A comparative review of TAM surface markers and chemokines in the tumor microenvironment of esophageal squamous cell carcinoma and other squamous cell carcinomas

Abstract Esophageal cancer is one of the most malignant tumors with the worst prognosis worldwide. It is mainly divided into two pathological subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Of these, ESCC is the main histological type. However, most ESCC patients exhibit a poor response to existing treatment options. In recent years, the tumor microenvironment (TME) and its associated molecules have become an important direction in the study of malignant tumors. In TME of ESCC, tumor-associated macrophages (TAMs) dominate the immune cell component, including M1, which has tumor suppressor function, and M2, which promotes tumor progression. Surface markers of TAMs are potential biomarkers for diagnosis and prognosis, and chemokines secreted by TAMs or tumor cells play a key role in promoting tumor growth and metastasis. However, the specific mechanism of TAMs in ESCC has not yet been fully clarified. In this review, we focus primarily on the role of TAM surface markers and chemokines in the TME, and illustrates their function in ESCC by comparing TAMs’ behavior in other squamous cell carcinomas. This will help deepen the understanding of the TME in ESCC, holding great potential to break through the current bottleneck in improving prognosis with ESCC treatment.