Effect of the immune microenvironment on prognosis in oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is amongst the most lethal cancers worldwide, with poor treatment response leading to low survival rates. Recent improvements have been achieved by including the tumour microenvironment (TME) and patients' immune profiles in treatment decisions. We already know that patients with immune-enriched/inflamed TME have better survival outcomes. However, OAC TME is largely immunosuppressed and appears to be treatment-resistant. Immunotherapeutic strategies are already part of the therapeutic plans in OAC; a greater understanding of the immune microenvironment underlying oesophageal adenocarcinoma is needed if we are to exploit the inherent cancer-fighting capabilities of each patient's immune system. Therefore, implementing the crosstalks between the tumour and its microenvironment (TME) might be the key to improving overall survival. In this review, we discuss accumulated evidence regarding TME and immune checkpoint inhibitors in OAC, as well as recent and ongoing therapeutic attempts to improve patient treatment and outcomes at an individual level.