Immune Checkpoint Inhibitors in Esophageal Carcinoma: Assessment of Efficacy Predictors of Response in Clinical Trials.

Esophageal carcinoma (EC) is among the most common causes of cancer-related deaths worldwide. Even with the improvement of multidisciplinary treatment modalities, advanced unresectable EC patients had limited systemic therapeutic options for an extended period. Recently, immune checkpoint inhibitors (ICIs) have been introduced to advanced EC management in both first-line and second-line options, as well as in postoperative settings in resectable EC after preoperative chemoradiation. Herein, the authors present a comprehensive review of clinical trials on administering ICIs in EC patients while discussing reported clinical, molecular, and immune biomarkers and their predictive value for treatment efficacy.