A Case of Complete Response to ICI Therapy for Unresectable Esophageal Squamous Cell Carcinoma

Contrary to previous reports that associated high Treg infiltration with reduced efficacy of ICIs, our patient demonstrated exceptional long-term CR. Potential influencing factors include synergistic chemotherapy effects, altered Treg function, and minimal presence of tumor-associated macrophages. This case underscores the complexity of tumor microenvironment interactions and suggests further investigation into Treg biology in predicting ICI treatment outcomes in ESCC.