Conclusions
ESCC
In this randomized clinical trial of patients aged 70 years and older with ESCC treated with SIB-RT with or without concurrent and consolidated oral S-1 chemotherapy, the combination of SIB-RT technique with concurrent and consolidated oral S-1 chemotherapy yielded improvements in OS and PFS for patients aged 70 years and older with ESCC. SIB-RT with oral S-1 chemotherapy should be considered as an option for definitive treatment approaches for patients aged 70 years and older with inoperable ESCC, as it improved survival outcomes without additional treatment-related toxic effects compared with SIB-RT alone.