PD-L1 expression in tumor metastasis is different between uveal melanoma and cutaneous melanoma

• Published in: Immunotherapy Vol. 9; no. 16; pp. 1323 - 1330
• Main Authors: Javed, Asad, Arguello, David, Johnston, Curtis, Gatalica, Zoran, Terai, Mizue, Weight, Ryan M, Orloff, Marlana, Mastrangelo, Michael J, Sato, Takami
• Format: Journal Article
• Language: English
• Published: England Future Medicine Ltd 01.12.2017
• Subjects: Antibodies, Monoclonal - therapeutic use; Apoptosis; B7-H1 Antigen - immunology; Biomarkers; Cancer; Diagnosis, Differential; Gene Expression Regulation; Humans; Immunoglobulins; Immunotherapy; Immunotherapy - methods; Laboratories; Life sciences; Liver; Lymphatic system; Lymphocytes; Lymphocytes, Tumor-Infiltrating - physiology; Medical prognosis; Melanoma; Melanoma - diagnosis; Melanoma - metabolism; Melanoma - therapy; Metastases; Metastasis; Neoplasm Metastasis; PD-1 protein; PD-L1 protein; Prognosis; Proteins; Skin Neoplasms - diagnosis; Skin Neoplasms - metabolism; Skin Neoplasms - therapy; Thyroid gland; Treatment Outcome; Tumor Escape; Tumor-infiltrating lymphocytes; Tumors; Uveal Neoplasms - diagnosis; Uveal Neoplasms - metabolism; Uveal Neoplasms - therapy; United States > US
• ISSN: 1750-743X; 1750-7448
• DOI: 10.2217/imt-2017-0066

To compare PD-L1 expression between metastatic uveal melanoma (MUM) and metastatic cutaneous melanoma (MCM). A total of 295 MCM and 78 MUM specimens were analyzed for tumor cell PD-L1 expression. Additionally, 91 MCM and 45 MUM specimens were analyzed for PD-1 expression on tumor-infiltrating lymphocytes. A total of 77/295 (26.1%) MCM specimens expressed PD-L1 as compared to 4/78 (5.1%) MUM specimens (p < 0.0001). PD-1 expression on tumor-infiltrating lymphocytes was greater in MCM (73.6%; 67/91) than in MUM (51.1%; 23/45), respectively (p = 0.009). Significant differences exist in PD-L1 expression between MCM and MUM. The lower PD-L1 expression in MUM may provide a rationale for failure of PD-1 inhibitor therapy and suggests that immune evasion in this disease may occur via alternative mechanisms.