Immune checkpoint blockade therapy for esophageal squamous cell carcinoma
Esophageal cancer (EC) is the eleventh most common cause of cancer worldwide (459,299 cases) and the sixth most common cause of cancer mortality (439,000 deaths) (1). Esophageal squamous cell carcinoma (ESCC) is one of the major histological types, whose incidence has been decreasing in West, but remains the most common type in Asia, Africa, and South America. Prognosis of metastatic ESCC is poor even though it initially sensitive to combination chemotherapy, but resistance emerges rapidly. There has not been an effective targeted agent to treat ESCC.