Analysis of Expression of Programmed Cell Death Ligand 1 (PD-L1) and BRAFV600E Mutation in Thyroid Cancer

• Published in: Cancers Vol. 15; no. 13; p. 3449
• Main Authors: Sekino, Mizuki, Iwadate, Manabu, Yamaya, Yukie, Matsumoto, Yoshiko, Suzuki, Satoshi, Mizunuma, Hiroshi, Nakano, Keiichi, Nakamura, Izumi, Suzuki, Shinichi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30-06-2023; MDPI
• Subjects: Antibodies; Antigens; Apoptosis; Biomarkers; Biopsy; Cancer therapies; CD8 antigen; Cell activation; Cell death; Cells; Cloning; Cytotoxicity; Flow cytometry; Humoral immunity; Immune checkpoint inhibitors; Immune status; Immunosurveillance; Immunotherapy; Iodine; Ligands; Lung cancer; Lymphocytes; Lymphocytes T; Medical prognosis; Melanoma; Mutation; Patients; PD-L1 protein; Prognosis; Skin cancer; Surgery; Thyroid cancer; Tumor cells; Tumor microenvironment; Tumors; United Kingdom > UK; United States > US
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers15133449

In thyroid cancer, it has been suggested that PD-L1 overexpression is associated with some clinicopathological factors and prognosis. The aim of this study is to characterize the expression of PD-L1, the presence of the BRAFV600E mutation, as well as cellular and humoral immunity in thyroid cancer, and to investigate the factors that predict the effectiveness of anti-PD-L1 antibody therapy. Blood samples were collected from 33 patients who were newly diagnosed with thyroid cancer after surgery or biopsy. PD-L1 expression, BRAFV600E mutation, and CD8+ expression were examined by immunohistological staining using clinical thyroid cancer specimens. With a PD-L1 staining cut-off value of 1%, 13 (39.4%) patients were classified as PD-L1 positive. Stimulation Index (SI) is an indicator of T cell activation. PD-L1 expression was significantly correlated with low SI level (p = 0.046). Moreover, BRAFV600E mutation was detected in 24 of the 33 (72.7%) patients, and was significantly associated with PD-L1 expression (p = 0.047). In addition, enhanced CD8+ expression was significantly associated with PD-L1 expression (p = 0.003). Multivariate analyses confirmed that high CRP levels (p = 0.039) were independently and significantly associated with poor progression-free survival. These findings suggest that elevated PD-L1 status can be a prognostic indicator for survival in patients with thyroid cancer when comprehensively assessed using the expression of CD8+, the presence of BRAFV600E mutation and the patient’s immune status.