Promising immunotherapies for esophageal cancer

Introduction: Esophageal cancer (EC) is the eighth most common cancer in the world, and the prognosis of EC is still poor. Although immunotherapy has been developed in melanoma and lung cancer, it is also expected to show efficacy in EC. Currently, several clinical trials are ongoing to evaluate the safety and efficacy of immunotherapies, immune checkpoint inhibitors, adoptive T cell transfer, and therapeutic cancer vaccines in EC. Areas covered: This review provides an overview and the status of immunotherapy in EC. Clinical significance of molecules related immune checkpoints, especially PD-1 and PD-L1 is presented and the designs, results and future directions of clinical trials using immunotherapy in EC are provided. Expert opinion: To bring immunotherapy to the forefront of treatment for EC, it is necessary to select patients who can obtain a high efficacy of immunotherapy and to also elucidate the correct timing for administration. Moreover, combination therapies of immunotherapy with existing chemotherapy or radiation or other immunotherapy with different mechanisms of action must be evaluated to achieve excellent outcomes in patients with EC.