Current and future perspectives in unresectable locally advanced esophageal squamous cell cancer (Review)

Definitive concurrent chemoradiotherapy has been the main standard treatment method for unresectable locally advanced esophageal squamous cell cancer (ESCC) since 1999. However, several disadvantages continue to be associated with this type of treatment, including a high local failure rate (reaching similar to 50% within 3 years) and a median overall survival (OS) time of 16.9 months. In addition, the 5-year overall survival rate of patients remains relatively low, at only similar to 21% for patients with ESCC with TNM stage T1-3N0-1M0. Burgeoning clinical trials and continually updating treatment modalities are currently in the process of being developed for the treatment of unresectable locally advanced ESCC. Compared with definitive concurrent chemoradiotherapy alone, clinical trials that have examined the efficacy of induction therapy, consolidation therapy, immunotherapy and targeted therapy have observed a prolonged median progression-free survival and OS. Salvage surgery can also bring benefits to some patients. Therefore, the present review aimed to provide a comprehensive overview on the latest progress that is being made in the development of treatment strategies for unresectable locally advanced ESCC, taking into account the several new challenges that need to be overcome.