Research advances in immunotherapy for locally advanced esophageal cancer

Esophageal cancer is a malignancy with high incidence and mortality rates, and most patients are already at locally advanced stage at diagnosis. Conventional standard treatments, such as definitive concurrent chemoradiotherapy (dCRT), still have limitations in efficacy. Immunotherapy can activate systemic antitumor immune response, and its combination with dCRT can further amplify antitumor effects, playing an important role in the treatment of locally advanced esophageal cancer. Immunotherapy combined with dCRT is gradually becoming a key component of comprehensive treatment strategies for esophageal cancer; howe-ver, the optimal combination approach remains unclear, and its specific benefits require further confirmation through large-sample clinical trials and long-term follow-up data. This review systematically summarizes the research advances in immunotherapy for locally advanced esophageal cancer from the perspectives of antitumor mechanisms, predictive biomarkers of immunotherapy efficacy, and clinical applications of immunotherapy combined with dCRT, and discusses future research directions for combination immunotherapy, with the aim of providing a basis for optimizing treatment strategies for locally advanced esophageal cancer.