Research Progress of Predictive Markers for Efficacy of Immune Checkpoint Inhibitors for Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is the main prevalent histological type of esophageal cancer worldwide, with a high mortality and poor prognosis due to advanced stage at diagnosis. Surgical resection after neoadjuvant therapy is the main treatment for ESCC. With the rise of immunotherapy, immunotherapy on ESCC has been shown to improve outcomes, especially the immune checkpoint inhibitors (ICIs). As the efficacy of immunotherapy for ESCC is limited, it is helpful to screen patients who may benefit from immunotherapy by looking for predictive biomarkers of efficacy of immunotherapy. In this paper, based on the current literature on immunotherapy and related biomarkers, we review the research progress on predictive markers of ICIs for ESCC, in hopes of providing assistances for the precise treatment and prognosis determination.