Tumor immune microenvironment and immune checkpoint inhibitors in esophageal squamous cell carcinoma

• Published in: Cancer science 2020-09, Vol.111 (9), p.3132-3141
• Main Authors: Baba, Yoshifumi, Nomoto, Daichi, Okadome, Kazuo, Ishimoto, Takatsugu, Iwatsuki, Masaaki, Miyamoto, Yuji, Yoshida, Naoya, Baba, Hideo
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Antineoplastic Agents, Immunological - pharmacology; Antineoplastic Agents, Immunological - therapeutic use; Apoptosis; B7-H1 Antigen - antagonists & inhibitors; B7-H1 Antigen - metabolism; Biomarkers; Biomarkers, Tumor; Cancer therapies; Chemotherapy; Clinical trials; Dendritic Cells - immunology; Dendritic Cells - metabolism; Drugs; Esophageal cancer; Esophageal Neoplasms - drug therapy; Esophageal Neoplasms - etiology; Esophageal Neoplasms - metabolism; Esophageal Neoplasms - pathology; Esophageal Squamous Cell Carcinoma - drug therapy; Esophageal Squamous Cell Carcinoma - etiology; Esophageal Squamous Cell Carcinoma - metabolism; Esophageal Squamous Cell Carcinoma - pathology; Esophagus; Humans; Immune checkpoint inhibitors; immune microenvironment; Immune system; Immunology; Immunomodulation - drug effects; Immunotherapy; Killer Cells, Natural - immunology; Killer Cells, Natural - metabolism; Lymphocytes; Lymphocytes, Tumor-Infiltrating - immunology; Lymphocytes, Tumor-Infiltrating - metabolism; Lymphocytes, Tumor-Infiltrating - pathology; Macrophages; Macrophages - immunology; Macrophages - metabolism; Macrophages - pathology; Medical prognosis; Metastasis; Monoclonal antibodies; Mutation; Myeloid-Derived Suppressor Cells - immunology; Myeloid-Derived Suppressor Cells - metabolism; Myeloid-Derived Suppressor Cells - pathology; Patients; PD-1 protein; PD-L1 protein; Review; Squamous cell carcinoma; Suppressor cells; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; T-Lymphocytes - metabolism; tumor immunity; Tumor Microenvironment - drug effects; Tumor Microenvironment - immunology; Tumors
• ISSN: 1347-9032; 1349-7006
• DOI: 10.1111/cas.14541

Esophageal squamous cell carcinoma (ESCC) is the main prevalent histological type of esophageal cancer, predominantly constituting 90% of cases worldwide. Despite the development of multidisciplinary therapeutic approaches, its prognosis remains unfavorable. Recently, the development of monoclonal antibodies inhibiting programmed death 1 (PD‐1) or programmed death‐ligand 1 (PD‐L1) has led to marked therapeutic responses among multiple malignancies including ESCC. However, only a few patients achieved clinical benefits due to resistance. Therefore, precise and accurate predictive biomarkers should be identified for personalized immunotherapy in clinical settings. Because the tumor immune microenvironment can potentially influence the patient's response to immune checkpoint inhibitors, tumor immunity, such as PD‐L1 expression on tumors, tumor‐infiltrating lymphocytes, tumor‐associated macrophages, and myeloid‐derived suppressor cells, in ESCC should be further investigated. In this review, accumulated evidence regarding the tumor immune microenvironment and immune checkpoint inhibitors in ESCC are summarized. Because the tumor immune microenvironment can potentially influence the patient's response to immune checkpoint inhibitors, tumor immunity, such as PD‐L1 expression on tumors, tumor‐infiltrating lymphocytes, tumor‐associated macrophages, and myeloid‐derived suppressor cells, in ESCC should be further investigated. In this review, accumulated evidence regarding the tumor immune microenvironment and immune checkpoint inhibitors in ESCC are summarized.