Development of chemotherapeutics for unresectable advanced esophageal cancer

Introduction The prognosis of unresectable advanced esophageal squamous cell carcinoma (ESCC) has gradually improved due to efforts for the development of systemic chemotherapy or concurrent chemoradiotherapy.Areas covered Chemotherapeutic agents such as cytotoxic agents, molecular-targeted agents, and immune checkpoint inhibitors, sometimes used with irradiation, lead in the treatment of unresectable advanced ESCC. Here, we review the latest treatment strategies for unresectable advanced ESCC and discuss future perspectives.Expert opinion Immunotherapeutic agents will be part of the treatment of unresectable advanced ESCC in the near future. However, definitive predictive biomarkers to determine good patient candidates remain unclear for immunotherapy in patients with ESCC. Further research is warranted to identify those biomarkers working individually and in combination. Moreover, genome-based therapeutics enable individualized and patient-specific treatment. The development of molecular-targeted drugs against actionable or druggable genes is in progress.