanced stages. PD-L1 expressionwas positive in 92.5%. Neither the PD-L1 nor CD8- lymphocytes had overall survival impact, however high PD-L1 correlated with better survival in advanced stage subgroup (p = 0.036), high CD8-lymphocytes infiltration had better survival but did not reach significance. Therewas significant correlation between the CD8-lymphocyte infiltration; whether epithelial or stromal, and tumor PD-L1 expression; p-value of 0.001 and < 0.0001 respectively. Subgroup of patients with low CD8+ infiltration and low PD-L1 had the worst survival.

Conclusion: There is a correlation between CD8- l lymphocytes infiltration and PD-L1 expression inlaryngeal cancer and high PD-L1 expression is associated with better OS in advanced stages. Key words: PD-L1, CD8, laryngeal cancer, tumor microenvironment.