The emerging role of immunotherapy for esophageal cancer

The management of esophageal cancer has not changed significantly over the last decade. Survival rates remain poor in locally advanced and metastatic disease. Newer treatment modalities are desperately needed if we are to improve 5-year overall survival rates. Immunotherapeutic strategies hold great promise, but a much greater understanding of the immune microenvironment underlying squamous cell and esophageal adenocarcinoma is needed if we are to exploit the inherent cancer fighting capabilities of each patient's immune system.

Here we describe current and future predictive biomarkers, provide a synopsis of the most significant trial results to date, and explain pivotal ongoing phase III trials.

Recent findings suggest that esophageal squamous cell carcinoma may be more sensitive to single agent PD-1 inhibition than esophageal adenocarcinoma, and selecting patients according to PD-L1 combined positive score (CPS) of at least 10 or more may predict higher response rate. We await data indicating the optimal immuno-oncology (IO-IO) combinations that will allow more patients to respond, however it is likely that personalized immunotherapy may be required for the majority. At the present time, it is hoped that chemotherapy combined with PD-1 inhibition will be an optimal strategy, but we await confirmation from soon-to-be published phase III trials.